| Message ID | 20210924021254.27096-8-linkinjeon@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | a bunch of patches that have not yet been reviewed | expand |
I found null dereferencing kenel oops while testing and updated this patch. Please review the below patch, thanks! From 85e1ce56bb0c37e8ea2083cd0e62e160f2bf6677 Mon Sep 17 00:00:00 2001 From: Namjae Jeon <linkinjeon@kernel.org> Date: Fri, 24 Sep 2021 13:07:17 +0900 Subject: [PATCH] ksmbd: add validation in smb2 negotiate This patch add validation to check request buffer check in smb2 negotiate and fix null pointer dereferencing oops in smb3_preauth_hash_rsp() that found from manual test. Signed-off-by: Namjae Jeon <linkinjeon@kernel.org> --- fs/ksmbd/smb2pdu.c | 42 +++++++++++++++++++++++++++++++++++++++++- fs/ksmbd/smb_common.c | 22 ++++++++++++++++++++-- 2 files changed, 61 insertions(+), 3 deletions(-) diff --git a/fs/ksmbd/smb2pdu.c b/fs/ksmbd/smb2pdu.c index 4c7e7aaba525..9eb8b86ddb27 100644 --- a/fs/ksmbd/smb2pdu.c +++ b/fs/ksmbd/smb2pdu.c @@ -1081,6 +1081,7 @@ int smb2_handle_negotiate(struct ksmbd_work *work) struct smb2_negotiate_req *req = work->request_buf; struct smb2_negotiate_rsp *rsp = work->response_buf; int rc = 0; + unsigned int smb2_buf_len, smb2_neg_size; __le32 status; ksmbd_debug(SMB, "Received negotiate request\n"); @@ -1098,6 +1099,44 @@ int smb2_handle_negotiate(struct ksmbd_work *work) goto err_out; } + smb2_buf_len = get_rfc1002_len(work->request_buf); + smb2_neg_size = offsetof(struct smb2_negotiate_req, Dialects) - 4; + if (conn->dialect == SMB311_PROT_ID) { + unsigned int nego_ctxt_off = le32_to_cpu(req->NegotiateContextOffset); + + if (smb2_buf_len < nego_ctxt_off) { + rsp->hdr.Status = STATUS_INVALID_PARAMETER; + rc = -EINVAL; + goto err_out; + } + + if (smb2_neg_size > nego_ctxt_off) { + rsp->hdr.Status = STATUS_INVALID_PARAMETER; + rc = -EINVAL; + goto err_out; + } + + if (smb2_neg_size + le16_to_cpu(req->DialectCount) * sizeof(__le16) > + nego_ctxt_off) { + rsp->hdr.Status = STATUS_INVALID_PARAMETER; + rc = -EINVAL; + goto err_out; + } + } else { + if (smb2_neg_size > smb2_buf_len) { + rsp->hdr.Status = STATUS_INVALID_PARAMETER; + rc = -EINVAL; + goto err_out; + } + + if (smb2_neg_size + le16_to_cpu(req->DialectCount) * sizeof(__le16) > + smb2_buf_len) { + rsp->hdr.Status = STATUS_INVALID_PARAMETER; + rc = -EINVAL; + goto err_out; + } + } + conn->cli_cap = le32_to_cpu(req->Capabilities); switch (conn->dialect) { case SMB311_PROT_ID: @@ -8335,7 +8374,8 @@ void smb3_preauth_hash_rsp(struct ksmbd_work *work) WORK_BUFFERS(work, req, rsp); - if (le16_to_cpu(req->Command) == SMB2_NEGOTIATE_HE) + if (le16_to_cpu(req->Command) == SMB2_NEGOTIATE_HE && + conn->preauth_info) ksmbd_gen_preauth_integrity_hash(conn, (char *)rsp, conn->preauth_info->Preauth_HashValue); diff --git a/fs/ksmbd/smb_common.c b/fs/ksmbd/smb_common.c index 20bd5b8e3c0a..85937d497dcb 100644 --- a/fs/ksmbd/smb_common.c +++ b/fs/ksmbd/smb_common.c @@ -234,13 +234,22 @@ int ksmbd_lookup_dialect_by_id(__le16 *cli_dialects, __le16 dialects_count) static int ksmbd_negotiate_smb_dialect(void *buf) { - __le32 proto; + int smb_buf_length = get_rfc1002_len(buf); + __le32 proto = ((struct smb2_hdr *)buf)->ProtocolId; - proto = ((struct smb2_hdr *)buf)->ProtocolId; if (proto == SMB2_PROTO_NUMBER) { struct smb2_negotiate_req *req; + int smb2_neg_size = + offsetof(struct smb2_negotiate_req, Dialects) - 4; req = (struct smb2_negotiate_req *)buf; + if (smb2_neg_size > smb_buf_length) + goto err_out; + + if (smb2_neg_size + le16_to_cpu(req->DialectCount) * sizeof(__le16) > + smb_buf_length) + goto err_out; + return ksmbd_lookup_dialect_by_id(req->Dialects, req->DialectCount); } @@ -250,10 +259,19 @@ static int ksmbd_negotiate_smb_dialect(void *buf) struct smb_negotiate_req *req; req = (struct smb_negotiate_req *)buf; + if (le16_to_cpu(req->ByteCount) < 2) + goto err_out; + + if (offsetof(struct smb_negotiate_req, DialectsArray) - 4 + + le16_to_cpu(req->ByteCount) > smb_buf_length) { + goto err_out; + } + return ksmbd_lookup_dialect_by_name(req->DialectsArray, req->ByteCount); } +err_out: return BAD_PROT_ID; }
diff --git a/fs/ksmbd/smb2pdu.c b/fs/ksmbd/smb2pdu.c index 4f7b5e18a7b9..9f45779c5f95 100644 --- a/fs/ksmbd/smb2pdu.c +++ b/fs/ksmbd/smb2pdu.c @@ -1081,6 +1081,7 @@ int smb2_handle_negotiate(struct ksmbd_work *work) struct smb2_negotiate_req *req = work->request_buf; struct smb2_negotiate_rsp *rsp = work->response_buf; int rc = 0; + unsigned int smb2_buf_len, smb2_neg_size; __le32 status; ksmbd_debug(SMB, "Received negotiate request\n"); @@ -1098,6 +1099,44 @@ int smb2_handle_negotiate(struct ksmbd_work *work) goto err_out; } + smb2_buf_len = get_rfc1002_len(work->request_buf); + smb2_neg_size = offsetof(struct smb2_negotiate_req, Dialects) - 4; + if (conn->dialect == SMB311_PROT_ID) { + unsigned int nego_ctxt_off = le32_to_cpu(req->NegotiateContextOffset); + + if (smb2_buf_len < nego_ctxt_off) { + rsp->hdr.Status = STATUS_INVALID_PARAMETER; + rc = -EINVAL; + goto err_out; + } + + if (smb2_neg_size > nego_ctxt_off) { + rsp->hdr.Status = STATUS_INVALID_PARAMETER; + rc = -EINVAL; + goto err_out; + } + + if (smb2_neg_size + le16_to_cpu(req->DialectCount) * sizeof(__le16) > + nego_ctxt_off) { + rsp->hdr.Status = STATUS_INVALID_PARAMETER; + rc = -EINVAL; + goto err_out; + } + } else { + if (smb2_neg_size > smb2_buf_len) { + rsp->hdr.Status = STATUS_INVALID_PARAMETER; + rc = -EINVAL; + goto err_out; + } + + if (smb2_neg_size + le16_to_cpu(req->DialectCount) * sizeof(__le16) > + smb2_buf_len) { + rsp->hdr.Status = STATUS_INVALID_PARAMETER; + rc = -EINVAL; + goto err_out; + } + } + conn->cli_cap = le32_to_cpu(req->Capabilities); switch (conn->dialect) { case SMB311_PROT_ID: diff --git a/fs/ksmbd/smb_common.c b/fs/ksmbd/smb_common.c index 20bd5b8e3c0a..85937d497dcb 100644 --- a/fs/ksmbd/smb_common.c +++ b/fs/ksmbd/smb_common.c @@ -234,13 +234,22 @@ int ksmbd_lookup_dialect_by_id(__le16 *cli_dialects, __le16 dialects_count) static int ksmbd_negotiate_smb_dialect(void *buf) { - __le32 proto; + int smb_buf_length = get_rfc1002_len(buf); + __le32 proto = ((struct smb2_hdr *)buf)->ProtocolId; - proto = ((struct smb2_hdr *)buf)->ProtocolId; if (proto == SMB2_PROTO_NUMBER) { struct smb2_negotiate_req *req; + int smb2_neg_size = + offsetof(struct smb2_negotiate_req, Dialects) - 4; req = (struct smb2_negotiate_req *)buf; + if (smb2_neg_size > smb_buf_length) + goto err_out; + + if (smb2_neg_size + le16_to_cpu(req->DialectCount) * sizeof(__le16) > + smb_buf_length) + goto err_out; + return ksmbd_lookup_dialect_by_id(req->Dialects, req->DialectCount); } @@ -250,10 +259,19 @@ static int ksmbd_negotiate_smb_dialect(void *buf) struct smb_negotiate_req *req; req = (struct smb_negotiate_req *)buf; + if (le16_to_cpu(req->ByteCount) < 2) + goto err_out; + + if (offsetof(struct smb_negotiate_req, DialectsArray) - 4 + + le16_to_cpu(req->ByteCount) > smb_buf_length) { + goto err_out; + } + return ksmbd_lookup_dialect_by_name(req->DialectsArray, req->ByteCount); } +err_out: return BAD_PROT_ID; }
This patch add validation to check request buffer check in smb2 negotiate. Cc: Tom Talpey <tom@talpey.com> Cc: Ronnie Sahlberg <ronniesahlberg@gmail.com> Cc: Ralph Böhme <slow@samba.org> Cc: Steve French <smfrench@gmail.com> Cc: Hyunchul Lee <hyc.lee@gmail.com> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org> --- fs/ksmbd/smb2pdu.c | 39 +++++++++++++++++++++++++++++++++++++++ fs/ksmbd/smb_common.c | 22 ++++++++++++++++++++-- 2 files changed, 59 insertions(+), 2 deletions(-)