Re: FAILED: patch "[PATCH] io_uring: fix filename leak in __io_openat_prep()" failed to apply to 5.15-stable tree

[Jens Axboe <axboe@kernel.dk>]

[-- Attachment #1: Type: text/plain, Size: 408 bytes --]

On 12/29/25 4:34 AM, gregkh@linuxfoundation.org wrote:
> 
> The patch below does not apply to the 5.15-stable tree.
> If someone wants it applied there, or to any other stable or longterm
> tree, then please email the backport, including the original git commit
> id to <stable@vger.kernel.org>.

Here's one for 5.15-stable AND 5.10-stable. Please apply to both, as they
share the same base.

-- 
Jens Axboe

[-- Attachment #2: 0001-io_uring-fix-filename-leak-in-__io_openat_prep.patch --]
[-- Type: text/x-patch, Size: 1895 bytes --]

From 9ea6b9cb5285a1245845dedde05638005aba037b Mon Sep 17 00:00:00 2001
From: Prithvi Tambewagh <activprithvi@gmail.com>
Date: Thu, 25 Dec 2025 12:58:29 +0530
Subject: [PATCH] io_uring: fix filename leak in __io_openat_prep()

 __io_openat_prep() allocates a struct filename using getname(). However,
for the condition of the file being installed in the fixed file table as
well as having O_CLOEXEC flag set, the function returns early. At that
point, the request doesn't have REQ_F_NEED_CLEANUP flag set. Due to this,
the memory for the newly allocated struct filename is not cleaned up,
causing a memory leak.

Fix this by setting the REQ_F_NEED_CLEANUP for the request just after the
successful getname() call, so that when the request is torn down, the
filename will be cleaned up, along with other resources needing cleanup.

Reported-by: syzbot+00e61c43eb5e4740438f@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=00e61c43eb5e4740438f
Tested-by: syzbot+00e61c43eb5e4740438f@syzkaller.appspotmail.com
Cc: stable@vger.kernel.org
Signed-off-by: Prithvi Tambewagh <activprithvi@gmail.com>
Fixes: b9445598d8c6 ("io_uring: openat directly into fixed fd table")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
 io_uring/io_uring.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index 43dd54c576d6..e5889ec0273f 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -4326,13 +4326,13 @@ static int __io_openat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe
 		req->open.filename = NULL;
 		return ret;
 	}
+	req->flags |= REQ_F_NEED_CLEANUP;
 
 	req->open.file_slot = READ_ONCE(sqe->file_index);
 	if (req->open.file_slot && (req->open.how.flags & O_CLOEXEC))
 		return -EINVAL;
 
 	req->open.nofile = rlimit(RLIMIT_NOFILE);
-	req->flags |= REQ_F_NEED_CLEANUP;
 	return 0;
 }
 
-- 
2.51.0