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authorDave Weinstein <olorin@google.com>2016-07-28 11:55:41 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2016-08-10 12:57:45 -0700
commit7de249964f5578e67b99699c5f0b405738d820a2 (patch)
tree2aab15125670ef4ec443563156d6808b612dd18b /arch/arm
parent9512c47ec2e4f7e1f28ba66e09de536987a6057f (diff)
arm: oabi compat: add missing access checks
Add access checks to sys_oabi_epoll_wait() and sys_oabi_semtimedop(). This fixes CVE-2016-3857, a local privilege escalation under CONFIG_OABI_COMPAT. Cc: stable@vger.kernel.org Reported-by: Chiachih Wu <wuchiachih@gmail.com> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Dave Weinstein <olorin@google.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/arm')
-rw-r--r--arch/arm/kernel/sys_oabi-compat.c8
1 files changed, 7 insertions, 1 deletions
diff --git a/arch/arm/kernel/sys_oabi-compat.c b/arch/arm/kernel/sys_oabi-compat.c
index 087acb569b63..5f221acd21ae 100644
--- a/arch/arm/kernel/sys_oabi-compat.c
+++ b/arch/arm/kernel/sys_oabi-compat.c
@@ -279,8 +279,12 @@ asmlinkage long sys_oabi_epoll_wait(int epfd,
mm_segment_t fs;
long ret, err, i;
- if (maxevents <= 0 || maxevents > (INT_MAX/sizeof(struct epoll_event)))
+ if (maxevents <= 0 ||
+ maxevents > (INT_MAX/sizeof(*kbuf)) ||
+ maxevents > (INT_MAX/sizeof(*events)))
return -EINVAL;
+ if (!access_ok(VERIFY_WRITE, events, sizeof(*events) * maxevents))
+ return -EFAULT;
kbuf = kmalloc(sizeof(*kbuf) * maxevents, GFP_KERNEL);
if (!kbuf)
return -ENOMEM;
@@ -317,6 +321,8 @@ asmlinkage long sys_oabi_semtimedop(int semid,
if (nsops < 1 || nsops > SEMOPM)
return -EINVAL;
+ if (!access_ok(VERIFY_READ, tsops, sizeof(*tsops) * nsops))
+ return -EFAULT;
sops = kmalloc(sizeof(*sops) * nsops, GFP_KERNEL);
if (!sops)
return -ENOMEM;