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authorNishank Trivedi <nistrive@cisco.com>2012-09-12 13:32:49 +0000
committerDavid S. Miller <davem@davemloft.net>2012-09-13 17:10:00 -0400
commit6af773e786ad617b0264ebe06ba60675c01f3e51 (patch)
treedacac8780f7e78d8c634b8029235a025389e361d
parent7b5342d9026d537cbc01fd30b7cd9bac9b07b5ad (diff)
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pktgen: fix crash with vlan and packet size less than 46
If vlan option is being specified in the pktgen and packet size being requested is less than 46 bytes, despite being illogical request, pktgen should not crash the kernel. BUG: unable to handle kernel paging request at ffff88021fb82000 Process kpktgend_0 (pid: 1184, threadinfo ffff880215f1a000, task ffff880218544530) Call Trace: [<ffffffffa0637cd2>] ? pktgen_finalize_skb+0x222/0x300 [pktgen] [<ffffffff814f0084>] ? build_skb+0x34/0x1c0 [<ffffffffa0639b11>] pktgen_thread_worker+0x5d1/0x1790 [pktgen] [<ffffffffa03ffb10>] ? igb_xmit_frame_ring+0xa30/0xa30 [igb] [<ffffffff8107ba20>] ? wake_up_bit+0x40/0x40 [<ffffffff8107ba20>] ? wake_up_bit+0x40/0x40 [<ffffffffa0639540>] ? spin+0x240/0x240 [pktgen] [<ffffffff8107b4e3>] kthread+0x93/0xa0 [<ffffffff81615de4>] kernel_thread_helper+0x4/0x10 [<ffffffff8107b450>] ? flush_kthread_worker+0x80/0x80 [<ffffffff81615de0>] ? gs_change+0x13/0x13 The root cause of why pktgen is not able to handle this case is due to comparison of signed (datalen) and unsigned data (sizeof), which eventually passes a huge number to skb_put(). Signed-off-by: Nishank Trivedi <nistrive@cisco.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--net/core/pktgen.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/net/core/pktgen.c b/net/core/pktgen.c
index cce9e53528b1..148e73d2c451 100644
--- a/net/core/pktgen.c
+++ b/net/core/pktgen.c
@@ -2721,7 +2721,7 @@ static struct sk_buff *fill_packet_ipv4(struct net_device *odev,
/* Eth + IPh + UDPh + mpls */
datalen = pkt_dev->cur_pkt_size - 14 - 20 - 8 -
pkt_dev->pkt_overhead;
- if (datalen < sizeof(struct pktgen_hdr))
+ if (datalen < 0 || datalen < sizeof(struct pktgen_hdr))
datalen = sizeof(struct pktgen_hdr);
udph->source = htons(pkt_dev->cur_udp_src);