xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

signal: fix information leak in copy_siginfo_to_user

Browse Source 
This function may copy the si_addr_lsb, si_lower and si_upper fields to
user mode when they haven't been initialized, which can leak kernel
stack data to user mode.

Just checking the value of si_code is insufficient because the same
si_code value is shared between multiple signals.  This is solved by
checking the value of si_signo in addition to si_code.

Signed-off-by: Amanieu d'Antras <amanieu@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Amanieu d'Antras
2015-08-06 15:46:29 -07:00
committed by Linus Torvalds
parent 3c00cb5e68
commit 26135022f8
2 changed files with 8 additions and 4 deletions
Download Patch File Download Diff File Expand all files Collapse all files

3
arch/arm64/kernel/signal32.c
View File

@@ -168,7 +168,8 @@ int copy_siginfo_to_user32(compat_siginfo_t __user *to, const siginfo_t *from)
* Other callers might not initialize the si_lsb field,
* so check explicitely for the right codes here.
*/
if (from->si_code == BUS_MCEERR_AR || from->si_code == BUS_MCEERR_AO)
if (from->si_signo == SIGBUS &&
(from->si_code == BUS_MCEERR_AR || from->si_code == BUS_MCEERR_AO))
err |= __put_user(from->si_addr_lsb, &to->si_addr_lsb);
#endif
break;