From: Namjae Jeon <linkinjeon@kernel.org>
Date: Sun, 5 Mar 2023 12:04:00 +0000 (+0900)
Subject: ksmbd: add low bound validation to FSCTL_SET_ZERO_DATA
X-Git-Tag: v6.2.9~154
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=bb4aeb8b3f95f499d7f7e19bfb8241e79eb8f5f6;p=thirdparty%2Fkernel%2Fstable.git

ksmbd: add low bound validation to FSCTL_SET_ZERO_DATA

[ Upstream commit 2d74ec97131b1179a373b6d521f195c84e894eb6 ]

Smatch static checker warning:
 fs/ksmbd/smb2pdu.c:7759 smb2_ioctl()
 warn: no lower bound on 'off'

Fix unexpected result that could caused from negative off and bfz.

Fixes: b5e5f9dfc915 ("ksmbd: check invalid FileOffset and BeyondFinalZero in FSCTL_ZERO_DATA")
Reported-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

diff --git a/fs/ksmbd/smb2pdu.c b/fs/ksmbd/smb2pdu.c
index 875eecc6b95e7..abe7ea1c8a2f5 100644
--- a/fs/ksmbd/smb2pdu.c
+++ b/fs/ksmbd/smb2pdu.c
@@ -7770,7 +7770,7 @@ int smb2_ioctl(struct ksmbd_work *work)
 
 		off = le64_to_cpu(zero_data->FileOffset);
 		bfz = le64_to_cpu(zero_data->BeyondFinalZero);
-		if (off > bfz) {
+		if (off < 0 || bfz < 0 || off > bfz) {
 			ret = -EINVAL;
 			goto out;
 		}