From: Namjae Jeon <linkinjeon@xxxxxxxxxx> commit a80a486d72e20bd12c335bcd38b6e6f19356b0aa upstream. 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@xxxxxxxxxxxxxxx Reported-by: Xuanzhe Yu <yuxuanzhe@xxxxxxxxxxx> Signed-off-by: Namjae Jeon <linkinjeon@xxxxxxxxxx> Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx> Stable-dep-of: c6cd2e8d2d9a ("ksmbd: fix potencial out-of-bounds when buffer offset is invalid") Signed-off-by: Vamsi Krishna Brahmajosyula <vamsi-krishna.brahmajosyula@xxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/smb/server/smb2misc.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) --- a/fs/smb/server/smb2misc.c +++ b/fs/smb/server/smb2misc.c @@ -107,7 +107,10 @@ static int smb2_get_data_area_len(unsign 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); Patches currently in stable-queue which might be from linkinjeon@xxxxxxxxxx are queue-6.1/ksmbd-fix-potencial-out-of-bounds-when-buffer-offset-is-invalid.patch queue-6.1/ksmbd-fix-slab-out-of-bounds-in-smb_strndup_from_utf16.patch