[PATCH 6.18 145/430] ksmbd: fix buffer validation by including null terminator size in EA length

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

6.18-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Namjae Jeon <linkinjeon@kernel.org>

commit 95d7a890e4b03e198836d49d699408fd1867cb55 upstream.

The smb2_set_ea function, which handles Extended Attributes (EA),
was performing buffer validation checks that incorrectly omitted the size
of the null terminating character (+1 byte) for EA Name.
This patch fixes the issue by explicitly adding '+ 1' to EaNameLength where
the null terminator is expected to be present in the buffer, ensuring
the validation accurately reflects the total required buffer size.

Cc: stable@vger.kernel.org
Reported-by: Roger <roger.andersen@protonmail.com>
Reported-by: Stanislas Polu <spolu@dust.tt>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 fs/smb/server/smb2pdu.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/fs/smb/server/smb2pdu.c
+++ b/fs/smb/server/smb2pdu.c
@@ -2373,7 +2373,7 @@ static int smb2_set_ea(struct smb2_ea_in
 	int rc = 0;
 	unsigned int next = 0;
 
-	if (buf_len < sizeof(struct smb2_ea_info) + eabuf->EaNameLength +
+	if (buf_len < sizeof(struct smb2_ea_info) + eabuf->EaNameLength + 1 +
 			le16_to_cpu(eabuf->EaValueLength))
 		return -EINVAL;
 
@@ -2450,7 +2450,7 @@ next:
 			break;
 		}
 
-		if (buf_len < sizeof(struct smb2_ea_info) + eabuf->EaNameLength +
+		if (buf_len < sizeof(struct smb2_ea_info) + eabuf->EaNameLength + 1 +
 				le16_to_cpu(eabuf->EaValueLength)) {
 			rc = -EINVAL;
 			break;