From: Manfred Spraul <manfred@xxxxxxxxxxxxxxxx> Subject: ipc/util.c: correct comment in ipc_obtain_object_check The comment that explains ipc_obtain_object_check is wrong: The function checks the sequence number, not the reference counter. Note that checking the reference counter would be meaningless: The reference counter is decreased without holding any locks, thus an object with kern_ipc_perm.deleted=true may disappear at the end of the next rcu grace period. Link: http://lkml.kernel.org/r/20180712185241.4017-6-manfred@xxxxxxxxxxxxxxxx Signed-off-by: Manfred Spraul <manfred@xxxxxxxxxxxxxxxx> Reviewed-by: Davidlohr Bueso <dbueso@xxxxxxx> Cc: Davidlohr Bueso <dave@xxxxxxxxxxxx> Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx> Cc: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> Cc: Kees Cook <keescook@xxxxxxxxxxxx> Cc: Michael Kerrisk <mtk.manpages@xxxxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- ipc/util.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/ipc/util.c~ipc-utilc-correct-comment-in-ipc_obtain_object_check +++ a/ipc/util.c @@ -629,8 +629,8 @@ err: * @ids: ipc identifier set * @id: ipc id to look for * - * Similar to ipc_obtain_object_idr() but also checks - * the ipc object reference counter. + * Similar to ipc_obtain_object_idr() but also checks the ipc object + * sequence number. * * Call inside the RCU critical section. * The ipc object is *not* locked on exit. _
