From: Qian Cai cai@redhat.com
[ 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@redhat.com Signed-off-by: Al Viro viro@zeniv.linux.org.uk Signed-off-by: Sasha Levin sashal@kernel.org --- 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 */