Commit b4d8a58f authored by Hsuan-Chi Kuo's avatar Hsuan-Chi Kuo Committed by Kees Cook
Browse files

seccomp: Fix setting loaded filter count during TSYNC 



The desired behavior is to set the caller's filter count to thread's.
This value is reported via /proc, so this fixes the inaccurate count
exposed to userspace; it is not used for reference counting, etc.

Signed-off-by: default avatarHsuan-Chi Kuo <hsuanchikuo@gmail.com>
Link: https://lore.kernel.org/r/20210304233708.420597-1-hsuanchikuo@gmail.com


Co-developed-by: default avatarWiktor Garbacz <wiktorg@google.com>
Signed-off-by: default avatarWiktor Garbacz <wiktorg@google.com>
Link: https://lore.kernel.org/lkml/20210810125158.329849-1-wiktorg@google.com


Signed-off-by: default avatarKees Cook <keescook@chromium.org>
Cc: stable@vger.kernel.org
Fixes: c818c03b ("seccomp: Report number of loaded filters in /proc/$pid/status")
parent 19d67694

kernel/seccomp.c

+1 −1
Original line number Diff line number Diff line
@@ -602,7 +602,7 @@ static inline void seccomp_sync_threads(unsigned long flags) 
		smp_store_release(&thread->seccomp.filter,

				  caller->seccomp.filter);

		atomic_set(&thread->seccomp.filter_count,

			   atomic_read(&thread->seccomp.filter_count));

			   atomic_read(&caller->seccomp.filter_count));



		/*

		 * Don't let an unprivileged task work around