From: David Disseldorp <ddiss@suse.de>
Date: Tue, 7 Mar 2023 15:21:06 +0000 (+0100)
Subject: watch_queue: fix IOC_WATCH_QUEUE_SET_SIZE alloc error paths
X-Git-Tag: v5.15.103~45
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b43cb0f087676db71a7baf3bec65b6439353b10d;p=thirdparty%2Fkernel%2Fstable.git

watch_queue: fix IOC_WATCH_QUEUE_SET_SIZE alloc error paths

[ Upstream commit 03e1d60e177eedbd302b77af4ea5e21b5a7ade31 ]

The watch_queue_set_size() allocation error paths return the ret value
set via the prior pipe_resize_ring() call, which will always be zero.

As a result, IOC_WATCH_QUEUE_SET_SIZE callers such as "keyctl watch"
fail to detect kernel wqueue->notes allocation failures and proceed to
KEYCTL_WATCH_KEY, with any notifications subsequently lost.

Fixes: c73be61cede58 ("pipe: Add general notification queue support")
Signed-off-by: David Disseldorp <ddiss@suse.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

diff --git a/kernel/watch_queue.c b/kernel/watch_queue.c
index 1059ef6c3711a..54cbaa9711398 100644
--- a/kernel/watch_queue.c
+++ b/kernel/watch_queue.c
@@ -274,6 +274,7 @@ long watch_queue_set_size(struct pipe_inode_info *pipe, unsigned int nr_notes)
 	if (ret < 0)
 		goto error;
 
+	ret = -ENOMEM;
 	pages = kcalloc(sizeof(struct page *), nr_pages, GFP_KERNEL);
 	if (!pages)
 		goto error;