Handle mismatched open calls

commit 38bd49064a1ecb67baad33598e3d824448ab11ec upstream.

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>
Acked-by: Sachin Prabhu <sprabhu@redhat.com>
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index 94661cf77ae8d206c4c7cc237e8d5f63f1c1b406..b3830f7ab260c8dacc5b97e3d6dbf7a43ab587f6 100644 (file)
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -241,6 +241,7 @@ 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 */
@@ -1314,12 +1315,19 @@ 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  */
        bool multiEnd:1;        /* both received */
 };
 
+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
@@ -1451,6 +1459,9 @@ 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/cifssmb.c b/fs/cifs/cifssmb.c
index e3fed9249a04f09929e772c0f4c9b0955263b13b..586fdac05ec2fa2b4aa048d445de29444df7ca99 100644 (file)
--- a/fs/cifs/cifssmb.c
+++ b/fs/cifs/cifssmb.c
@@ -1423,6 +1423,8 @@ cifs_readv_discard(struct TCP_Server_Info *server, struct mid_q_entry *mid)
 
        length = discard_remaining_data(server);
        dequeue_mid(mid, rdata->result);
+       mid->resp_buf = server->smallbuf;
+       server->smallbuf = NULL;
        return length;
 }
 
@@ -1534,6 +1536,8 @@ cifs_readv_receive(struct TCP_Server_Info *server, struct mid_q_entry *mid)
                return cifs_readv_discard(server, mid);
 
        dequeue_mid(mid, false);
+       mid->resp_buf = server->smallbuf;
+       server->smallbuf = NULL;
        return length;
 }
 

diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 893be0722643038f3a043c11d0300b107de47577..b8015de88e8c637837ec1dd710db921f7cb87053 100644 (file)
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -882,10 +882,19 @@ 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 3d383489b9cf313395e94a0bff4a719501b4b309..97307808ae42c06224888d8461cc506ee2e3dbba 100644 (file)
--- a/fs/cifs/smb2misc.c
+++ b/fs/cifs/smb2misc.c
@@ -654,3 +654,47 @@ 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_hdr *hdr = (struct smb2_hdr *)buffer;
+       struct smb2_create_rsp *rsp = (struct smb2_create_rsp *)buffer;
+       struct cifs_tcon *tcon;
+       struct close_cancelled_open *cancelled;
+
+       if (hdr->Command != SMB2_CREATE || hdr->Status != STATUS_SUCCESS)
+               return 0;
+
+       cancelled = kzalloc(sizeof(*cancelled), GFP_KERNEL);
+       if (!cancelled)
+               return -ENOMEM;
+
+       tcon = smb2_find_smb_tcon(server, hdr->SessionId, 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 5d456ebb381386e5299cf61123400f4985480e9a..007abf7195afa81a195aa404c9dfe1d5160a1365 100644 (file)
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -1565,6 +1565,7 @@ 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,
@@ -1645,6 +1646,7 @@ 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,
@@ -1727,6 +1729,7 @@ 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,
@@ -1815,6 +1818,7 @@ 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 f2d511a6971b88c0019526bcd5b3938383f4f106..04ef6e914597260c25369495c2e400400ecc4074 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,
@@ -158,6 +162,9 @@ 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 bc9a7b63464347ad4036f41a60fc2a2fdc1bfe6e..390b0d0198f8fb13ae3b39854489dd128977b4f4 100644 (file)
--- a/fs/cifs/smb2transport.c
+++ b/fs/cifs/smb2transport.c
@@ -115,22 +115,68 @@ smb3_crypto_shash_allocate(struct TCP_Server_Info *server)
 }
 
 static struct cifs_ses *
-smb2_find_smb_ses(struct smb2_hdr *smb2hdr, struct TCP_Server_Info *server)
+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 != smb2hdr->SessionId)
+               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)
@@ -142,7 +188,7 @@ smb2_calc_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server)
        struct smb2_hdr *smb2_pdu = (struct smb2_hdr *)iov[0].iov_base;
        struct cifs_ses *ses;
 
-       ses = smb2_find_smb_ses(smb2_pdu, server);
+       ses = smb2_find_smb_ses(server, smb2_pdu->SessionId);
        if (!ses) {
                cifs_dbg(VFS, "%s: Could not find session\n", __func__);
                return 0;
@@ -359,7 +405,7 @@ smb3_calc_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server)
        struct smb2_hdr *smb2_pdu = (struct smb2_hdr *)iov[0].iov_base;
        struct cifs_ses *ses;
 
-       ses = smb2_find_smb_ses(smb2_pdu, server);
+       ses = smb2_find_smb_ses(server, smb2_pdu->SessionId);
        if (!ses) {
                cifs_dbg(VFS, "%s: Could not find session\n", __func__);
                return 0;

diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c
index 206a597b2293cb2ea2d0e6606e8e8f0e01ff9e0b..cc26d4138d708628c9fb60be778b55243c322669 100644 (file)
--- a/fs/cifs/transport.c
+++ b/fs/cifs/transport.c
@@ -727,9 +727,11 @@ SendReceive2(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, buf, 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);
                        cifs_small_buf_release(buf);