[patch added to 3.12-stable] arm: oabi compat: add missing access checks
From: Jiri Slaby <hidden>
Date: 2016-08-18 12:50:09
Subsystem:
arm port, the rest · Maintainers:
Russell King, Linus Torvalds
From: Dave Weinstein <redacted> This patch has been added to the 3.12 stable tree. If you have any objections, please let us know. =============== 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 <redacted> Reviewed-by: Kees Cook <redacted> Reviewed-by: Nicolas Pitre <redacted> Signed-off-by: Dave Weinstein <redacted> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Jiri Slaby <redacted> --- arch/arm/kernel/sys_oabi-compat.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/arch/arm/kernel/sys_oabi-compat.c b/arch/arm/kernel/sys_oabi-compat.c
index 3e94811690ce..a0aee80b608d 100644
--- a/arch/arm/kernel/sys_oabi-compat.c
+++ b/arch/arm/kernel/sys_oabi-compat.c@@ -275,8 +275,12 @@ 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;
@@ -313,6 +317,8 @@ 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;
--
2.9.3