From 7a33488705008b5bb5f8d95d05326dcc64fc55f4 Mon Sep 17 00:00:00 2001 From: Ralph Boehme Date: Fri, 15 Oct 2021 12:52:58 +0900 Subject: [PATCH] ksmbd: validate credit charge after validating SMB2 PDU body size smb2_validate_credit_charge() accesses fields in the SMB2 PDU body, but until smb2_calc_size() is called the PDU has not yet been verified to be large enough to access the PDU dynamic part length field. Acked-by: Namjae Jeon Signed-off-by: Ralph Boehme Signed-off-by: Steve French --- fs/ksmbd/smb2misc.c | 19 ++++++++++--------- 1 file changed, 10 insertions(+), 9 deletions(-) diff --git a/fs/ksmbd/smb2misc.c b/fs/ksmbd/smb2misc.c index e7e441c8f050db..030ca57c378498 100644 --- a/fs/ksmbd/smb2misc.c +++ b/fs/ksmbd/smb2misc.c @@ -400,26 +400,20 @@ int ksmbd_smb2_check_message(struct ksmbd_work *work) } } - if ((work->conn->vals->capabilities & SMB2_GLOBAL_CAP_LARGE_MTU) && - smb2_validate_credit_charge(work->conn, hdr)) { - work->conn->ops->set_rsp_status(work, STATUS_INVALID_PARAMETER); - return 1; - } - if (smb2_calc_size(hdr, &clc_len)) return 1; if (len != clc_len) { /* client can return one byte more due to implied bcc[0] */ if (clc_len == len + 1) - return 0; + goto validate_credit; /* * Some windows servers (win2016) will pad also the final * PDU in a compound to 8 bytes. */ if (ALIGN(clc_len, 8) == len) - return 0; + goto validate_credit; /* * windows client also pad up to 8 bytes when compounding. @@ -432,7 +426,7 @@ int ksmbd_smb2_check_message(struct ksmbd_work *work) "cli req padded more than expected. Length %d not %d for cmd:%d mid:%llu\n", len, clc_len, command, le64_to_cpu(hdr->MessageId)); - return 0; + goto validate_credit; } ksmbd_debug(SMB, @@ -443,6 +437,13 @@ int ksmbd_smb2_check_message(struct ksmbd_work *work) return 1; } +validate_credit: + if ((work->conn->vals->capabilities & SMB2_GLOBAL_CAP_LARGE_MTU) && + smb2_validate_credit_charge(work->conn, hdr)) { + work->conn->ops->set_rsp_status(work, STATUS_INVALID_PARAMETER); + return 1; + } + return 0; }