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

Message ID 20180417004918.29213-2-longli@linuxonhyperv.com
State New
Headers show
Series
  • [1/6] cifs: smbd: Check for iov length on sending the last iov
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Commit Message

Long Li April 17, 2018, 12:49 a.m.
From: Long Li <longli@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.

Signed-off-by: Long Li <longli@microsoft.com>
---
 fs/cifs/smb2pdu.c | 38 ++++++++++++++++++++++----------------
 1 file changed, 22 insertions(+), 16 deletions(-)

Comments

Parav Pandit April 17, 2018, 4:01 a.m. | #1
> -----Original Message-----
> From: linux-rdma-owner@vger.kernel.org [mailto:linux-rdma-
> owner@vger.kernel.org] On Behalf Of Long Li
> Sent: Monday, April 16, 2018 7:49 PM
> To: Steve French <sfrench@samba.org>; linux-cifs@vger.kernel.org; samba-
> technical@lists.samba.org; linux-kernel@vger.kernel.org; linux-
> rdma@vger.kernel.org; stable@vger.kernel.org
> Cc: longli <longli@microsoft.com>
> Subject: [PATCH 2/6] cifs: Allocate validate negoation request through kmalloc
> 
> From: Long Li <longli@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.

> Signed-off-by: Long Li <longli@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 *)&vneg_inbuf, sizeof(struct
> validate_negotiate_info_req),
> +		(char *)pneg_inbuf, sizeof(struct validate_negotiate_info_req),
>  		(char **)&pneg_rsp, &rsplen);
> 
>  	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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Greg KH April 17, 2018, 7:30 a.m. | #2
On Mon, Apr 16, 2018 at 05:49:14PM -0700, Long Li wrote:
> From: Long Li <longli@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.
> 
> Signed-off-by: Long Li <longli@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;
>  	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 *)&vneg_inbuf, sizeof(struct validate_negotiate_info_req),
> +		(char *)pneg_inbuf, sizeof(struct validate_negotiate_info_req),
>  		(char **)&pneg_rsp, &rsplen);
>  
>  	if (rc != 0) {
>  		cifs_dbg(VFS, "validate protocol negotiate failed: %d\n", rc);
> +		kfree(pneg_inbuf);
>  		return -EIO;
>  	}
>  
> @@ -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

<formletter>

This is not the correct way to submit patches for inclusion in the
stable kernel tree.  Please read:
    https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html
for how to do this properly.

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Long Li April 17, 2018, 6:11 p.m. | #3
> Subject: RE: [PATCH 2/6] cifs: Allocate validate negoation request through
> kmalloc
> 
> 
> 
> > -----Original Message-----
> > From: linux-rdma-owner@vger.kernel.org [mailto:linux-rdma-
> > owner@vger.kernel.org] On Behalf Of Long Li
> > Sent: Monday, April 16, 2018 7:49 PM
> > To: Steve French <sfrench@samba.org>; linux-cifs@vger.kernel.org;
> > samba- technical@lists.samba.org; linux-kernel@vger.kernel.org; linux-
> > rdma@vger.kernel.org; stable@vger.kernel.org
> > Cc: longli <longli@microsoft.com>
> > Subject: [PATCH 2/6] cifs: Allocate validate negoation request through
> > kmalloc
> >
> > From: Long Li <longli@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 <longli@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 *)&vneg_inbuf, sizeof(struct
> > validate_negotiate_info_req),
> > +		(char *)pneg_inbuf, sizeof(struct
> validate_negotiate_info_req),
> >  		(char **)&pneg_rsp, &rsplen);
> >
> >  	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
> >
> > --
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Patch

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 *)&vneg_inbuf, sizeof(struct validate_negotiate_info_req),
+		(char *)pneg_inbuf, sizeof(struct validate_negotiate_info_req),
 		(char **)&pneg_rsp, &rsplen);
 
 	if (rc != 0) {
 		cifs_dbg(VFS, "validate protocol negotiate failed: %d\n", rc);
+		kfree(pneg_inbuf);
 		return -EIO;
 	}
 
@@ -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;
 }