Commit [694f69] Maximize Restore History

CRED: Fix RCU warning due to previous patch fixing __task_cred()'s checks

Commit 8f92054e7ca1 ("CRED: Fix __task_cred()'s lockdep check and banner
comment") fixed the lockdep checks on __task_cred(). This has shown up
a place in the signalling code where a lock should be held - namely that
check_kill_permission() requires its callers to hold the RCU lock.

Fix group_send_sig_info() to get the RCU read lock around its call to
check_kill_permission().

Without this patch, the following warning can occur:

===================================================
[ INFO: suspicious rcu_dereference_check() usage. ]
---------------------------------------------------
kernel/signal.c:660 invoked rcu_dereference_check() without protection!
...

Reported-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

David Howells David Howells 2010-08-04

Linus Torvalds Linus Torvalds 2010-08-04

changed kernel/signal.c
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