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[v6.1,1/2] ksmbd: fix slab-out-of-bounds in smb_strndup_from_utf16()

Message ID 20241115083240.230361-2-vamsi-krishna.brahmajosyula@broadcom.com
State New
Headers show
Series ksmbd: fix potencial out-of-bounds when buffer offset is invalid | expand

Commit Message

Vamsi Krishna Brahmajosyula Nov. 15, 2024, 8:32 a.m. UTC 
From: Namjae Jeon <linkinjeon@kernel.org>

[ Upstream commit a80a486d72e20bd12c335bcd38b6e6f19356b0aa ]

If ->NameOffset of smb2_create_req is smaller than Buffer offset of
smb2_create_req, slab-out-of-bounds read can happen from smb2_open.
This patch set the minimum value of the name offset to the buffer offset
to validate name length of smb2_create_req().

Cc: stable@vger.kernel.org
Reported-by: Xuanzhe Yu <yuxuanzhe@outlook.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Stable-dep-of: c6cd2e8d2d9a ("ksmbd: fix potencial out-of-bounds when buffer offset is invalid")
Signed-off-by: Vamsi Krishna Brahmajosyula <vamsi-krishna.brahmajosyula@broadcom.com>
---
 fs/smb/server/smb2misc.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/fs/smb/server/smb2misc.c b/fs/smb/server/smb2misc.c
index 03dded29a980..7c872ffb4b0a 100644
--- a/fs/smb/server/smb2misc.c
+++ b/fs/smb/server/smb2misc.c
@@ -107,7 +107,10 @@  static int smb2_get_data_area_len(unsigned int *off, unsigned int *len,
 	case SMB2_CREATE:
 	{
 		unsigned short int name_off =
-			le16_to_cpu(((struct smb2_create_req *)hdr)->NameOffset);
+			max_t(unsigned short int,
+			      le16_to_cpu(((struct smb2_create_req *)hdr)->NameOffset),
+			      offsetof(struct smb2_create_req, Buffer));
+
 		unsigned short int name_len =
 			le16_to_cpu(((struct smb2_create_req *)hdr)->NameLength);