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 --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);