io_uring: Fix filename leak in __io_openat_prep

[PATCH] io_uring: Fix filename leak in __io_openat_prep

Posted by Prithvi Tambewagh 1 month, 2 weeks ago

#syz test git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git b927546677c876e26eba308550207c2ddf812a43

Signed-off-by: Prithvi Tambewagh <activprithvi@gmail.com>
---
 io_uring/openclose.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/io_uring/openclose.c b/io_uring/openclose.c
index bfeb91b31bba..fc190a3d8112 100644
--- a/io_uring/openclose.c
+++ b/io_uring/openclose.c
@@ -75,8 +75,11 @@ static int __io_openat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe
 	}
 
 	open->file_slot = READ_ONCE(sqe->file_index);
-	if (open->file_slot && (open->how.flags & O_CLOEXEC))
+	if (open->file_slot && (open->how.flags & O_CLOEXEC)) {
+		putname(open->filename);
+		open->filename = NULL;
 		return -EINVAL;
+	}
 
 	open->nofile = rlimit(RLIMIT_NOFILE);
 	req->flags |= REQ_F_NEED_CLEANUP;

base-commit: b927546677c876e26eba308550207c2ddf812a43
-- 
2.34.1

Re: [syzbot] [fs?] memory leak in getname_flags

Posted by syzbot 1 month, 2 weeks ago

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-by: syzbot+00e61c43eb5e4740438f@syzkaller.appspotmail.com
Tested-by: syzbot+00e61c43eb5e4740438f@syzkaller.appspotmail.com

Tested on:

commit:         b9275466 Merge tag 'dma-mapping-6.19-2025-12-22' of gi..
git tree:       git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
console output: https://syzkaller.appspot.com/x/log.txt?x=170e209a580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=d60836e327fd6756
dashboard link: https://syzkaller.appspot.com/bug?extid=00e61c43eb5e4740438f
compiler:       gcc (Debian 12.2.0-14+deb12u1) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
patch:          https://syzkaller.appspot.com/x/patch.diff?x=11e790fc580000

Note: testing is done by a robot and is best-effort only.