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net/colo.c: fix segmentation fault when packet is not parsed correctly

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When COLO use only one vnet_hdr_support parameter between
filter-redirector and filter-mirror(or colo-compare), COLO will crash
with segmentation fault. Back track as follow:

Thread 1 "qemu-system-x86" received signal SIGSEGV, Segmentation fault.
0x0000555555cb200b in eth_get_l2_hdr_length (p=0x0)
    at /home/tao/project/COLO/colo-qemu/include/net/eth.h:296
296         uint16_t proto = be16_to_cpu(PKT_GET_ETH_HDR(p)->h_proto);
(gdb) bt
0  0x0000555555cb200b in eth_get_l2_hdr_length (p=0x0)
    at /home/tao/project/COLO/colo-qemu/include/net/eth.h:296
1  0x0000555555cb22b4 in parse_packet_early (pkt=0x555556a44840) at
net/colo.c:49
2  0x0000555555cb2b91 in is_tcp_packet (pkt=0x555556a44840) at
net/filter-rewriter.c:63

So wrong vnet_hdr_len will cause pkt->data become NULL. Add check to
raise error and add trace-events to track vnet_hdr_len.

Signed-off-by: Tao Xu <tao3.xu@intel.com>
Signed-off-by: Zhang Chen <chen.zhang@intel.com>
Reviewed-by: Li Zhijian <lizhijian@fujitsu.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
This commit is contained in:
Zhang Chen 2022-04-01 11:47:02 +08:00 committed by Jason Wang
parent 94c36c4875
commit 8bdab83b34
2 changed files with 9 additions and 1 deletions
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9
net/colo.c
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@ -46,7 +46,14 @@ int parse_packet_early(Packet *pkt)
static const uint8_t vlan[] = {0x81, 0x00}; static const uint8_t vlan[] = {0x81, 0x00};
uint8_t *data = pkt->data + pkt->vnet_hdr_len; uint8_t *data = pkt->data + pkt->vnet_hdr_len;
uint16_t l3_proto; uint16_t l3_proto;
ssize_t l2hdr_len = eth_get_l2_hdr_length(data); ssize_t l2hdr_len;
if (data == NULL) {
trace_colo_proxy_main_vnet_info("This packet is not parsed correctly, "
"pkt->vnet_hdr_len", pkt->vnet_hdr_len);
return 1;
}
l2hdr_len = eth_get_l2_hdr_length(data);
if (pkt->size < ETH_HLEN + pkt->vnet_hdr_len) { if (pkt->size < ETH_HLEN + pkt->vnet_hdr_len) {
trace_colo_proxy_main("pkt->size < ETH_HLEN"); trace_colo_proxy_main("pkt->size < ETH_HLEN");

1
net/trace-events
View File

@ -9,6 +9,7 @@ vhost_user_event(const char *chr, int event) "chr: %s got event: %d"
# colo.c # colo.c
colo_proxy_main(const char *chr) ": %s" colo_proxy_main(const char *chr) ": %s"
colo_proxy_main_vnet_info(const char *sta, int size) ": %s = %d"
# colo-compare.c # colo-compare.c
colo_compare_main(const char *chr) ": %s" colo_compare_main(const char *chr) ": %s"