[PATCH] thunderbolt: Fix some right shifting to zero bugs

[PATCH] thunderbolt: Fix some right shifting to zero bugs

[Dan Carpenter]

The problematic code looks like this:

	res_seq = res_hdr->xd_hdr.length_sn & TB_XDOMAIN_SN_MASK;
	res_seq >>= TB_XDOMAIN_SN_SHIFT;

TB_XDOMAIN_SN_SHIFT is 27, and right shifting a u8 27 bits is always
going to result in zero.  The fix is to declare these variables as u32.

Fixes: d1ff70241a27 ("thunderbolt: Add support for XDomain discovery protocol")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>

diff --git a/drivers/thunderbolt/xdomain.c b/drivers/thunderbolt/xdomain.c
index f2d06f6f7be9..c6ca170e1f4f 100644
--- a/drivers/thunderbolt/xdomain.c
+++ b/drivers/thunderbolt/xdomain.c
@@ -56,7 +56,7 @@ static bool tb_xdomain_match(const struct tb_cfg_request *req,
 	case TB_CFG_PKG_XDOMAIN_RESP: {
 		const struct tb_xdp_header *res_hdr = pkg->buffer;
 		const struct tb_xdp_header *req_hdr = req->request;
-		u8 req_seq, res_seq;
+		u32 req_seq, res_seq;
 
 		if (pkg->frame.size < req->response_size / 4)
 			return false;
@@ -476,7 +476,7 @@ static void tb_xdp_handle_request(struct work_struct *work)
 	struct tb_ctl *ctl = tb->ctl;
 	const uuid_t *uuid;
 	int ret = 0;
-	u8 sequence;
+	u32 sequence;
 	u64 route;
 
 	route = ((u64)xhdr->route_hi << 32 | xhdr->route_lo) & ~BIT_ULL(63);
diff --git a/drivers/net/thunderbolt.c b/drivers/net/thunderbolt.c
index 1a7bc0bf4598..435854688a7a 100644
--- a/drivers/net/thunderbolt.c
+++ b/drivers/net/thunderbolt.c
@@ -394,7 +394,7 @@ static int tbnet_handle_packet(const void *buf, size_t size, void *data)
 	struct tbnet *net = data;
 	u32 command_id;
 	int ret = 0;
-	u8 sequence;
+	u32 sequence;
 	u64 route;
 
 	/* Make sure the packet is for us */

Re: [PATCH] thunderbolt: Fix some right shifting to zero bugs

[Mika Westerberg]

On Fri, Oct 13, 2017 at 02:29:59PM +0300, Dan Carpenter wrote:
> The problematic code looks like this:
> 
> 	res_seq = res_hdr->xd_hdr.length_sn & TB_XDOMAIN_SN_MASK;
> 	res_seq >>= TB_XDOMAIN_SN_SHIFT;
> 
> TB_XDOMAIN_SN_SHIFT is 27, and right shifting a u8 27 bits is always
> going to result in zero.  The fix is to declare these variables as u32.
> 
> Fixes: d1ff70241a27 ("thunderbolt: Add support for XDomain discovery protocol")

I think this requires two patches as the drivers/net/thunderbolt.c is
added by another commit.

Also please CC netdev@vger.kernel.org and David Miller as the patches
are in his net-next tree.

The fixes themselves look good, though.

[PATCH 1/2 v2 net-next] thunderbolt: Fix a couple right shifting to zero bugs

[Dan Carpenter]

The problematic code looks like this:

	res_seq = res_hdr->xd_hdr.length_sn & TB_XDOMAIN_SN_MASK;
	res_seq >>= TB_XDOMAIN_SN_SHIFT;

TB_XDOMAIN_SN_SHIFT is 27, and right shifting a u8 27 bits is always
going to result in zero.  The fix is to declare these variables as u32.

Fixes: d1ff70241a27 ("thunderbolt: Add support for XDomain discovery protocol")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
v2: I accidentally sent this through the wrong list, so I'm resending to
    netdev.  Also Mika asked me to split it up because the Fixes tags
    are different for these patches.

diff --git a/drivers/thunderbolt/xdomain.c b/drivers/thunderbolt/xdomain.c
index 138027537d29..ff8d91189e99 100644
--- a/drivers/thunderbolt/xdomain.c
+++ b/drivers/thunderbolt/xdomain.c
@@ -56,7 +56,7 @@ static bool tb_xdomain_match(const struct tb_cfg_request *req,
 	case TB_CFG_PKG_XDOMAIN_RESP: {
 		const struct tb_xdp_header *res_hdr = pkg->buffer;
 		const struct tb_xdp_header *req_hdr = req->request;
-		u8 req_seq, res_seq;
+		u32 req_seq, res_seq;
 
 		if (pkg->frame.size < req->response_size / 4)
 			return false;
@@ -476,7 +476,7 @@ static void tb_xdp_handle_request(struct work_struct *work)
 	struct tb_ctl *ctl = tb->ctl;
 	const uuid_t *uuid;
 	int ret = 0;
-	u8 sequence;
+	u32 sequence;
 	u64 route;
 
 	route = ((u64)xhdr->route_hi << 32 | xhdr->route_lo) & ~BIT_ULL(63);

[PATCH 2/2 net-next] thunderbolt: Right shifting to zero bug in tbnet_handle_packet()

[Dan Carpenter]

There is a problem when we do:

	sequence = pkg->hdr.length_sn & TBIP_HDR_SN_MASK;
	sequence >>= TBIP_HDR_SN_SHIFT;

TBIP_HDR_SN_SHIFT is 27, and right shifting a u8 27 bits is always
going to result in zero.  The fix is to declare these variables as u32.

Fixes: e69b6c02b4c3 ("net: Add support for networking over Thunderbolt cable")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>

diff --git a/drivers/net/thunderbolt.c b/drivers/net/thunderbolt.c
index 1a7bc0bf4598..435854688a7a 100644
--- a/drivers/net/thunderbolt.c
+++ b/drivers/net/thunderbolt.c
@@ -394,7 +394,7 @@ static int tbnet_handle_packet(const void *buf, size_t size, void *data)
 	struct tbnet *net = data;
 	u32 command_id;
 	int ret = 0;
-	u8 sequence;
+	u32 sequence;
 	u64 route;
 
 	/* Make sure the packet is for us */

Re: [PATCH 2/2 net-next] thunderbolt: Right shifting to zero bug in tbnet_handle_packet()

[Bernat, Yehezkel]

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Re: [PATCH 1/2 v2 net-next] thunderbolt: Fix a couple right shifting to zero bugs

[David Miller]

From: Dan Carpenter <dan.carpenter@oracle.com>
Date: Tue, 17 Oct 2017 15:32:17 +0300

> The problematic code looks like this:
> 
> 	res_seq = res_hdr->xd_hdr.length_sn & TB_XDOMAIN_SN_MASK;
> 	res_seq >>= TB_XDOMAIN_SN_SHIFT;
> 
> TB_XDOMAIN_SN_SHIFT is 27, and right shifting a u8 27 bits is always
> going to result in zero.  The fix is to declare these variables as u32.
> 
> Fixes: d1ff70241a27 ("thunderbolt: Add support for XDomain discovery protocol")
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>

Applied.

Re: [PATCH 2/2 net-next] thunderbolt: Right shifting to zero bug in tbnet_handle_packet()

[David Miller]

From: Dan Carpenter <dan.carpenter@oracle.com>
Date: Tue, 17 Oct 2017 15:33:01 +0300

> There is a problem when we do:
> 
> 	sequence = pkg->hdr.length_sn & TBIP_HDR_SN_MASK;
> 	sequence >>= TBIP_HDR_SN_SHIFT;
> 
> TBIP_HDR_SN_SHIFT is 27, and right shifting a u8 27 bits is always
> going to result in zero.  The fix is to declare these variables as u32.
> 
> Fixes: e69b6c02b4c3 ("net: Add support for networking over Thunderbolt cable")
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>

Applied.