From patchwork Thu Apr 6 18:24:07 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Sachin Prabhu X-Patchwork-Id: 9668031 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id B2A93602B8 for ; Thu, 6 Apr 2017 18:24:13 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id C4842285BD for ; Thu, 6 Apr 2017 18:24:13 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id B8F8A285CA; Thu, 6 Apr 2017 18:24:13 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, T_TVD_MIME_EPI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A6188285BD for ; Thu, 6 Apr 2017 18:24:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754797AbdDFSYM (ORCPT ); Thu, 6 Apr 2017 14:24:12 -0400 Received: from mx1.redhat.com ([209.132.183.28]:52924 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751972AbdDFSYL (ORCPT ); Thu, 6 Apr 2017 14:24:11 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 8A9C1A327D; Thu, 6 Apr 2017 18:24:10 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 8A9C1A327D Authentication-Results: ext-mx10.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx10.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=sprabhu@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com 8A9C1A327D Received: from ovpn-116-23.ams2.redhat.com (ovpn-116-23.ams2.redhat.com [10.36.116.23]) by smtp.corp.redhat.com (Postfix) with ESMTP id 142755C88B; Thu, 6 Apr 2017 18:24:08 +0000 (UTC) Message-ID: <1491503047.8010.2.camel@redhat.com> Subject: Re: [bug report] Handle mismatched open calls From: Sachin Prabhu To: Dan Carpenter Cc: linux-cifs@vger.kernel.org, smfrench In-Reply-To: <1491473227.3042.2.camel@redhat.com> References: <20170406091021.GA28584@mwanda> <1491473227.3042.2.camel@redhat.com> Date: Thu, 06 Apr 2017 19:24:07 +0100 Mime-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.39]); Thu, 06 Apr 2017 18:24:10 +0000 (UTC) Sender: linux-cifs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-cifs@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP On Thu, 2017-04-06 at 11:07 +0100, Sachin Prabhu wrote: > On Thu, 2017-04-06 at 12:11 +0300, Dan Carpenter wrote: > > Hello Sachin Prabhu, > > > > The patch 96b75d0508f8: "Handle mismatched open calls" from Mar 3, > > 2017, leads to the following static checker warning: > > > > fs/cifs/cifssmb.c:1530 cifs_readv_receive() > > error: potential NULL dereference 'server->smallbuf'. > > > > fs/cifs/cifssmb.c > >   1519          cifs_dbg(FYI, "0: iov_base=%p iov_len=%u\n", > >   1520                   rdata->iov[0].iov_base, server- > > >total_read); > >   1521   > >   1522          mid->resp_buf = server->smallbuf; > >   1523          server->smallbuf = NULL; > >                 ^^^^^^^^^^^^^^^^^^^^^^^ > > We set this to NULL here > > > >   1524   > >   1525          /* how much data is in the response? */ > >   1526          data_len = server->ops->read_data_length(buf); > >   1527          if (data_offset + data_len > buflen) { > >   1528                  /* data_len is corrupt -- discard frame */ > >   1529                  rdata->result = -EIO; > >   1530                  return cifs_readv_discard(server, mid); > >                                                   ^^^^^^ > > but we need it here. > > > >   1531          } > >   1532   > >   1533          length = rdata->read_into_pages(server, rdata, > > data_len); > >   1534          if (length < 0) > >   1535                  return length; > > > > regards, > > dan carpenter > > Thanks Dan, > Hello Dan, I have attached a patch which replaces the original "Handle mismatched open calls" patch from the for-next branch. Can you please run it against the static checker. In the patch, we pass a buffer to cifs_discard_remaining_data() instead of using server->small_buf to obtain the rfc len. Thanks Sachin Prabhu From 83f1e5cca033c358b98ebc53389787dfa9051934 Mon Sep 17 00:00:00 2001 From: Sachin Prabhu Date: Fri, 3 Mar 2017 15:41:38 -0800 Subject: [PATCH] Handle mismatched open calls A signal can interrupt a SendReceive call which result in incoming responses to the call being ignored. This is a problem for calls such as open which results in the successful response being ignored. This results in an open file resource on the server. The patch looks into responses which were cancelled after being sent and in case of successful open closes the open fids. For this patch, the check is only done in SendReceive2() RH-bz: 1403319 v2: Search for sess and tcon while under spinlock v3: Allocate struct cancelled before we pick the tcon v4: Rebase against latest upstream. v5: Fix oops caused by async reads v6: Pass buffer to cifs_discard_remaining_data() Signed-off-by: Sachin Prabhu Reviewed-by: Pavel Shilovsky Cc: Stable --- fs/cifs/cifsglob.h | 11 ++++++++++ fs/cifs/cifsproto.h | 3 ++- fs/cifs/cifssmb.c | 11 ++++++---- fs/cifs/connect.c | 13 +++++++++-- fs/cifs/smb2misc.c | 48 ++++++++++++++++++++++++++++++++++++++++ fs/cifs/smb2ops.c | 8 +++++-- fs/cifs/smb2proto.h | 7 ++++++ fs/cifs/smb2transport.c | 58 +++++++++++++++++++++++++++++++++++++++++++++---- fs/cifs/transport.c | 3 +++ 9 files changed, 149 insertions(+), 13 deletions(-) diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h index c565e0db..d07f13a 100644 --- a/fs/cifs/cifsglob.h +++ b/fs/cifs/cifsglob.h @@ -243,6 +243,7 @@ struct smb_version_operations { /* verify the message */ int (*check_message)(char *, unsigned int, struct TCP_Server_Info *); bool (*is_oplock_break)(char *, struct TCP_Server_Info *); + int (*handle_cancelled_mid)(char *, struct TCP_Server_Info *); void (*downgrade_oplock)(struct TCP_Server_Info *, struct cifsInodeInfo *, bool); /* process transaction2 response */ @@ -1344,6 +1345,7 @@ struct mid_q_entry { void *callback_data; /* general purpose pointer for callback */ void *resp_buf; /* pointer to received SMB header */ int mid_state; /* wish this were enum but can not pass to wait_event */ + unsigned int mid_flags; __le16 command; /* smb command code */ bool large_buf:1; /* if valid response, is pointer to large buf */ bool multiRsp:1; /* multiple trans2 responses for one request */ @@ -1351,6 +1353,12 @@ struct mid_q_entry { bool decrypted:1; /* decrypted entry */ }; +struct close_cancelled_open { + struct cifs_fid fid; + struct cifs_tcon *tcon; + struct work_struct work; +}; + /* Make code in transport.c a little cleaner by moving update of optional stats into function below */ #ifdef CONFIG_CIFS_STATS2 @@ -1482,6 +1490,9 @@ static inline void free_dfs_info_array(struct dfs_info3_param *param, #define MID_RESPONSE_MALFORMED 0x10 #define MID_SHUTDOWN 0x20 +/* Flags */ +#define MID_WAIT_CANCELLED 1 /* Cancelled while waiting for response */ + /* Types of response buffer returned from SendReceive2 */ #define CIFS_NO_BUFFER 0 /* Response buffer not returned */ #define CIFS_SMALL_BUFFER 1 diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h index 97e5d23..ec5e5e5 100644 --- a/fs/cifs/cifsproto.h +++ b/fs/cifs/cifsproto.h @@ -79,7 +79,8 @@ extern void cifs_delete_mid(struct mid_q_entry *mid); extern void cifs_wake_up_task(struct mid_q_entry *mid); extern int cifs_handle_standard(struct TCP_Server_Info *server, struct mid_q_entry *mid); -extern int cifs_discard_remaining_data(struct TCP_Server_Info *server); +extern int cifs_discard_remaining_data(struct TCP_Server_Info *server, + char *buf); extern int cifs_call_async(struct TCP_Server_Info *server, struct smb_rqst *rqst, mid_receive_t *receive, mid_callback_t *callback, diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c index 0669506..967b9263 100644 --- a/fs/cifs/cifssmb.c +++ b/fs/cifs/cifssmb.c @@ -1400,9 +1400,9 @@ CIFS_open(const unsigned int xid, struct cifs_open_parms *oparms, int *oplock, * current bigbuf. */ int -cifs_discard_remaining_data(struct TCP_Server_Info *server) +cifs_discard_remaining_data(struct TCP_Server_Info *server, char *buf) { - unsigned int rfclen = get_rfc1002_length(server->smallbuf); + unsigned int rfclen = get_rfc1002_length(buf); int remaining = rfclen + 4 - server->total_read; while (remaining > 0) { @@ -1426,7 +1426,7 @@ cifs_readv_discard(struct TCP_Server_Info *server, struct mid_q_entry *mid) int length; struct cifs_readdata *rdata = mid->callback_data; - length = cifs_discard_remaining_data(server); + length = cifs_discard_remaining_data(server, mid->resp_buf); dequeue_mid(mid, rdata->result); return length; } @@ -1459,7 +1459,7 @@ cifs_readv_receive(struct TCP_Server_Info *server, struct mid_q_entry *mid) if (server->ops->is_status_pending && server->ops->is_status_pending(buf, server, 0)) { - cifs_discard_remaining_data(server); + cifs_discard_remaining_data(server, buf); return -1; } @@ -1519,6 +1519,9 @@ cifs_readv_receive(struct TCP_Server_Info *server, struct mid_q_entry *mid) cifs_dbg(FYI, "0: iov_base=%p iov_len=%u\n", rdata->iov[0].iov_base, server->total_read); + mid->resp_buf = server->smallbuf; + server->smallbuf = NULL; + /* how much data is in the response? */ data_len = server->ops->read_data_length(buf); if (data_offset + data_len > buflen) { diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c index 9ae695a..131663b 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -904,10 +904,19 @@ cifs_demultiplex_thread(void *p) server->lstrp = jiffies; if (mid_entry != NULL) { + if ((mid_entry->mid_flags & MID_WAIT_CANCELLED) && + mid_entry->mid_state == MID_RESPONSE_RECEIVED && + (server->ops->handle_cancelled_mid)) + server->ops->handle_cancelled_mid( + mid_entry->resp_buf, + server); + if (!mid_entry->multiRsp || mid_entry->multiEnd) mid_entry->callback(mid_entry); - } else if (!server->ops->is_oplock_break || - !server->ops->is_oplock_break(buf, server)) { + } else if (server->ops->is_oplock_break && + server->ops->is_oplock_break(buf, server)) { + cifs_dbg(FYI, "Received oplock break\n"); + } else { cifs_dbg(VFS, "No task to wake, unknown frame received! NumMids %d\n", atomic_read(&midCount)); cifs_dump_mem("Received Data is: ", buf, diff --git a/fs/cifs/smb2misc.c b/fs/cifs/smb2misc.c index fd516ea..f50e3ef 100644 --- a/fs/cifs/smb2misc.c +++ b/fs/cifs/smb2misc.c @@ -659,3 +659,51 @@ smb2_is_valid_oplock_break(char *buffer, struct TCP_Server_Info *server) cifs_dbg(FYI, "Can not process oplock break for non-existent connection\n"); return false; } + +void +smb2_cancelled_close_fid(struct work_struct *work) +{ + struct close_cancelled_open *cancelled = container_of(work, + struct close_cancelled_open, work); + + cifs_dbg(VFS, "Close unmatched open\n"); + + SMB2_close(0, cancelled->tcon, cancelled->fid.persistent_fid, + cancelled->fid.volatile_fid); + cifs_put_tcon(cancelled->tcon); + kfree(cancelled); +} + +int +smb2_handle_cancelled_mid(char *buffer, struct TCP_Server_Info *server) +{ + struct smb2_sync_hdr *sync_hdr = get_sync_hdr(buffer); + struct smb2_create_rsp *rsp = (struct smb2_create_rsp *)buffer; + struct cifs_tcon *tcon; + struct close_cancelled_open *cancelled; + + if ((sync_hdr->Command != SMB2_CREATE) || + (sync_hdr->Status != STATUS_SUCCESS)) + return 0; + + cancelled = (struct close_cancelled_open *) + kzalloc(sizeof(struct close_cancelled_open), + GFP_KERNEL); + if (!cancelled) + return -ENOMEM; + + tcon = smb2_find_smb_tcon(server, sync_hdr->SessionId, + sync_hdr->TreeId); + if (!tcon) { + kfree(cancelled); + return -ENOENT; + } + + cancelled->fid.persistent_fid = rsp->PersistentFileId; + cancelled->fid.volatile_fid = rsp->VolatileFileId; + cancelled->tcon = tcon; + INIT_WORK(&cancelled->work, smb2_cancelled_close_fid); + queue_work(cifsiod_wq, &cancelled->work); + + return 0; +} diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c index 583a0e2..7b12a72 100644 --- a/fs/cifs/smb2ops.c +++ b/fs/cifs/smb2ops.c @@ -2195,7 +2195,7 @@ receive_encrypted_read(struct TCP_Server_Info *server, struct mid_q_entry **mid) if (rc) goto free_pages; - rc = cifs_discard_remaining_data(server); + rc = cifs_discard_remaining_data(server, buf); if (rc) goto free_pages; @@ -2221,7 +2221,7 @@ receive_encrypted_read(struct TCP_Server_Info *server, struct mid_q_entry **mid) kfree(pages); return rc; discard_data: - cifs_discard_remaining_data(server); + cifs_discard_remaining_data(server, buf); goto free_pages; } @@ -2329,6 +2329,7 @@ struct smb_version_operations smb20_operations = { .clear_stats = smb2_clear_stats, .print_stats = smb2_print_stats, .is_oplock_break = smb2_is_valid_oplock_break, + .handle_cancelled_mid = smb2_handle_cancelled_mid, .downgrade_oplock = smb2_downgrade_oplock, .need_neg = smb2_need_neg, .negotiate = smb2_negotiate, @@ -2411,6 +2412,7 @@ struct smb_version_operations smb21_operations = { .clear_stats = smb2_clear_stats, .print_stats = smb2_print_stats, .is_oplock_break = smb2_is_valid_oplock_break, + .handle_cancelled_mid = smb2_handle_cancelled_mid, .downgrade_oplock = smb2_downgrade_oplock, .need_neg = smb2_need_neg, .negotiate = smb2_negotiate, @@ -2495,6 +2497,7 @@ struct smb_version_operations smb30_operations = { .print_stats = smb2_print_stats, .dump_share_caps = smb2_dump_share_caps, .is_oplock_break = smb2_is_valid_oplock_break, + .handle_cancelled_mid = smb2_handle_cancelled_mid, .downgrade_oplock = smb2_downgrade_oplock, .need_neg = smb2_need_neg, .negotiate = smb2_negotiate, @@ -2589,6 +2592,7 @@ struct smb_version_operations smb311_operations = { .print_stats = smb2_print_stats, .dump_share_caps = smb2_dump_share_caps, .is_oplock_break = smb2_is_valid_oplock_break, + .handle_cancelled_mid = smb2_handle_cancelled_mid, .downgrade_oplock = smb2_downgrade_oplock, .need_neg = smb2_need_neg, .negotiate = smb2_negotiate, diff --git a/fs/cifs/smb2proto.h b/fs/cifs/smb2proto.h index 69e3587..6853454 100644 --- a/fs/cifs/smb2proto.h +++ b/fs/cifs/smb2proto.h @@ -48,6 +48,10 @@ extern struct mid_q_entry *smb2_setup_request(struct cifs_ses *ses, struct smb_rqst *rqst); extern struct mid_q_entry *smb2_setup_async_request( struct TCP_Server_Info *server, struct smb_rqst *rqst); +extern struct cifs_ses *smb2_find_smb_ses(struct TCP_Server_Info *server, + __u64 ses_id); +extern struct cifs_tcon *smb2_find_smb_tcon(struct TCP_Server_Info *server, + __u64 ses_id, __u32 tid); extern int smb2_calc_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server); extern int smb3_calc_signature(struct smb_rqst *rqst, @@ -164,6 +168,9 @@ extern int SMB2_set_compression(const unsigned int xid, struct cifs_tcon *tcon, extern int SMB2_oplock_break(const unsigned int xid, struct cifs_tcon *tcon, const u64 persistent_fid, const u64 volatile_fid, const __u8 oplock_level); +extern int smb2_handle_cancelled_mid(char *buffer, + struct TCP_Server_Info *server); +void smb2_cancelled_close_fid(struct work_struct *work); extern int SMB2_QFS_info(const unsigned int xid, struct cifs_tcon *tcon, u64 persistent_file_id, u64 volatile_file_id, struct kstatfs *FSData); diff --git a/fs/cifs/smb2transport.c b/fs/cifs/smb2transport.c index 7c3bb1b..e3c8a9c 100644 --- a/fs/cifs/smb2transport.c +++ b/fs/cifs/smb2transport.c @@ -115,23 +115,72 @@ smb3_crypto_shash_allocate(struct TCP_Server_Info *server) return 0; } -struct cifs_ses * -smb2_find_smb_ses(struct TCP_Server_Info *server, __u64 ses_id) +static struct cifs_ses * +_smb2_find_smb_ses(struct TCP_Server_Info *server, __u64 ses_id) { struct cifs_ses *ses; - spin_lock(&cifs_tcp_ses_lock); list_for_each_entry(ses, &server->smb_ses_list, smb_ses_list) { if (ses->Suid != ses_id) continue; - spin_unlock(&cifs_tcp_ses_lock); return ses; } + + return NULL; +} + +struct cifs_ses * +smb2_find_smb_ses(struct TCP_Server_Info *server, __u64 ses_id) +{ + struct cifs_ses *ses; + + spin_lock(&cifs_tcp_ses_lock); + ses = _smb2_find_smb_ses(server, ses_id); spin_unlock(&cifs_tcp_ses_lock); + return ses; +} + +static struct cifs_tcon * +_smb2_find_smb_sess_tcon(struct cifs_ses *ses, __u32 tid) +{ + struct list_head *tmp; + struct cifs_tcon *tcon; + + list_for_each(tmp, &ses->tcon_list) { + tcon = list_entry(tmp, struct cifs_tcon, tcon_list); + if (tcon->tid != tid) + continue; + ++tcon->tc_count; + return tcon; + } + return NULL; } +/* + * Obtain tcon corresponding to the tid in the given + * cifs_ses + */ + +struct cifs_tcon * +smb2_find_smb_tcon(struct TCP_Server_Info *server, __u64 ses_id, __u32 tid) +{ + struct cifs_ses *ses; + struct cifs_tcon *tcon; + + spin_lock(&cifs_tcp_ses_lock); + ses = _smb2_find_smb_ses(server, ses_id); + if (!ses) { + spin_unlock(&cifs_tcp_ses_lock); + return NULL; + } + tcon = _smb2_find_smb_sess_tcon(ses, tid); + spin_unlock(&cifs_tcp_ses_lock); + + return tcon; +} + int smb2_calc_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server) { @@ -511,6 +560,7 @@ smb2_mid_entry_alloc(const struct smb2_sync_hdr *shdr, atomic_inc(&midCount); temp->mid_state = MID_REQUEST_ALLOCATED; + temp->mid_flags = 0; return temp; } diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c index 526f053..d82a4ae 100644 --- a/fs/cifs/transport.c +++ b/fs/cifs/transport.c @@ -752,9 +752,12 @@ cifs_send_recv(const unsigned int xid, struct cifs_ses *ses, rc = wait_for_response(ses->server, midQ); if (rc != 0) { + cifs_dbg(FYI, "Cancelling wait for mid %lu\n", + (unsigned long)midQ->mid); send_cancel(ses->server, rqst, midQ); spin_lock(&GlobalMid_Lock); if (midQ->mid_state == MID_REQUEST_SUBMITTED) { + midQ->mid_flags |= MID_WAIT_CANCELLED; midQ->callback = DeleteMidQEntry; spin_unlock(&GlobalMid_Lock); add_credits(ses->server, 1, optype); -- 2.9.3