Commit Graph

386 Commits

Author SHA1 Message Date
Al Viro e1f4fb3251 allow build_open_flags() to return an error
Change-Id: Ief5582ec8c4aeb4fb7bf9b2abd51b3d65ae9e81c
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-07-27 22:08:22 +02:00
Davidlohr Bueso 7c1a95e0ae mm: per-thread vma caching
This patch is a continuation of efforts trying to optimize find_vma(),
avoiding potentially expensive rbtree walks to locate a vma upon faults.
The original approach (https://lkml.org/lkml/2013/11/1/410), where the
largest vma was also cached, ended up being too specific and random,
thus further comparison with other approaches were needed.  There are
two things to consider when dealing with this, the cache hit rate and
the latency of find_vma().  Improving the hit-rate does not necessarily
translate in finding the vma any faster, as the overhead of any fancy
caching schemes can be too high to consider.

We currently cache the last used vma for the whole address space, which
provides a nice optimization, reducing the total cycles in find_vma() by
up to 250%, for workloads with good locality.  On the other hand, this
simple scheme is pretty much useless for workloads with poor locality.
Analyzing ebizzy runs shows that, no matter how many threads are
running, the mmap_cache hit rate is less than 2%, and in many situations
below 1%.

The proposed approach is to replace this scheme with a small per-thread
cache, maximizing hit rates at a very low maintenance cost.
Invalidations are performed by simply bumping up a 32-bit sequence
number.  The only expensive operation is in the rare case of a seq
number overflow, where all caches that share the same address space are
flushed.  Upon a miss, the proposed replacement policy is based on the
page number that contains the virtual address in question.  Concretely,
the following results are seen on an 80 core, 8 socket x86-64 box:

1) System bootup: Most programs are single threaded, so the per-thread
   scheme does improve ~50% hit rate by just adding a few more slots to
   the cache.

+----------------+----------+------------------+
| caching scheme | hit-rate | cycles (billion) |
+----------------+----------+------------------+
| baseline       | 50.61%   | 19.90            |
| patched        | 73.45%   | 13.58            |
+----------------+----------+------------------+

2) Kernel build: This one is already pretty good with the current
   approach as we're dealing with good locality.

+----------------+----------+------------------+
| caching scheme | hit-rate | cycles (billion) |
+----------------+----------+------------------+
| baseline       | 75.28%   | 11.03            |
| patched        | 88.09%   | 9.31             |
+----------------+----------+------------------+

3) Oracle 11g Data Mining (4k pages): Similar to the kernel build workload.

+----------------+----------+------------------+
| caching scheme | hit-rate | cycles (billion) |
+----------------+----------+------------------+
| baseline       | 70.66%   | 17.14            |
| patched        | 91.15%   | 12.57            |
+----------------+----------+------------------+

4) Ebizzy: There's a fair amount of variation from run to run, but this
   approach always shows nearly perfect hit rates, while baseline is just
   about non-existent.  The amounts of cycles can fluctuate between
   anywhere from ~60 to ~116 for the baseline scheme, but this approach
   reduces it considerably.  For instance, with 80 threads:

+----------------+----------+------------------+
| caching scheme | hit-rate | cycles (billion) |
+----------------+----------+------------------+
| baseline       | 1.06%    | 91.54            |
| patched        | 99.97%   | 14.18            |
+----------------+----------+------------------+

[akpm@linux-foundation.org: fix nommu build, per Davidlohr]
[akpm@linux-foundation.org: document vmacache_valid() logic]
[akpm@linux-foundation.org: attempt to untangle header files]
[akpm@linux-foundation.org: add vmacache_find() BUG_ON]
[hughd@google.com: add vmacache_valid_mm() (from Oleg)]
[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: adjust and enhance comments]
Signed-off-by: Davidlohr Bueso <davidlohr@hp.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: Michel Lespinasse <walken@google.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Tested-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-07-27 22:08:06 +02:00
Kees Cook 072b1b5320 exec: Limit arg stack to at most 75% of _STK_LIM
commit da029c11e6b12f321f36dac8771e833b65cec962 upstream.

To avoid pathological stack usage or the need to special-case setuid
execs, just limit all arg stack usage to at most 75% of _STK_LIM (6MB).

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[bwh: Backported to 3.16: replaced code is slightly different]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2019-07-27 21:51:48 +02:00
Aleksa Sarai 6c052f20c2 fs: exec: apply CLOEXEC before changing dumpable task flags
commit 613cc2b6f272c1a8ad33aefa21cad77af23139f7 upstream.

If you have a process that has set itself to be non-dumpable, and it
then undergoes exec(2), any CLOEXEC file descriptors it has open are
"exposed" during a race window between the dumpable flags of the process
being reset for exec(2) and CLOEXEC being applied to the file
descriptors. This can be exploited by a process by attempting to access
/proc/<pid>/fd/... during this window, without requiring CAP_SYS_PTRACE.

The race in question is after set_dumpable has been (for get_link,
though the trace is basically the same for readlink):

[vfs]
-> proc_pid_link_inode_operations.get_link
   -> proc_pid_get_link
      -> proc_fd_access_allowed
         -> ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);

Which will return 0, during the race window and CLOEXEC file descriptors
will still be open during this window because do_close_on_exec has not
been called yet. As a result, the ordering of these calls should be
reversed to avoid this race window.

This is of particular concern to container runtimes, where joining a
PID namespace with file descriptors referring to the host filesystem
can result in security issues (since PRCTL_SET_DUMPABLE doesn't protect
against access of CLOEXEC file descriptors -- file descriptors which may
reference filesystem objects the container shouldn't have access to).

Cc: dev@opencontainers.org
Reported-by: Michael Crosby <crosbymichael@gmail.com>
Signed-off-by: Aleksa Sarai <asarai@suse.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Willy Tarreau <w@1wt.eu>
2019-07-27 21:43:25 +02:00
Daniel Rosenberg bd093bef49 vfs: Add permission2 for filesystems with per mount permissions
This allows filesystems to use their mount private data to
influence the permssions they return in permission2. It has
been separated into a new call to avoid disrupting current
permission users.

Change-Id: I9d416e3b8b6eca84ef3e336bd2af89ddd51df6ca
Signed-off-by: Daniel Rosenberg <drosen@google.com>
2018-02-06 13:12:19 +01:00
Andrea Arcangeli 81d457e978 fs/exec: fix use after free in execve
"file" can be already freed if bprm->file is NULL after
search_binary_handler() return. binfmt_script will do exactly that for
example. If the VM reuses the file after fput run(), this will result in
a use ater free.

So obtain d_is_su before search_binary_handler() runs.

This should explain this crash:

[25333.009554] Unable to handle kernel NULL pointer dereference at virtual address 00000185
[..]
[25333.009918] [2:             am:21861] PC is at do_execve+0x354/0x474

Change-Id: I2a8a814d1c0aa75625be83cb30432cf13f1a0681
Signed-off-by: Kevin F. Haggerty <haggertk@lineageos.org>
2017-08-07 16:08:30 +00:00
Kees Cook c8843024bf fs/exec.c: account for argv/envp pointers
commit 98da7d08850fb8bdeb395d6368ed15753304aa0c upstream.

When limiting the argv/envp strings during exec to 1/4 of the stack limit,
the storage of the pointers to the strings was not included.  This means
that an exec with huge numbers of tiny strings could eat 1/4 of the stack
limit in strings and then additional space would be later used by the
pointers to the strings.

For example, on 32-bit with a 8MB stack rlimit, an exec with 1677721
single-byte strings would consume less than 2MB of stack, the max (8MB /
4) amount allowed, but the pointers to the strings would consume the
remaining additional stack space (1677721 * 4 == 6710884).

The result (1677721 + 6710884 == 8388605) would exhaust stack space
entirely.  Controlling this stack exhaustion could result in
pathological behavior in setuid binaries (CVE-2017-1000365).

[akpm@linux-foundation.org: additional commenting from Kees]
Fixes: b6a2fea393 ("mm: variable length argument support")
Link: http://lkml.kernel.org/r/20170622001720.GA32173@beast
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Qualys Security Advisory <qsa@qualys.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Change-Id: I9db26a068e9448fb688a87fe3bae876f23483583
2017-07-10 23:24:32 +00:00
LuK1337 40e2de6755 kernel: Fix mismerge of `kernel: Only expose su when daemon is running`
Change-Id: Id9d3135ee6aba529b934aea521d15e1252d315d7
2017-05-16 22:40:21 +02:00
Tom Marshall 169c186dc8 kernel: Only expose su when daemon is running
It has been claimed that the PG implementation of 'su' has security
vulnerabilities even when disabled.  Unfortunately, the people that
find these vulnerabilities often like to keep them private so they
can profit from exploits while leaving users exposed to malicious
hackers.

In order to reduce the attack surface for vulnerabilites, it is
therefore necessary to make 'su' completely inaccessible when it
is not in use (except by the root and system users).

Change-Id: I79716c72f74d0b7af34ec3a8054896c6559a181d
2017-05-15 14:43:52 +00:00
LuK1337 fc9499e55a Import latest Samsung release
* Package version: T713XXU2BQCO

Change-Id: I293d9e7f2df458c512d59b7a06f8ca6add610c99
2017-04-18 03:43:52 +02:00
Kaushal Kumar 4a36e44c45 This is the 3.10.84 stable release
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Merge upstream tag 'v3.10.84' into LA.BR.1.3.3

This merge brings us up-to-date as of upstream tag v3.10.84

* tag 'v3.10.84' (317 commits):
  Linux 3.10.84
  fs: Fix S_NOSEC handling
  KVM: x86: make vapics_in_nmi_mode atomic
  MIPS: Fix KVM guest fixmap address
  x86/PCI: Use host bridge _CRS info on Foxconn K8M890-8237A
  powerpc/perf: Fix book3s kernel to userspace backtraces
  arm: KVM: force execution of HCPTR access on VM exit
  Revert "crypto: talitos - convert to use be16_add_cpu()"
  crypto: talitos - avoid memleak in talitos_alg_alloc()
  sctp: Fix race between OOTB responce and route removal
  packet: avoid out of bounds read in round robin fanout
  packet: read num_members once in packet_rcv_fanout()
  bridge: fix br_stp_set_bridge_priority race conditions
  bridge: fix multicast router rlist endless loop
  sparc: Use GFP_ATOMIC in ldc_alloc_exp_dring() as it can be called in softirq context
  Linux 3.10.83
  bus: mvebu: pass the coherency availability information at init time
  KVM: nSVM: Check for NRIPS support before updating control field
  ARM: clk-imx6q: refine sata's parent
  d_walk() might skip too much
  ipv6: update ip6_rt_last_gc every time GC is run
  ipv6: prevent fib6_run_gc() contention
  xfrm: Increase the garbage collector threshold
  Btrfs: make xattr replace operations atomic
  x86/microcode/intel: Guard against stack overflow in the loader
  fs: take i_mutex during prepare_binprm for set[ug]id executables
  hpsa: add missing pci_set_master in kdump path
  hpsa: refine the pci enable/disable handling
  sb_edac: Fix erroneous bytes->gigabytes conversion
  ACPICA: Utilities: Cleanup to remove useless ACPI_PRINTF/FORMAT_xxx helpers.
  ACPICA: Utilities: Cleanup to convert physical address printing formats.
  __ptrace_may_access() should not deny sub-threads
  include/linux/sched.h: don't use task->pid/tgid in same_thread_group/has_group_leader_pid
  netfilter: Zero the tuple in nfnl_cthelper_parse_tuple()
  netfilter: nfnetlink_cthelper: Remove 'const' and '&' to avoid warnings
  config: Enable NEED_DMA_MAP_STATE by default when SWIOTLB is selected
  get rid of s_files and files_lock
  fput: turn "list_head delayed_fput_list" into llist_head
  Linux 3.10.82
  lpfc: Add iotag memory barrier
  pipe: iovec: Fix memory corruption when retrying atomic copy as non-atomic
  drm/mgag200: Reject non-character-cell-aligned mode widths
  tracing: Have filter check for balanced ops
  crypto: caam - fix RNG buffer cache alignment
  Linux 3.10.81
  btrfs: cleanup orphans while looking up default subvolume
  btrfs: incorrect handling for fiemap_fill_next_extent return
  cfg80211: wext: clear sinfo struct before calling driver
  mm/memory_hotplug.c: set zone->wait_table to null after freeing it
  drm/i915: Fix DDC probe for passive adapters
  pata_octeon_cf: fix broken build
  ozwpan: unchecked signed subtraction leads to DoS
  ozwpan: divide-by-zero leading to panic
  ozwpan: Use proper check to prevent heap overflow
  MIPS: Fix enabling of DEBUG_STACKOVERFLOW
  ring-buffer-benchmark: Fix the wrong sched_priority of producer
  USB: serial: ftdi_sio: Add support for a Motion Tracker Development Board
  USB: cp210x: add ID for HubZ dual ZigBee and Z-Wave dongle
  block: fix ext_dev_lock lockdep report
  Input: elantech - fix detection of touchpads where the revision matches a known rate
  ALSA: usb-audio: add MAYA44 USB+ mixer control names
  ALSA: usb-audio: Add mic volume fix quirk for Logitech Quickcam Fusion
  ALSA: hda/realtek - Add a fixup for another Acer Aspire 9420
  iio: adis16400: Compute the scan mask from channel indices
  iio: adis16400: Use != channel indices for the two voltage channels
  iio: adis16400: Report pressure channel scale
  xen: netback: read hotplug script once at start of day.
  udp: fix behavior of wrong checksums
  net_sched: invoke ->attach() after setting dev->qdisc
  unix/caif: sk_socket can disappear when state is unlocked
  net: dp83640: fix broken calibration routine.
  bridge: fix parsing of MLDv2 reports
  ipv4: Avoid crashing in ip_error
  net: phy: Allow EEE for all RGMII variants
  Linux 3.10.80
  fs/binfmt_elf.c:load_elf_binary(): return -EINVAL on zero-length mappings
  vfs: read file_handle only once in handle_to_path
  ACPI / init: Fix the ordering of acpi_reserve_resources()
  Input: elantech - fix semi-mt protocol for v3 HW
  rtlwifi: rtl8192cu: Fix kernel deadlock
  md/raid5: don't record new size if resize_stripes fails.
  svcrpc: fix potential GSSX_ACCEPT_SEC_CONTEXT decoding failures
  ARM: fix missing syscall trace exit
  ARM: dts: imx27: only map 4 Kbyte for fec registers
  crypto: s390/ghash - Fix incorrect ghash icv buffer handling.
  rt2x00: add new rt2800usb device DWA 130
  libata: Ignore spurious PHY event on LPM policy change
  libata: Add helper to determine when PHY events should be ignored
  ext4: check for zero length extent explicitly
  ext4: convert write_begin methods to stable_page_writes semantics
  mmc: atmel-mci: fix bad variable type for clkdiv
  powerpc: Align TOC to 256 bytes
  usb: gadget: configfs: Fix interfaces array NULL-termination
  usb-storage: Add NO_WP_DETECT quirk for Lacie 059f:0651 devices
  USB: cp210x: add ID for KCF Technologies PRN device
  USB: pl2303: Remove support for Samsung I330
  USB: visor: Match I330 phone more precisely
  xhci: gracefully handle xhci_irq dead device
  xhci: Solve full event ring by increasing TRBS_PER_SEGMENT to 256
  xhci: fix isoc endpoint dequeue from advancing too far on transaction error
  target/pscsi: Don't leak scsi_host if hba is VIRTUAL_HOST
  ASoC: wm8994: correct BCLK DIV 348 to 384
  ASoC: wm8960: fix "RINPUT3" audio route error
  ASoC: mc13783: Fix wrong mask value used in mc13xxx_reg_rmw() calls
  ALSA: hda - Add headphone quirk for Lifebook E752
  ALSA: hda - Add Conexant codecs CX20721, CX20722, CX20723 and CX20724
  d_walk() might skip too much
  lib: Fix strnlen_user() to not touch memory after specified maximum
  hwmon: (ntc_thermistor) Ensure iio channel is of type IIO_VOLTAGE
  libceph: request a new osdmap if lingering request maps to no osd
  lguest: fix out-by-one error in address checking.
  fs, omfs: add NULL terminator in the end up the token list
  KVM: MMU: fix CR4.SMEP=1, CR0.WP=0 with shadow pages
  net: socket: Fix the wrong returns for recvmsg and sendmsg
  kernel: use the gnu89 standard explicitly
  staging, rtl8192e, LLVMLinux: Remove unused inline prototype
  staging: rtl8712, rtl8712: avoid lots of build warnings
  staging, rtl8192e, LLVMLinux: Change extern inline to static inline
  drm/i915: Fix declaration of intel_gmbus_{is_forced_bit/is_port_falid}
  staging: wlags49_h2: fix extern inline functions
  Linux 3.10.79
  ACPICA: Utilities: Cleanup to enforce ACPI_PHYSADDR_TO_PTR()/ACPI_PTR_TO_PHYSADDR().
  ACPICA: Tables: Change acpi_find_root_pointer() to use acpi_physical_address.
  revert "softirq: Add support for triggering softirq work on softirqs"
  sound/oss: fix deadlock in sequencer_ioctl(SNDCTL_SEQ_OUTOFBAND)
  mmc: card: Don't access RPMB partitions for normal read/write
  pinctrl: Don't just pretend to protect pinctrl_maps, do it for real
  drm/i915: Add missing MacBook Pro models with dual channel LVDS
  ARM: mvebu: armada-xp-openblocks-ax3-4: Disable internal RTC
  ARM: dts: imx23-olinuxino: Fix dr_mode of usb0
  ARM: dts: imx28: Fix AUART4 TX-DMA interrupt name
  ARM: dts: imx25: Add #pwm-cells to pwm4
  gpio: sysfs: fix memory leaks and device hotplug
  gpio: unregister gpiochip device before removing it
  xen/console: Update console event channel on resume
  mm/memory-failure: call shake_page() when error hits thp tail page
  nilfs2: fix sanity check of btree level in nilfs_btree_root_broken()
  ocfs2: dlm: fix race between purge and get lock resource
  Linux 3.10.78
  ARC: signal handling robustify
  UBI: fix soft lockup in ubi_check_volume()
  Drivers: hv: vmbus: Don't wait after requesting offers
  ARM: dts: dove: Fix uart[23] reg property
  staging: panel: fix lcd type
  usb: gadget: printer: enqueue printer's response for setup request
  usb: host: oxu210hp: use new USB_RESUME_TIMEOUT
  3w-sas: fix command completion race
  3w-9xxx: fix command completion race
  3w-xxxx: fix command completion race
  ext4: fix data corruption caused by unwritten and delayed extents
  rbd: end I/O the entire obj_request on error
  serial: of-serial: Remove device_type = "serial" registration
  ALSA: hda - Fix mute-LED fixed mode
  ALSA: emu10k1: Emu10k2 32 bit DMA mode
  ALSA: emu10k1: Fix card shortname string buffer overflow
  ALSA: emux: Fix mutex deadlock in OSS emulation
  ALSA: emux: Fix mutex deadlock at unloading
  ipv4: Missing sk_nulls_node_init() in ping_unhash().
  Linux 3.10.77
  s390: Fix build error
  nosave: consolidate __nosave_{begin,end} in <asm/sections.h>
  memstick: mspro_block: add missing curly braces
  C6x: time: Ensure consistency in __init
  wl18xx: show rx_frames_per_rates as an array as it really is
  lib: memzero_explicit: use barrier instead of OPTIMIZER_HIDE_VAR
  e1000: add dummy allocator to fix race condition between mtu change and netpoll
  ksoftirqd: Enable IRQs and call cond_resched() before poking RCU
  RCU pathwalk breakage when running into a symlink overmounting something
  drm/i915: cope with large i2c transfers
  drm/radeon: fix doublescan modes (v2)
  i2c: core: Export bus recovery functions
  IB/mlx4: Fix WQE LSO segment calculation
  IB/core: don't disallow registering region starting at 0x0
  IB/core: disallow registering 0-sized memory region
  stk1160: Make sure current buffer is released
  mvsas: fix panic on expander attached SATA devices
  Drivers: hv: vmbus: Fix a bug in the error path in vmbus_open()
  xtensa: provide __NR_sync_file_range2 instead of __NR_sync_file_range
  xtensa: xtfpga: fix hardware lockup caused by LCD driver
  ACPICA: Utilities: split IO address types from data type models.
  drivers: parport: Kconfig: exclude arm64 for PARPORT_PC
  scsi: storvsc: Fix a bug in copy_from_bounce_buffer()
  UBI: fix check for "too many bytes"
  UBI: initialize LEB number variable
  UBI: fix out of bounds write
  UBI: account for bitflips in both the VID header and data
  tools/power turbostat: Use $(CURDIR) instead of $(PWD) and add support for O= option in Makefile
  powerpc/perf: Cap 64bit userspace backtraces to PERF_MAX_STACK_DEPTH
  ext4: make fsync to sync parent dir in no-journal for real this time
  arm64: kernel: compiling issue, need delete read_current_timer()
  video: vgacon: Don't build on arm64
  console: Disable VGA text console support on cris
  drivers: parport: Kconfig: exclude h8300 for PARPORT_PC
  parport: disable PC-style parallel port support on cris
  rtlwifi: rtl8192cu: Add new device ID
  rtlwifi: rtl8192cu: Add new USB ID
  ptrace: fix race between ptrace_resume() and wait_task_stopped()
  fs/binfmt_elf.c: fix bug in loading of PIE binaries
  Input: elantech - fix absolute mode setting on some ASUS laptops
  ALSA: emu10k1: don't deadlock in proc-functions
  usb: core: hub: use new USB_RESUME_TIMEOUT
  usb: host: sl811: use new USB_RESUME_TIMEOUT
  usb: host: xhci: use new USB_RESUME_TIMEOUT
  usb: host: isp116x: use new USB_RESUME_TIMEOUT
  usb: host: r8a66597: use new USB_RESUME_TIMEOUT
  usb: define a generic USB_RESUME_TIMEOUT macro
  usb: phy: Find the right match in devm_usb_phy_match
  ARM: S3C64XX: Use fixed IRQ bases to avoid conflicts on Cragganmore
  ARM: 8320/1: fix integer overflow in ELF_ET_DYN_BASE
  power_supply: lp8788-charger: Fix leaked power supply on probe fail
  ring-buffer: Replace this_cpu_*() with __this_cpu_*()
  spi: spidev: fix possible arithmetic overflow for multi-transfer message
  cdc-wdm: fix endianness bug in debug statements
  MIPS: Hibernate: flush TLB entries earlier
  KVM: use slowpath for cross page cached accesses
  s390/hibernate: fix save and restore of kernel text section
  KVM: s390: Zero out current VMDB of STSI before including level3 data.
  usb: gadget: composite: enable BESL support
  Btrfs: fix inode eviction infinite loop after cloning into it
  Btrfs: fix log tree corruption when fs mounted with -o discard
  tcp: avoid looping in tcp_send_fin()
  tcp: fix possible deadlock in tcp_send_fin()
  ip_forward: Drop frames with attached skb->sk
  Linux 3.10.76
  dcache: Fix locking bugs in backported "deal with deadlock in d_walk()"
  arc: mm: Fix build failure
  sb_edac: avoid INTERNAL ERROR message in EDAC with unspecified channel
  x86: mm: move mmap_sem unlock from mm_fault_error() to caller
  vm: make stack guard page errors return VM_FAULT_SIGSEGV rather than SIGBUS
  vm: add VM_FAULT_SIGSEGV handling support
  deal with deadlock in d_walk()
  move d_rcu from overlapping d_child to overlapping d_alias
  kconfig: Fix warning "‘jump’ may be used uninitialized"
  KVM: x86: SYSENTER emulation is broken
  netfilter: conntrack: disable generic tracking for known protocols
  Bluetooth: Ignore isochronous endpoints for Intel USB bootloader
  Bluetooth: Add support for Intel bootloader devices
  Bluetooth: btusb: Add IMC Networks (Broadcom based)
  Bluetooth: Add firmware update for Atheros 0cf3:311f
  Bluetooth: Enable Atheros 0cf3:311e for firmware upload
  mm: Fix NULL pointer dereference in madvise(MADV_WILLNEED) support
  splice: Apply generic position and size checks to each write
  jfs: fix readdir regression
  serial: 8250_dw: Fix deadlock in LCR workaround
  benet: Call dev_kfree_skby_any instead of kfree_skb.
  ixgb: Call dev_kfree_skby_any instead of dev_kfree_skb.
  tg3: Call dev_kfree_skby_any instead of dev_kfree_skb.
  bnx2: Call dev_kfree_skby_any instead of dev_kfree_skb.
  r8169: Call dev_kfree_skby_any instead of dev_kfree_skb.
  8139too: Call dev_kfree_skby_any instead of dev_kfree_skb.
  8139cp: Call dev_kfree_skby_any instead of kfree_skb.
  tcp: tcp_make_synack() should clear skb->tstamp
  tcp: fix FRTO undo on cumulative ACK of SACKed range
  ipv6: Don't reduce hop limit for an interface
  tcp: prevent fetching dst twice in early demux code
  remove extra definitions of U32_MAX
  conditionally define U32_MAX
  Linux 3.10.75
  pagemap: do not leak physical addresses to non-privileged userspace
  console: Fix console name size mismatch
  IB/mlx4: Saturate RoCE port PMA counters in case of overflow
  kernel.h: define u8, s8, u32, etc. limits
  net: llc: use correct size for sysctl timeout entries
  net: rds: use correct size for max unacked packets and bytes
  ipc: fix compat msgrcv with negative msgtyp
  core, nfqueue, openvswitch: fix compilation warning
  media: s5p-mfc: fix mmap support for 64bit arch
  iscsi target: fix oops when adding reject pdu
  ocfs2: _really_ sync the right range
  be2iscsi: Fix kernel panic when device initialization fails
  cifs: fix use-after-free bug in find_writable_file
  usb: xhci: apply XHCI_AVOID_BEI quirk to all Intel xHCI controllers
  cpuidle: ACPI: do not overwrite name and description of C0
  dmaengine: omap-dma: Fix memory leak when terminating running transfer
  iio: imu: Use iio_trigger_get for indio_dev->trig assignment
  iio: inv_mpu6050: Clear timestamps fifo while resetting hardware fifo
  Defer processing of REQ_PREEMPT requests for blocked devices
  USB: ftdi_sio: Use jtag quirk for SNAP Connect E10
  USB: ftdi_sio: Added custom PID for Synapse Wireless product
  radeon: Do not directly dereference pointers to BIOS area.
  writeback: fix possible underflow in write bandwidth calculation
  writeback: add missing INITIAL_JIFFIES init in global_update_bandwidth()
  mm/memory hotplug: postpone the reset of obsolete pgdat
  nbd: fix possible memory leak
  iwlwifi: dvm: run INIT firmware again upon .start()
  IB/uverbs: Prevent integer overflow in ib_umem_get address arithmetic
  IB/core: Avoid leakage from kernel to user space
  tcp: Fix crash in TCP Fast Open
  selinux: fix sel_write_enforce broken return value
  ALSA: hda - Fix headphone pin config for Lifebook T731
  ALSA: usb - Creative USB X-Fi Pro SB1095 volume knob support
  ALSA: hda - Add one more node in the EAPD supporting candidate list
  Linux 3.10.74
  net: ethernet: pcnet32: Setup the SRAM and NOUFLO on Am79C97{3, 5}
  powerpc/mpc85xx: Add ranges to etsec2 nodes
  hfsplus: fix B-tree corruption after insertion at position 0
  dm: hold suspend_lock while suspending device during device deletion
  vt6655: RFbSetPower fix missing rate RATE_12M
  perf: Fix irq_work 'tail' recursion
  Revert "iwlwifi: mvm: fix failure path when power_update fails in add_interface"
  mac80211: drop unencrypted frames in mesh fwding
  mac80211: disable u-APSD queues by default
  nl80211: ignore HT/VHT capabilities without QoS/WMM
  tcm_qla2xxx: Fix incorrect use of __transport_register_session
  tcm_fc: missing curly braces in ft_invl_hw_context()
  ASoC: wm8955: Fix wrong value references for boolean kctl
  ASoC: adav80x: Fix wrong value references for boolean kctl
  ASoC: ak4641: Fix wrong value references for boolean kctl
  ASoC: wm8904: Fix wrong value references for boolean kctl
  ASoC: wm8903: Fix wrong value references for boolean kctl
  ASoC: wm2000: Fix wrong value references for boolean kctl
  ASoC: wm8731: Fix wrong value references for boolean kctl
  ASoC: tas5086: Fix wrong value references for boolean kctl
  ASoC: wm8960: Fix wrong value references for boolean kctl
  ASoC: cs4271: Fix wrong value references for boolean kctl
  ASoC: sgtl5000: remove useless register write clearing CHRGPUMP_POWERUP

Change-Id: Ib7976ee2c7224e39074157e28db4158db40b00db
Signed-off-by: Kaushal Kumar <kaushalk@codeaurora.org>
2015-09-30 13:25:40 +05:30
Jann Horn 9eae8ac6ab fs: take i_mutex during prepare_binprm for set[ug]id executables
commit 8b01fc86b9f425899f8a3a8fc1c47d73c2c20543 upstream.

This prevents a race between chown() and execve(), where chowning a
setuid-user binary to root would momentarily make the binary setuid
root.

This patch was mostly written by Linus Torvalds.

Signed-off-by: Jann Horn <jann@thejh.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Charles Williams <ciwillia@brocade.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Sheng Yong <shengyong1@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-07-03 19:48:09 -07:00
Kees Cook 008f3de62a seccomp: implement SECCOMP_FILTER_FLAG_TSYNC
Applying restrictive seccomp filter programs to large or diverse
codebases often requires handling threads which may be started early in
the process lifetime (e.g., by code that is linked in). While it is
possible to apply permissive programs prior to process start up, it is
difficult to further restrict the kernel ABI to those threads after that
point.

This change adds a new seccomp syscall flag to SECCOMP_SET_MODE_FILTER for
synchronizing thread group seccomp filters at filter installation time.

When calling seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC,
filter) an attempt will be made to synchronize all threads in current's
threadgroup to its new seccomp filter program. This is possible iff all
threads are using a filter that is an ancestor to the filter current is
attempting to synchronize to. NULL filters (where the task is running as
SECCOMP_MODE_NONE) are also treated as ancestors allowing threads to be
transitioned into SECCOMP_MODE_FILTER. If prctrl(PR_SET_NO_NEW_PRIVS,
...) has been set on the calling thread, no_new_privs will be set for
all synchronized threads too. On success, 0 is returned. On failure,
the pid of one of the failing threads will be returned and no filters
will have been applied.

The race conditions against another thread are:
- requesting TSYNC (already handled by sighand lock)
- performing a clone (already handled by sighand lock)
- changing its filter (already handled by sighand lock)
- calling exec (handled by cred_guard_mutex)
The clone case is assisted by the fact that new threads will have their
seccomp state duplicated from their parent before appearing on the tasklist.

Holding cred_guard_mutex means that seccomp filters cannot be assigned
while in the middle of another thread's exec (potentially bypassing
no_new_privs or similar). The call to de_thread() may kill threads waiting
for the mutex.

Changes across threads to the filter pointer includes a barrier.

Based on patches by Will Drewry.

Suggested-by: Julien Tinnes <jln@chromium.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Andy Lutomirski <luto@amacapital.net>
Git-commit: f14a5db2398afed8f416d244e6da6b23940997c6
Git-repo: https://android.googlesource.com/kernel/common.git
Signed-off-by: Ian Maund <imaund@codeaurora.org>
2015-03-19 14:52:56 -07:00
Kees Cook 97ac68bd2b sched: move no_new_privs into new atomic flags
Since seccomp transitions between threads requires updates to the
no_new_privs flag to be atomic, the flag must be part of an atomic flag
set. This moves the nnp flag into a separate task field, and introduces
accessors.

Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Andy Lutomirski <luto@amacapital.net>
Git-commit: 9d0ff694bc22fb458acb763811a677696c60725b
Git-repo: https://android.googlesource.com/kernel/common.git
Signed-off-by: Ian Maund <imaund@codeaurora.org>
2015-03-19 14:52:51 -07:00
James Hogan 56ecdc3d9e metag: Reduce maximum stack size to 256MB
commit d71f290b4e98a39f49f2595a13be3b4d5ce8e1f1 upstream.

Specify the maximum stack size for arches where the stack grows upward
(parisc and metag) in asm/processor.h rather than hard coding in
fs/exec.c so that metag can specify a smaller value of 256MB rather than
1GB.

This fixes a BUG on metag if the RLIMIT_STACK hard limit is increased
beyond a safe value by root. E.g. when starting a process after running
"ulimit -H -s unlimited" it will then attempt to use a stack size of the
maximum 1GB which is far too big for metag's limited user virtual
address space (stack_top is usually 0x3ffff000):

BUG: failure at fs/exec.c:589/shift_arg_pages()!

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Helge Deller <deller@gmx.de>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: linux-parisc@vger.kernel.org
Cc: linux-metag@vger.kernel.org
Cc: John David Anglin <dave.anglin@bell.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-06-07 13:25:38 -07:00
Kees Cook d389d610b1 exec/ptrace: fix get_dumpable() incorrect tests
commit d049f74f2dbe71354d43d393ac3a188947811348 upstream.

The get_dumpable() return value is not boolean.  Most users of the
function actually want to be testing for non-SUID_DUMP_USER(1) rather than
SUID_DUMP_DISABLE(0).  The SUID_DUMP_ROOT(2) is also considered a
protected state.  Almost all places did this correctly, excepting the two
places fixed in this patch.

Wrong logic:
    if (dumpable == SUID_DUMP_DISABLE) { /* be protective */ }
        or
    if (dumpable == 0) { /* be protective */ }
        or
    if (!dumpable) { /* be protective */ }

Correct logic:
    if (dumpable != SUID_DUMP_USER) { /* be protective */ }
        or
    if (dumpable != 1) { /* be protective */ }

Without this patch, if the system had set the sysctl fs/suid_dumpable=2, a
user was able to ptrace attach to processes that had dropped privileges to
that user.  (This may have been partially mitigated if Yama was enabled.)

The macros have been moved into the file that declares get/set_dumpable(),
which means things like the ia64 code can see them too.

CVE-2013-2929

Reported-by: Vasily Kulikov <segoon@openwall.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-29 11:11:44 -08:00
Linus Torvalds 8e220cfd1a Fix TLB gather virtual address range invalidation corner cases
commit 2b047252d087be7f2ba088b4933cd904f92e6fce upstream.

Ben Tebulin reported:

 "Since v3.7.2 on two independent machines a very specific Git
  repository fails in 9/10 cases on git-fsck due to an SHA1/memory
  failures.  This only occurs on a very specific repository and can be
  reproduced stably on two independent laptops.  Git mailing list ran
  out of ideas and for me this looks like some very exotic kernel issue"

and bisected the failure to the backport of commit 53a59fc67f ("mm:
limit mmu_gather batching to fix soft lockups on !CONFIG_PREEMPT").

That commit itself is not actually buggy, but what it does is to make it
much more likely to hit the partial TLB invalidation case, since it
introduces a new case in tlb_next_batch() that previously only ever
happened when running out of memory.

The real bug is that the TLB gather virtual memory range setup is subtly
buggered.  It was introduced in commit 597e1c3580 ("mm/mmu_gather:
enable tlb flush range in generic mmu_gather"), and the range handling
was already fixed at least once in commit e6c495a96ce0 ("mm: fix the TLB
range flushed when __tlb_remove_page() runs out of slots"), but that fix
was not complete.

The problem with the TLB gather virtual address range is that it isn't
set up by the initial tlb_gather_mmu() initialization (which didn't get
the TLB range information), but it is set up ad-hoc later by the
functions that actually flush the TLB.  And so any such case that forgot
to update the TLB range entries would potentially miss TLB invalidates.

Rather than try to figure out exactly which particular ad-hoc range
setup was missing (I personally suspect it's the hugetlb case in
zap_huge_pmd(), which didn't have the same logic as zap_pte_range()
did), this patch just gets rid of the problem at the source: make the
TLB range information available to tlb_gather_mmu(), and initialize it
when initializing all the other tlb gather fields.

This makes the patch larger, but conceptually much simpler.  And the end
result is much more understandable; even if you want to play games with
partial ranges when invalidating the TLB contents in chunks, now the
range information is always there, and anybody who doesn't want to
bother with it won't introduce subtle bugs.

Ben verified that this fixes his problem.

Reported-bisected-and-tested-by: Ben Tebulin <tebulin@googlemail.com>
Build-testing-by: Stephen Rothwell <sfr@canb.auug.org.au>
Build-testing-by: Richard Weinberger <richard.weinberger@gmail.com>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-08-20 08:43:05 -07:00
Stephane Eranian 2976b10f05 perf: Disable monitoring on setuid processes for regular users
There was a a bug in setup_new_exec(), whereby
the test to disabled perf monitoring was not
correct because the new credentials for the
process were not yet committed and therefore
the get_dumpable() test was never firing.

The patch fixes the problem by moving the
perf_event test until after the credentials
are committed.

Signed-off-by: Stephane Eranian <eranian@google.com>
Tested-by: Jiri Olsa <jolsa@redhat.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: <stable@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-06-26 11:40:18 +02:00
Linus Torvalds 20b4fb4852 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull VFS updates from Al Viro,

Misc cleanups all over the place, mainly wrt /proc interfaces (switch
create_proc_entry to proc_create(), get rid of the deprecated
create_proc_read_entry() in favor of using proc_create_data() and
seq_file etc).

7kloc removed.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (204 commits)
  don't bother with deferred freeing of fdtables
  proc: Move non-public stuff from linux/proc_fs.h to fs/proc/internal.h
  proc: Make the PROC_I() and PDE() macros internal to procfs
  proc: Supply a function to remove a proc entry by PDE
  take cgroup_open() and cpuset_open() to fs/proc/base.c
  ppc: Clean up scanlog
  ppc: Clean up rtas_flash driver somewhat
  hostap: proc: Use remove_proc_subtree()
  drm: proc: Use remove_proc_subtree()
  drm: proc: Use minor->index to label things, not PDE->name
  drm: Constify drm_proc_list[]
  zoran: Don't print proc_dir_entry data in debug
  reiserfs: Don't access the proc_dir_entry in r_open(), r_start() r_show()
  proc: Supply an accessor for getting the data from a PDE's parent
  airo: Use remove_proc_subtree()
  rtl8192u: Don't need to save device proc dir PDE
  rtl8187se: Use a dir under /proc/net/r8180/
  proc: Add proc_mkdir_data()
  proc: Move some bits from linux/proc_fs.h to linux/{of.h,signal.h,tty.h}
  proc: Move PDE_NET() to fs/proc/proc_net.c
  ...
2013-05-01 17:51:54 -07:00
Oleg Nesterov e56fb28740 exec: do not abuse ->cred_guard_mutex in threadgroup_lock()
threadgroup_lock() takes signal->cred_guard_mutex to ensure that
thread_group_leader() is stable.  This doesn't look nice, the scope of
this lock in do_execve() is huge.

And as Dave pointed out this can lead to deadlock, we have the
following dependencies:

	do_execve:		cred_guard_mutex -> i_mutex
	cgroup_mount:		i_mutex -> cgroup_mutex
	attach_task_by_pid:	cgroup_mutex -> cred_guard_mutex

Change de_thread() to take threadgroup_change_begin() around the
switch-the-leader code and change threadgroup_lock() to avoid
->cred_guard_mutex.

Note that de_thread() can't sleep with ->group_rwsem held, this can
obviously deadlock with the exiting leader if the writer is active, so it
does threadgroup_change_end() before schedule().

Reported-by: Dave Jones <davej@redhat.com>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-30 17:04:07 -07:00
Oleg Nesterov 12eaaf309a set_task_comm: kill the pointless memset() + wmb()
set_task_comm() does memset() + wmb() before strlcpy().  This buys
nothing and to add to the confusion, the comment is wrong.

- We do not need memset() to be "safe from non-terminating string
  reads", the final char is always zero and we never change it.

- wmb() is paired with nothing, it cannot prevent from printing
  the mixture of the old/new data unless the reader takes the lock.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: John Stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-30 17:04:07 -07:00
Hugh Dickins 6ee8630e02 mm: allow arch code to control the user page table ceiling
On architectures where a pgd entry may be shared between user and kernel
(e.g.  ARM+LPAE), freeing page tables needs a ceiling other than 0.
This patch introduces a generic USER_PGTABLES_CEILING that arch code can
override.  It is the responsibility of the arch code setting the ceiling
to ensure the complete freeing of the page tables (usually in
pgd_free()).

[catalin.marinas@arm.com: commit log; shift_arg_pages(), asm-generic/pgtables.h changes]
Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: <stable@vger.kernel.org>	[3.3+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-29 15:54:34 -07:00
Al Viro 3dc20cb282 new helper: read_code()
switch binfmts that use ->read() to that (and to kernel_read()
in several cases in binfmt_flat - sure, it's nommu, but still,
doing ->read() into kmalloc'ed buffer...)

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-04-29 15:40:23 -04:00
Kees Cook e579d2c259 coredump: remove redundant defines for dumpable states
The existing SUID_DUMP_* defines duplicate the newer SUID_DUMPABLE_*
defines introduced in 54b501992d ("coredump: warn about unsafe
suid_dumpable / core_pattern combo").  Remove the new ones, and use the
prior values instead.

Signed-off-by: Kees Cook <keescook@chromium.org>
Reported-by: Chen Gang <gang.chen@asianux.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Alan Cox <alan@linux.intel.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Doug Ledford <dledford@redhat.com>
Cc: Serge Hallyn <serge.hallyn@canonical.com>
Cc: James Morris <james.l.morris@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-27 19:10:11 -08:00
Yuanhan Liu 9cc64ceaa8 fs/exec.c: make bprm_mm_init() static
There is only one user of bprm_mm_init, and it's inside the same file.

Signed-off-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-02-26 02:46:13 -05:00
Al Viro 496ad9aa8e new helper: file_inode(file)
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-02-22 23:31:31 -05:00
Xi Wang 6d92d4f6a7 fs/exec.c: work around icc miscompilation
The tricky problem is this check:

	if (i++ >= max)

icc (mis)optimizes this check as:

	if (++i > max)

The check now becomes a no-op since max is MAX_ARG_STRINGS (0x7FFFFFFF).

This is "allowed" by the C standard, assuming i++ never overflows,
because signed integer overflow is undefined behavior.  This
optimization effectively reverts the previous commit 362e6663ef
("exec.c, compat.c: fix count(), compat_count() bounds checking") that
tries to fix the check.

This patch simply moves ++ after the check.

Signed-off-by: Xi Wang <xi.wang@gmail.com>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-01-11 14:54:55 -08:00
Linus Torvalds 4c9a44aebe Merge branch 'akpm' (Andrew's patch-bomb)
Merge the rest of Andrew's patches for -rc1:
 "A bunch of fixes and misc missed-out-on things.

  That'll do for -rc1.  I still have a batch of IPC patches which still
  have a possible bug report which I'm chasing down."

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (25 commits)
  keys: use keyring_alloc() to create module signing keyring
  keys: fix unreachable code
  sendfile: allows bypassing of notifier events
  SGI-XP: handle non-fatal traps
  fat: fix incorrect function comment
  Documentation: ABI: remove testing/sysfs-devices-node
  proc: fix inconsistent lock state
  linux/kernel.h: fix DIV_ROUND_CLOSEST with unsigned divisors
  memcg: don't register hotcpu notifier from ->css_alloc()
  checkpatch: warn on uapi #includes that #include <uapi/...
  revert "rtc: recycle id when unloading a rtc driver"
  mm: clean up transparent hugepage sysfs error messages
  hfsplus: add error message for the case of failure of sync fs in delayed_sync_fs() method
  hfsplus: rework processing of hfs_btree_write() returned error
  hfsplus: rework processing errors in hfsplus_free_extents()
  hfsplus: avoid crash on failed block map free
  kcmp: include linux/ptrace.h
  drivers/rtc/rtc-imxdi.c: must include <linux/spinlock.h>
  mm: cma: WARN if freed memory is still in use
  exec: do not leave bprm->interp on stack
  ...
2012-12-20 20:00:43 -08:00
Linus Torvalds 54d46ea993 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal
Pull signal handling cleanups from Al Viro:
 "sigaltstack infrastructure + conversion for x86, alpha and um,
  COMPAT_SYSCALL_DEFINE infrastructure.

  Note that there are several conflicts between "unify
  SS_ONSTACK/SS_DISABLE definitions" and UAPI patches in mainline;
  resolution is trivial - just remove definitions of SS_ONSTACK and
  SS_DISABLED from arch/*/uapi/asm/signal.h; they are all identical and
  include/uapi/linux/signal.h contains the unified variant."

Fixed up conflicts as per Al.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal:
  alpha: switch to generic sigaltstack
  new helpers: __save_altstack/__compat_save_altstack, switch x86 and um to those
  generic compat_sys_sigaltstack()
  introduce generic sys_sigaltstack(), switch x86 and um to it
  new helper: compat_user_stack_pointer()
  new helper: restore_altstack()
  unify SS_ONSTACK/SS_DISABLE definitions
  new helper: current_user_stack_pointer()
  missing user_stack_pointer() instances
  Bury the conditionals from kernel_thread/kernel_execve series
  COMPAT_SYSCALL_DEFINE: infrastructure
2012-12-20 18:05:28 -08:00
Kees Cook b66c598401 exec: do not leave bprm->interp on stack
If a series of scripts are executed, each triggering module loading via
unprintable bytes in the script header, kernel stack contents can leak
into the command line.

Normally execution of binfmt_script and binfmt_misc happens recursively.
However, when modules are enabled, and unprintable bytes exist in the
bprm->buf, execution will restart after attempting to load matching
binfmt modules.  Unfortunately, the logic in binfmt_script and
binfmt_misc does not expect to get restarted.  They leave bprm->interp
pointing to their local stack.  This means on restart bprm->interp is
left pointing into unused stack memory which can then be copied into the
userspace argv areas.

After additional study, it seems that both recursion and restart remains
the desirable way to handle exec with scripts, misc, and modules.  As
such, we need to protect the changes to interp.

This changes the logic to require allocation for any changes to the
bprm->interp.  To avoid adding a new kmalloc to every exec, the default
value is left as-is.  Only when passing through binfmt_script or
binfmt_misc does an allocation take place.

For a proof of concept, see DoTest.sh from:

   http://www.halfdog.net/Security/2012/LinuxKernelBinfmtScriptStackDataDisclosure/

Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: halfdog <me@halfdog.net>
Cc: P J P <ppandit@redhat.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-20 17:40:19 -08:00
Al Viro ae903caae2 Bury the conditionals from kernel_thread/kernel_execve series
All architectures have
	CONFIG_GENERIC_KERNEL_THREAD
	CONFIG_GENERIC_KERNEL_EXECVE
	__ARCH_WANT_SYS_EXECVE
None of them have __ARCH_WANT_KERNEL_EXECVE and there are only two callers
of kernel_execve() (which is a trivial wrapper for do_execve() now) left.
Kill the conditionals and make both callers use do_execve().

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-12-19 18:07:38 -05:00
Linus Torvalds 848b81415c Merge branch 'akpm' (Andrew's patch-bomb)
Merge misc patches from Andrew Morton:
 "Incoming:

   - lots of misc stuff

   - backlight tree updates

   - lib/ updates

   - Oleg's percpu-rwsem changes

   - checkpatch

   - rtc

   - aoe

   - more checkpoint/restart support

  I still have a pile of MM stuff pending - Pekka should be merging
  later today after which that is good to go.  A number of other things
  are twiddling thumbs awaiting maintainer merges."

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (180 commits)
  scatterlist: don't BUG when we can trivially return a proper error.
  docs: update documentation about /proc/<pid>/fdinfo/<fd> fanotify output
  fs, fanotify: add @mflags field to fanotify output
  docs: add documentation about /proc/<pid>/fdinfo/<fd> output
  fs, notify: add procfs fdinfo helper
  fs, exportfs: add exportfs_encode_inode_fh() helper
  fs, exportfs: escape nil dereference if no s_export_op present
  fs, epoll: add procfs fdinfo helper
  fs, eventfd: add procfs fdinfo helper
  procfs: add ability to plug in auxiliary fdinfo providers
  tools/testing/selftests/kcmp/kcmp_test.c: print reason for failure in kcmp_test
  breakpoint selftests: print failure status instead of cause make error
  kcmp selftests: print fail status instead of cause make error
  kcmp selftests: make run_tests fix
  mem-hotplug selftests: print failure status instead of cause make error
  cpu-hotplug selftests: print failure status instead of cause make error
  mqueue selftests: print failure status instead of cause make error
  vm selftests: print failure status instead of cause make error
  ubifs: use prandom_bytes
  mtd: nandsim: use prandom_bytes
  ...
2012-12-17 20:58:12 -08:00
Kees Cook d740269867 exec: use -ELOOP for max recursion depth
To avoid an explosion of request_module calls on a chain of abusive
scripts, fail maximum recursion with -ELOOP instead of -ENOEXEC. As soon
as maximum recursion depth is hit, the error will fail all the way back
up the chain, aborting immediately.

This also has the side-effect of stopping the user's shell from attempting
to reexecute the top-level file as a shell script. As seen in the
dash source:

        if (cmd != path_bshell && errno == ENOEXEC) {
                *argv-- = cmd;
                *argv = cmd = path_bshell;
                goto repeat;
        }

The above logic was designed for running scripts automatically that lacked
the "#!" header, not to re-try failed recursion. On a legitimate -ENOEXEC,
things continue to behave as the shell expects.

Additionally, when tracking recursion, the binfmt handlers should not be
involved. The recursion being tracked is the depth of calls through
search_binary_handler(), so that function should be exclusively responsible
for tracking the depth.

Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: halfdog <me@halfdog.net>
Cc: P J P <ppandit@redhat.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-17 17:15:23 -08:00
Linus Torvalds 6a2b60b17b Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull user namespace changes from Eric Biederman:
 "While small this set of changes is very significant with respect to
  containers in general and user namespaces in particular.  The user
  space interface is now complete.

  This set of changes adds support for unprivileged users to create user
  namespaces and as a user namespace root to create other namespaces.
  The tyranny of supporting suid root preventing unprivileged users from
  using cool new kernel features is broken.

  This set of changes completes the work on setns, adding support for
  the pid, user, mount namespaces.

  This set of changes includes a bunch of basic pid namespace
  cleanups/simplifications.  Of particular significance is the rework of
  the pid namespace cleanup so it no longer requires sending out
  tendrils into all kinds of unexpected cleanup paths for operation.  At
  least one case of broken error handling is fixed by this cleanup.

  The files under /proc/<pid>/ns/ have been converted from regular files
  to magic symlinks which prevents incorrect caching by the VFS,
  ensuring the files always refer to the namespace the process is
  currently using and ensuring that the ptrace_mayaccess permission
  checks are always applied.

  The files under /proc/<pid>/ns/ have been given stable inode numbers
  so it is now possible to see if different processes share the same
  namespaces.

  Through the David Miller's net tree are changes to relax many of the
  permission checks in the networking stack to allowing the user
  namespace root to usefully use the networking stack.  Similar changes
  for the mount namespace and the pid namespace are coming through my
  tree.

  Two small changes to add user namespace support were commited here adn
  in David Miller's -net tree so that I could complete the work on the
  /proc/<pid>/ns/ files in this tree.

  Work remains to make it safe to build user namespaces and 9p, afs,
  ceph, cifs, coda, gfs2, ncpfs, nfs, nfsd, ocfs2, and xfs so the
  Kconfig guard remains in place preventing that user namespaces from
  being built when any of those filesystems are enabled.

  Future design work remains to allow root users outside of the initial
  user namespace to mount more than just /proc and /sys."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (38 commits)
  proc: Usable inode numbers for the namespace file descriptors.
  proc: Fix the namespace inode permission checks.
  proc: Generalize proc inode allocation
  userns: Allow unprivilged mounts of proc and sysfs
  userns: For /proc/self/{uid,gid}_map derive the lower userns from the struct file
  procfs: Print task uids and gids in the userns that opened the proc file
  userns: Implement unshare of the user namespace
  userns: Implent proc namespace operations
  userns: Kill task_user_ns
  userns: Make create_new_namespaces take a user_ns parameter
  userns: Allow unprivileged use of setns.
  userns: Allow unprivileged users to create new namespaces
  userns: Allow setting a userns mapping to your current uid.
  userns: Allow chown and setgid preservation
  userns: Allow unprivileged users to create user namespaces.
  userns: Ignore suid and sgid on binaries if the uid or gid can not be mapped
  userns: fix return value on mntns_install() failure
  vfs: Allow unprivileged manipulation of the mount namespace.
  vfs: Only support slave subtrees across different user namespaces
  vfs: Add a user namespace reference from struct mnt_namespace
  ...
2012-12-17 15:44:47 -08:00
Al Viro 71613c3b87 get rid of pt_regs argument of ->load_binary()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-11-28 21:53:38 -05:00
Al Viro 3c456bfc4b get rid of pt_regs argument of search_binary_handler()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-11-28 21:53:38 -05:00
Al Viro 835ab32dff get rid of pt_regs argument of do_execve_common()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-11-28 21:53:37 -05:00
Al Viro da3d4c5fa5 get rid of pt_regs argument of do_execve()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-11-28 21:53:37 -05:00
Al Viro d03d26e58f make compat_do_execve() static, lose pt_regs argument
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-11-28 21:53:37 -05:00
Eric W. Biederman 3cdf5b45ff userns: Ignore suid and sgid on binaries if the uid or gid can not be mapped
When performing an exec where the binary lives in one user namespace and
the execing process lives in another usre namespace there is the possibility
that the target uids can not be represented.

Instead of failing the exec simply ignore the suid/sgid bits and run
the binary with lower privileges.   We already do this in the case
of MNT_NOSUID so this should be a well tested code path.

As the user and group are not changed this should not introduce any
security issues.

Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-11-19 05:59:23 -08:00
Oleg Nesterov b40a79591c freezer: exec should clear PF_NOFREEZE along with PF_KTHREAD
flush_old_exec() clears PF_KTHREAD but forgets about PF_NOFREEZE.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: stable@vger.kernel.org
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2012-10-25 22:28:12 +02:00
Jeff Layton 669abf4e55 vfs: make path_openat take a struct filename pointer
...and fix up the callers. For do_file_open_root, just declare a
struct filename on the stack and fill out the .name field. For
do_filp_open, make it also take a struct filename pointer, and fix up its
callers to call it appropriately.

For filp_open, add a variant that takes a struct filename pointer and turn
filp_open into a wrapper around it.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-10-12 20:15:09 -04:00
Jeff Layton 91a27b2a75 vfs: define struct filename and have getname() return it
getname() is intended to copy pathname strings from userspace into a
kernel buffer. The result is just a string in kernel space. It would
however be quite helpful to be able to attach some ancillary info to
the string.

For instance, we could attach some audit-related info to reduce the
amount of audit-related processing needed. When auditing is enabled,
we could also call getname() on the string more than once and not
need to recopy it from userspace.

This patchset converts the getname()/putname() interfaces to return
a struct instead of a string. For now, the struct just tracks the
string in kernel space and the original userland pointer for it.

Later, we'll add other information to the struct as it becomes
convenient.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-10-12 20:14:55 -04:00
Linus Torvalds 42859eea96 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal
Pull generic execve() changes from Al Viro:
 "This introduces the generic kernel_thread() and kernel_execve()
  functions, and switches x86, arm, alpha, um and s390 over to them."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal: (26 commits)
  s390: convert to generic kernel_execve()
  s390: switch to generic kernel_thread()
  s390: fold kernel_thread_helper() into ret_from_fork()
  s390: fold execve_tail() into start_thread(), convert to generic sys_execve()
  um: switch to generic kernel_thread()
  x86, um/x86: switch to generic sys_execve and kernel_execve
  x86: split ret_from_fork
  alpha: introduce ret_from_kernel_execve(), switch to generic kernel_execve()
  alpha: switch to generic kernel_thread()
  alpha: switch to generic sys_execve()
  arm: get rid of execve wrapper, switch to generic execve() implementation
  arm: optimized current_pt_regs()
  arm: introduce ret_from_kernel_execve(), switch to generic kernel_execve()
  arm: split ret_from_fork, simplify kernel_thread() [based on patch by rmk]
  generic sys_execve()
  generic kernel_execve()
  new helper: current_pt_regs()
  preparation for generic kernel_thread()
  um: kill thread->forking
  um: let signal_delivered() do SIGTRAP on singlestepping into handler
  ...
2012-10-10 12:02:25 +09:00
Michel Lespinasse 38a76013ad mm: avoid taking rmap locks in move_ptes()
During mremap(), the destination VMA is generally placed after the
original vma in rmap traversal order: in move_vma(), we always have
new_pgoff >= vma->vm_pgoff, and as a result new_vma->vm_pgoff >=
vma->vm_pgoff unless vma_merge() merged the new vma with an adjacent one.

When the destination VMA is placed after the original in rmap traversal
order, we can avoid taking the rmap locks in move_ptes().

Essentially, this reintroduces the optimization that had been disabled in
"mm anon rmap: remove anon_vma_moveto_tail".  The difference is that we
don't try to impose the rmap traversal order; instead we just rely on
things being in the desired order in the common case and fall back to
taking locks in the uncommon case.  Also we skip the i_mmap_mutex in
addition to the anon_vma lock: in both cases, the vmas are traversed in
increasing vm_pgoff order with ties resolved in tree insertion order.

Signed-off-by: Michel Lespinasse <walken@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Daniel Santos <daniel.santos@pobox.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-09 16:22:42 +09:00
Oleg Nesterov d5bbd43d5f exec: make de_thread() killable
Change de_thread() to use KILLABLE rather than UNINTERRUPTIBLE while
waiting for other threads.  The only complication is that we should
clear ->group_exit_task and ->notify_count before we return, and we
should do this under tasklist_lock.  -EAGAIN is used to match the
initial signal_group_exit() check/return, it doesn't really matter.

This fixes the (unlikely) race with coredump.  de_thread() checks
signal_group_exit() before it starts to kill the subthreads, but this
can't help if another CLONE_VM (but non CLONE_THREAD) task starts the
coredumping after de_thread() unlocks ->siglock.  In this case the
killed sub-thread can block in exit_mm() waiting for coredump_finish(),
execing thread waits for that sub-thead, and the coredumping thread
waits for execing thread.  Deadlock.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-09 06:53:20 +09:00
Oleg Nesterov 0f4cfb2e4e coredump: use SUID_DUMPABLE_ENABLED rather than hardcoded 1
Cosmetic. Change setup_new_exec() and task_dumpable() to use
SUID_DUMPABLE_ENABLED for /bin/grep.

[akpm@linux-foundation.org: checkpatch fixes]
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-06 03:05:16 +09:00
Alex Kelly 179899fd5d coredump: update coredump-related headers
Create a new header file, fs/coredump.h, which contains functions only
used by the new coredump.c.  It also moves do_coredump to the
include/linux/coredump.h header file, for consistency.

Signed-off-by: Alex Kelly <alex.page.kelly@gmail.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-06 03:05:15 +09:00
Alex Kelly 10c28d937e coredump: move core dump functionality into its own file
This prepares for making core dump functionality optional.

The variable "suid_dumpable" and associated functions are left in fs/exec.c
because they're used elsewhere, such as in ptrace.

Signed-off-by: Alex Kelly <alex.page.kelly@gmail.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-10-02 21:35:55 -04:00
Al Viro 38b983b346 generic sys_execve()
Selected by __ARCH_WANT_SYS_EXECVE in unistd.h.  Requires
	* working current_pt_regs()
	* *NOT* doing a syscall-in-kernel kind of kernel_execve()
implementation.  Using generic kernel_execve() is fine.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-09-30 22:20:51 -04:00