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

Signed-off-by: Sachin Prabhu <sprabhu@redhat.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Cc: Stable <stable@vger.kernel.org>

diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index d42dd3288647808216a6c22c56731dc960e525f8..c34bdb12c8e668c8dbfb5918c5e77819a55960ad 100644 (file)
--- 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 */
@@ -1343,6 +1344,7 @@ 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  */
@@ -1350,6 +1352,12 @@ 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
@@ -1481,6 +1489,9 @@ 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 97e5d236d26559806ca8bc278f7c248e0579ef77..ec5e5e514fdd4a2556fa15974e869cdba5e3bd91 100644 (file)
--- 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 066950671929682399974fb4fb8641cf78c60855..967b92631807a95786a264acf80833f0e0dbb147 100644 (file)
--- a/fs/cifs/cifssmb.c
+++ b/fs/cifs/cifssmb.c
@@ -1400,9 +1400,9 @@ openRetry:
  * 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 9ae695ae3ed7be3788db2a889e34cde8a3224c9c..0c7596cef4b88639c50b3efdb86a511f349ac451 100644 (file)
--- 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 fd516ea8b8f89c46cb1d9977d53fbbb9d16de9d3..1a04b3a5beb164cb22c166f5c7ac03b65e70d00b 100644 (file)
--- a/fs/cifs/smb2misc.c
+++ b/fs/cifs/smb2misc.c
@@ -659,3 +659,49 @@ 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 = kzalloc(sizeof(*cancelled), 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 0231108d9387a4af3448a2d89451a4c86a0bc17c..b6bdf93042ebcef2388e7ebcdb1d5ba54e9742b3 100644 (file)
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -2188,7 +2188,7 @@ 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;
 
@@ -2214,7 +2214,7 @@ free_pages:
        kfree(pages);
        return rc;
 discard_data:
-       cifs_discard_remaining_data(server);
+       cifs_discard_remaining_data(server, buf);
        goto free_pages;
 }
 
@@ -2322,6 +2322,7 @@ 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,
@@ -2404,6 +2405,7 @@ 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,
@@ -2488,6 +2490,7 @@ 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,
@@ -2582,6 +2585,7 @@ 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 69e35873b1de734991fbe027fd68b97b505d01c3..6853454fc871a7947591effb0c98d55accd955dc 100644 (file)
--- 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 7c3bb1bd7eedfd044e0a7716951a39181a9e1bae..506b67fc93d9611ea859cf738126fb2d67e52e16 100644 (file)
--- a/fs/cifs/smb2transport.c
+++ b/fs/cifs/smb2transport.c
@@ -115,23 +115,70 @@ 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_unlocked(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_unlocked(server, ses_id);
        spin_unlock(&cifs_tcp_ses_lock);
 
+       return ses;
+}
+
+static struct cifs_tcon *
+smb2_find_smb_sess_tcon_unlocked(struct cifs_ses *ses, __u32  tid)
+{
+       struct cifs_tcon *tcon;
+
+       list_for_each_entry(tcon, &ses->tcon_list, 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_unlocked(server, ses_id);
+       if (!ses) {
+               spin_unlock(&cifs_tcp_ses_lock);
+               return NULL;
+       }
+       tcon = smb2_find_smb_sess_tcon_unlocked(ses, tid);
+       spin_unlock(&cifs_tcp_ses_lock);
+
+       return tcon;
+}
+
 int
 smb2_calc_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server)
 {

diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c
index 526f0533cb4e8ca0eb1209561bd4bf59db9af864..f6e13a977fc8e907e3fa89fc0a5d14a4ab0eccd5 100644 (file)
--- a/fs/cifs/transport.c
+++ b/fs/cifs/transport.c
@@ -752,9 +752,11 @@ 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 %llu\n", 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);