(cherry picked from commit https://lkml.org/lkml/2016/2/4/833)
Replace calls to get_random_int() followed by a cast to (unsigned long)
with calls to get_random_long(). Also address shifting bug which, in case
of x86 removed entropy mask for mmap_rnd_bits values > 31 bits.
Bug: 26963541
Signed-off-by: Daniel Cashman <dcashman@android.com>
Signed-off-by: Daniel Cashman <dcashman@google.com>
Change-Id: Iac34b63294ec120edcbf8760186667a84a5cf556
(cherry picked from commit https://lkml.org/lkml/2015/12/21/339)
x86: arch_mmap_rnd() uses hard-coded values, 8 for 32-bit and 28 for
64-bit, to generate the random offset for the mmap base address.
This value represents a compromise between increased ASLR
effectiveness and avoiding address-space fragmentation. Replace it
with a Kconfig option, which is sensibly bounded, so that platform
developers may choose where to place this compromise. Keep default
values as new minimums.
Bug: 24047224
Signed-off-by: Daniel Cashman <dcashman@android.com>
Signed-off-by: Daniel Cashman <dcashman@google.com>
Change-Id: Id1fb53df5fedc909b79f3d952f120e6104900f24
Almost clean cherry pick of c6e9d6f388,
includes change made by merge 0891ad829d.
The getrandom(2) system call was requested by the LibreSSL Portable
developers. It is analoguous to the getentropy(2) system call in
OpenBSD.
The rationale of this system call is to provide resiliance against
file descriptor exhaustion attacks, where the attacker consumes all
available file descriptors, forcing the use of the fallback code where
/dev/[u]random is not available. Since the fallback code is often not
well-tested, it is better to eliminate this potential failure mode
entirely.
The other feature provided by this new system call is the ability to
request randomness from the /dev/urandom entropy pool, but to block
until at least 128 bits of entropy has been accumulated in the
/dev/urandom entropy pool. Historically, the emphasis in the
/dev/urandom development has been to ensure that urandom pool is
initialized as quickly as possible after system boot, and preferably
before the init scripts start execution.
This is because changing /dev/urandom reads to block represents an
interface change that could potentially break userspace which is not
acceptable. In practice, on most x86 desktop and server systems, in
general the entropy pool can be initialized before it is needed (and
in modern kernels, we will printk a warning message if not). However,
on an embedded system, this may not be the case. And so with this new
interface, we can provide the functionality of blocking until the
urandom pool has been initialized. Any userspace program which uses
this new functionality must take care to assure that if it is used
during the boot process, that it will not cause the init scripts or
other portions of the system startup to hang indefinitely.
SYNOPSIS
#include <linux/random.h>
int getrandom(void *buf, size_t buflen, unsigned int flags);
DESCRIPTION
The system call getrandom() fills the buffer pointed to by buf
with up to buflen random bytes which can be used to seed user
space random number generators (i.e., DRBG's) or for other
cryptographic uses. It should not be used for Monte Carlo
simulations or other programs/algorithms which are doing
probabilistic sampling.
If the GRND_RANDOM flags bit is set, then draw from the
/dev/random pool instead of the /dev/urandom pool. The
/dev/random pool is limited based on the entropy that can be
obtained from environmental noise, so if there is insufficient
entropy, the requested number of bytes may not be returned.
If there is no entropy available at all, getrandom(2) will
either block, or return an error with errno set to EAGAIN if
the GRND_NONBLOCK bit is set in flags.
If the GRND_RANDOM bit is not set, then the /dev/urandom pool
will be used. Unlike using read(2) to fetch data from
/dev/urandom, if the urandom pool has not been sufficiently
initialized, getrandom(2) will block (or return -1 with the
errno set to EAGAIN if the GRND_NONBLOCK bit is set in flags).
The getentropy(2) system call in OpenBSD can be emulated using
the following function:
int getentropy(void *buf, size_t buflen)
{
int ret;
if (buflen > 256)
goto failure;
ret = getrandom(buf, buflen, 0);
if (ret < 0)
return ret;
if (ret == buflen)
return 0;
failure:
errno = EIO;
return -1;
}
RETURN VALUE
On success, the number of bytes that was filled in the buf is
returned. This may not be all the bytes requested by the
caller via buflen if insufficient entropy was present in the
/dev/random pool, or if the system call was interrupted by a
signal.
On error, -1 is returned, and errno is set appropriately.
ERRORS
EINVAL An invalid flag was passed to getrandom(2)
EFAULT buf is outside the accessible address space.
EAGAIN The requested entropy was not available, and
getentropy(2) would have blocked if the
GRND_NONBLOCK flag was not set.
EINTR While blocked waiting for entropy, the call was
interrupted by a signal handler; see the description
of how interrupted read(2) calls on "slow" devices
are handled with and without the SA_RESTART flag
in the signal(7) man page.
NOTES
For small requests (buflen <= 256) getrandom(2) will not
return EINTR when reading from the urandom pool once the
entropy pool has been initialized, and it will return all of
the bytes that have been requested. This is the recommended
way to use getrandom(2), and is designed for compatibility
with OpenBSD's getentropy() system call.
However, if you are using GRND_RANDOM, then getrandom(2) may
block until the entropy accounting determines that sufficient
environmental noise has been gathered such that getrandom(2)
will be operating as a NRBG instead of a DRBG for those people
who are working in the NIST SP 800-90 regime. Since it may
block for a long time, these guarantees do *not* apply. The
user may want to interrupt a hanging process using a signal,
so blocking until all of the requested bytes are returned
would be unfriendly.
For this reason, the user of getrandom(2) MUST always check
the return value, in case it returns some error, or if fewer
bytes than requested was returned. In the case of
!GRND_RANDOM and small request, the latter should never
happen, but the careful userspace code (and all crypto code
should be careful) should check for this anyway!
Finally, unless you are doing long-term key generation (and
perhaps not even then), you probably shouldn't be using
GRND_RANDOM. The cryptographic algorithms used for
/dev/urandom are quite conservative, and so should be
sufficient for all purposes. The disadvantage of GRND_RANDOM
is that it can block, and the increased complexity required to
deal with partially fulfilled getrandom(2) requests.
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Zach Brown <zab@zabbo.net>
Bug: http://b/29621447
Change-Id: I189ba74070dd6d918b0fdf83ff30bb74ec0f7556
(cherry picked from commit 4af712e8df)
[flex1911]: backport to 3.4
Under CONFIG_STRICT_DEVMEM, reading System RAM through /dev/mem is
disallowed. However, on x86, the first 1MB was always allowed for BIOS
and similar things, regardless of it actually being System RAM. It was
possible for heap to end up getting allocated in low 1MB RAM, and then
read by things like x86info or dd, which would trip hardened usercopy:
usercopy: kernel memory exposure attempt detected from ffff880000090000 (dma-kmalloc-256) (4096 bytes)
This changes the x86 exception for the low 1MB by reading back zeros for
System RAM areas instead of blindly allowing them. More work is needed to
extend this to mmap, but currently mmap doesn't go through usercopy, so
hardened usercopy won't Oops the kernel.
Change-Id: I27594af6146e7643217e3babcfd088592b7dbd4b
Reported-by: Tommi Rantala <tommi.t.rantala@nokia.com>
Tested-by: Tommi Rantala <tommi.t.rantala@nokia.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
commit 1be7107fbe18eed3e319a6c3e83c78254b693acb upstream.
Stack guard page is a useful feature to reduce a risk of stack smashing
into a different mapping. We have been using a single page gap which
is sufficient to prevent having stack adjacent to a different mapping.
But this seems to be insufficient in the light of the stack usage in
userspace. E.g. glibc uses as large as 64kB alloca() in many commonly
used functions. Others use constructs liks gid_t buffer[NGROUPS_MAX]
which is 256kB or stack strings with MAX_ARG_STRLEN.
This will become especially dangerous for suid binaries and the default
no limit for the stack size limit because those applications can be
tricked to consume a large portion of the stack and a single glibc call
could jump over the guard page. These attacks are not theoretical,
unfortunatelly.
Make those attacks less probable by increasing the stack guard gap
to 1MB (on systems with 4k pages; but make it depend on the page size
because systems with larger base pages might cap stack allocations in
the PAGE_SIZE units) which should cover larger alloca() and VLA stack
allocations. It is obviously not a full fix because the problem is
somehow inherent, but it should reduce attack space a lot.
One could argue that the gap size should be configurable from userspace,
but that can be done later when somebody finds that the new 1MB is wrong
for some special case applications. For now, add a kernel command line
option (stack_guard_gap) to specify the stack gap size (in page units).
Implementation wise, first delete all the old code for stack guard page:
because although we could get away with accounting one extra page in a
stack vma, accounting a larger gap can break userspace - case in point,
a program run with "ulimit -S -v 20000" failed when the 1MB gap was
counted for RLIMIT_AS; similar problems could come with RLIMIT_MLOCK
and strict non-overcommit mode.
Instead of keeping gap inside the stack vma, maintain the stack guard
gap as a gap between vmas: using vm_start_gap() in place of vm_start
(or vm_end_gap() in place of vm_end if VM_GROWSUP) in just those few
places which need to respect the gap - mainly arch_get_unmapped_area(),
and and the vma tree's subtree_gap support for that.
Change-Id: I611023b0bfe1cab7b3e5da13e331a7baaaaf6eb0
Original-patch-by: Oleg Nesterov <oleg@redhat.com>
Original-patch-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Hugh Dickins <hughd@google.com>
[wt: backport to 4.11: adjust context]
[wt: backport to 4.9: adjust context ; kernel doc was not in admin-guide]
[wt: backport to 4.4: adjust context ; drop ppc hugetlb_radix changes]
[wt: backport to 3.18: adjust context ; no FOLL_POPULATE ;
s390 uses generic arch_get_unmapped_area()]
[wt: backport to 3.16: adjust context]
[wt: backport to 3.10: adjust context ; code logic in PARISC's
arch_get_unmapped_area() wasn't found ; code inserted into
expand_upwards() and expand_downwards() runs under anon_vma lock;
changes for gup.c:faultin_page go to memory.c:__get_user_pages();
included Hugh Dickins' fixes]
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Flex1911 <dedsa2002@gmail.com>
Preparatory patch to make the idle thread allocation for secondary
cpus generic.
Change-Id: I93b918d42eceb5bd3c8281fb48504f34352f382d
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Hirokazu Takata <takata@linux-m32r.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: David Howells <dhowells@redhat.com>
Cc: James E.J. Bottomley <jejb@parisc-linux.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: x86@kernel.org
Link: http://lkml.kernel.org/r/20120420124556.964170564@linutronix.de
commit 22eab1108781eff09961ae7001704f7bd8fb1dce upstream.
When restarting a syscall with regs->ax == -ERESTART_RESTARTBLOCK,
regs->ax is assigned to a restart_syscall number. For x32 tasks, this
syscall number must have __X32_SYSCALL_BIT set, otherwise it will be
an x86_64 syscall number instead of a valid x32 syscall number. This
issue has been there since the introduction of x32.
Reported-by: strace/tests/restart_syscall.test
Reported-and-tested-by: Elvira Khabirova <lineprinter0@gmail.com>
Signed-off-by: Dmitry V. Levin <ldv@altlinux.org>
Cc: Elvira Khabirova <lineprinter0@gmail.com>
Link: http://lkml.kernel.org/r/20151130215436.GA25996@altlinux.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Zefan Li <lizefan@huawei.com>
commit 04633df0c43d710e5f696b06539c100898678235 upstream.
When we get loaded by a 64-bit bootloader, kernel entry point is
startup_64 in head_64.S. We don't trust any and all bootloaders because
some will fiddle with CPU configuration so we go ahead and massage each
CPU into sanity again.
For example, some dell BIOSes have this XD disable feature which set
IA32_MISC_ENABLE[34] and disable NX. This might be some dumb workaround
for other OSes but Linux sure doesn't need it.
A similar thing is present in the Surface 3 firmware - see
https://bugzilla.kernel.org/show_bug.cgi?id=106051 - which sets this bit
only on the BSP:
# rdmsr -a 0x1a0
400850089
850089
850089
850089
I know, right?!
There's not even an off switch in there.
So fix all those cases by sanitizing the 64-bit entry point too. For
that, make verify_cpu() callable in 64-bit mode also.
Requested-and-debugged-by: "H. Peter Anvin" <hpa@zytor.com>
Reported-and-tested-by: Bastien Nocera <bugzilla@hadess.net>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1446739076-21303-1-git-send-email-bp@alien8.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
[lizf: Backported to 3.4: adjust context]
Signed-off-by: Zefan Li <lizefan@huawei.com>
commit b7a584598aea7ca73140cb87b40319944dd3393f upstream.
On Xen PV, regs->flags doesn't reliably reflect IOPL and the
exit-to-userspace code doesn't change IOPL. We need to context
switch it manually.
I'm doing this without going through paravirt because this is
specific to Xen PV. After the dust settles, we can merge this with
the 32-bit code, tidy up the iopl syscall implementation, and remove
the set_iopl pvop entirely.
Fixes XSA-171.
Reviewewd-by: Jan Beulich <JBeulich@suse.com>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jan Beulich <JBeulich@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/693c3bd7aeb4d3c27c92c622b7d0f554a458173c.1458162709.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
[ kamal: backport to 3.19-stable: no X86_FEATURE_XENPV so just call
xen_pv_domain() directly ]
Acked-by: Andy Lutomirski <luto <at> kernel.org>
Signed-off-by: Kamal Mostafa <kamal <at> canonical.com>
Signed-off-by: Zefan Li <lizefan@huawei.com>
commit eddd3826a1a0190e5235703d1e666affa4d13b96 upstream.
Dmitry Vyukov reported the following using trinity and the memory
error detector AddressSanitizer
(https://code.google.com/p/address-sanitizer/wiki/AddressSanitizerForKernel).
[ 124.575597] ERROR: AddressSanitizer: heap-buffer-overflow on
address ffff88002e280000
[ 124.576801] ffff88002e280000 is located 131938492886538 bytes to
the left of 28857600-byte region [ffffffff81282e0a, ffffffff82e0830a)
[ 124.578633] Accessed by thread T10915:
[ 124.579295] inlined in describe_heap_address
./arch/x86/mm/asan/report.c:164
[ 124.579295] #0 ffffffff810dd277 in asan_report_error
./arch/x86/mm/asan/report.c:278
[ 124.580137] #1 ffffffff810dc6a0 in asan_check_region
./arch/x86/mm/asan/asan.c:37
[ 124.581050] #2 ffffffff810dd423 in __tsan_read8 ??:0
[ 124.581893] #3 ffffffff8107c093 in get_wchan
./arch/x86/kernel/process_64.c:444
The address checks in the 64bit implementation of get_wchan() are
wrong in several ways:
- The lower bound of the stack is not the start of the stack
page. It's the start of the stack page plus sizeof (struct
thread_info)
- The upper bound must be:
top_of_stack - TOP_OF_KERNEL_STACK_PADDING - 2 * sizeof(unsigned long).
The 2 * sizeof(unsigned long) is required because the stack pointer
points at the frame pointer. The layout on the stack is: ... IP FP
... IP FP. So we need to make sure that both IP and FP are in the
bounds.
Fix the bound checks and get rid of the mix of numeric constants, u64
and unsigned long. Making all unsigned long allows us to use the same
function for 32bit as well.
Use READ_ONCE() when accessing the stack. This does not prevent a
concurrent wakeup of the task and the stack changing, but at least it
avoids TOCTOU.
Also check task state at the end of the loop. Again that does not
prevent concurrent changes, but it avoids walking for nothing.
Add proper comments while at it.
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Reported-by: Sasha Levin <sasha.levin@oracle.com>
Based-on-patch-from: Wolfram Gloger <wmglo@dent.med.uni-muenchen.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@alien8.de>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Kostya Serebryany <kcc@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: kasan-dev <kasan-dev@googlegroups.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Wolfram Gloger <wmglo@dent.med.uni-muenchen.de>
Link: http://lkml.kernel.org/r/20150930083302.694788319@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
[lizf: Backported to 3.4:
- s/READ_ONCE/ACCESS_ONCE
- remove TOP_OF_KERNEL_STACK_PADDING]
Signed-off-by: Zefan Li <lizefan@huawei.com>
commit 64c98e7f49100b637cd20a6c63508caed6bbba7a upstream.
Sanitizing the e820 map may produce extra E820 entries which would result in
the topmost E820 entries being removed. The removed entries would typically
include the top E820 usable RAM region and thus result in the domain having
signicantly less RAM available to it.
Fix by allowing sanitize_e820_map to use the full size of the allocated E820
array.
Signed-off-by: Malcolm Crossley <malcolm.crossley@citrix.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
[lizf: Backported to 3.4: s/map/xen_e820_map]
Signed-off-by: Zefan Li <lizefan@huawei.com>
commit 3afb1121800128aae9f5722e50097fcf1a9d4d88 upstream.
These have roughly the same purpose as the SMRR, which we do not need
to implement in KVM. However, Linux accesses MSR_K8_TSEG_ADDR at
boot, which causes problems when running a Xen dom0 under KVM.
Just return 0, meaning that processor protection of SMRAM is not
in effect.
Reported-by: M A Young <m.a.young@durham.ac.uk>
Acked-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Zefan Li <lizefan@huawei.com>
commit 03da3ff1cfcd7774c8780d2547ba0d995f7dc03d upstream.
In 2007, commit 07190a08ee ("Mark TSC on GeodeLX reliable")
bypassed verification of the TSC on Geode LX. However, this code
(now in the check_system_tsc_reliable() function in
arch/x86/kernel/tsc.c) was only present if CONFIG_MGEODE_LX was
set.
OpenWRT has recently started building its generic Geode target
for Geode GX, not LX, to include support for additional
platforms. This broke the timekeeping on LX-based devices,
because the TSC wasn't marked as reliable:
https://dev.openwrt.org/ticket/20531
By adding a runtime check on is_geode_lx(), we can also include
the fix if CONFIG_MGEODEGX1 or CONFIG_X86_GENERIC are set, thus
fixing the problem.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Cc: Andres Salomon <dilinger@queued.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Marcelo Tosatti <marcelo@kvack.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1442409003.131189.87.camel@infradead.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Zefan Li <lizefan@huawei.com>
commit 71c6da846be478a61556717ef1ee1cea91f5d6a8 upstream.
Currently context size (cra_ctxsize) doesn't specified for
ghash_async_alg. Which means it's zero. Thus crypto_create_tfm()
doesn't allocate needed space for ghash_async_ctx, so any
read/write to ctx (e.g. in ghash_async_init_tfm()) is not valid.
Signed-off-by: Andrey Ryabinin <aryabinin@odin.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Zefan Li <lizefan@huawei.com>
commit 7cae2bedcbd4680b155999655e49c27b9cf020fa upstream.
As reported at https://bugs.launchpad.net/qemu/+bug/1494350,
it is possible to have vcpu->arch.st.last_steal initialized
from a thread other than vcpu thread, say the iothread, via
KVM_SET_MSRS.
Which can cause an overflow later (when subtracting from vcpu threads
sched_info.run_delay).
To avoid that, move steal time accumulation to vcpu entry time,
before copying steal time data to guest.
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Reviewed-by: David Matlack <dmatlack@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Zefan Li <lizefan@huawei.com>
commit 0d430e3fb3f7cdc13c0d22078b820f682821b45a upstream.
This was meant to print base address and entry count; make it do so
again.
Fixes: 37868fe113ff "x86/ldt: Make modify_ldt synchronous"
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andy Lutomirski <luto@kernel.org>
Link: http://lkml.kernel.org/r/56797D8402000078000C24F0@prv-mh.provo.novell.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
[lizf: Backported to 3.4: adjust context]
Signed-off-by: Zefan Li <lizefan@huawei.com>
commit cbdb967af3d54993f5814f1cee0ed311a055377d upstream.
This is needed to avoid the possibility that the guest triggers
an infinite stream of #DB exceptions (CVE-2015-8104).
VMX is not affected: because it does not save DR6 in the VMCS,
it already intercepts #DB unconditionally.
Reported-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
[bwh: Backported to 3.2, with thanks to Paolo:
- update_db_bp_intercept() was called update_db_intercept()
- The remaining call is in svm_guest_debug() rather than through svm_x86_ops]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Zefan Li <lizefan@huawei.com>
commit 54a20552e1eae07aa240fa370a0293e006b5faed upstream.
It was found that a guest can DoS a host by triggering an infinite
stream of "alignment check" (#AC) exceptions. This causes the
microcode to enter an infinite loop where the core never receives
another interrupt. The host kernel panics pretty quickly due to the
effects (CVE-2015-5307).
Signed-off-by: Eric Northup <digitaleric@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
[lizf: Backported to 3.4:
- adjust filename
- adjust context
- add definition of AC_VECTOR]
Signed-off-by: Zefan Li <lizefan@huawei.com>
commit 4809146b86c3d41ce588fdb767d021e2a80600dd upstream.
Commit 37868fe113ff ("x86/ldt: Make modify_ldt synchronous")
introduced a new struct ldt_struct anchored at mm->context.ldt.
Adapt the x86 fpu emulation code to use that new structure.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: billm@melbpc.org.au
Link: http://lkml.kernel.org/r/1438883674-1240-1-git-send-email-jgross@suse.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Zefan Li <lizefan@huawei.com>
commit 136d9d83c07c5e30ac49fc83b27e8c4842f108fc upstream.
Commit 37868fe113ff ("x86/ldt: Make modify_ldt synchronous")
introduced a new struct ldt_struct anchored at mm->context.ldt.
convert_ip_to_linear() was changed to reflect this, but indexing
into the ldt has to be changed as the pointer is no longer void *.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: bp@suse.de
Link: http://lkml.kernel.org/r/1438848278-12906-1-git-send-email-jgross@suse.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Zefan Li <lizefan@huawei.com>
commit 37868fe113ff2ba814b3b4eb12df214df555f8dc upstream.
modify_ldt() has questionable locking and does not synchronize
threads. Improve it: redesign the locking and synchronize all
threads' LDTs using an IPI on all modifications.
This will dramatically slow down modify_ldt in multithreaded
programs, but there shouldn't be any multithreaded programs that
care about modify_ldt's performance in the first place.
This fixes some fallout from the CVE-2015-5157 fixes.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jan Beulich <jbeulich@suse.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: security@kernel.org <security@kernel.org>
Cc: xen-devel <xen-devel@lists.xen.org>
Link: http://lkml.kernel.org/r/4c6978476782160600471bd865b318db34c7b628.1438291540.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
[bwh: Backported to 3.2:
- Adjust context
- Drop comment changes in switch_mm()
- Drop changes to get_segment_base() in arch/x86/kernel/cpu/perf_event.c
- Open-code lockless_dereference(), smp_store_release(), on_each_cpu_mask()]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
[lizf: Backported to 3.4: adjust context]
Signed-off-by: Zefan Li <lizefan@huawei.com>
commit aa1acff356bbedfd03b544051f5b371746735d89 upstream.
The update_va_mapping hypercall can fail if the VA isn't present
in the guest's page tables. Under certain loads, this can
result in an OOPS when the target address is in unpopulated vmap
space.
While we're at it, add comments to help explain what's going on.
This isn't a great long-term fix. This code should probably be
changed to use something like set_memory_ro.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: David Vrabel <dvrabel@cantab.net>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jan Beulich <jbeulich@suse.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: security@kernel.org <security@kernel.org>
Cc: xen-devel <xen-devel@lists.xen.org>
Link: http://lkml.kernel.org/r/0b0e55b995cda11e7829f140b833ef932fcabe3a.1438291540.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Zefan Li <lizefan@huawei.com>
commit db1385624c686fe99fe2d1b61a36e1537b915d08 upstream.
Legacy NMI watchdog didn't work after migration/resume, because
vapics_in_nmi_mode was left at 0.
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
[lizf: Backported to 3.4:
- adjust context
- s/kvm_apic_get_reg/apic_get_reg/]
Signed-off-by: Zefan Li <lizefan@huawei.com>
commit 42720138b06301cc8a7ee8a495a6d021c4b6a9bc upstream.
Writes were a bit racy, but hard to turn into a bug at the same time.
(Particularly because modern Linux doesn't use this feature anymore.)
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
[Actually the next patch makes it much, much easier to trigger the race
so I'm including this one for stable@ as well. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
[lizf: Backported to 3.4: adjust context]
Signed-off-by: Zefan Li <lizefan@huawei.com>
commit 1dace0116d0b05c967d94644fc4dfe96be2ecd3d upstream.
The Foxconn K8M890-8237A has two PCI host bridges, and we can't assign
resources correctly without the information from _CRS that tells us which
address ranges are claimed by which bridge. In the bugs mentioned below,
we incorrectly assign a sound card address (this example is from 1033299):
bus: 00 index 2 [mem 0x80000000-0xfcffffffff]
ACPI: PCI Root Bridge [PCI0] (domain 0000 [bus 00-7f])
pci_root PNP0A08:00: host bridge window [mem 0x80000000-0xbfefffff] (ignored)
pci_root PNP0A08:00: host bridge window [mem 0xc0000000-0xdfffffff] (ignored)
pci_root PNP0A08:00: host bridge window [mem 0xf0000000-0xfebfffff] (ignored)
ACPI: PCI Root Bridge [PCI1] (domain 0000 [bus 80-ff])
pci_root PNP0A08:01: host bridge window [mem 0xbff00000-0xbfffffff] (ignored)
pci 0000:80:01.0: [1106:3288] type 0 class 0x000403
pci 0000:80:01.0: reg 10: [mem 0xbfffc000-0xbfffffff 64bit]
pci 0000:80:01.0: address space collision: [mem 0xbfffc000-0xbfffffff 64bit] conflicts with PCI Bus #00 [mem 0x80000000-0xfcffffffff]
pci 0000:80:01.0: BAR 0: assigned [mem 0xfd00000000-0xfd00003fff 64bit]
BUG: unable to handle kernel paging request at ffffc90000378000
IP: [<ffffffffa0345f63>] azx_create+0x37c/0x822 [snd_hda_intel]
We assigned 0xfd_0000_0000, but that is not in any of the host bridge
windows, and the sound card doesn't work.
Turn on pci=use_crs automatically for this system.
Link: https://bugs.launchpad.net/ubuntu/+source/alsa-driver/+bug/931368
Link: https://bugs.launchpad.net/ubuntu/+source/alsa-driver/+bug/1033299
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Zefan Li <lizefan@huawei.com>
commit b1a74bf821 upstream.
Preemption is disabled between kernel_fpu_begin/end() and as such
it is not a good idea to use these routines in kvm_load/put_guest_fpu()
which can be very far apart.
kvm_load/put_guest_fpu() routines are already called with
preemption disabled and KVM already uses the preempt notifier to save
the guest fpu state using kvm_put_guest_fpu().
So introduce __kernel_fpu_begin/end() routines which don't touch
preemption and use them instead of kernel_fpu_begin/end()
for KVM's use model of saving/restoring guest FPU state.
Also with this change (and with eagerFPU model), fix the host cr0.TS vm-exit
state in the case of VMX. For eagerFPU case, host cr0.TS is always clear.
So no need to worry about it. For the traditional lazyFPU restore case,
change the cr0.TS bit for the host state during vm-exit to be always clear
and cr0.TS bit is set in the __vmx_load_host_state() when the FPU
(guest FPU or the host task's FPU) state is not active. This ensures
that the host/guest FPU state is properly saved, restored
during context-switch and with interrupts (using irq_fpu_usable()) not
stomping on the active FPU state.
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Link: http://lkml.kernel.org/r/1348164109.26695.338.camel@sbsiddha-desk.sc.intel.com
Cc: Avi Kivity <avi@redhat.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Signed-off-by: Zefan Li <lizefan@huawei.com>
[xr: Backported to 3.4: Adjust context]
Signed-off-by: Rui Xiang <rui.xiang@huawei.com>
Signed-off-by: Zefan Li <lizefan@huawei.com>
commit 9c1c3fac53 upstream.
kvm's guest fpu save/restore should be wrapped around
kernel_fpu_begin/end(). This will avoid for example taking a DNA
in kvm_load_guest_fpu() when it tries to load the fpu immediately
after doing unlazy_fpu() on the host side.
More importantly this will prevent the host process fpu from being
corrupted.
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Link: http://lkml.kernel.org/r/1345842782-24175-4-git-send-email-suresh.b.siddha@intel.com
Cc: Avi Kivity <avi@redhat.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: Rui Xiang <rui.xiang@huawei.com>
Signed-off-by: Zefan Li <lizefan@huawei.com>
commit 3f7352bf21f8fd7ba3e2fcef9488756f188e12be upstream.
x86 has variable length encoding. x86 JIT compiler is trying
to pick the shortest encoding for given bpf instruction.
While doing so the jump targets are changing, so JIT is doing
multiple passes over the program. Typical program needs 3 passes.
Some very short programs converge with 2 passes. Large programs
may need 4 or 5. But specially crafted bpf programs may hit the
pass limit and if the program converges on the last iteration
the JIT compiler will be producing an image full of 'int 3' insns.
Fix this corner case by doing final iteration over bpf program.
Fixes: 0a14842f5a ("net: filter: Just In Time compiler for x86-64")
Reported-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Tested-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
[lizf: Backported to 3.4: adjust context]
Signed-off-by: Zefan Li <lizefan@huawei.com>
commit 17fea54bf0ab34fa09a06bbde2f58ed7bbdf9299 upstream.
Derek noticed that a critical MCE gets reported with the wrong
error type description:
[Hardware Error]: CPU 34: Machine Check Exception: 5 Bank 9: f200003f000100b0
[Hardware Error]: RIP !INEXACT! 10:<ffffffff812e14c1> {intel_idle+0xb1/0x170}
[Hardware Error]: TSC 49587b8e321cb
[Hardware Error]: PROCESSOR 0:306e4 TIME 1431561296 SOCKET 1 APIC 29
[Hardware Error]: Some CPUs didn't answer in synchronization
[Hardware Error]: Machine check: Invalid
^^^^^^^
The last line with 'Invalid' should have printed the high level
MCE error type description we get from mce_severity, i.e.
something like:
[Hardware Error]: Machine check: Action required: data load error in a user process
this happens due to the fact that mce_no_way_out() iterates over
all MCA banks and possibly overwrites the @msg argument which is
used in the panic printing later.
Change behavior to take the message of only and the (last)
critical MCE it detects.
Reported-by: Derek <denc716@gmail.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Link: http://lkml.kernel.org/r/1431936437-25286-3-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
[lizf: Backported to 3.4: adjust context]
Signed-off-by: Zefan Li <lizefan@huawei.com>
commit 898761158be7682082955e3efa4ad24725305fc7 upstream.
smep_andnot_wp is initialized in kvm_init_shadow_mmu and shadow pages
should not be reused for different values of it. Thus, it has to be
added to the mask in kvm_mmu_pte_write.
Reviewed-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
[lizf: Backported to 3.4: adjust context]
Signed-off-by: Zefan Li <lizefan@huawei.com>
commit b44915927ca88084a7292e4ddd4cf91036f365e1 upstream.
The comment line regarding IOMMU_INIT and IOMMU_INIT_FINISH
macros is incorrect:
"The standard vs the _FINISH differs in that the _FINISH variant
will continue detecting other IOMMUs in the call list..."
It should be "..the *standard* variant will continue
detecting..."
Fix that. Also, make it readable while at it.
Signed-off-by: Aravind Gopalakrishnan <Aravind.Gopalakrishnan@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: konrad.wilk@oracle.com
Fixes: 6e96366933 ("x86, iommu: Update header comments with appropriate naming")
Link: http://lkml.kernel.org/r/1428508017-5316-1-git-send-email-Aravind.Gopalakrishnan@amd.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Zefan Li <lizefan@huawei.com>
commit a6dfa128ce5c414ab46b1d690f7a1b8decb8526d upstream.
A huge amount of NIC drivers use the DMA API, however if
compiled under 32-bit an very important part of the DMA API can
be ommitted leading to the drivers not working at all
(especially if used with 'swiotlb=force iommu=soft').
As Prashant Sreedharan explains it: "the driver [tg3] uses
DEFINE_DMA_UNMAP_ADDR(), dma_unmap_addr_set() to keep a copy of
the dma "mapping" and dma_unmap_addr() to get the "mapping"
value. On most of the platforms this is a no-op, but ... with
"iommu=soft and swiotlb=force" this house keeping is required,
... otherwise we pass 0 while calling pci_unmap_/pci_dma_sync_
instead of the DMA address."
As such enable this even when using 32-bit kernels.
Reported-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Prashant Sreedharan <prashant@broadcom.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michael Chan <mchan@broadcom.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: boris.ostrovsky@oracle.com
Cc: cascardo@linux.vnet.ibm.com
Cc: david.vrabel@citrix.com
Cc: sanjeevb@broadcom.com
Cc: siva.kallam@broadcom.com
Cc: vyasevich@gmail.com
Cc: xen-devel@lists.xensource.com
Link: http://lkml.kernel.org/r/20150417190448.GA9462@l.oracle.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Ben Hutchings <ben@decadent.org.uk>
[lizf: Backported to 3.4: adjust context]
Signed-off-by: Zefan Li <lizefan@huawei.com>
commit 55c844a4dd upstream.
When rebooting our 24 CPU Westmere servers with 3.4-rc6, we
always see this warning msg:
Restarting system.
machine restart
------------[ cut here ]------------
WARNING: at arch/x86/kernel/smp.c:125
native_smp_send_reschedule+0x74/0xa7() Hardware name: X8DTN
Modules linked in: igb [last unloaded: scsi_wait_scan]
Pid: 1, comm: systemd-shutdow Not tainted 3.4.0-rc6+ #22
Call Trace:
<IRQ> [<ffffffff8102a41f>] warn_slowpath_common+0x7e/0x96
[<ffffffff8102a44c>] warn_slowpath_null+0x15/0x17
[<ffffffff81018cf7>] native_smp_send_reschedule+0x74/0xa7
[<ffffffff810561c1>] trigger_load_balance+0x279/0x2a6
[<ffffffff81050112>] scheduler_tick+0xe0/0xe9
[<ffffffff81036768>] update_process_times+0x60/0x70
[<ffffffff81062f2f>] tick_sched_timer+0x68/0x92
[<ffffffff81046e33>] __run_hrtimer+0xb3/0x13c
[<ffffffff81062ec7>] ? tick_nohz_handler+0xd0/0xd0
[<ffffffff810474f2>] hrtimer_interrupt+0xdb/0x198
[<ffffffff81019a35>] smp_apic_timer_interrupt+0x81/0x94
[<ffffffff81655187>] apic_timer_interrupt+0x67/0x70
<EOI> [<ffffffff8101a3c4>] ? default_send_IPI_mask_allbutself_phys+0xb4/0xc4
[<ffffffff8101c680>] physflat_send_IPI_allbutself+0x12/0x14
[<ffffffff81018db4>] native_nmi_stop_other_cpus+0x8a/0xd6
[<ffffffff810188ba>] native_machine_shutdown+0x50/0x67
[<ffffffff81018926>] machine_shutdown+0xa/0xc
[<ffffffff8101897e>] native_machine_restart+0x20/0x32
[<ffffffff810189b0>] machine_restart+0xa/0xc
[<ffffffff8103b196>] kernel_restart+0x47/0x4c
[<ffffffff8103b2e6>] sys_reboot+0x13e/0x17c
[<ffffffff8164e436>] ? _raw_spin_unlock_bh+0x10/0x12
[<ffffffff810fcac9>] ? bdi_queue_work+0xcf/0xd8
[<ffffffff810fe82f>] ? __bdi_start_writeback+0xae/0xb7
[<ffffffff810e0d64>] ? iterate_supers+0xa3/0xb7
[<ffffffff816547a2>] system_call_fastpath+0x16/0x1b
---[ end trace 320af5cb1cb60c5b ]---
The root cause seems to be the
default_send_IPI_mask_allbutself_phys() takes quite some time (I
measured it could be several ms) to complete sending NMIs to all
the other 23 CPUs, and for HZ=250/1000 system, the time is long
enough for a timer interrupt to happen, which will in turn
trigger to kick load balance to a stopped CPU and cause this
warning in native_smp_send_reschedule().
So disabling the local irq before stop_other_cpu() can fix this
problem (tested 25 times reboot ok), and it is fine as there
should be nobody caring the timer interrupt in such reboot
stage.
The latest 3.4 kernel slightly changes this behavior by sending
REBOOT_VECTOR first and only send NMI_VECTOR if the REBOOT_VCTOR
fails, and this patch is still needed to prevent the problem.
Signed-off-by: Feng Tang <feng.tang@intel.com>
Acked-by: Don Zickus <dzickus@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20120530231541.4c13433a@feng-i7
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Vinson Lee <vlee@twopensource.com>
[lizf: Backported to 3.4: adjust context]
Signed-off-by: Zefan Li <lizefan@huawei.com>
commit 80313b3078fcd2ca51970880d90757f05879a193 upstream.
The ASRock Q1900DC-ITX mainboard (Baytrail-D) hangs randomly in
both BIOS and UEFI mode while rebooting unless reboot=pci is
used. Add a quirk to reboot via the pci method.
The problem is very intermittent and hard to debug, it might succeed
rebooting just fine 40 times in a row - but fails half a dozen times
the next day. It seems to be slightly less common in BIOS CSM mode
than native UEFI (with the CSM disabled), but it does happen in either
mode. Since I've started testing this patch in late january, rebooting
has been 100% reliable.
Most of the time it already hangs during POST, but occasionally it
might even make it through the bootloader and the kernel might even
start booting, but then hangs before the mode switch. The same symptoms
occur with grub-efi, gummiboot and grub-pc, just as well as (at least)
kernel 3.16-3.19 and 4.0-rc6 (I haven't tried older kernels than 3.16).
Upgrading to the most current mainboard firmware of the ASRock
Q1900DC-ITX, version 1.20, does not improve the situation.
( Searching the web seems to suggest that other Bay Trail-D mainboards
might be affected as well. )
--
Signed-off-by: Stefan Lippers-Hollmann <s.l-h@gmx.de>
Cc: Matt Fleming <matt.fleming@intel.com>
Link: http://lkml.kernel.org/r/20150330224427.0fb58e42@mir
Signed-off-by: Ingo Molnar <mingo@kernel.org>
[lizf: Backported to 3.4: adjust context]
Signed-off-by: Zefan Li <lizefan@huawei.com>
commit ccfe8c3f7e52ae83155cb038753f4c75b774ca8a upstream.
The kernel crypto API logic requires the caller to provide the
length of (ciphertext || authentication tag) as cryptlen for the
AEAD decryption operation. Thus, the cipher implementation must
calculate the size of the plaintext output itself and cannot simply use
cryptlen.
The RFC4106 GCM decryption operation tries to overwrite cryptlen memory
in req->dst. As the destination buffer for decryption only needs to hold
the plaintext memory but cryptlen references the input buffer holding
(ciphertext || authentication tag), the assumption of the destination
buffer length in RFC4106 GCM operation leads to a too large size. This
patch simply uses the already calculated plaintext size.
In addition, this patch fixes the offset calculation of the AAD buffer
pointer: as mentioned before, cryptlen already includes the size of the
tag. Thus, the tag does not need to be added. With the addition, the AAD
will be written beyond the already allocated buffer.
Note, this fixes a kernel crash that can be triggered from user space
via AF_ALG(aead) -- simply use the libkcapi test application
from [1] and update it to use rfc4106-gcm-aes.
Using [1], the changes were tested using CAVS vectors to demonstrate
that the crypto operation still delivers the right results.
[1] http://www.chronox.de/libkcapi.html
CC: Tadeusz Struk <tadeusz.struk@intel.com>
Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Zefan Li <lizefan@huawei.com>
commit 394838c96013ba414a24ffe7a2a593a9154daadf upstream.
The one in do_debug() is probably harmless, but better safe than sorry.
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/d67deaa9df5458363623001f252d1aee3215d014.1425948056.git.luto@amacapital.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
[lizf: Backported to 3.4: drop the change to do_bounds()]
Signed-off-by: Zefan Li <lizefan@huawei.com>
commit e893286918d2cde3a94850d8f7101cd1039e0c62 upstream.
On gcc5 the kernel does not link:
ld: .eh_frame_hdr table[4] FDE at 0000000000000648 overlaps table[5] FDE at 0000000000000670.
Because prior GCC versions always emitted NOPs on ALIGN directives, but
gcc5 started omitting them.
.LSTARTFDEDLSI1 says:
/* HACK: The dwarf2 unwind routines will subtract 1 from the
return address to get an address in the middle of the
presumed call instruction. Since we didn't get here via
a call, we need to include the nop before the real start
to make up for it. */
.long .LSTART_sigreturn-1-. /* PC-relative start address */
But commit 69d0627a7f ("x86 vDSO: reorder vdso32 code") from 2.6.25
replaced .org __kernel_vsyscall+32,0x90 by ALIGN right before
__kernel_sigreturn.
Of course, ALIGN need not generate any NOP in there. Esp. gcc5 collapses
vclock_gettime.o and int80.o together with no generated NOPs as "ALIGN".
So fix this by adding to that point at least a single NOP and make the
function ALIGN possibly with more NOPs then.
Kudos for reporting and diagnosing should go to Richard.
Reported-by: Richard Biener <rguenther@suse.de>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Acked-by: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1425543211-12542-1-git-send-email-jslaby@suse.cz
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Zefan Li <lizefan@huawei.com>
commit 956421fbb74c3a6261903f3836c0740187cf038b upstream.
'ret_from_fork' checks TIF_IA32 to determine whether 'pt_regs' and
the related state make sense for 'ret_from_sys_call'. This is
entirely the wrong check. TS_COMPAT would make a little more
sense, but there's really no point in keeping this optimization
at all.
This fixes a return to the wrong user CS if we came from int
0x80 in a 64-bit task.
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/4710be56d76ef994ddf59087aad98c000fbab9a4.1424989793.git.luto@amacapital.net
[ Backported from tip:x86/asm. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Zefan Li <lizefan@huawei.com>
commit 4ff6f8e61eb7f96d3ca535c6d240f863ccd6fb7d upstream.
This has been broken for a long time: it broke first in 2.6.35, then was
almost fixed in 2.6.36 but this one-liner slipped through the cracks.
The bug shows up as an infinite loop in Windows 7 (and newer) boot on
32-bit hosts without EPT.
Windows uses CMPXCHG8B to write to page tables, which causes a
page fault if running without EPT; the emulator is then called from
kvm_mmu_page_fault. The loop then happens if the higher 4 bytes are
not 0; the common case for this is that the NX bit (bit 63) is 1.
Fixes: 6550e1f165
Fixes: 16518d5ada
Reported-by: Erik Rull <erik.rull@rdsoftware.de>
Tested-by: Erik Rull <erik.rull@rdsoftware.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Zefan Li <lizefan@huawei.com>
commit 3b56496865 upstream.
This adds the workaround for erratum 793 as a precaution in case not
every BIOS implements it. This addresses CVE-2013-6885.
Erratum text:
[Revision Guide for AMD Family 16h Models 00h-0Fh Processors,
document 51810 Rev. 3.04 November 2013]
793 Specific Combination of Writes to Write Combined Memory Types and
Locked Instructions May Cause Core Hang
Description
Under a highly specific and detailed set of internal timing
conditions, a locked instruction may trigger a timing sequence whereby
the write to a write combined memory type is not flushed, causing the
locked instruction to stall indefinitely.
Potential Effect on System
Processor core hang.
Suggested Workaround
BIOS should set MSR
C001_1020[15] = 1b.
Fix Planned
No fix planned
[ hpa: updated description, fixed typo in MSR name ]
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/20140114230711.GS29865@pd.tnic
Tested-by: Aravind Gopalakrishnan <aravind.gopalakrishnan@amd.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
[bwh: Backported to 3.2:
- Adjust filename
- Venkatesh Srinivas pointed out we should use {rd,wr}msrl_safe() to
avoid crashing on KVM. This was fixed upstream by commit 8f86a7373a
("x86, AMD: Convert to the new bit access MSR accessors") but that's too
much trouble to backport. Here we must use {rd,wr}msrl_amd_safe().]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Cc: Moritz Muehlenhoff <jmm@debian.org>
Cc: Venkatesh Srinivas <venkateshs@google.com>
Signed-off-by: Zefan Li <lizefan@huawei.com>
commit 4e7c22d447bb6d7e37bfe39ff658486ae78e8d77 upstream.
The issue is that the stack for processes is not properly randomized on
64 bit architectures due to an integer overflow.
The affected function is randomize_stack_top() in file
"fs/binfmt_elf.c":
static unsigned long randomize_stack_top(unsigned long stack_top)
{
unsigned int random_variable = 0;
if ((current->flags & PF_RANDOMIZE) &&
!(current->personality & ADDR_NO_RANDOMIZE)) {
random_variable = get_random_int() & STACK_RND_MASK;
random_variable <<= PAGE_SHIFT;
}
return PAGE_ALIGN(stack_top) + random_variable;
return PAGE_ALIGN(stack_top) - random_variable;
}
Note that, it declares the "random_variable" variable as "unsigned int".
Since the result of the shifting operation between STACK_RND_MASK (which
is 0x3fffff on x86_64, 22 bits) and PAGE_SHIFT (which is 12 on x86_64):
random_variable <<= PAGE_SHIFT;
then the two leftmost bits are dropped when storing the result in the
"random_variable". This variable shall be at least 34 bits long to hold
the (22+12) result.
These two dropped bits have an impact on the entropy of process stack.
Concretely, the total stack entropy is reduced by four: from 2^28 to
2^30 (One fourth of expected entropy).
This patch restores back the entropy by correcting the types involved
in the operations in the functions randomize_stack_top() and
stack_maxrandom_size().
The successful fix can be tested with:
$ for i in `seq 1 10`; do cat /proc/self/maps | grep stack; done
7ffeda566000-7ffeda587000 rw-p 00000000 00:00 0 [stack]
7fff5a332000-7fff5a353000 rw-p 00000000 00:00 0 [stack]
7ffcdb7a1000-7ffcdb7c2000 rw-p 00000000 00:00 0 [stack]
7ffd5e2c4000-7ffd5e2e5000 rw-p 00000000 00:00 0 [stack]
...
Once corrected, the leading bytes should be between 7ffc and 7fff,
rather than always being 7fff.
Signed-off-by: Hector Marco-Gisbert <hecmargi@upv.es>
Signed-off-by: Ismael Ripoll <iripoll@upv.es>
[ Rebased, fixed 80 char bugs, cleaned up commit message, added test example and CVE ]
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Fixes: CVE-2015-1593
Link: http://lkml.kernel.org/r/20150214173350.GA18393@www.outflux.net
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Zefan Li <lizefan@huawei.com>
commit 33692f27597fcab536d7cbbcc8f52905133e4aa7 upstream.
The core VM already knows about VM_FAULT_SIGBUS, but cannot return a
"you should SIGSEGV" error, because the SIGSEGV case was generally
handled by the caller - usually the architecture fault handler.
That results in lots of duplication - all the architecture fault
handlers end up doing very similar "look up vma, check permissions, do
retries etc" - but it generally works. However, there are cases where
the VM actually wants to SIGSEGV, and applications _expect_ SIGSEGV.
In particular, when accessing the stack guard page, libsigsegv expects a
SIGSEGV. And it usually got one, because the stack growth is handled by
that duplicated architecture fault handler.
However, when the generic VM layer started propagating the error return
from the stack expansion in commit fee7e49d4514 ("mm: propagate error
from stack expansion even for guard page"), that now exposed the
existing VM_FAULT_SIGBUS result to user space. And user space really
expected SIGSEGV, not SIGBUS.
To fix that case, we need to add a VM_FAULT_SIGSEGV, and teach all those
duplicate architecture fault handlers about it. They all already have
the code to handle SIGSEGV, so it's about just tying that new return
value to the existing code, but it's all a bit annoying.
This is the mindless minimal patch to do this. A more extensive patch
would be to try to gather up the mostly shared fault handling logic into
one generic helper routine, and long-term we really should do that
cleanup.
Just from this patch, you can generally see that most architectures just
copied (directly or indirectly) the old x86 way of doing things, but in
the meantime that original x86 model has been improved to hold the VM
semaphore for shorter times etc and to handle VM_FAULT_RETRY and other
"newer" things, so it would be a good idea to bring all those
improvements to the generic case and teach other architectures about
them too.
Reported-and-tested-by: Takashi Iwai <tiwai@suse.de>
Tested-by: Jan Engelhardt <jengelh@inai.de>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> # "s390 still compiles and boots"
Cc: linux-arch@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[bwh: Backported to 3.2:
- Adjust filenames, context
- Drop arc, metag, nios2 and lustre changes
- For sh, patch both 32-bit and 64-bit implementations to use goto bad_area
- For s390, pass int_code and trans_exc_code as arguments to do_no_context()
and do_sigsegv()]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
[lizf: Backported to 3.4:
- adjust context in arch/power/mm/fault.c
- apply the original change in upstream commit for s390]
Signed-off-by: Zefan Li <lizefan@huawei.com>
commit 237d28db036e411f22c03cfd5b0f6dc2aa9bf3bc upstream.
If the function graph tracer traces a jprobe callback, the system will
crash. This can easily be demonstrated by compiling the jprobe
sample module that is in the kernel tree, loading it and running the
function graph tracer.
# modprobe jprobe_example.ko
# echo function_graph > /sys/kernel/debug/tracing/current_tracer
# ls
The first two commands end up in a nice crash after the first fork.
(do_fork has a jprobe attached to it, so "ls" just triggers that fork)
The problem is caused by the jprobe_return() that all jprobe callbacks
must end with. The way jprobes works is that the function a jprobe
is attached to has a breakpoint placed at the start of it (or it uses
ftrace if fentry is supported). The breakpoint handler (or ftrace callback)
will copy the stack frame and change the ip address to return to the
jprobe handler instead of the function. The jprobe handler must end
with jprobe_return() which swaps the stack and does an int3 (breakpoint).
This breakpoint handler will then put back the saved stack frame,
simulate the instruction at the beginning of the function it added
a breakpoint to, and then continue on.
For function tracing to work, it hijakes the return address from the
stack frame, and replaces it with a hook function that will trace
the end of the call. This hook function will restore the return
address of the function call.
If the function tracer traces the jprobe handler, the hook function
for that handler will not be called, and its saved return address
will be used for the next function. This will result in a kernel crash.
To solve this, pause function tracing before the jprobe handler is called
and unpause it before it returns back to the function it probed.
Some other updates:
Used a variable "saved_sp" to hold kcb->jprobe_saved_sp. This makes the
code look a bit cleaner and easier to understand (various tries to fix
this bug required this change).
Note, if fentry is being used, jprobes will change the ip address before
the function graph tracer runs and it will not be able to trace the
function that the jprobe is probing.
Link: http://lkml.kernel.org/r/20150114154329.552437962@goodmis.org
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
[lizf: Backported to 3.4:
- adjust filename
- adjust context]
Signed-off-by: Zefan Li <lizefan@huawei.com>
commit b485342bd79af363c77ef1a421c4a0aef2de9812 upstream.
Commit a074335a37 ("x86, um: Mark system call tables readonly") was
supposed to mark the sys_call_table in UML as RO by adding the const,
but it doesn't have the desired effect as it's nevertheless being placed
into the data section since __cacheline_aligned enforces sys_call_table
being placed into .data..cacheline_aligned instead. We need to use
the ____cacheline_aligned version instead to fix this issue.
Before:
$ nm -v arch/x86/um/sys_call_table_64.o | grep -1 "sys_call_table"
U sys_writev
0000000000000000 D sys_call_table
0000000000000000 D syscall_table_size
After:
$ nm -v arch/x86/um/sys_call_table_64.o | grep -1 "sys_call_table"
U sys_writev
0000000000000000 R sys_call_table
0000000000000000 D syscall_table_size
Fixes: a074335a37 ("x86, um: Mark system call tables readonly")
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Zefan Li <lizefan@huawei.com>
commit 394f56fe480140877304d342dec46d50dc823d46 upstream.
The theory behind vdso randomization is that it's mapped at a random
offset above the top of the stack. To avoid wasting a page of
memory for an extra page table, the vdso isn't supposed to extend
past the lowest PMD into which it can fit. Other than that, the
address should be a uniformly distributed address that meets all of
the alignment requirements.
The current algorithm is buggy: the vdso has about a 50% probability
of being at the very end of a PMD. The current algorithm also has a
decent chance of failing outright due to incorrect handling of the
case where the top of the stack is near the top of its PMD.
This fixes the implementation. The paxtest estimate of vdso
"randomisation" improves from 11 bits to 18 bits. (Disclaimer: I
don't know what the paxtest code is actually calculating.)
It's worth noting that this algorithm is inherently biased: the vdso
is more likely to end up near the end of its PMD than near the
beginning. Ideally we would either nix the PMD sharing requirement
or jointly randomize the vdso and the stack to reduce the bias.
In the mean time, this is a considerable improvement with basically
no risk of compatibility issues, since the allowed outputs of the
algorithm are unchanged.
As an easy test, doing this:
for i in `seq 10000`
do grep -P vdso /proc/self/maps |cut -d- -f1
done |sort |uniq -d
used to produce lots of output (1445 lines on my most recent run).
A tiny subset looks like this:
7fffdfffe000
7fffe01fe000
7fffe05fe000
7fffe07fe000
7fffe09fe000
7fffe0bfe000
7fffe0dfe000
Note the suspicious fe000 endings. With the fix, I get a much more
palatable 76 repeated addresses.
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
[lizf: Backported to 3.4:
- adjust context
- adjust comment]
Signed-off-by: Zefan Li <lizefan@huawei.com>
commit 3fb2f4237bb452eb4e98f6a5dbd5a445b4fed9d0 upstream.
It turns out that there's a lurking ABI issue. GCC, when
compiling this in a 32-bit program:
struct user_desc desc = {
.entry_number = idx,
.base_addr = base,
.limit = 0xfffff,
.seg_32bit = 1,
.contents = 0, /* Data, grow-up */
.read_exec_only = 0,
.limit_in_pages = 1,
.seg_not_present = 0,
.useable = 0,
};
will leave .lm uninitialized. This means that anything in the
kernel that reads user_desc.lm for 32-bit tasks is unreliable.
Revert the .lm check in set_thread_area(). The value never did
anything in the first place.
Fixes: 0e58af4e1d21 ("x86/tls: Disallow unusual TLS segments")
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/d7875b60e28c512f6a6fc0baf5714d58e7eaadbb.1418856405.git.luto@amacapital.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
[lizf: Backported to 3.4: adjust filename]
Signed-off-by: Zefan Li <lizefan@huawei.com>
commit 0e58af4e1d2166e9e33375a0f121e4867010d4f8 upstream.
Users have no business installing custom code segments into the
GDT, and segments that are not present but are otherwise valid
are a historical source of interesting attacks.
For completeness, block attempts to set the L bit. (Prior to
this patch, the L bit would have been silently dropped.)
This is an ABI break. I've checked glibc, musl, and Wine, and
none of them look like they'll have any trouble.
Note to stable maintainers: this is a hardening patch that fixes
no known bugs. Given the possibility of ABI issues, this
probably shouldn't be backported quickly.
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: security@kernel.org <security@kernel.org>
Cc: Willy Tarreau <w@1wt.eu>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Zefan Li <lizefan@huawei.com>
