FAILED: patch "[PATCH] ksmbd: return end of file for reads past a named stream's" failed to apply to 5.15-stable tree

[<gregkh@linuxfoundation.org>]

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>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y
git checkout FETCH_HEAD
git cherry-pick -x 626611dc22a3b63b3264a7a797d9dbc530234fcd
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026110335-embattled-grievance-334f@gregkh' --subject-prefix 'PATCH 5.15.y' 'HEAD^..'

Possible dependencies:



thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 626611dc22a3b63b3264a7a797d9dbc530234fcd Mon Sep 17 00:00:00 2001
From: DaeMyung Kang <charsyam@gmail.com>
Date: Fri, 9 Oct 2026 00:25:35 +0900
Subject: [PATCH] ksmbd: return end of file for reads past a named stream's
 data

A READ on a non-empty named stream at or beyond its end fails with
STATUS_INVALID_PARAMETER. ksmbd_vfs_stream_read() returns -EINVAL when
the offset is not below the stream length, and smb2_read() maps -EINVAL
to that status.

smb2_read() already turns a zero-byte read into STATUS_END_OF_FILE, the
status a regular file returns at its end, and an empty stream already
takes that path. Return 0 instead of -EINVAL so that non-empty streams
do the same. Clients that read a stream until end of file otherwise get
an error once they have read all of its data.

The buffered copychunk path converts a zero-byte source read to -EIO,
as it does for a regular file that shrinks during copying.

Fixes: 2ae1a6cc4302 ("cifsd: fix potential read overflow in ksmbd_vfs_stream_read()")
Cc: stable@vger.kernel.org
Signed-off-by: DaeMyung Kang <charsyam@gmail.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>

diff --git a/fs/smb/server/vfs.c b/fs/smb/server/vfs.c
index a6230ed64e11..02ee73d8d631 100644
--- a/fs/smb/server/vfs.c
+++ b/fs/smb/server/vfs.c
@@ -270,7 +270,7 @@ static int ksmbd_vfs_stream_read(struct ksmbd_file *fp, char *buf, loff_t *pos,
 		return (int)v_len;
 
 	if (v_len <= *pos) {
-		count = -EINVAL;
+		count = 0;
 		goto free_buf;
 	}