tree 255fa7484e68697aedfa97658a962dc804ab16f3
parent 26135022f85105ad725cda103fa069e29e83bd16
author Amanieu d'Antras <amanieu@gmail.com> 1438901193 -0700
committer Linus Torvalds <torvalds@linux-foundation.org> 1438911580 +0300

signalfd: fix information leak in signalfd_copyinfo

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>