diff options
| author | Dave Weinstein <olorin@google.com> | 2016-07-28 11:55:41 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-08-16 09:33:17 +0200 |
| commit | e6b25dc115a4642eb7cfc93477f9f3d57ebaf391 (patch) | |
| tree | 3a3e88578a683206caa2f6ffe4d69478a934c9d8 | |
| parent | 33f28b1257b81a4a929792f31a6f1363c830ca4d (diff) | |
| download | lwn-e6b25dc115a4642eb7cfc93477f9f3d57ebaf391.tar.gz lwn-e6b25dc115a4642eb7cfc93477f9f3d57ebaf391.zip | |
arm: oabi compat: add missing access checks
commit 7de249964f5578e67b99699c5f0b405738d820a2 upstream.
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.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | arch/arm/kernel/sys_oabi-compat.c | 8 |
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; |