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@xxxxxxx>
---
Version 2:
- document "keyctl watch" behaviour with this bug
kernel/watch_queue.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/kernel/watch_queue.c b/kernel/watch_queue.c
index a6f9bdd956c3..f10f403104e7 100644
--- a/kernel/watch_queue.c
+++ b/kernel/watch_queue.c
@@ -273,6 +273,7 @@ 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;
--
2.35.3
