signalfd: fix information leak in signalfd_copyinfo

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commit 3ead7c52bd upstream.

This function may copy the si_addr_lsb field to user mode when it hasn'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>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>

...

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Amanieu d'Antras 2015-08-06 15:46:33 -07:00 • committed by Luis Henriques

parent f27f75ca7a

commit 3a6d9db06b

1 changed files with 3 additions and 2 deletions

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fs/signalfd.c

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