From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Morton Subject: [patch 35/35] ipc/util.c: sysvipc_find_ipc() should increase position index Date: Fri, 10 Apr 2020 14:34:13 -0700 Message-ID: <20200410213413._tpYkgUyu%akpm@linux-foundation.org> References: <20200410143047.bf34a933ce1affdc042c7c80@linux-foundation.org> Reply-To: linux-kernel@vger.kernel.org Return-path: Received: from mail.kernel.org ([198.145.29.99]:48468 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726663AbgDJVeN (ORCPT ); Fri, 10 Apr 2020 17:34:13 -0400 In-Reply-To: <20200410143047.bf34a933ce1affdc042c7c80@linux-foundation.org> Sender: mm-commits-owner@vger.kernel.org List-Id: mm-commits@vger.kernel.org To: akpm@linux-foundation.org, dave@stgolabs.net, linux-mm@kvack.org, longman@redhat.com, manfred@colorfullife.com, mingo@redhat.com, mm-commits@vger.kernel.org, neilb@suse.com, oberpar@linux.ibm.com, rostedt@goodmis.org, torvalds@linux-foundation.org, viro@zeniv.linux.org.uk, vvs@virtuozzo.com From: Vasily Averin Subject: 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 Link: http://lkml.kernel.org/r/b7a20945-e315-8bb0-21e6-3875c14a8494@virtuozzo.com Signed-off-by: Vasily Averin Acked-by: Waiman Long Cc: Davidlohr Bueso Cc: Manfred Spraul Cc: Al Viro Cc: Ingo Molnar Cc: NeilBrown Cc: Peter Oberparleiter Cc: Steven Rostedt Signed-off-by: Andrew Morton --- ipc/util.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/ipc/util.c~sysvipc_find_ipc-should-increase-position-index +++ a/ipc/util.c @@ -764,13 +764,13 @@ static struct kern_ipc_perm *sysvipc_fin total++; } + *new_pos = pos + 1; if (total >= ids->in_use) return NULL; for (; pos < ipc_mni; pos++) { ipc = idr_find(&ids->ipcs_idr, pos); if (ipc != NULL) { - *new_pos = pos + 1; rcu_read_lock(); ipc_lock_object(ipc); return ipc; _