From f1a411873c85b642f13b01f21b534c2bab81fc1b Mon Sep 17 00:00:00 2001 From: Namjae Jeon Date: Sun, 28 May 2023 00:23:09 +0900 Subject: ksmbd: fix out-of-bound read in deassemble_neg_contexts() The check in the beginning is `clen + sizeof(struct smb2_neg_context) <= len_of_ctxts`, but in the end of loop, `len_of_ctxts` will subtract `((clen + 7) & ~0x7) + sizeof(struct smb2_neg_context)`, which causes integer underflow when clen does the 8 alignment. We should use `(clen + 7) & ~0x7` in the check to avoid underflow from happening. Then there are some variables that need to be declared unsigned instead of signed. [ 11.671070] BUG: KASAN: slab-out-of-bounds in smb2_handle_negotiate+0x799/0x1610 [ 11.671533] Read of size 2 at addr ffff888005e86cf2 by task kworker/0:0/7 ... [ 11.673383] Call Trace: [ 11.673541] [ 11.673679] dump_stack_lvl+0x33/0x50 [ 11.673913] print_report+0xcc/0x620 [ 11.674671] kasan_report+0xae/0xe0 [ 11.675171] kasan_check_range+0x35/0x1b0 [ 11.675412] smb2_handle_negotiate+0x799/0x1610 [ 11.676217] ksmbd_smb_negotiate_common+0x526/0x770 [ 11.676795] handle_ksmbd_work+0x274/0x810 ... Cc: stable@vger.kernel.org Signed-off-by: Chih-Yen Chang Tested-by: Chih-Yen Chang Signed-off-by: Namjae Jeon Signed-off-by: Steve French --- fs/smb/server/smb2pdu.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) (limited to 'fs') diff --git a/fs/smb/server/smb2pdu.c b/fs/smb/server/smb2pdu.c index 7a81541de602..25c0ba04c59d 100644 --- a/fs/smb/server/smb2pdu.c +++ b/fs/smb/server/smb2pdu.c @@ -963,13 +963,13 @@ static void decode_sign_cap_ctxt(struct ksmbd_conn *conn, static __le32 deassemble_neg_contexts(struct ksmbd_conn *conn, struct smb2_negotiate_req *req, - int len_of_smb) + unsigned int len_of_smb) { /* +4 is to account for the RFC1001 len field */ struct smb2_neg_context *pctx = (struct smb2_neg_context *)req; int i = 0, len_of_ctxts; - int offset = le32_to_cpu(req->NegotiateContextOffset); - int neg_ctxt_cnt = le16_to_cpu(req->NegotiateContextCount); + unsigned int offset = le32_to_cpu(req->NegotiateContextOffset); + unsigned int neg_ctxt_cnt = le16_to_cpu(req->NegotiateContextCount); __le32 status = STATUS_INVALID_PARAMETER; ksmbd_debug(SMB, "decoding %d negotiate contexts\n", neg_ctxt_cnt); @@ -983,7 +983,7 @@ static __le32 deassemble_neg_contexts(struct ksmbd_conn *conn, while (i++ < neg_ctxt_cnt) { int clen, ctxt_len; - if (len_of_ctxts < sizeof(struct smb2_neg_context)) + if (len_of_ctxts < (int)sizeof(struct smb2_neg_context)) break; pctx = (struct smb2_neg_context *)((char *)pctx + offset); @@ -1038,9 +1038,8 @@ static __le32 deassemble_neg_contexts(struct ksmbd_conn *conn, } /* offsets must be 8 byte aligned */ - clen = (clen + 7) & ~0x7; - offset = clen + sizeof(struct smb2_neg_context); - len_of_ctxts -= clen + sizeof(struct smb2_neg_context); + offset = (ctxt_len + 7) & ~0x7; + len_of_ctxts -= offset; } return status; } -- cgit v1.2.3 From fc6c6a3c324c1b3e93a03d0cfa3749c781f23de0 Mon Sep 17 00:00:00 2001 From: Namjae Jeon Date: Sun, 28 May 2023 00:23:41 +0900 Subject: ksmbd: fix out-of-bound read in parse_lease_state() This bug is in parse_lease_state, and it is caused by the missing check of `struct create_context`. When the ksmbd traverses the create_contexts, it doesn't check if the field of `NameOffset` and `Next` is valid, The KASAN message is following: [ 6.664323] BUG: KASAN: slab-out-of-bounds in parse_lease_state+0x7d/0x280 [ 6.664738] Read of size 2 at addr ffff888005c08988 by task kworker/0:3/103 ... [ 6.666644] Call Trace: [ 6.666796] [ 6.666933] dump_stack_lvl+0x33/0x50 [ 6.667167] print_report+0xcc/0x620 [ 6.667903] kasan_report+0xae/0xe0 [ 6.668374] kasan_check_range+0x35/0x1b0 [ 6.668621] parse_lease_state+0x7d/0x280 [ 6.668868] smb2_open+0xbe8/0x4420 [ 6.675137] handle_ksmbd_work+0x282/0x820 Use smb2_find_context_vals() to find smb2 create request lease context. smb2_find_context_vals validate create context fields. Cc: stable@vger.kernel.org Reported-by: Chih-Yen Chang Tested-by: Chih-Yen Chang Signed-off-by: Namjae Jeon Signed-off-by: Steve French --- fs/smb/server/oplock.c | 66 ++++++++++++++++++-------------------------------- 1 file changed, 24 insertions(+), 42 deletions(-) (limited to 'fs') diff --git a/fs/smb/server/oplock.c b/fs/smb/server/oplock.c index db181bdad73a..844b303baf29 100644 --- a/fs/smb/server/oplock.c +++ b/fs/smb/server/oplock.c @@ -1415,56 +1415,38 @@ void create_lease_buf(u8 *rbuf, struct lease *lease) */ struct lease_ctx_info *parse_lease_state(void *open_req) { - char *data_offset; struct create_context *cc; - unsigned int next = 0; - char *name; - bool found = false; struct smb2_create_req *req = (struct smb2_create_req *)open_req; - struct lease_ctx_info *lreq = kzalloc(sizeof(struct lease_ctx_info), - GFP_KERNEL); + struct lease_ctx_info *lreq; + + cc = smb2_find_context_vals(req, SMB2_CREATE_REQUEST_LEASE, 4); + if (IS_ERR_OR_NULL(cc)) + return NULL; + + lreq = kzalloc(sizeof(struct lease_ctx_info), GFP_KERNEL); if (!lreq) return NULL; - data_offset = (char *)req + le32_to_cpu(req->CreateContextsOffset); - cc = (struct create_context *)data_offset; - do { - cc = (struct create_context *)((char *)cc + next); - name = le16_to_cpu(cc->NameOffset) + (char *)cc; - if (le16_to_cpu(cc->NameLength) != 4 || - strncmp(name, SMB2_CREATE_REQUEST_LEASE, 4)) { - next = le32_to_cpu(cc->Next); - continue; - } - found = true; - break; - } while (next != 0); + if (sizeof(struct lease_context_v2) == le32_to_cpu(cc->DataLength)) { + struct create_lease_v2 *lc = (struct create_lease_v2 *)cc; - if (found) { - if (sizeof(struct lease_context_v2) == le32_to_cpu(cc->DataLength)) { - struct create_lease_v2 *lc = (struct create_lease_v2 *)cc; - - memcpy(lreq->lease_key, lc->lcontext.LeaseKey, SMB2_LEASE_KEY_SIZE); - lreq->req_state = lc->lcontext.LeaseState; - lreq->flags = lc->lcontext.LeaseFlags; - lreq->duration = lc->lcontext.LeaseDuration; - memcpy(lreq->parent_lease_key, lc->lcontext.ParentLeaseKey, - SMB2_LEASE_KEY_SIZE); - lreq->version = 2; - } else { - struct create_lease *lc = (struct create_lease *)cc; + memcpy(lreq->lease_key, lc->lcontext.LeaseKey, SMB2_LEASE_KEY_SIZE); + lreq->req_state = lc->lcontext.LeaseState; + lreq->flags = lc->lcontext.LeaseFlags; + lreq->duration = lc->lcontext.LeaseDuration; + memcpy(lreq->parent_lease_key, lc->lcontext.ParentLeaseKey, + SMB2_LEASE_KEY_SIZE); + lreq->version = 2; + } else { + struct create_lease *lc = (struct create_lease *)cc; - memcpy(lreq->lease_key, lc->lcontext.LeaseKey, SMB2_LEASE_KEY_SIZE); - lreq->req_state = lc->lcontext.LeaseState; - lreq->flags = lc->lcontext.LeaseFlags; - lreq->duration = lc->lcontext.LeaseDuration; - lreq->version = 1; - } - return lreq; + memcpy(lreq->lease_key, lc->lcontext.LeaseKey, SMB2_LEASE_KEY_SIZE); + lreq->req_state = lc->lcontext.LeaseState; + lreq->flags = lc->lcontext.LeaseFlags; + lreq->duration = lc->lcontext.LeaseDuration; + lreq->version = 1; } - - kfree(lreq); - return NULL; + return lreq; } /** -- cgit v1.2.3 From 25933573ef48f3586f559c2cac6c436c62dcf63f Mon Sep 17 00:00:00 2001 From: Namjae Jeon Date: Tue, 30 May 2023 21:42:34 +0900 Subject: ksmbd: fix posix_acls and acls dereferencing possible ERR_PTR() Dan reported the following error message: fs/smb/server/smbacl.c:1296 smb_check_perm_dacl() error: 'posix_acls' dereferencing possible ERR_PTR() fs/smb/server/vfs.c:1323 ksmbd_vfs_make_xattr_posix_acl() error: 'posix_acls' dereferencing possible ERR_PTR() fs/smb/server/vfs.c:1830 ksmbd_vfs_inherit_posix_acl() error: 'acls' dereferencing possible ERR_PTR() __get_acl() returns a mix of error pointers and NULL. This change it with IS_ERR_OR_NULL(). Fixes: e2f34481b24d ("cifsd: add server-side procedures for SMB3") Cc: stable@vger.kernel.org Reported-by: Dan Carpenter Signed-off-by: Namjae Jeon Signed-off-by: Steve French --- fs/smb/server/smbacl.c | 4 ++-- fs/smb/server/vfs.c | 4 ++-- 2 files changed, 4 insertions(+), 4 deletions(-) (limited to 'fs') diff --git a/fs/smb/server/smbacl.c b/fs/smb/server/smbacl.c index 6d6cfb6957a9..0a5862a61c77 100644 --- a/fs/smb/server/smbacl.c +++ b/fs/smb/server/smbacl.c @@ -1290,7 +1290,7 @@ int smb_check_perm_dacl(struct ksmbd_conn *conn, const struct path *path, if (IS_ENABLED(CONFIG_FS_POSIX_ACL)) { posix_acls = get_inode_acl(d_inode(path->dentry), ACL_TYPE_ACCESS); - if (posix_acls && !found) { + if (!IS_ERR_OR_NULL(posix_acls) && !found) { unsigned int id = -1; pa_entry = posix_acls->a_entries; @@ -1314,7 +1314,7 @@ int smb_check_perm_dacl(struct ksmbd_conn *conn, const struct path *path, } } } - if (posix_acls) + if (!IS_ERR_OR_NULL(posix_acls)) posix_acl_release(posix_acls); } diff --git a/fs/smb/server/vfs.c b/fs/smb/server/vfs.c index 6f302919e9f7..f9fb778247e7 100644 --- a/fs/smb/server/vfs.c +++ b/fs/smb/server/vfs.c @@ -1321,7 +1321,7 @@ static struct xattr_smb_acl *ksmbd_vfs_make_xattr_posix_acl(struct mnt_idmap *id return NULL; posix_acls = get_inode_acl(inode, acl_type); - if (!posix_acls) + if (IS_ERR_OR_NULL(posix_acls)) return NULL; smb_acl = kzalloc(sizeof(struct xattr_smb_acl) + @@ -1830,7 +1830,7 @@ int ksmbd_vfs_inherit_posix_acl(struct mnt_idmap *idmap, return -EOPNOTSUPP; acls = get_inode_acl(parent_inode, ACL_TYPE_DEFAULT); - if (!acls) + if (IS_ERR_OR_NULL(acls)) return -ENOENT; pace = acls->a_entries; -- cgit v1.2.3 From 368ba06881c395f1c9a7ba22203cf8d78b4addc0 Mon Sep 17 00:00:00 2001 From: Namjae Jeon Date: Tue, 30 May 2023 23:10:31 +0900 Subject: ksmbd: check the validation of pdu_size in ksmbd_conn_handler_loop The length field of netbios header must be greater than the SMB header sizes(smb1 or smb2 header), otherwise the packet is an invalid SMB packet. If `pdu_size` is 0, ksmbd allocates a 4 bytes chunk to `conn->request_buf`. In the function `get_smb2_cmd_val` ksmbd will read cmd from `rcv_hdr->Command`, which is `conn->request_buf + 12`, causing the KASAN detector to print the following error message: [ 7.205018] BUG: KASAN: slab-out-of-bounds in get_smb2_cmd_val+0x45/0x60 [ 7.205423] Read of size 2 at addr ffff8880062d8b50 by task ksmbd:42632/248 ... [ 7.207125] [ 7.209191] get_smb2_cmd_val+0x45/0x60 [ 7.209426] ksmbd_conn_enqueue_request+0x3a/0x100 [ 7.209712] ksmbd_server_process_request+0x72/0x160 [ 7.210295] ksmbd_conn_handler_loop+0x30c/0x550 [ 7.212280] kthread+0x160/0x190 [ 7.212762] ret_from_fork+0x1f/0x30 [ 7.212981] Cc: stable@vger.kernel.org Reported-by: Chih-Yen Chang Signed-off-by: Namjae Jeon Signed-off-by: Steve French --- fs/smb/server/connection.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) (limited to 'fs') diff --git a/fs/smb/server/connection.c b/fs/smb/server/connection.c index 4882a812ea86..e11d4a1e63d7 100644 --- a/fs/smb/server/connection.c +++ b/fs/smb/server/connection.c @@ -294,6 +294,9 @@ bool ksmbd_conn_alive(struct ksmbd_conn *conn) return true; } +#define SMB1_MIN_SUPPORTED_HEADER_SIZE (sizeof(struct smb_hdr)) +#define SMB2_MIN_SUPPORTED_HEADER_SIZE (sizeof(struct smb2_hdr) + 4) + /** * ksmbd_conn_handler_loop() - session thread to listen on new smb requests * @p: connection instance @@ -350,6 +353,9 @@ int ksmbd_conn_handler_loop(void *p) if (pdu_size > MAX_STREAM_PROT_LEN) break; + if (pdu_size < SMB1_MIN_SUPPORTED_HEADER_SIZE) + break; + /* 4 for rfc1002 length field */ /* 1 for implied bcc[0] */ size = pdu_size + 4 + 1; @@ -377,6 +383,12 @@ int ksmbd_conn_handler_loop(void *p) continue; } + if (((struct smb2_hdr *)smb2_get_msg(conn->request_buf))->ProtocolId == + SMB2_PROTO_NUMBER) { + if (pdu_size < SMB2_MIN_SUPPORTED_HEADER_SIZE) + break; + } + if (!default_conn_ops.process_fn) { pr_err("No connection request callback\n"); break; -- cgit v1.2.3 From 1c1bcf2d3ea061613119b534f57507c377df20f9 Mon Sep 17 00:00:00 2001 From: Namjae Jeon Date: Wed, 31 May 2023 17:59:32 +0900 Subject: ksmbd: validate smb request protocol id This patch add the validation for smb request protocol id. If it is not one of the four ids(SMB1_PROTO_NUMBER, SMB2_PROTO_NUMBER, SMB2_TRANSFORM_PROTO_NUM, SMB2_COMPRESSION_TRANSFORM_ID), don't allow processing the request. And this will fix the following KASAN warning also. [ 13.905265] BUG: KASAN: slab-out-of-bounds in init_smb2_rsp_hdr+0x1b9/0x1f0 [ 13.905900] Read of size 16 at addr ffff888005fd2f34 by task kworker/0:2/44 ... [ 13.908553] Call Trace: [ 13.908793] [ 13.908995] dump_stack_lvl+0x33/0x50 [ 13.909369] print_report+0xcc/0x620 [ 13.910870] kasan_report+0xae/0xe0 [ 13.911519] kasan_check_range+0x35/0x1b0 [ 13.911796] init_smb2_rsp_hdr+0x1b9/0x1f0 [ 13.912492] handle_ksmbd_work+0xe5/0x820 Cc: stable@vger.kernel.org Reported-by: Chih-Yen Chang Signed-off-by: Namjae Jeon Signed-off-by: Steve French --- fs/smb/server/connection.c | 5 +++-- fs/smb/server/smb_common.c | 14 +++++++++++++- 2 files changed, 16 insertions(+), 3 deletions(-) (limited to 'fs') diff --git a/fs/smb/server/connection.c b/fs/smb/server/connection.c index e11d4a1e63d7..2a717d158f02 100644 --- a/fs/smb/server/connection.c +++ b/fs/smb/server/connection.c @@ -364,8 +364,6 @@ int ksmbd_conn_handler_loop(void *p) break; memcpy(conn->request_buf, hdr_buf, sizeof(hdr_buf)); - if (!ksmbd_smb_request(conn)) - break; /* * We already read 4 bytes to find out PDU size, now @@ -383,6 +381,9 @@ int ksmbd_conn_handler_loop(void *p) continue; } + if (!ksmbd_smb_request(conn)) + break; + if (((struct smb2_hdr *)smb2_get_msg(conn->request_buf))->ProtocolId == SMB2_PROTO_NUMBER) { if (pdu_size < SMB2_MIN_SUPPORTED_HEADER_SIZE) diff --git a/fs/smb/server/smb_common.c b/fs/smb/server/smb_common.c index af0c2a9b8529..569e5eecdf3d 100644 --- a/fs/smb/server/smb_common.c +++ b/fs/smb/server/smb_common.c @@ -158,7 +158,19 @@ int ksmbd_verify_smb_message(struct ksmbd_work *work) */ bool ksmbd_smb_request(struct ksmbd_conn *conn) { - return conn->request_buf[0] == 0; + __le32 *proto = (__le32 *)smb2_get_msg(conn->request_buf); + + if (*proto == SMB2_COMPRESSION_TRANSFORM_ID) { + pr_err_ratelimited("smb2 compression not support yet"); + return false; + } + + if (*proto != SMB1_PROTO_NUMBER && + *proto != SMB2_PROTO_NUMBER && + *proto != SMB2_TRANSFORM_PROTO_NUM) + return false; + + return true; } static bool supported_protocol(int idx) -- cgit v1.2.3