diff options
| author | Christopher Oo <t-chriso@microsoft.com> | 2015-06-26 02:10:48 +0300 |
|---|---|---|
| committer | Steve French <smfrench@gmail.com> | 2015-08-20 18:19:25 +0300 |
| commit | 5fb4e288a025af1abc5c67ecebf30fbf6b3edad1 (patch) | |
| tree | 751d20a93eb2f92415213fc068e6daa95e839119 /fs/cifs/smb2pdu.c | |
| parent | 0a6d0b64120759df8b9291af92d998ed1cbefc9d (diff) | |
| download | linux-5fb4e288a025af1abc5c67ecebf30fbf6b3edad1.tar.xz | |
cifs: Fix use-after-free on mid_q_entry
With CIFS_DEBUG_2 enabled, additional debug information is tracked inside each
mid_q_entry struct, however cifs_save_when_sent may use the mid_q_entry after it
has been freed from the appropriate callback if the transport layer has very low
latency. Holding the srv_mutex fixes this use-after-free, as cifs_save_when_sent
is called while the srv_mutex is held while the request is sent.
Signed-off-by: Christopher Oo <t-chriso@microsoft.com>
Diffstat (limited to 'fs/cifs/smb2pdu.c')
| -rw-r--r-- | fs/cifs/smb2pdu.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c index b8b4f08ee094..070fb2ad85ce 100644 --- a/fs/cifs/smb2pdu.c +++ b/fs/cifs/smb2pdu.c @@ -1626,7 +1626,9 @@ smb2_echo_callback(struct mid_q_entry *mid) if (mid->mid_state == MID_RESPONSE_RECEIVED) credits_received = le16_to_cpu(smb2->hdr.CreditRequest); + mutex_lock(&server->srv_mutex); DeleteMidQEntry(mid); + mutex_unlock(&server->srv_mutex); add_credits(server, credits_received, CIFS_ECHO_OP); } @@ -1810,7 +1812,9 @@ smb2_readv_callback(struct mid_q_entry *mid) cifs_stats_fail_inc(tcon, SMB2_READ_HE); queue_work(cifsiod_wq, &rdata->work); + mutex_lock(&server->srv_mutex); DeleteMidQEntry(mid); + mutex_unlock(&server->srv_mutex); add_credits(server, credits_received, 0); } @@ -1938,6 +1942,7 @@ smb2_writev_callback(struct mid_q_entry *mid) { struct cifs_writedata *wdata = mid->callback_data; struct cifs_tcon *tcon = tlink_tcon(wdata->cfile->tlink); + struct TCP_Server_Info *server = tcon->ses->server; unsigned int written; struct smb2_write_rsp *rsp = (struct smb2_write_rsp *)mid->resp_buf; unsigned int credits_received = 1; @@ -1977,7 +1982,9 @@ smb2_writev_callback(struct mid_q_entry *mid) cifs_stats_fail_inc(tcon, SMB2_WRITE_HE); queue_work(cifsiod_wq, &wdata->work); + mutex_lock(&server->srv_mutex); DeleteMidQEntry(mid); + mutex_unlock(&server->srv_mutex); add_credits(tcon->ses->server, credits_received, 0); } |