Commit 8a018eb5 authored by Qian Cai's avatar Qian Cai Committed by Al Viro

pipe: Fix memory leaks in create_pipe_files()

        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 c73be61c ("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: c73be61c ("pipe: Add general notification queue support")
Signed-off-by: default avatarQian Cai <cai@redhat.com>
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 933a3752
...@@ -913,19 +913,18 @@ int create_pipe_files(struct file **res, int flags) ...@@ -913,19 +913,18 @@ int create_pipe_files(struct file **res, int flags)
{ {
struct inode *inode = get_pipe_inode(); struct inode *inode = get_pipe_inode();
struct file *f; struct file *f;
int error;
if (!inode) if (!inode)
return -ENFILE; return -ENFILE;
if (flags & O_NOTIFICATION_PIPE) { if (flags & O_NOTIFICATION_PIPE) {
#ifdef CONFIG_WATCH_QUEUE error = watch_queue_init(inode->i_pipe);
if (watch_queue_init(inode->i_pipe) < 0) { if (error) {
free_pipe_info(inode->i_pipe);
iput(inode); iput(inode);
return -ENOMEM; return error;
} }
#else
return -ENOPKG;
#endif
} }
f = alloc_file_pseudo(inode, pipe_mnt, "", f = alloc_file_pseudo(inode, pipe_mnt, "",
......
...@@ -122,6 +122,12 @@ static inline void remove_watch_list(struct watch_list *wlist, u64 id) ...@@ -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) #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
#endif /* _LINUX_WATCH_QUEUE_H */ #endif /* _LINUX_WATCH_QUEUE_H */
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