From f69aecb49968e14196366bbe896eab0a904229f5 Mon Sep 17 00:00:00 2001 From: David Howells Date: Mon, 21 Mar 2022 11:18:54 +0000 Subject: watch_queue: Actually free the watch [ Upstream commit 3d8dcf278b1ee1eff1e90be848fa2237db4c07a7 ] free_watch() does everything barring actually freeing the watch object. Fix this by adding the missing kfree. kmemleak produces a report something like the following. Note that as an address can be seen in the first word, the watch would appear to have gone through call_rcu(). BUG: memory leak unreferenced object 0xffff88810ce4a200 (size 96): comm "syz-executor352", pid 3605, jiffies 4294947473 (age 13.720s) hex dump (first 32 bytes): e0 82 48 0d 81 88 ff ff 00 00 00 00 00 00 00 00 ..H............. 80 a2 e4 0c 81 88 ff ff 00 00 00 00 00 00 00 00 ................ backtrace: [] kmalloc include/linux/slab.h:581 [inline] [] kzalloc include/linux/slab.h:714 [inline] [] keyctl_watch_key+0xec/0x2e0 security/keys/keyctl.c:1800 [] __do_sys_keyctl+0x3c4/0x490 security/keys/keyctl.c:2016 [] do_syscall_x64 arch/x86/entry/common.c:50 [inline] [] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 [] entry_SYSCALL_64_after_hwframe+0x44/0xae Fixes: c73be61cede5 ("pipe: Add general notification queue support") Reported-and-tested-by: syzbot+6e2de48f06cdb2884bfc@syzkaller.appspotmail.com Signed-off-by: David Howells Signed-off-by: Sasha Levin --- kernel/watch_queue.c | 1 + 1 file changed, 1 insertion(+) (limited to 'kernel') diff --git a/kernel/watch_queue.c b/kernel/watch_queue.c index 12348b41d7ad..38a135d68c05 100644 --- a/kernel/watch_queue.c +++ b/kernel/watch_queue.c @@ -398,6 +398,7 @@ static void free_watch(struct rcu_head *rcu) put_watch_queue(rcu_access_pointer(watch->queue)); atomic_dec(&watch->cred->user->nr_watches); put_cred(watch->cred); + kfree(watch); } static void __put_watch(struct kref *kref) -- cgit v1.2.3