From a80a486d72e20bd12c335bcd38b6e6f19356b0aa Mon Sep 17 00:00:00 2001 From: Namjae Jeon Date: Sat, 16 Mar 2024 23:36:36 +0900 Subject: ksmbd: fix slab-out-of-bounds in smb_strndup_from_utf16() 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 Signed-off-by: Namjae Jeon Signed-off-by: Steve French --- fs/smb/server/smb2misc.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'fs/smb') 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); -- cgit v1.2.3