pipe: Fix memory leaks in create_pipe_files()
authorQian Cai <cai@redhat.com>
Thu, 1 Oct 2020 12:50:55 +0000 (08:50 -0400)
committerAl Viro <viro@zeniv.linux.org.uk>
Thu, 1 Oct 2020 13:40:35 +0000 (09:40 -0400)
commit8a018eb55e3ac033592afbcb476b0ffe64465b12
treebd8bac805f42321871049858655790092ea623ae
parent933a3752babcf6513117d5773d2b70782d6ad149
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 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>
fs/pipe.c
include/linux/watch_queue.h