[PATCH] bnx2x: dont dereference tcp header on non tcp frames

Eric Dumazet
2011-04-20T07:31:58Z

Le mardi 19 avril 2011 à 18:11 +0200, Eric Dumazet a écrit :
> Hi guys
>
> bnx2x_set_pbd_csum() / bnx2x_set_pbd_csum_e2() seem to read
> tcp_hdrlen(skb) even for non TCP frames ?
>
> Also, (skb_network_header(skb) - skb->data) is signed, so
> (skb_network_header(skb) - skb->data) / 2 is a bit expensive...
>

I managed to trigger a kmemcheck fault using netperf -t UDP_RR

02:00.1 Ethernet controller: Broadcom Corporation NetXtreme II BCM57711E 10Gigabit PCIe

[ 341.246514] WARNING: kmemcheck: Caught 8-bit read from uninitialized memory (ffff88011800ec30)
[ 341.247155] c0a8146ea907c4550009aa456ed2000008000400040000001400030000000000
[ 341.249789] i i i i i i i i i i i i i u u u u u u u u u u u u u u u u u u u
[ 341.252425] ^
[ 341.252773]
[ 341.252937] Pid: 4122, comm: netperf Not tainted 2.6.39-rc4-00237-ge3de956-dirty #549 HP ProLiant BL460c G6
[ 341.253768] RIP: 0010:[<ffffffff812f5224>] [<ffffffff812f5224>] bnx2x_start_xmit+0xce4/0x13f0
[ 341.254476] RSP: 0018:ffff8801158b38b8 EFLAGS: 00010286
[ 341.254879] RAX: ffff88011800ec24 RBX: ffff880118e44820 RCX: 0000000000000007
[ 341.255400] RDX: 000000000000000a RSI: ffff880118e44820 RDI: ffff88011800ec40
[ 341.255918] RBP: ffff8801158b39b8 R08: ffff88011800ec40 R09: ffff88011800ec00
[ 341.256439] R10: 0000000000000000 R11: 000000006e14a8c0 R12: ffff880118f4db00
[ 341.256958] R13: 0000000000000481 R14: 0000000000000040 R15: ffff880118ff18e0
[ 341.257479] FS: 0000000000000000(0000) GS:ffff88011fc00000(0063) knlGS:00000000f77e16c0
[ 341.258081] CS: 0010 DS: 002b ES: 002b CR0: 000000008005003b
[ 341.258511] CR2: ffff880119856058 CR3: 0000000115879000 CR4: 00000000000006f0
[ 341.259033] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 341.259551] DR3: 0000000000000000 DR6: 00000000ffff4ff0 DR7: 0000000000000400
[ 341.260072] [<ffffffff8137fac5>] dev_hard_start_xmit+0x365/0x690
[ 341.260593] [<ffffffff81398bf7>] sch_direct_xmit+0xb7/0x1c0
[ 341.261091] [<ffffffff81383da8>] dev_queue_xmit+0x1a8/0x5d0
[ 341.261583] [<ffffffff813c2842>] ip_finish_output+0x122/0x2f0
[ 341.262122] [<ffffffff813c163e>] ip_output+0x7e/0xc0
[ 341.262609] [<ffffffff813c1194>] ip_local_out+0x24/0x30
[ 341.263114] [<ffffffff813c11b6>] ip_send_skb+0x16/0x70
[ 341.263611] [<ffffffff813e1326>] udp_send_skb+0x126/0x380
[ 341.264129] [<ffffffff813e300c>] udp_sendmsg+0x2cc/0x790
[ 341.264637] [<ffffffff813eaf44>] inet_sendmsg+0x84/0xc0
[ 341.265143] [<ffffffff8136d98b>] sock_sendmsg+0xbb/0xf0
[ 341.265646] [<ffffffff8136e1e5>] sys_sendto+0x105/0x140
[ 341.266151] [<ffffffff8136e22f>] sys_send+0xf/0x20
[ 341.266625] [<ffffffff813969fd>] compat_sys_socketcall+0xfd/0x1f0
[ 341.267186] [<ffffffff8146b8e9>] sysenter_dispatch+0x7/0x27

[PATCH] bnx2x: dont dereference tcp header on non tcp frames

bnx2x_set_pbd_csum() & bnx2x_set_pbd_csum_e2() use
tcp_hdrlen(skb) even for non TCP frames

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Dmitry Kravkov <dmitry@broadcom.com>
Cc: Eilon Greenstein <eilong@broadcom.com>
---
drivers/net/bnx2x/bnx2x_cmn.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/net/bnx2x/bnx2x_cmn.c b/drivers/net/bnx2x/bnx2x_cmn.c
index e83ac6d..a16a638 100644
--- a/drivers/net/bnx2x/bnx2x_cmn.c
+++ b/drivers/net/bnx2x/bnx2x_cmn.c
@@ -2019,7 +2019,9 @@ static inline void bnx2x_set_pbd_gso(struct sk_buff *skb,
static inline u8 bnx2x_set_pbd_csum_e2(struct bnx2x *bp, struct sk_buff *skb,
u32 *parsing_data, u32 xmit_type)
{
- *parsing_data |= ((tcp_hdrlen(skb)/4) <<
+ u8 tcphlen = (xmit_type & XMIT_CSUM_TCP) ? tcp_hdrlen(skb) : 0;
+
+ *parsing_data |= ((tcphlen/4) <<
ETH_TX_PARSE_BD_E2_TCP_HDR_LENGTH_DW_SHIFT) &
ETH_TX_PARSE_BD_E2_TCP_HDR_LENGTH_DW;

@@ -2027,7 +2029,7 @@ static inline u8 bnx2x_set_pbd_csum_e2(struct bnx2x *bp, struct sk_buff *skb,
ETH_TX_PARSE_BD_E2_TCP_HDR_START_OFFSET_W_SHIFT) &
ETH_TX_PARSE_BD_E2_TCP_HDR_START_OFFSET_W;

- return skb_transport_header(skb) + tcp_hdrlen(skb) - skb->data;
+ return skb_transport_header(skb) + tcphlen - skb->data;
}

/**
@@ -2044,6 +2046,7 @@ static inline u8 bnx2x_set_pbd_csum(struct bnx2x *bp, struct sk_buff *skb,
u32 xmit_type)
{
u8 hlen = (skb_network_header(skb) - skb->data) / 2;
+ u8 tcphlen = (xmit_type & XMIT_CSUM_TCP) ? tcp_hdrlen(skb) : 0;

/* for now NS flag is not used in Linux */
pbd->global_data =
@@ -2053,7 +2056,7 @@ static inline u8 bnx2x_set_pbd_csum(struct bnx2x *bp, struct sk_buff *skb,
pbd->ip_hlen_w = (skb_transport_header(skb) -
skb_network_header(skb)) / 2;

- hlen += pbd->ip_hlen_w + tcp_hdrlen(skb) / 2;
+ hlen += pbd->ip_hlen_w + tcphlen / 2;

pbd->total_hlen_w = cpu_to_le16(hlen);
hlen = hlen*2;