OpenCloudOS-Kernel/net/core
Pravin B Shelar a17ad09617 net: Fix zero-copy head len calculation.
In some cases skb head could be locked and entire header
data is pulled from skb. When skb_zerocopy() called in such cases,
following BUG is triggered. This patch fixes it by copying entire
skb in such cases.
This could be optimized incase this is performance bottleneck.

---8<---
kernel BUG at net/core/skbuff.c:2961!
invalid opcode: 0000 [#1] SMP PTI
CPU: 2 PID: 0 Comm: swapper/2 Tainted: G           OE     5.4.0-77-generic #86-Ubuntu
Hardware name: OpenStack Foundation OpenStack Nova, BIOS 1.13.0-1ubuntu1.1 04/01/2014
RIP: 0010:skb_zerocopy+0x37a/0x3a0
RSP: 0018:ffffbcc70013ca38 EFLAGS: 00010246
Call Trace:
 <IRQ>
 queue_userspace_packet+0x2af/0x5e0 [openvswitch]
 ovs_dp_upcall+0x3d/0x60 [openvswitch]
 ovs_dp_process_packet+0x125/0x150 [openvswitch]
 ovs_vport_receive+0x77/0xd0 [openvswitch]
 netdev_port_receive+0x87/0x130 [openvswitch]
 netdev_frame_hook+0x4b/0x60 [openvswitch]
 __netif_receive_skb_core+0x2b4/0xc90
 __netif_receive_skb_one_core+0x3f/0xa0
 __netif_receive_skb+0x18/0x60
 process_backlog+0xa9/0x160
 net_rx_action+0x142/0x390
 __do_softirq+0xe1/0x2d6
 irq_exit+0xae/0xb0
 do_IRQ+0x5a/0xf0
 common_interrupt+0xf/0xf

Code that triggered BUG:
int
skb_zerocopy(struct sk_buff *to, struct sk_buff *from, int len, int hlen)
{
        int i, j = 0;
        int plen = 0; /* length of skb->head fragment */
        int ret;
        struct page *page;
        unsigned int offset;

        BUG_ON(!from->head_frag && !hlen);

Signed-off-by: Pravin B Shelar <pshelar@ovn.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-18 09:42:17 -07:00
..
Makefile
bpf_sk_storage.c
datagram.c
datagram.h
dev.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf 2021-07-15 14:39:45 -07:00
dev_addr_lists.c
dev_ioctl.c
devlink.c
drop_monitor.c
dst.c
dst_cache.c
failover.c
fib_notifier.c
fib_rules.c
filter.c Networking changes for 5.14. 2021-06-30 15:51:09 -07:00
flow_dissector.c
flow_offload.c
gen_estimator.c
gen_stats.c
gro_cells.c
hwbm.c
link_watch.c
lwt_bpf.c
lwtunnel.c
neighbour.c
net-procfs.c
net-sysfs.c
net-sysfs.h
net-traces.c
net_namespace.c
netclassid_cgroup.c
netevent.c
netpoll.c asm-generic/unaligned: Unify asm/unaligned.h around struct helper 2021-07-02 12:43:40 -07:00
netprio_cgroup.c
page_pool.c
pktgen.c
ptp_classifier.c
request_sock.c
rtnetlink.c net: say "local" instead of "static" addresses in ndo_dflt_fdb_{add,del} 2021-06-29 11:31:57 -07:00
scm.c
secure_seq.c
selftests.c
skbuff.c net: Fix zero-copy head len calculation. 2021-07-18 09:42:17 -07:00
skmsg.c bpf, sockmap: Fix potential memory leak on unlikely error case 2021-07-15 19:49:12 +02:00
sock.c sock: unlock on error in sock_setsockopt() 2021-07-07 20:49:12 -07:00
sock_diag.c
sock_map.c
sock_reuseport.c
stream.c
sysctl_net_core.c
timestamping.c
tso.c
utils.c
xdp.c