subject:"RE\: \[PATCH 2\/6\] cifs\: Allocate validate negoation request through kmalloc"

RE: [PATCH 2/6] cifs: Allocate validate negoation request through kmalloc

2018-04-17 Thread Long Li

> Subject: RE: [PATCH 2/6] cifs: Allocate validate negoation request through
> kmalloc
> 
> 
> 
> > -Original Message-
> > From: linux-rdma-ow...@vger.kernel.org [mailto:linux-rdma-
> > ow...@vger.kernel.org] On Behalf Of Long Li
> > Sent: Monday, April 16, 2018 7:49 PM
> > To: Steve French <sfre...@samba.org>; linux-c...@vger.kernel.org;
> > samba- techni...@lists.samba.org; linux-kernel@vger.kernel.org; linux-
> > r...@vger.kernel.org; sta...@vger.kernel.org
> > Cc: longli <lon...@microsoft.com>
> > Subject: [PATCH 2/6] cifs: Allocate validate negoation request through
> > kmalloc
> >
> > From: Long Li <lon...@microsoft.com>
> >
> > The data buffer allocated on the stack can't be DMA'ed, and hence
> > can't send through RDMA via SMB Direct.
> >
> > Fix this by allocating the request on the heap in smb3_validate_negotiate.
> >
> Please provide Fixes ("12-letters commit id") "commit string" which
> introduced this issue and it is getting fixed here, so that other can apply 
> this
> fix to older versions.

Will do.

> 
> > Signed-off-by: Long Li <lon...@microsoft.com>
> > ---
> >  fs/cifs/smb2pdu.c | 38 ++
> >  1 file changed, 22 insertions(+), 16 deletions(-)
> >
> > diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c index
> > 0f044c4..abbefe2
> > 100644
> > --- a/fs/cifs/smb2pdu.c
> > +++ b/fs/cifs/smb2pdu.c
> > @@ -730,7 +730,7 @@ SMB2_negotiate(const unsigned int xid, struct
> > cifs_ses
> > *ses)  int smb3_validate_negotiate(const unsigned int xid, struct
> > cifs_tcon
> > *tcon)  {
> > int rc = 0;
> > -   struct validate_negotiate_info_req vneg_inbuf;
> > +   struct validate_negotiate_info_req *pneg_inbuf;
> [..]
> 
> > rc = SMB2_ioctl(xid, tcon, NO_FILE_ID, NO_FILE_ID,
> > FSCTL_VALIDATE_NEGOTIATE_INFO, true /* is_fsctl */,
> > -   (char *)_inbuf, sizeof(struct
> > validate_negotiate_info_req),
> > +   (char *)pneg_inbuf, sizeof(struct
> validate_negotiate_info_req),
> > (char **)_rsp, );
> >
> > if (rc != 0) {
> > cifs_dbg(VFS, "validate protocol negotiate failed: %d\n", rc);
> > +   kfree(pneg_inbuf);
> > return -EIO;
> Instead of duplicating code here, please jump to err_rsp_free label. Kfree()
> takes care to not panic for NULL pointer.
> Or for clarity define new label.

I will fix this.

> 
> > }
> >
> > @@ -838,12 +842,14 @@ int smb3_validate_negotiate(const unsigned int
> > xid, struct cifs_tcon *tcon)
> >
> > /* validate negotiate successful */
> > cifs_dbg(FYI, "validate negotiate info successful\n");
> > +   kfree(pneg_inbuf);
> > kfree(pneg_rsp);
> > return 0;
> >
> >  vneg_out:
> > cifs_dbg(VFS, "protocol revalidation - security settings
> > mismatch\n");
> >  err_rsp_free:
> > +   kfree(pneg_inbuf);
> > kfree(pneg_rsp);
> > return -EIO;
> >  }
> > --
> > 2.7.4
> >
> > --
> > To unsubscribe from this list: send the line "unsubscribe linux-rdma"
> > in the body of a message to majord...@vger.kernel.org More
> majordomo
> > info at
> >
> https://na01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fvger.k
> > ernel.org%2Fmajordomo-
> info.html=02%7C01%7Clongli%40microsoft.com%
> >
> 7Cc8c0b791819745b7403408d5a417d9d2%7C72f988bf86f141af91ab2d7cd011d
> b47%
> >
> 7C1%7C0%7C636595344704783010=99vU6g%2FE5b8TG8Dn2MngmNw
> pP5MghgdoV
> > hBf0sak%2B0w%3D=0

RE: [PATCH 2/6] cifs: Allocate validate negoation request through kmalloc

2018-04-17 Thread Long Li

> Subject: RE: [PATCH 2/6] cifs: Allocate validate negoation request through
> kmalloc
> 
> 
> 
> > -Original Message-
> > From: linux-rdma-ow...@vger.kernel.org [mailto:linux-rdma-
> > ow...@vger.kernel.org] On Behalf Of Long Li
> > Sent: Monday, April 16, 2018 7:49 PM
> > To: Steve French ; linux-c...@vger.kernel.org;
> > samba- techni...@lists.samba.org; linux-kernel@vger.kernel.org; linux-
> > r...@vger.kernel.org; sta...@vger.kernel.org
> > Cc: longli 
> > Subject: [PATCH 2/6] cifs: Allocate validate negoation request through
> > kmalloc
> >
> > From: Long Li 
> >
> > The data buffer allocated on the stack can't be DMA'ed, and hence
> > can't send through RDMA via SMB Direct.
> >
> > Fix this by allocating the request on the heap in smb3_validate_negotiate.
> >
> Please provide Fixes ("12-letters commit id") "commit string" which
> introduced this issue and it is getting fixed here, so that other can apply 
> this
> fix to older versions.

Will do.

> 
> > Signed-off-by: Long Li 
> > ---
> >  fs/cifs/smb2pdu.c | 38 ++
> >  1 file changed, 22 insertions(+), 16 deletions(-)
> >
> > diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c index
> > 0f044c4..abbefe2
> > 100644
> > --- a/fs/cifs/smb2pdu.c
> > +++ b/fs/cifs/smb2pdu.c
> > @@ -730,7 +730,7 @@ SMB2_negotiate(const unsigned int xid, struct
> > cifs_ses
> > *ses)  int smb3_validate_negotiate(const unsigned int xid, struct
> > cifs_tcon
> > *tcon)  {
> > int rc = 0;
> > -   struct validate_negotiate_info_req vneg_inbuf;
> > +   struct validate_negotiate_info_req *pneg_inbuf;
> [..]
> 
> > rc = SMB2_ioctl(xid, tcon, NO_FILE_ID, NO_FILE_ID,
> > FSCTL_VALIDATE_NEGOTIATE_INFO, true /* is_fsctl */,
> > -   (char *)_inbuf, sizeof(struct
> > validate_negotiate_info_req),
> > +   (char *)pneg_inbuf, sizeof(struct
> validate_negotiate_info_req),
> > (char **)_rsp, );
> >
> > if (rc != 0) {
> > cifs_dbg(VFS, "validate protocol negotiate failed: %d\n", rc);
> > +   kfree(pneg_inbuf);
> > return -EIO;
> Instead of duplicating code here, please jump to err_rsp_free label. Kfree()
> takes care to not panic for NULL pointer.
> Or for clarity define new label.

I will fix this.

> 
> > }
> >
> > @@ -838,12 +842,14 @@ int smb3_validate_negotiate(const unsigned int
> > xid, struct cifs_tcon *tcon)
> >
> > /* validate negotiate successful */
> > cifs_dbg(FYI, "validate negotiate info successful\n");
> > +   kfree(pneg_inbuf);
> > kfree(pneg_rsp);
> > return 0;
> >
> >  vneg_out:
> > cifs_dbg(VFS, "protocol revalidation - security settings
> > mismatch\n");
> >  err_rsp_free:
> > +   kfree(pneg_inbuf);
> > kfree(pneg_rsp);
> > return -EIO;
> >  }
> > --
> > 2.7.4
> >
> > --
> > To unsubscribe from this list: send the line "unsubscribe linux-rdma"
> > in the body of a message to majord...@vger.kernel.org More
> majordomo
> > info at
> >
> https://na01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fvger.k
> > ernel.org%2Fmajordomo-
> info.html=02%7C01%7Clongli%40microsoft.com%
> >
> 7Cc8c0b791819745b7403408d5a417d9d2%7C72f988bf86f141af91ab2d7cd011d
> b47%
> >
> 7C1%7C0%7C636595344704783010=99vU6g%2FE5b8TG8Dn2MngmNw
> pP5MghgdoV
> > hBf0sak%2B0w%3D=0

Re: [PATCH 2/6] cifs: Allocate validate negoation request through kmalloc

2018-04-17 Thread Greg KH

On Mon, Apr 16, 2018 at 05:49:14PM -0700, Long Li wrote:
> From: Long Li 
> 
> The data buffer allocated on the stack can't be DMA'ed, and hence can't send
> through RDMA via SMB Direct.
> 
> Fix this by allocating the request on the heap in smb3_validate_negotiate.
> 
> Signed-off-by: Long Li 
> ---
>  fs/cifs/smb2pdu.c | 38 ++
>  1 file changed, 22 insertions(+), 16 deletions(-)
> 
> diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
> index 0f044c4..abbefe2 100644
> --- a/fs/cifs/smb2pdu.c
> +++ b/fs/cifs/smb2pdu.c
> @@ -730,7 +730,7 @@ SMB2_negotiate(const unsigned int xid, struct cifs_ses 
> *ses)
>  int smb3_validate_negotiate(const unsigned int xid, struct cifs_tcon *tcon)
>  {
>   int rc = 0;
> - struct validate_negotiate_info_req vneg_inbuf;
> + struct validate_negotiate_info_req *pneg_inbuf;
>   struct validate_negotiate_info_rsp *pneg_rsp = NULL;
>   u32 rsplen;
>   u32 inbuflen; /* max of 4 dialects */
> @@ -741,6 +741,9 @@ int smb3_validate_negotiate(const unsigned int xid, 
> struct cifs_tcon *tcon)
>   if (tcon->ses->server->rdma)
>   return 0;
>  #endif
> + pneg_inbuf = kmalloc(sizeof(*pneg_inbuf), GFP_KERNEL);
> + if (!pneg_inbuf)
> + return -ENOMEM;
>  
>   /* In SMB3.11 preauth integrity supersedes validate negotiate */
>   if (tcon->ses->server->dialect == SMB311_PROT_ID)
> @@ -764,52 +767,53 @@ int smb3_validate_negotiate(const unsigned int xid, 
> struct cifs_tcon *tcon)
>   if (tcon->ses->session_flags & SMB2_SESSION_FLAG_IS_NULL)
>   cifs_dbg(VFS, "Unexpected null user (anonymous) auth flag sent 
> by server\n");
>  
> - vneg_inbuf.Capabilities =
> + pneg_inbuf->Capabilities =
>   cpu_to_le32(tcon->ses->server->vals->req_capabilities);
> - memcpy(vneg_inbuf.Guid, tcon->ses->server->client_guid,
> + memcpy(pneg_inbuf->Guid, tcon->ses->server->client_guid,
>   SMB2_CLIENT_GUID_SIZE);
>  
>   if (tcon->ses->sign)
> - vneg_inbuf.SecurityMode =
> + pneg_inbuf->SecurityMode =
>   cpu_to_le16(SMB2_NEGOTIATE_SIGNING_REQUIRED);
>   else if (global_secflags & CIFSSEC_MAY_SIGN)
> - vneg_inbuf.SecurityMode =
> + pneg_inbuf->SecurityMode =
>   cpu_to_le16(SMB2_NEGOTIATE_SIGNING_ENABLED);
>   else
> - vneg_inbuf.SecurityMode = 0;
> + pneg_inbuf->SecurityMode = 0;
>  
>  
>   if (strcmp(tcon->ses->server->vals->version_string,
>   SMB3ANY_VERSION_STRING) == 0) {
> - vneg_inbuf.Dialects[0] = cpu_to_le16(SMB30_PROT_ID);
> - vneg_inbuf.Dialects[1] = cpu_to_le16(SMB302_PROT_ID);
> - vneg_inbuf.DialectCount = cpu_to_le16(2);
> + pneg_inbuf->Dialects[0] = cpu_to_le16(SMB30_PROT_ID);
> + pneg_inbuf->Dialects[1] = cpu_to_le16(SMB302_PROT_ID);
> + pneg_inbuf->DialectCount = cpu_to_le16(2);
>   /* structure is big enough for 3 dialects, sending only 2 */
>   inbuflen = sizeof(struct validate_negotiate_info_req) - 2;
>   } else if (strcmp(tcon->ses->server->vals->version_string,
>   SMBDEFAULT_VERSION_STRING) == 0) {
> - vneg_inbuf.Dialects[0] = cpu_to_le16(SMB21_PROT_ID);
> - vneg_inbuf.Dialects[1] = cpu_to_le16(SMB30_PROT_ID);
> - vneg_inbuf.Dialects[2] = cpu_to_le16(SMB302_PROT_ID);
> - vneg_inbuf.DialectCount = cpu_to_le16(3);
> + pneg_inbuf->Dialects[0] = cpu_to_le16(SMB21_PROT_ID);
> + pneg_inbuf->Dialects[1] = cpu_to_le16(SMB30_PROT_ID);
> + pneg_inbuf->Dialects[2] = cpu_to_le16(SMB302_PROT_ID);
> + pneg_inbuf->DialectCount = cpu_to_le16(3);
>   /* structure is big enough for 3 dialects */
>   inbuflen = sizeof(struct validate_negotiate_info_req);
>   } else {
>   /* otherwise specific dialect was requested */
> - vneg_inbuf.Dialects[0] =
> + pneg_inbuf->Dialects[0] =
>   cpu_to_le16(tcon->ses->server->vals->protocol_id);
> - vneg_inbuf.DialectCount = cpu_to_le16(1);
> + pneg_inbuf->DialectCount = cpu_to_le16(1);
>   /* structure is big enough for 3 dialects, sending only 1 */
>   inbuflen = sizeof(struct validate_negotiate_info_req) - 4;
>   }
>  
>   rc = SMB2_ioctl(xid, tcon, NO_FILE_ID, NO_FILE_ID,
>   FSCTL_VALIDATE_NEGOTIATE_INFO, true /* is_fsctl */,
> - (char *)_inbuf, sizeof(struct validate_negotiate_info_req),
> + (char *)pneg_inbuf, sizeof(struct validate_negotiate_info_req),
>   (char **)_rsp, );
>  
>   if (rc != 0) {
>   cifs_dbg(VFS, "validate protocol negotiate failed: %d\n", rc);
> +

Re: [PATCH 2/6] cifs: Allocate validate negoation request through kmalloc

2018-04-17 Thread Greg KH

On Mon, Apr 16, 2018 at 05:49:14PM -0700, Long Li wrote:
> From: Long Li 
> 
> The data buffer allocated on the stack can't be DMA'ed, and hence can't send
> through RDMA via SMB Direct.
> 
> Fix this by allocating the request on the heap in smb3_validate_negotiate.
> 
> Signed-off-by: Long Li 
> ---
>  fs/cifs/smb2pdu.c | 38 ++
>  1 file changed, 22 insertions(+), 16 deletions(-)
> 
> diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
> index 0f044c4..abbefe2 100644
> --- a/fs/cifs/smb2pdu.c
> +++ b/fs/cifs/smb2pdu.c
> @@ -730,7 +730,7 @@ SMB2_negotiate(const unsigned int xid, struct cifs_ses 
> *ses)
>  int smb3_validate_negotiate(const unsigned int xid, struct cifs_tcon *tcon)
>  {
>   int rc = 0;
> - struct validate_negotiate_info_req vneg_inbuf;
> + struct validate_negotiate_info_req *pneg_inbuf;
>   struct validate_negotiate_info_rsp *pneg_rsp = NULL;
>   u32 rsplen;
>   u32 inbuflen; /* max of 4 dialects */
> @@ -741,6 +741,9 @@ int smb3_validate_negotiate(const unsigned int xid, 
> struct cifs_tcon *tcon)
>   if (tcon->ses->server->rdma)
>   return 0;
>  #endif
> + pneg_inbuf = kmalloc(sizeof(*pneg_inbuf), GFP_KERNEL);
> + if (!pneg_inbuf)
> + return -ENOMEM;
>  
>   /* In SMB3.11 preauth integrity supersedes validate negotiate */
>   if (tcon->ses->server->dialect == SMB311_PROT_ID)
> @@ -764,52 +767,53 @@ int smb3_validate_negotiate(const unsigned int xid, 
> struct cifs_tcon *tcon)
>   if (tcon->ses->session_flags & SMB2_SESSION_FLAG_IS_NULL)
>   cifs_dbg(VFS, "Unexpected null user (anonymous) auth flag sent 
> by server\n");
>  
> - vneg_inbuf.Capabilities =
> + pneg_inbuf->Capabilities =
>   cpu_to_le32(tcon->ses->server->vals->req_capabilities);
> - memcpy(vneg_inbuf.Guid, tcon->ses->server->client_guid,
> + memcpy(pneg_inbuf->Guid, tcon->ses->server->client_guid,
>   SMB2_CLIENT_GUID_SIZE);
>  
>   if (tcon->ses->sign)
> - vneg_inbuf.SecurityMode =
> + pneg_inbuf->SecurityMode =
>   cpu_to_le16(SMB2_NEGOTIATE_SIGNING_REQUIRED);
>   else if (global_secflags & CIFSSEC_MAY_SIGN)
> - vneg_inbuf.SecurityMode =
> + pneg_inbuf->SecurityMode =
>   cpu_to_le16(SMB2_NEGOTIATE_SIGNING_ENABLED);
>   else
> - vneg_inbuf.SecurityMode = 0;
> + pneg_inbuf->SecurityMode = 0;
>  
>  
>   if (strcmp(tcon->ses->server->vals->version_string,
>   SMB3ANY_VERSION_STRING) == 0) {
> - vneg_inbuf.Dialects[0] = cpu_to_le16(SMB30_PROT_ID);
> - vneg_inbuf.Dialects[1] = cpu_to_le16(SMB302_PROT_ID);
> - vneg_inbuf.DialectCount = cpu_to_le16(2);
> + pneg_inbuf->Dialects[0] = cpu_to_le16(SMB30_PROT_ID);
> + pneg_inbuf->Dialects[1] = cpu_to_le16(SMB302_PROT_ID);
> + pneg_inbuf->DialectCount = cpu_to_le16(2);
>   /* structure is big enough for 3 dialects, sending only 2 */
>   inbuflen = sizeof(struct validate_negotiate_info_req) - 2;
>   } else if (strcmp(tcon->ses->server->vals->version_string,
>   SMBDEFAULT_VERSION_STRING) == 0) {
> - vneg_inbuf.Dialects[0] = cpu_to_le16(SMB21_PROT_ID);
> - vneg_inbuf.Dialects[1] = cpu_to_le16(SMB30_PROT_ID);
> - vneg_inbuf.Dialects[2] = cpu_to_le16(SMB302_PROT_ID);
> - vneg_inbuf.DialectCount = cpu_to_le16(3);
> + pneg_inbuf->Dialects[0] = cpu_to_le16(SMB21_PROT_ID);
> + pneg_inbuf->Dialects[1] = cpu_to_le16(SMB30_PROT_ID);
> + pneg_inbuf->Dialects[2] = cpu_to_le16(SMB302_PROT_ID);
> + pneg_inbuf->DialectCount = cpu_to_le16(3);
>   /* structure is big enough for 3 dialects */
>   inbuflen = sizeof(struct validate_negotiate_info_req);
>   } else {
>   /* otherwise specific dialect was requested */
> - vneg_inbuf.Dialects[0] =
> + pneg_inbuf->Dialects[0] =
>   cpu_to_le16(tcon->ses->server->vals->protocol_id);
> - vneg_inbuf.DialectCount = cpu_to_le16(1);
> + pneg_inbuf->DialectCount = cpu_to_le16(1);
>   /* structure is big enough for 3 dialects, sending only 1 */
>   inbuflen = sizeof(struct validate_negotiate_info_req) - 4;
>   }
>  
>   rc = SMB2_ioctl(xid, tcon, NO_FILE_ID, NO_FILE_ID,
>   FSCTL_VALIDATE_NEGOTIATE_INFO, true /* is_fsctl */,
> - (char *)_inbuf, sizeof(struct validate_negotiate_info_req),
> + (char *)pneg_inbuf, sizeof(struct validate_negotiate_info_req),
>   (char **)_rsp, );
>  
>   if (rc != 0) {
>   cifs_dbg(VFS, "validate protocol negotiate failed: %d\n", rc);
> + kfree(pneg_inbuf);
>   return -EIO;
>   }
>

RE: [PATCH 2/6] cifs: Allocate validate negoation request through kmalloc

2018-04-16 Thread Parav Pandit



> -Original Message-
> From: linux-rdma-ow...@vger.kernel.org [mailto:linux-rdma-
> ow...@vger.kernel.org] On Behalf Of Long Li
> Sent: Monday, April 16, 2018 7:49 PM
> To: Steve French ; linux-c...@vger.kernel.org; samba-
> techni...@lists.samba.org; linux-kernel@vger.kernel.org; linux-
> r...@vger.kernel.org; sta...@vger.kernel.org
> Cc: longli 
> Subject: [PATCH 2/6] cifs: Allocate validate negoation request through kmalloc
> 
> From: Long Li 
> 
> The data buffer allocated on the stack can't be DMA'ed, and hence can't send
> through RDMA via SMB Direct.
> 
> Fix this by allocating the request on the heap in smb3_validate_negotiate.
> 
Please provide Fixes ("12-letters commit id") "commit string" which introduced 
this issue and it is getting fixed here, so that other can apply this fix to 
older versions.

> Signed-off-by: Long Li 
> ---
>  fs/cifs/smb2pdu.c | 38 ++
>  1 file changed, 22 insertions(+), 16 deletions(-)
> 
> diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c index 0f044c4..abbefe2
> 100644
> --- a/fs/cifs/smb2pdu.c
> +++ b/fs/cifs/smb2pdu.c
> @@ -730,7 +730,7 @@ SMB2_negotiate(const unsigned int xid, struct cifs_ses
> *ses)  int smb3_validate_negotiate(const unsigned int xid, struct cifs_tcon
> *tcon)  {
>   int rc = 0;
> - struct validate_negotiate_info_req vneg_inbuf;
> + struct validate_negotiate_info_req *pneg_inbuf;
[..]
 
>   rc = SMB2_ioctl(xid, tcon, NO_FILE_ID, NO_FILE_ID,
>   FSCTL_VALIDATE_NEGOTIATE_INFO, true /* is_fsctl */,
> - (char *)_inbuf, sizeof(struct
> validate_negotiate_info_req),
> + (char *)pneg_inbuf, sizeof(struct validate_negotiate_info_req),
>   (char **)_rsp, );
> 
>   if (rc != 0) {
>   cifs_dbg(VFS, "validate protocol negotiate failed: %d\n", rc);
> + kfree(pneg_inbuf);
>   return -EIO;
Instead of duplicating code here, please jump to err_rsp_free label. Kfree() 
takes care to not panic for NULL pointer.
Or for clarity define new label.

>   }
> 
> @@ -838,12 +842,14 @@ int smb3_validate_negotiate(const unsigned int xid,
> struct cifs_tcon *tcon)
> 
>   /* validate negotiate successful */
>   cifs_dbg(FYI, "validate negotiate info successful\n");
> + kfree(pneg_inbuf);
>   kfree(pneg_rsp);
>   return 0;
> 
>  vneg_out:
>   cifs_dbg(VFS, "protocol revalidation - security settings mismatch\n");
>  err_rsp_free:
> + kfree(pneg_inbuf);
>   kfree(pneg_rsp);
>   return -EIO;
>  }
> --
> 2.7.4
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the 
> body
> of a message to majord...@vger.kernel.org More majordomo info at
> http://vger.kernel.org/majordomo-info.html

RE: [PATCH 2/6] cifs: Allocate validate negoation request through kmalloc

2018-04-16 Thread Parav Pandit



> -Original Message-
> From: linux-rdma-ow...@vger.kernel.org [mailto:linux-rdma-
> ow...@vger.kernel.org] On Behalf Of Long Li
> Sent: Monday, April 16, 2018 7:49 PM
> To: Steve French ; linux-c...@vger.kernel.org; samba-
> techni...@lists.samba.org; linux-kernel@vger.kernel.org; linux-
> r...@vger.kernel.org; sta...@vger.kernel.org
> Cc: longli 
> Subject: [PATCH 2/6] cifs: Allocate validate negoation request through kmalloc
> 
> From: Long Li 
> 
> The data buffer allocated on the stack can't be DMA'ed, and hence can't send
> through RDMA via SMB Direct.
> 
> Fix this by allocating the request on the heap in smb3_validate_negotiate.
> 
Please provide Fixes ("12-letters commit id") "commit string" which introduced 
this issue and it is getting fixed here, so that other can apply this fix to 
older versions.

> Signed-off-by: Long Li 
> ---
>  fs/cifs/smb2pdu.c | 38 ++
>  1 file changed, 22 insertions(+), 16 deletions(-)
> 
> diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c index 0f044c4..abbefe2
> 100644
> --- a/fs/cifs/smb2pdu.c
> +++ b/fs/cifs/smb2pdu.c
> @@ -730,7 +730,7 @@ SMB2_negotiate(const unsigned int xid, struct cifs_ses
> *ses)  int smb3_validate_negotiate(const unsigned int xid, struct cifs_tcon
> *tcon)  {
>   int rc = 0;
> - struct validate_negotiate_info_req vneg_inbuf;
> + struct validate_negotiate_info_req *pneg_inbuf;
[..]
 
>   rc = SMB2_ioctl(xid, tcon, NO_FILE_ID, NO_FILE_ID,
>   FSCTL_VALIDATE_NEGOTIATE_INFO, true /* is_fsctl */,
> - (char *)_inbuf, sizeof(struct
> validate_negotiate_info_req),
> + (char *)pneg_inbuf, sizeof(struct validate_negotiate_info_req),
>   (char **)_rsp, );
> 
>   if (rc != 0) {
>   cifs_dbg(VFS, "validate protocol negotiate failed: %d\n", rc);
> + kfree(pneg_inbuf);
>   return -EIO;
Instead of duplicating code here, please jump to err_rsp_free label. Kfree() 
takes care to not panic for NULL pointer.
Or for clarity define new label.

>   }
> 
> @@ -838,12 +842,14 @@ int smb3_validate_negotiate(const unsigned int xid,
> struct cifs_tcon *tcon)
> 
>   /* validate negotiate successful */
>   cifs_dbg(FYI, "validate negotiate info successful\n");
> + kfree(pneg_inbuf);
>   kfree(pneg_rsp);
>   return 0;
> 
>  vneg_out:
>   cifs_dbg(VFS, "protocol revalidation - security settings mismatch\n");
>  err_rsp_free:
> + kfree(pneg_inbuf);
>   kfree(pneg_rsp);
>   return -EIO;
>  }
> --
> 2.7.4
> 
> --
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RE: [PATCH 2/6] cifs: Allocate validate negoation request through kmalloc

RE: [PATCH 2/6] cifs: Allocate validate negoation request through kmalloc

Re: [PATCH 2/6] cifs: Allocate validate negoation request through kmalloc

Re: [PATCH 2/6] cifs: Allocate validate negoation request through kmalloc

RE: [PATCH 2/6] cifs: Allocate validate negoation request through kmalloc

RE: [PATCH 2/6] cifs: Allocate validate negoation request through kmalloc

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