From: Vasily Averin <v...@virtuozzo.com> [ Upstream commit 89163f93c6f969da5811af5377cc10173583123b ]
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 <v...@virtuozzo.com> Signed-off-by: Andrew Morton <a...@linux-foundation.org> Acked-by: Waiman Long <long...@redhat.com> Cc: Davidlohr Bueso <d...@stgolabs.net> Cc: Manfred Spraul <manf...@colorfullife.com> Cc: Al Viro <v...@zeniv.linux.org.uk> Cc: Ingo Molnar <mi...@redhat.com> Cc: NeilBrown <ne...@suse.com> Cc: Peter Oberparleiter <ober...@linux.ibm.com> Cc: Steven Rostedt <rost...@goodmis.org> Link: http://lkml.kernel.org/r/b7a20945-e315-8bb0-21e6-3875c14a8...@virtuozzo.com Signed-off-by: Linus Torvalds <torva...@linux-foundation.org> Signed-off-by: Sasha Levin <sas...@kernel.org> --- ipc/util.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/ipc/util.c b/ipc/util.c index 798cad18dd878..e65ecf3ccbdab 100644 --- a/ipc/util.c +++ b/ipc/util.c @@ -751,13 +751,13 @@ static struct kern_ipc_perm *sysvipc_find_ipc(struct ipc_ids *ids, loff_t pos, total++; } + *new_pos = pos + 1; if (total >= ids->in_use) return NULL; for (; pos < IPCMNI; pos++) { ipc = idr_find(&ids->ipcs_idr, pos); if (ipc != NULL) { - *new_pos = pos + 1; rcu_read_lock(); ipc_lock_object(ipc); return ipc; -- 2.20.1
