cifs: fix credits leak for SMB1 oplock breaks
diff mbox series

Message ID 20190426003223.4763-2-lsahlber@redhat.com
State New
Headers show
Series
  • cifs: fix credits leak for SMB1 oplock breaks
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Commit Message

Ronnie Sahlberg April 26, 2019, 12:32 a.m. UTC
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
---
 fs/cifs/cifsglob.h  |  1 +
 fs/cifs/cifssmb.c   |  2 +-
 fs/cifs/transport.c | 10 +++++-----
 3 files changed, 7 insertions(+), 6 deletions(-)

Comments

Pavel Shilovsky April 26, 2019, 4:38 p.m. UTC | #1
чт, 25 апр. 2019 г. в 18:43, Ronnie Sahlberg <lsahlber@redhat.com>:
>
> Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
> ---
>  fs/cifs/cifsglob.h  |  1 +
>  fs/cifs/cifssmb.c   |  2 +-
>  fs/cifs/transport.c | 10 +++++-----
>  3 files changed, 7 insertions(+), 6 deletions(-)
>
> diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
> index 621640195713..7a65124f70f9 100644
> --- a/fs/cifs/cifsglob.h
> +++ b/fs/cifs/cifsglob.h
> @@ -1701,6 +1701,7 @@ static inline bool is_retryable_error(int error)
>
>  #define   CIFS_HAS_CREDITS 0x0400    /* already has credits */
>  #define   CIFS_TRANSFORM_REQ 0x0800    /* transform request before sending */
> +#define   CIFS_NO_SRV_RSP    0x1000    /* there is no server response */
>
>  /* Security Flags: indicate type of session setup needed */
>  #define   CIFSSEC_MAY_SIGN     0x00001
> diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c
> index f43747c062a7..6050851edcb8 100644
> --- a/fs/cifs/cifssmb.c
> +++ b/fs/cifs/cifssmb.c
> @@ -2540,7 +2540,7 @@ CIFSSMBLock(const unsigned int xid, struct cifs_tcon *tcon,
>
>         if (lockType == LOCKING_ANDX_OPLOCK_RELEASE) {
>                 /* no response expected */
> -               flags = CIFS_ASYNC_OP | CIFS_OBREAK_OP;
> +               flags = CIFS_NO_SRV_RSP | CIFS_ASYNC_OP | CIFS_OBREAK_OP;
>                 pSMB->Timeout = 0;
>         } else if (waitFlag) {
>                 flags = CIFS_BLOCKING_OP; /* blocking operation, no timeout */
> diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c
> index 5c59c498f56a..5573e38b13f3 100644
> --- a/fs/cifs/transport.c
> +++ b/fs/cifs/transport.c
> @@ -1073,8 +1073,11 @@ compound_send_recv(const unsigned int xid, struct cifs_ses *ses,
>
>         mutex_unlock(&ses->server->srv_mutex);
>
> -       if (rc < 0) {
> -               /* Sending failed for some reason - return credits back */
> +       /*
> +        * If sending failed for some reason or it is an oplock break that we

probably indicate that it is SMB1 oplock break?

> +        * will not receive a response to - return credits back
> +        */
> +       if (rc < 0 || (flags & CIFS_NO_SRV_RSP)) {
>                 for (i = 0; i < num_rqst; i++)
>                         add_credits(ses->server, &credits[i], optype);

A no-op callback is still needed to be set here or above for
CIFS_NO_SRV_RSP requests. Otherwise we may end up adding credits
twice: here and in the demultiplex thread.

>                 goto out;
> @@ -1095,9 +1098,6 @@ compound_send_recv(const unsigned int xid, struct cifs_ses *ses,
>                 smb311_update_preauth_hash(ses, rqst[0].rq_iov,
>                                            rqst[0].rq_nvec);
>
> -       if ((flags & CIFS_TIMEOUT_MASK) == CIFS_ASYNC_OP)
> -               goto out;
> -
>         for (i = 0; i < num_rqst; i++) {
>                 rc = wait_for_response(ses->server, midQ[i]);
>                 if (rc != 0)
> --
> 2.13.6
>


--
Best regards,
Pavel Shilovsky
ronnie sahlberg April 27, 2019, 8:08 a.m. UTC | #2
On Sat, Apr 27, 2019 at 2:38 AM Pavel Shilovsky <piastryyy@gmail.com> wrote:
>
> чт, 25 апр. 2019 г. в 18:43, Ronnie Sahlberg <lsahlber@redhat.com>:
> >
> > Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
> > ---
> >  fs/cifs/cifsglob.h  |  1 +
> >  fs/cifs/cifssmb.c   |  2 +-
> >  fs/cifs/transport.c | 10 +++++-----
> >  3 files changed, 7 insertions(+), 6 deletions(-)
> >
> > diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
> > index 621640195713..7a65124f70f9 100644
> > --- a/fs/cifs/cifsglob.h
> > +++ b/fs/cifs/cifsglob.h
> > @@ -1701,6 +1701,7 @@ static inline bool is_retryable_error(int error)
> >
> >  #define   CIFS_HAS_CREDITS 0x0400    /* already has credits */
> >  #define   CIFS_TRANSFORM_REQ 0x0800    /* transform request before sending */
> > +#define   CIFS_NO_SRV_RSP    0x1000    /* there is no server response */
> >
> >  /* Security Flags: indicate type of session setup needed */
> >  #define   CIFSSEC_MAY_SIGN     0x00001
> > diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c
> > index f43747c062a7..6050851edcb8 100644
> > --- a/fs/cifs/cifssmb.c
> > +++ b/fs/cifs/cifssmb.c
> > @@ -2540,7 +2540,7 @@ CIFSSMBLock(const unsigned int xid, struct cifs_tcon *tcon,
> >
> >         if (lockType == LOCKING_ANDX_OPLOCK_RELEASE) {
> >                 /* no response expected */
> > -               flags = CIFS_ASYNC_OP | CIFS_OBREAK_OP;
> > +               flags = CIFS_NO_SRV_RSP | CIFS_ASYNC_OP | CIFS_OBREAK_OP;
> >                 pSMB->Timeout = 0;
> >         } else if (waitFlag) {
> >                 flags = CIFS_BLOCKING_OP; /* blocking operation, no timeout */
> > diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c
> > index 5c59c498f56a..5573e38b13f3 100644
> > --- a/fs/cifs/transport.c
> > +++ b/fs/cifs/transport.c
> > @@ -1073,8 +1073,11 @@ compound_send_recv(const unsigned int xid, struct cifs_ses *ses,
> >
> >         mutex_unlock(&ses->server->srv_mutex);
> >
> > -       if (rc < 0) {
> > -               /* Sending failed for some reason - return credits back */
> > +       /*
> > +        * If sending failed for some reason or it is an oplock break that we
>
> probably indicate that it is SMB1 oplock break?
>
> > +        * will not receive a response to - return credits back
> > +        */
> > +       if (rc < 0 || (flags & CIFS_NO_SRV_RSP)) {
> >                 for (i = 0; i < num_rqst; i++)
> >                         add_credits(ses->server, &credits[i], optype);
>
> A no-op callback is still needed to be set here or above for
> CIFS_NO_SRV_RSP requests. Otherwise we may end up adding credits
> twice: here and in the demultiplex thread.

I don't think we need one. Since there will never be a reply we will
never invoke the callback from the demultiplex thread.


>
> >                 goto out;
> > @@ -1095,9 +1098,6 @@ compound_send_recv(const unsigned int xid, struct cifs_ses *ses,
> >                 smb311_update_preauth_hash(ses, rqst[0].rq_iov,
> >                                            rqst[0].rq_nvec);
> >
> > -       if ((flags & CIFS_TIMEOUT_MASK) == CIFS_ASYNC_OP)
> > -               goto out;
> > -
> >         for (i = 0; i < num_rqst; i++) {
> >                 rc = wait_for_response(ses->server, midQ[i]);
> >                 if (rc != 0)
> > --
> > 2.13.6
> >
>
>
> --
> Best regards,
> Pavel Shilovsky
Pavel Shilovsky April 29, 2019, 6:58 p.m. UTC | #3
сб, 27 апр. 2019 г. в 01:08, ronnie sahlberg <ronniesahlberg@gmail.com>:
>
> On Sat, Apr 27, 2019 at 2:38 AM Pavel Shilovsky <piastryyy@gmail.com> wrote:
> >
> > чт, 25 апр. 2019 г. в 18:43, Ronnie Sahlberg <lsahlber@redhat.com>:
> > >
> > > Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
> > > ---
> > >  fs/cifs/cifsglob.h  |  1 +
> > >  fs/cifs/cifssmb.c   |  2 +-
> > >  fs/cifs/transport.c | 10 +++++-----
> > >  3 files changed, 7 insertions(+), 6 deletions(-)
> > >
> > > diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
> > > index 621640195713..7a65124f70f9 100644
> > > --- a/fs/cifs/cifsglob.h
> > > +++ b/fs/cifs/cifsglob.h
> > > @@ -1701,6 +1701,7 @@ static inline bool is_retryable_error(int error)
> > >
> > >  #define   CIFS_HAS_CREDITS 0x0400    /* already has credits */
> > >  #define   CIFS_TRANSFORM_REQ 0x0800    /* transform request before sending */
> > > +#define   CIFS_NO_SRV_RSP    0x1000    /* there is no server response */
> > >
> > >  /* Security Flags: indicate type of session setup needed */
> > >  #define   CIFSSEC_MAY_SIGN     0x00001
> > > diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c
> > > index f43747c062a7..6050851edcb8 100644
> > > --- a/fs/cifs/cifssmb.c
> > > +++ b/fs/cifs/cifssmb.c
> > > @@ -2540,7 +2540,7 @@ CIFSSMBLock(const unsigned int xid, struct cifs_tcon *tcon,
> > >
> > >         if (lockType == LOCKING_ANDX_OPLOCK_RELEASE) {
> > >                 /* no response expected */
> > > -               flags = CIFS_ASYNC_OP | CIFS_OBREAK_OP;
> > > +               flags = CIFS_NO_SRV_RSP | CIFS_ASYNC_OP | CIFS_OBREAK_OP;
> > >                 pSMB->Timeout = 0;
> > >         } else if (waitFlag) {
> > >                 flags = CIFS_BLOCKING_OP; /* blocking operation, no timeout */
> > > diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c
> > > index 5c59c498f56a..5573e38b13f3 100644
> > > --- a/fs/cifs/transport.c
> > > +++ b/fs/cifs/transport.c
> > > @@ -1073,8 +1073,11 @@ compound_send_recv(const unsigned int xid, struct cifs_ses *ses,
> > >
> > >         mutex_unlock(&ses->server->srv_mutex);
> > >
> > > -       if (rc < 0) {
> > > -               /* Sending failed for some reason - return credits back */
> > > +       /*
> > > +        * If sending failed for some reason or it is an oplock break that we
> >
> > probably indicate that it is SMB1 oplock break?
> >
> > > +        * will not receive a response to - return credits back
> > > +        */
> > > +       if (rc < 0 || (flags & CIFS_NO_SRV_RSP)) {
> > >                 for (i = 0; i < num_rqst; i++)
> > >                         add_credits(ses->server, &credits[i], optype);
> >
> > A no-op callback is still needed to be set here or above for
> > CIFS_NO_SRV_RSP requests. Otherwise we may end up adding credits
> > twice: here and in the demultiplex thread.
>
> I don't think we need one. Since there will never be a reply we will
> never invoke the callback from the demultiplex thread.

Ok, this is according to the spec. Having a no-op callback would save
us from the server error but it's probably not worth the attention.

Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>.

I think this patch belongs to stable because the bug exists in 5.0.
Could you please add a description together with a stable tag and
resend?

--
Best regards,
Pavel Shilovsky

Patch
diff mbox series

diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index 621640195713..7a65124f70f9 100644
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -1701,6 +1701,7 @@  static inline bool is_retryable_error(int error)
 
 #define   CIFS_HAS_CREDITS 0x0400    /* already has credits */
 #define   CIFS_TRANSFORM_REQ 0x0800    /* transform request before sending */
+#define   CIFS_NO_SRV_RSP    0x1000    /* there is no server response */
 
 /* Security Flags: indicate type of session setup needed */
 #define   CIFSSEC_MAY_SIGN	0x00001
diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c
index f43747c062a7..6050851edcb8 100644
--- a/fs/cifs/cifssmb.c
+++ b/fs/cifs/cifssmb.c
@@ -2540,7 +2540,7 @@  CIFSSMBLock(const unsigned int xid, struct cifs_tcon *tcon,
 
 	if (lockType == LOCKING_ANDX_OPLOCK_RELEASE) {
 		/* no response expected */
-		flags = CIFS_ASYNC_OP | CIFS_OBREAK_OP;
+		flags = CIFS_NO_SRV_RSP | CIFS_ASYNC_OP | CIFS_OBREAK_OP;
 		pSMB->Timeout = 0;
 	} else if (waitFlag) {
 		flags = CIFS_BLOCKING_OP; /* blocking operation, no timeout */
diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c
index 5c59c498f56a..5573e38b13f3 100644
--- a/fs/cifs/transport.c
+++ b/fs/cifs/transport.c
@@ -1073,8 +1073,11 @@  compound_send_recv(const unsigned int xid, struct cifs_ses *ses,
 
 	mutex_unlock(&ses->server->srv_mutex);
 
-	if (rc < 0) {
-		/* Sending failed for some reason - return credits back */
+	/*
+	 * If sending failed for some reason or it is an oplock break that we
+	 * will not receive a response to - return credits back
+	 */
+	if (rc < 0 || (flags & CIFS_NO_SRV_RSP)) {
 		for (i = 0; i < num_rqst; i++)
 			add_credits(ses->server, &credits[i], optype);
 		goto out;
@@ -1095,9 +1098,6 @@  compound_send_recv(const unsigned int xid, struct cifs_ses *ses,
 		smb311_update_preauth_hash(ses, rqst[0].rq_iov,
 					   rqst[0].rq_nvec);
 
-	if ((flags & CIFS_TIMEOUT_MASK) == CIFS_ASYNC_OP)
-		goto out;
-
 	for (i = 0; i < num_rqst; i++) {
 		rc = wait_for_response(ses->server, midQ[i]);
 		if (rc != 0)