diff options
| author | Amanieu d'Antras <amanieu@gmail.com> | 2015-08-06 15:46:29 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-08-16 20:51:42 -0700 |
| commit | 16a49557bc101b804a0a74d4032556f8836b9469 (patch) | |
| tree | 63d5972b3fe4fb422090c245783208e98e3bdf89 /kernel | |
| parent | 5c233bffdb9ffd2c85d1f94ddd8be956ee2b353f (diff) | |
signal: fix information leak in copy_siginfo_to_user
commit 26135022f85105ad725cda103fa069e29e83bd16 upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/signal.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/kernel/signal.c b/kernel/signal.c index 113411bfe8b1..fa80d104cbec 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -2768,7 +2768,8 @@ int copy_siginfo_to_user(siginfo_t __user *to, siginfo_t *from) * Other callers might not initialize the si_lsb field, * so check explicitly 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; |