From: Qian Cai <cai@xxxxxxxxxx>
[ Upstream commit 8a018eb55e3ac033592afbcb476b0ffe64465b12 ]
Calling pipe2() with O_NOTIFICATION_PIPE could results in memory
leaks unless watch_queue_init() is successful.
In case of watch_queue_init() failure in pipe2() we are left
with inode and pipe_inode_info instances that need to be freed. That
failure exit has been introduced in commit c73be61cede5 ("pipe: Add
general notification queue support") and its handling should've been
identical to nearby treatment of alloc_file_pseudo() failures - it
is dealing with the same situation. As it is, the mainline kernel
leaks in that case.
Another problem is that CONFIG_WATCH_QUEUE and !CONFIG_WATCH_QUEUE
cases are treated differently (and the former leaks just pipe_inode_info,
the latter - both pipe_inode_info and inode).
Fixed by providing a dummy wacth_queue_init() in !CONFIG_WATCH_QUEUE
case and by having failures of wacth_queue_init() handled the same way
we handle alloc_file_pseudo() ones.
Fixes: c73be61cede5 ("pipe: Add general notification queue support")
Signed-off-by: Qian Cai <cai@xxxxxxxxxx>
Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
fs/pipe.c | 11 +++++------
include/linux/watch_queue.h | 6 ++++++
2 files changed, 11 insertions(+), 6 deletions(-)
diff --git a/fs/pipe.c b/fs/pipe.c
index 117db82b10af5..0ac197658a2d6 100644
--- a/fs/pipe.c
+++ b/fs/pipe.c
@@ -894,19 +894,18 @@ int create_pipe_files(struct file **res, int flags)
{
struct inode *inode = get_pipe_inode();
struct file *f;
+ int error;
if (!inode)
return -ENFILE;
if (flags & O_NOTIFICATION_PIPE) {
-#ifdef CONFIG_WATCH_QUEUE
- if (watch_queue_init(inode->i_pipe) < 0) {
+ error = watch_queue_init(inode->i_pipe);
+ if (error) {
+ free_pipe_info(inode->i_pipe);
iput(inode);
- return -ENOMEM;
+ return error;
}
-#else
- return -ENOPKG;
-#endif
}
f = alloc_file_pseudo(inode, pipe_mnt, "",
diff --git a/include/linux/watch_queue.h b/include/linux/watch_queue.h
index 5e08db2adc319..c994d1b2cdbaa 100644
--- a/include/linux/watch_queue.h
+++ b/include/linux/watch_queue.h
@@ -122,6 +122,12 @@ static inline void remove_watch_list(struct watch_list *wlist, u64 id)
*/
#define watch_sizeof(STRUCT) (sizeof(STRUCT) << WATCH_INFO_LENGTH__SHIFT)
+#else
+static inline int watch_queue_init(struct pipe_inode_info *pipe)
+{
+ return -ENOPKG;
+}
+
#endif
#endif /* _LINUX_WATCH_QUEUE_H */
--
2.25.1
