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authorDavid Howells <dhowells@redhat.com>2022-03-21 12:18:54 +0100
committerDavid Howells <dhowells@redhat.com>2022-03-21 13:48:32 +0100
commit3d8dcf278b1ee1eff1e90be848fa2237db4c07a7 (patch)
treea51a1838dc79a49a308ab525bcf135ed801febdc /kernel
parentwatch_queue: Fix NULL dereference in error cleanup (diff)
downloadlinux-3d8dcf278b1ee1eff1e90be848fa2237db4c07a7.tar.xz
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watch_queue: Actually free the watch
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: [<ffffffff8214e6cc>] kmalloc include/linux/slab.h:581 [inline] [<ffffffff8214e6cc>] kzalloc include/linux/slab.h:714 [inline] [<ffffffff8214e6cc>] keyctl_watch_key+0xec/0x2e0 security/keys/keyctl.c:1800 [<ffffffff8214ec84>] __do_sys_keyctl+0x3c4/0x490 security/keys/keyctl.c:2016 [<ffffffff84493a25>] do_syscall_x64 arch/x86/entry/common.c:50 [inline] [<ffffffff84493a25>] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 [<ffffffff84600068>] 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 <dhowells@redhat.com>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/watch_queue.c1
1 files changed, 1 insertions, 0 deletions
diff --git a/kernel/watch_queue.c b/kernel/watch_queue.c
index 5848d4795816..3990e4df3d7b 100644
--- a/kernel/watch_queue.c
+++ b/kernel/watch_queue.c
@@ -395,6 +395,7 @@ 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)