| commit | 5c17daa89308cc028fe336af58cf9d4e4d83298d | |
| author | Jan Kiszka <jan.kiszka@siemens.com> | |
| Thu, 10 May 2012 13:04:36 +0000 (10 10:04 -0300) | ||
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | |
| Mon, 21 May 2012 16:40:04 +0000 (21 09:40 -0700) | ||
| tree | f42c055ed6faeb2af7262e735b997d6ef437a416 | treesnapshot (tar.gz zip) |
| parent | 37de6be49f6c88f7d1306594b7aae5aeee2fa499 | commitdiff |
compat: Fix RT signal mask corruption via sigprocmask
commit b7dafa0ef3145c31d7753be0a08b3cbda51f0209 upstream.
compat_sys_sigprocmask reads a smaller signal mask from userspace than
sigprogmask accepts for setting. So the high word of blocked.sig[0]
will be cleared, releasing any potentially blocked RT signal.
This was discovered via userspace code that relies on get/setcontext.
glibc's i386 versions of those functions use sigprogmask instead of
rt_sigprogmask to save/restore signal mask and caused RT signal
unblocking this way.
As suggested by Linus, this replaces the sys_sigprocmask based compat
version with one that open-codes the required logic, including the merge
of the existing blocked set with the new one provided on SIG_SETMASK.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit b7dafa0ef3145c31d7753be0a08b3cbda51f0209 upstream.
compat_sys_sigprocmask reads a smaller signal mask from userspace than
sigprogmask accepts for setting. So the high word of blocked.sig[0]
will be cleared, releasing any potentially blocked RT signal.
This was discovered via userspace code that relies on get/setcontext.
glibc's i386 versions of those functions use sigprogmask instead of
rt_sigprogmask to save/restore signal mask and caused RT signal
unblocking this way.
As suggested by Linus, this replaces the sys_sigprocmask based compat
version with one that open-codes the required logic, including the merge
of the existing blocked set with the new one provided on SIG_SETMASK.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| kernel/compat.c | diffblobblamehistory |