ipc/util.c: sysvipc_find_ipc() should increase position index

If seq_file .next function does not change position index, read after
some lseek can generate unexpected output.

https://bugzilla.kernel.org/show_bug.cgi?id=206283
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Waiman Long <longman@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: NeilBrown <neilb@suse.com>
Cc: Peter Oberparleiter <oberpar@linux.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/b7a20945-e315-8bb0-21e6-3875c14a8494@virtuozzo.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Vasily Averin 2020-04-10 14:34:13 -07:00 committed by Linus Torvalds
parent f4d74ef622
commit 89163f93c6

View File

@ -764,13 +764,13 @@ static struct kern_ipc_perm *sysvipc_find_ipc(struct ipc_ids *ids, loff_t pos,
total++; total++;
} }
*new_pos = pos + 1;
if (total >= ids->in_use) if (total >= ids->in_use)
return NULL; return NULL;
for (; pos < ipc_mni; pos++) { for (; pos < ipc_mni; pos++) {
ipc = idr_find(&ids->ipcs_idr, pos); ipc = idr_find(&ids->ipcs_idr, pos);
if (ipc != NULL) { if (ipc != NULL) {
*new_pos = pos + 1;
rcu_read_lock(); rcu_read_lock();
ipc_lock_object(ipc); ipc_lock_object(ipc);
return ipc; return ipc;