Limit the size of copy to the minimum of what was asked
for or the number of results returned to prevent leaking of
uninitialized kernel memory to userspace.
Bug: 24157888
Signed-off-by: Patrick Tjin <pattjin@google.com>
Change-Id: I7433135ea3345905c053a81d0d759619b46c1430
System V IPCs are not compliant with Android's application lifecycle
because allocated resources are not freeable by the low memory killer.
This lead to global kernel resource leakage.
For example, there is no way to automatically release a SysV
semaphore allocated in the kernel when:
- a buggy or malicious process exits
- a non-buggy and non-malicious process crashes or is explicitly
killed.
Killing processes automatically to make room for new ones is an
important part of Android's application lifecycle implementation.
This means that, even assuming only non-buggy and non-malicious
code, it is very likely that over time, the kernel global tables
used to implement SysV IPCs will fill up.
Bug: 24551430
Bug: 22300191
Signed-off-by: Patrick Tjin <pattjin@google.com>
Change-Id: I98d592819974acbd5fb47d526ed1ce3700ae1bd5
Bug: 19863147
Refactor the interrupt disabling so that interrupts are disabled when
a cpu is hotplugged out, even if there are no perf events on that cpu,
but it holds the PMU irq.
(partially cherry-picked from "Perf: interrupt disable without bringing cpus up")
Change-Id: I9253d6a3bfa51b4b71d3ca51d4c306dd49ca5ef7
commit fdfa4c9528 upstream.
commit 809d29070f in stable/3.4.y.
arch/um/os-Linux/start_up.c: In function 'check_coredump_limit':
arch/um/os-Linux/start_up.c:338:16: error: storage size of 'lim' isn't known
arch/um/os-Linux/start_up.c:339:2: error: implicit declaration of function 'getrlimit' [-Werror=implicit-function-declaration]
Bug: 15413527
Change-Id: I81d930d9636bfc95e0c2140f2901628dc609df79
Signed-off-by: Sergei Trofimovich <slyfox@gentoo.org>
CC: Jeff Dike <jdike@addtoit.com>
CC: Richard Weinberger <richard@nod.at>
CC: Al Viro <viro@zeniv.linux.org.uk>
CC: user-mode-linux-devel@lists.sourceforge.net
CC: user-mode-linux-user@lists.sourceforge.net
CC: linux-kernel@vger.kernel.org
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
hardware reset notfication is sent by keypad driver if powerkey
button is pressed more than 7000 ms when can_reset flag is set.
Change-Id: I642c01cf9a53dbbd8a55f87e93310f920f1f1f3c
Signed-off-by: paris_yeh <paris_yeh@asus.com>
Commit 455bd4c430 ("ARM: 7668/1: fix memset-related crashes caused by
recent GCC (4.7.2) optimizations") attempted to fix a compliance issue
with the memset return value. However the memset itself became broken
by that patch for misaligned pointers.
This fixes the above by branching over the entry code from the
misaligned fixup code to avoid reloading the original pointer.
Also, because the function entry alignment is wrong in the Thumb mode
compilation, that fixup code is moved to the end.
While at it, the entry instructions are slightly reworked to help dual
issue pipelines.
Change-Id: I5db45a7de1e389bacb5d6e4513c0d446ae2c9440
Git-Commit: 418df63ada
Git-Repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Tested-by: Alexander Holler <holler@ahsoftware.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Stepan Moskovchenko <stepanm@codeaurora.org>
Recent GCC versions (e.g. GCC-4.7.2) perform optimizations based on
assumptions about the implementation of memset and similar functions.
The current ARM optimized memset code does not return the value of
its first argument, as is usually expected from standard implementations.
For instance in the following function:
void debug_mutex_lock_common(struct mutex *lock, struct mutex_waiter *waiter)
{
memset(waiter, MUTEX_DEBUG_INIT, sizeof(*waiter));
waiter->magic = waiter;
INIT_LIST_HEAD(&waiter->list);
}
compiled as:
800554d0 <debug_mutex_lock_common>:
800554d0: e92d4008 push {r3, lr}
800554d4: e1a00001 mov r0, r1
800554d8: e3a02010 mov r2, #16 ; 0x10
800554dc: e3a01011 mov r1, #17 ; 0x11
800554e0: eb04426e bl 80165ea0 <memset>
800554e4: e1a03000 mov r3, r0
800554e8: e583000c str r0, [r3, #12]
800554ec: e5830000 str r0, [r3]
800554f0: e5830004 str r0, [r3, #4]
800554f4: e8bd8008 pop {r3, pc}
GCC assumes memset returns the value of pointer 'waiter' in register r0; causing
register/memory corruptions.
This patch fixes the return value of the assembly version of memset.
It adds a 'mov' instruction and merges an additional load+store into
existing load/store instructions.
For ease of review, here is a breakdown of the patch into 4 simple steps:
Step 1
======
Perform the following substitutions:
ip -> r8, then
r0 -> ip,
and insert 'mov ip, r0' as the first statement of the function.
At this point, we have a memset() implementation returning the proper result,
but corrupting r8 on some paths (the ones that were using ip).
Step 2
======
Make sure r8 is saved and restored when (! CALGN(1)+0) == 1:
save r8:
- str lr, [sp, #-4]!
+ stmfd sp!, {r8, lr}
and restore r8 on both exit paths:
- ldmeqfd sp!, {pc} @ Now <64 bytes to go.
+ ldmeqfd sp!, {r8, pc} @ Now <64 bytes to go.
(...)
tst r2, #16
stmneia ip!, {r1, r3, r8, lr}
- ldr lr, [sp], #4
+ ldmfd sp!, {r8, lr}
Step 3
======
Make sure r8 is saved and restored when (! CALGN(1)+0) == 0:
save r8:
- stmfd sp!, {r4-r7, lr}
+ stmfd sp!, {r4-r8, lr}
and restore r8 on both exit paths:
bgt 3b
- ldmeqfd sp!, {r4-r7, pc}
+ ldmeqfd sp!, {r4-r8, pc}
(...)
tst r2, #16
stmneia ip!, {r4-r7}
- ldmfd sp!, {r4-r7, lr}
+ ldmfd sp!, {r4-r8, lr}
Step 4
======
Rewrite register list "r4-r7, r8" as "r4-r8".
Change-Id: I79a0d6897572b693d50f8ea8a94aa331bfcc59f8
Git-Commit: 455bd4c430
Git-Repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Signed-off-by: Ivan Djelic <ivan.djelic@parrot.com>
Reviewed-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Dirk Behme <dirk.behme@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Stepan Moskovchenko <stepanm@codeaurora.org>
Attempting to unregister it again will cause a panic
Bug: 18759663
Change-Id: Iff2adbc79136c55141f35b872cb70584d303a689
Signed-off-by: Naveen Ramaraj <nramaraj@codeaurora.org>
smd_pkt_release() relies on checks that would pass by default
(reference count == 0) to proceed with the release even if the
open was unsuccessful in the first place
Bug: b/18759663
Signed-off-by: Naveen Ramaraj <nramaraj@codeaurora.org>
The Logitech unifying driver depends on hidraw being available.
Recommending one without the other will cause the Logitech driver to
silently fail when connecting Logitech devices.
Change-Id: I635d851e1228c8b8ab3f31f8fd4688bb71bd7044
Signed-off-by: Olivier Gay <ogay@logitech.com>
Common SHA-1 structures are defined in <crypto/sha.h> for code sharing.
This patch changes SHA-1/ARM glue code to use these structures.
Change-Id: Iedcc2210314d52d7e13bf5d2b535052a18f04e49
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Jussi Kivilinna <jussi.kivilinna@iki.fi>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Fix the same alignment bug as in arm64 - we need to pass residue
unprocessed bytes as the last argument to blkcipher_walk_done.
Change-Id: I8d49b8a190327b46801a3db4884e2b309138525b
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org # 3.13+
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Building a multi-arch kernel results in:
arch/arm/crypto/built-in.o: In function `aesbs_xts_decrypt':
sha1_glue.c:(.text+0x15c8): undefined reference to `bsaes_xts_decrypt'
arch/arm/crypto/built-in.o: In function `aesbs_xts_encrypt':
sha1_glue.c:(.text+0x1664): undefined reference to `bsaes_xts_encrypt'
arch/arm/crypto/built-in.o: In function `aesbs_ctr_encrypt':
sha1_glue.c:(.text+0x184c): undefined reference to `bsaes_ctr32_encrypt_blocks'
arch/arm/crypto/built-in.o: In function `aesbs_cbc_decrypt':
sha1_glue.c:(.text+0x19b4): undefined reference to `bsaes_cbc_encrypt'
This code is already runtime-conditional on NEON being supported, so
there's no point compiling it out depending on the minimum build
architecture.
Change-Id: I219dc496b3ad60754f95a6db2a71ce73d037a6e0
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This avoids this file being incorrectly added to git.
Change-Id: Ibafeec2c5d3ca806737f8d865716d3b2ea419e93
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Bit sliced AES gives around 45% speedup on Cortex-A15 for encryption
and around 25% for decryption. This implementation of the AES algorithm
does not rely on any lookup tables so it is believed to be invulnerable
to cache timing attacks.
This algorithm processes up to 8 blocks in parallel in constant time. This
means that it is not usable by chaining modes that are strictly sequential
in nature, such as CBC encryption. CBC decryption, however, can benefit from
this implementation and runs about 25% faster. The other chaining modes
implemented in this module, XTS and CTR, can execute fully in parallel in
both directions.
The core code has been adopted from the OpenSSL project (in collaboration
with the original author, on cc). For ease of maintenance, this version is
identical to the upstream OpenSSL code, i.e., all modifications that were
required to make it suitable for inclusion into the kernel have been made
upstream. The original can be found here:
http://git.openssl.org/gitweb/?p=openssl.git;a=commit;h=6f6a6130
Note to integrators:
While this implementation is significantly faster than the existing table
based ones (generic or ARM asm), especially in CTR mode, the effects on
power efficiency are unclear as of yet. This code does fundamentally more
work, by calculating values that the table based code obtains by a simple
lookup; only by doing all of that work in a SIMD fashion, it manages to
perform better.
Change-Id: I936dc7142b91133c55c7cf0af6a565d219d62e11
Cc: Andy Polyakov <appro@openssl.org>
Acked-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Put the struct definitions for AES keys and the asm function prototypes in a
separate header and export the asm functions from the module.
This allows other drivers to use them directly.
Change-Id: I5ce0cf285e2981755adb55b66a846eb738cedd58
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
commit 40190c85f4 upstream.
Patch 638591c enabled building the AES assembler code in Thumb2 mode.
However, this code used arithmetic involving PC rather than adr{l}
instructions to generate PC-relative references to the lookup tables,
and this needs to take into account the different PC offset when
running in Thumb mode.
Change-Id: Iadf37cb5db3a826ced7b99e5ee6d298479355cbd
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Make the SHA1 asm code ABI conformant by making sure all stack
accesses occur above the stack pointer.
Origin:
http://git.openssl.org/gitweb/?p=openssl.git;a=commit;h=1a9d60d2
Change-Id: I1f17f23f168d40de14b907f470476b7fd9bdd274
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Nicolas Pitre <nico@linaro.org>
Cc: stable@vger.kernel.org
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This patch fixes aes-armv4.S and sha1-armv4-large.S to work
natively in Thumb. This allows ARM/Thumb interworking workarounds
to be removed.
I also take the opportunity to convert some explicit assembler
directives for exported functions to the standard
ENTRY()/ENDPROC().
For the code itself:
* In sha1_block_data_order, use of TEQ with sp is deprecated in
ARMv7 and not supported in Thumb. For the branches back to
.L_00_15 and .L_40_59, the TEQ is converted to a CMP, under the
assumption that clobbering the C flag here will not cause
incorrect behaviour.
For the first branch back to .L_20_39_or_60_79 the C flag is
important, so sp is moved temporarily into another register so
that TEQ can be used for the comparison.
* In the AES code, most forms of register-indexed addressing with
shifts and rotates are not permitted for loads and stores in
Thumb, so the address calculation is done using a separate
instruction for the Thumb case.
The resulting code is unlikely to be optimally scheduled, but it
should not have a large impact given the overall size of the code.
I haven't run any benchmarks.
Change-Id: I8b015aa239e5513d43680d82aeb93db07c5adf9f
Signed-off-by: Dave Martin <dave.martin@linaro.org>
Tested-by: David McCullough <ucdevel@gmail.com> (ARM only)
Acked-by: David McCullough <ucdevel@gmail.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Add assembler versions of AES and SHA1 for ARM platforms. This has provided
up to a 50% improvement in IPsec/TCP throughout for tunnels using AES128/SHA1.
Platform CPU SPeed Endian Before (bps) After (bps) Improvement
IXP425 533 MHz big 11217042 15566294 ~38%
KS8695 166 MHz little 3828549 5795373 ~51%
Change-Id: I6e950d8c858ef1134352bf959804eeaf5b879d7e
Signed-off-by: David McCullough <ucdevel@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Add a command line parameter to limit available memory (after
all carveouts are reserved) to the specified size. This can
be used to help test low memory situations.
Change-Id: Ia25e028315260b706365afe820e6e9986e8e7e2d
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Iliyan Malchev <malchev@google.com>
This adds the new "seccomp" syscall with both an "operation" and "flags"
parameter for future expansion. The third argument is a pointer value,
used with the SECCOMP_SET_MODE_FILTER operation. Currently, flags must
be 0. This is functionally equivalent to prctl(PR_SET_SECCOMP, ...).
In addition to the TSYNC flag later in this patch series, there is a
non-zero chance that this syscall could be used for configuring a fixed
argument area for seccomp-tracer-aware processes to pass syscall arguments
in the future. Hence, the use of "seccomp" not simply "seccomp_add_filter"
for this syscall. Additionally, this syscall uses operation, flags,
and user pointer for arguments because strictly passing arguments via
a user pointer would mean seccomp itself would be unable to trivially
filter the seccomp syscall itself.
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Andy Lutomirski <luto@amacapital.net>
Conflicts:
arch/x86/syscalls/syscall_32.tbl
arch/x86/syscalls/syscall_64.tbl
include/linux/syscalls.h
include/uapi/asm-generic/unistd.h
include/uapi/linux/seccomp.h
kernel/seccomp.c
kernel/sys_ni.c
ARM reuses r0 as the first argument. This fixes the mistaken
assumption in the original patchset. These will be merged
into one change when sent upstream.
Signed-off-by: Will Drewry <wad@chromium.org>
TEST=emerge tegra2_kaen; run seccomp testsuite
BUG=chromium-os:27878
Change-Id: Iaaa09995d35f78ee8cef7b600d526e71f3b2fcec
Reviewed-on: https://gerrit.chromium.org/gerrit/21342
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Will Drewry <wad@chromium.org>
Tested-by: Will Drewry <wad@chromium.org>
Signed-off-by: Sasha Levitskiy <sanek@google.com>
On tracehook-friendly platforms, a system call number of -1 falls
through without running much code or taking much action.
ARM is different. This adds a lightweight check to arm_syscall()
to make sure that ARM behaves the same way.
Signed-off-by: Will Drewry <wad@chromium.org>
TEST=building on tegra2 now. Will live test with seccomp testsuite. It was through SIGILL.
BUG=chromium-os:27878
Change-Id: Ie3896b54e9bfa21c22e0df456a47ad03c8d0aa3f
Reviewed-on: https://gerrit.chromium.org/gerrit/21251
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Will Drewry <wad@chromium.org>
Tested-by: Will Drewry <wad@chromium.org>
Signed-off-by: Sasha Levitskiy <sanek@google.com>
(I will post this upstream after the 3.5 merge window)
Reflect architectural support for seccomp filter.
Change-Id: I163078260e73a8fb7b9967ce740bd21f83902b8e
Signed-off-by: Will Drewry <wad@chromium.org>
BUG=chromium-os:27878
TEST=compiles for arm. Need to test on a live machine.
Change-Id: Ic0286cc7d150838fbfa05e259ea908aeeef1b864
Reviewed-on: https://gerrit.chromium.org/gerrit/21377
Reviewed-by: Will Drewry <wad@chromium.org>
Tested-by: Will Drewry <wad@chromium.org>
Signed-off-by: Sasha Levitskiy <sanek@google.com>
There is very little difference in the TIF_SECCOMP and TIF_SYSCALL_TRACE
patsh in entry-common.S. In order to add support for
CONFIG_HAVE_ARCH_SECCOMP_FILTER without mangling the assembly too
badly, seccomp was moved into the syscall_trace() handler.
Additionally, the return value for secure_computing() is now checked
and a -1 value will result in the system call being skipped.
(Reworked for 3.4 merge to just piggyback on the audit enter path.)
Signed-off-by: Will Drewry <wad@chromium.org>
BUG=chromium-os:27878
TEST=compiles for arm. Need to test on a live machine.
Change-Id: I9493f28c30356a10eccb320e0a2d1a141388af9a
Reviewed-on: https://gerrit.chromium.org/gerrit/21376
Reviewed-by: Will Drewry <wad@chromium.org>
Tested-by: Will Drewry <wad@chromium.org>
Signed-off-by: Sasha Levitskiy <sanek@google.com>
(I will post this upstream after the 3.5 merge window)
Provide an ARM implementation for asm-generic/syscall.h.
This is a pre-requisite for CONFIG_HAVE_ARCH_TRACEHOOK and
CONFIG_HAVE_ARCH_SECCOMP_FILTER. The latter is the forcing
function for this patch.
Change-Id: Idc5fa7b72691ec9d75418849733633df33482e53
Signed-off-by: Will Drewry <wad@chromium.org>
BUG=chromium-os:27878
TEST=compiles for arm. Need to test on a live machine.
Change-Id: I7b911b51085424aedd2beaf40683c3348b6cede1
Reviewed-on: https://gerrit.chromium.org/gerrit/21375
Reviewed-by: Will Drewry <wad@chromium.org>
Tested-by: Will Drewry <wad@chromium.org>
Signed-off-by: Sasha Levitskiy <sanek@google.com>
This change is inspired by
https://lkml.org/lkml/2012/4/16/14
which fixes the build warnings for arches that don't support
CONFIG_HAVE_ARCH_SECCOMP_FILTER.
In particular, there is no requirement for the return value of
secure_computing() to be checked unless the architecture supports
seccomp filter. Instead of silencing the warnings with (void)
a new static inline is added to encode the expected behavior
in a compiler and human friendly way.
v2: - cleans things up with a static inline
- removes sfr's signed-off-by since it is a different approach
v1: - matches sfr's original change
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Will Drewry <wad@chromium.org>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: James Morris <james.l.morris@oracle.com>
This change adds support for a new ptrace option, PTRACE_O_TRACESECCOMP,
and a new return value for seccomp BPF programs, SECCOMP_RET_TRACE.
When a tracer specifies the PTRACE_O_TRACESECCOMP ptrace option, the
tracer will be notified, via PTRACE_EVENT_SECCOMP, for any syscall that
results in a BPF program returning SECCOMP_RET_TRACE. The 16-bit
SECCOMP_RET_DATA mask of the BPF program return value will be passed as
the ptrace_message and may be retrieved using PTRACE_GETEVENTMSG.
If the subordinate process is not using seccomp filter, then no
system call notifications will occur even if the option is specified.
If there is no tracer with PTRACE_O_TRACESECCOMP when SECCOMP_RET_TRACE
is returned, the system call will not be executed and an -ENOSYS errno
will be returned to userspace.
This change adds a dependency on the system call slow path. Any future
efforts to use the system call fast path for seccomp filter will need to
address this restriction.
Signed-off-by: Will Drewry <wad@chromium.org>
Acked-by: Eric Paris <eparis@redhat.com>
v18: - rebase
- comment fatal_signal check
- acked-by
- drop secure_computing_int comment
v17: - ...
v16: - update PT_TRACE_MASK to 0xbf4 so that STOP isn't clear on SETOPTIONS call (indan@nul.nu)
[note PT_TRACE_MASK disappears in linux-next]
v15: - add audit support for non-zero return codes
- clean up style (indan@nul.nu)
v14: - rebase/nochanges
v13: - rebase on to 88ebdda615
(Brings back a change to ptrace.c and the masks.)
v12: - rebase to linux-next
- use ptrace_event and update arch/Kconfig to mention slow-path dependency
- drop all tracehook changes and inclusion (oleg@redhat.com)
v11: - invert the logic to just make it a PTRACE_SYSCALL accelerator
(indan@nul.nu)
v10: - moved to PTRACE_O_SECCOMP / PT_TRACE_SECCOMP
v9: - n/a
v8: - guarded PTRACE_SECCOMP use with an ifdef
v7: - introduced
Adds a new return value to seccomp filters that triggers a SIGSYS to be
delivered with the new SYS_SECCOMP si_code.
This allows in-process system call emulation, including just specifying
an errno or cleanly dumping core, rather than just dying.
Suggested-by: Markus Gutschke <markus@chromium.org>
Suggested-by: Julien Tinnes <jln@chromium.org>
Signed-off-by: Will Drewry <wad@chromium.org>
Acked-by: Eric Paris <eparis@redhat.com>
v18: - acked-by, rebase
- don't mention secure_computing_int() anymore
v15: - use audit_seccomp/skip
- pad out error spacing; clean up switch (indan@nul.nu)
v14: - n/a
v13: - rebase on to 88ebdda615
v12: - rebase on to linux-next
v11: - clarify the comment (indan@nul.nu)
- s/sigtrap/sigsys
v10: - use SIGSYS, syscall_get_arch, updates arch/Kconfig
note suggested-by (though original suggestion had other behaviors)
v9: - changes to SIGILL
v8: - clean up based on changes to dependent patches
v7: - introduction
This change enables SIGSYS, defines _sigfields._sigsys, and adds
x86 (compat) arch support. _sigsys defines fields which allow
a signal handler to receive the triggering system call number,
the relevant AUDIT_ARCH_* value for that number, and the address
of the callsite.
SIGSYS is added to the SYNCHRONOUS_MASK because it is desirable for it
to have setup_frame() called for it. The goal is to ensure that
ucontext_t reflects the machine state from the time-of-syscall and not
from another signal handler.
The first consumer of SIGSYS would be seccomp filter. In particular,
a filter program could specify a new return value, SECCOMP_RET_TRAP,
which would result in the system call being denied and the calling
thread signaled. This also means that implementing arch-specific
support can be dependent upon HAVE_ARCH_SECCOMP_FILTER.
Suggested-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Will Drewry <wad@chromium.org>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Reviewed-by: H. Peter Anvin <hpa@zytor.com>
Acked-by: Eric Paris <eparis@redhat.com>
v18: - added acked by, rebase
v17: - rebase and reviewed-by addition
v14: - rebase/nochanges
v13: - rebase on to 88ebdda615
v12: - reworded changelog (oleg@redhat.com)
v11: - fix dropped words in the change description
- added fallback copy_siginfo support.
- added __ARCH_SIGSYS define to allow stepped arch support.
v10: - first version based on suggestion
This change adds the SECCOMP_RET_ERRNO as a valid return value from a
seccomp filter. Additionally, it makes the first use of the lower
16-bits for storing a filter-supplied errno. 16-bits is more than
enough for the errno-base.h calls.
Returning errors instead of immediately terminating processes that
violate seccomp policy allow for broader use of this functionality
for kernel attack surface reduction. For example, a linux container
could maintain a whitelist of pre-existing system calls but drop
all new ones with errnos. This would keep a logically static attack
surface while providing errnos that may allow for graceful failure
without the downside of do_exit() on a bad call.
This change also changes the signature of __secure_computing. It
appears the only direct caller is the arm entry code and it clobbers
any possible return value (register) immediately.
Signed-off-by: Will Drewry <wad@chromium.org>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Eric Paris <eparis@redhat.com>
v18: - fix up comments and rebase
- fix bad var name which was fixed in later revs
- remove _int() and just change the __secure_computing signature
v16-v17: ...
v15: - use audit_seccomp and add a skip label. (eparis@redhat.com)
- clean up and pad out return codes (indan@nul.nu)
v14: - no change/rebase
v13: - rebase on to 88ebdda615
v12: - move to WARN_ON if filter is NULL
(oleg@redhat.com, luto@mit.edu, keescook@chromium.org)
- return immediately for filter==NULL (keescook@chromium.org)
- change evaluation to only compare the ACTION so that layered
errnos don't result in the lowest one being returned.
(keeschook@chromium.org)
v11: - check for NULL filter (keescook@chromium.org)
v10: - change loaders to fn
v9: - n/a
v8: - update Kconfig to note new need for syscall_set_return_value.
- reordered such that TRAP behavior follows on later.
- made the for loop a little less indent-y
v7: - introduced
[This patch depends on luto@mit.edu's no_new_privs patch:
https://lkml.org/lkml/2012/1/30/264
The whole series including Andrew's patches can be found here:
https://github.com/redpig/linux/tree/seccomp
Complete diff here:
https://github.com/redpig/linux/compare/1dc65fed...seccomp
]
This patch adds support for seccomp mode 2. Mode 2 introduces the
ability for unprivileged processes to install system call filtering
policy expressed in terms of a Berkeley Packet Filter (BPF) program.
This program will be evaluated in the kernel for each system call
the task makes and computes a result based on data in the format
of struct seccomp_data.
A filter program may be installed by calling:
struct sock_fprog fprog = { ... };
...
prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &fprog);
The return value of the filter program determines if the system call is
allowed to proceed or denied. If the first filter program installed
allows prctl(2) calls, then the above call may be made repeatedly
by a task to further reduce its access to the kernel. All attached
programs must be evaluated before a system call will be allowed to
proceed.
Filter programs will be inherited across fork/clone and execve.
However, if the task attaching the filter is unprivileged
(!CAP_SYS_ADMIN) the no_new_privs bit will be set on the task. This
ensures that unprivileged tasks cannot attach filters that affect
privileged tasks (e.g., setuid binary).
There are a number of benefits to this approach. A few of which are
as follows:
- BPF has been exposed to userland for a long time
- BPF optimization (and JIT'ing) are well understood
- Userland already knows its ABI: system call numbers and desired
arguments
- No time-of-check-time-of-use vulnerable data accesses are possible.
- system call arguments are loaded on access only to minimize copying
required for system call policy decisions.
Mode 2 support is restricted to architectures that enable
HAVE_ARCH_SECCOMP_FILTER. In this patch, the primary dependency is on
syscall_get_arguments(). The full desired scope of this feature will
add a few minor additional requirements expressed later in this series.
Based on discussion, SECCOMP_RET_ERRNO and SECCOMP_RET_TRACE seem to be
the desired additional functionality.
No architectures are enabled in this patch.
Signed-off-by: Will Drewry <wad@chromium.org>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Reviewed-by: Indan Zupancic <indan@nul.nu>
Acked-by: Eric Paris <eparis@redhat.com>
v18: - rebase to v3.4-rc2
- s/chk/check/ (akpm@linux-foundation.org,jmorris@namei.org)
- allocate with GFP_KERNEL|__GFP_NOWARN (indan@nul.nu)
- add a comment for get_u32 regarding endianness (akpm@)
- fix other typos, style mistakes (akpm@)
- added acked-by
v17: - properly guard seccomp filter needed headers (leann@ubuntu.com)
- tighten return mask to 0x7fff0000
v16: - no change
v15: - add a 4 instr penalty when counting a path to account for seccomp_filter
size (indan@nul.nu)
- drop the max insns to 256KB (indan@nul.nu)
- return ENOMEM if the max insns limit has been hit (indan@nul.nu)
- move IP checks after args (indan@nul.nu)
- drop !user_filter check (indan@nul.nu)
- only allow explicit bpf codes (indan@nul.nu)
- exit_code -> exit_sig
v14: - put/get_seccomp_filter takes struct task_struct
(indan@nul.nu,keescook@chromium.org)
- adds seccomp_chk_filter and drops general bpf_run/chk_filter user
- add seccomp_bpf_load for use by net/core/filter.c
- lower max per-process/per-hierarchy: 1MB
- moved nnp/capability check prior to allocation
(all of the above: indan@nul.nu)
v13: - rebase on to 88ebdda615
v12: - added a maximum instruction count per path (indan@nul.nu,oleg@redhat.com)
- removed copy_seccomp (keescook@chromium.org,indan@nul.nu)
- reworded the prctl_set_seccomp comment (indan@nul.nu)
v11: - reorder struct seccomp_data to allow future args expansion (hpa@zytor.com)
- style clean up, @compat dropped, compat_sock_fprog32 (indan@nul.nu)
- do_exit(SIGSYS) (keescook@chromium.org, luto@mit.edu)
- pare down Kconfig doc reference.
- extra comment clean up
v10: - seccomp_data has changed again to be more aesthetically pleasing
(hpa@zytor.com)
- calling convention is noted in a new u32 field using syscall_get_arch.
This allows for cross-calling convention tasks to use seccomp filters.
(hpa@zytor.com)
- lots of clean up (thanks, Indan!)
v9: - n/a
v8: - use bpf_chk_filter, bpf_run_filter. update load_fns
- Lots of fixes courtesy of indan@nul.nu:
-- fix up load behavior, compat fixups, and merge alloc code,
-- renamed pc and dropped __packed, use bool compat.
-- Added a hidden CONFIG_SECCOMP_FILTER to synthesize non-arch
dependencies
v7: (massive overhaul thanks to Indan, others)
- added CONFIG_HAVE_ARCH_SECCOMP_FILTER
- merged into seccomp.c
- minimal seccomp_filter.h
- no config option (part of seccomp)
- no new prctl
- doesn't break seccomp on systems without asm/syscall.h
(works but arg access always fails)
- dropped seccomp_init_task, extra free functions, ...
- dropped the no-asm/syscall.h code paths
- merges with network sk_run_filter and sk_chk_filter
v6: - fix memory leak on attach compat check failure
- require no_new_privs || CAP_SYS_ADMIN prior to filter
installation. (luto@mit.edu)
- s/seccomp_struct_/seccomp_/ for macros/functions (amwang@redhat.com)
- cleaned up Kconfig (amwang@redhat.com)
- on block, note if the call was compat (so the # means something)
v5: - uses syscall_get_arguments
(indan@nul.nu,oleg@redhat.com, mcgrathr@chromium.org)
- uses union-based arg storage with hi/lo struct to
handle endianness. Compromises between the two alternate
proposals to minimize extra arg shuffling and account for
endianness assuming userspace uses offsetof().
(mcgrathr@chromium.org, indan@nul.nu)
- update Kconfig description
- add include/seccomp_filter.h and add its installation
- (naive) on-demand syscall argument loading
- drop seccomp_t (eparis@redhat.com)
v4: - adjusted prctl to make room for PR_[SG]ET_NO_NEW_PRIVS
- now uses current->no_new_privs
(luto@mit.edu,torvalds@linux-foundation.com)
- assign names to seccomp modes (rdunlap@xenotime.net)
- fix style issues (rdunlap@xenotime.net)
- reworded Kconfig entry (rdunlap@xenotime.net)
v3: - macros to inline (oleg@redhat.com)
- init_task behavior fixed (oleg@redhat.com)
- drop creator entry and extra NULL check (oleg@redhat.com)
- alloc returns -EINVAL on bad sizing (serge.hallyn@canonical.com)
- adds tentative use of "always_unprivileged" as per
torvalds@linux-foundation.org and luto@mit.edu
v2: - (patch 2 only)
Add syscall_get_arch() to export the current AUDIT_ARCH_* based on system call
entry path.
Signed-off-by: Will Drewry <wad@chromium.org>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Reviewed-by: H. Peter Anvin <hpa@zytor.com>
Acked-by: Eric Paris <eparis@redhat.com>
v18: - update comment about x32 tasks
- rebase to v3.4-rc2
v17: rebase and reviewed-by
v14: rebase/nochanges
v13: rebase on to 88ebdda615
The RemoteFS server now uses the UIO driver. So add the UIO
device for APQ8064
CRs-Fixed: 592586
Bug: 12784954
Change-Id: Ia0d643a10827869bfe527bf15ba064842e509487
Signed-off-by: Pratibhasagar V <pratibha@codeaurora.org>
Signed-off-by: Mekala Natarajan <mekalan@codeaurora.org>
