linux/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
..
bpf_sk_storage.c bpf: Use struct_size() in kzalloc() 2021-05-13 15:58:00 -07:00
datagram.c udp: fix skb_copy_and_csum_datagram with odd segment sizes 2021-02-04 18:56:56 -08:00
datagram.h
dev_addr_lists.c net: core: Correct function name dev_uc_flush() in the kerneldoc 2021-03-28 17:56:56 -07:00
dev_ioctl.c net: fix dev_ifsioc_locked() race condition 2021-02-11 18:14:19 -08:00
dev.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf 2021-07-15 14:39:45 -07:00
devlink.c devlink: Protect rate list with lock while switching modes 2021-06-23 15:46:25 -07:00
drop_monitor.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2021-03-25 15:31:22 -07:00
dst_cache.c
dst.c net, bpf: Fix ip6ip6 crash with collect_md populated skbs 2021-03-10 12:24:18 -08:00
failover.c
fib_notifier.c
fib_rules.c fib: Return the correct errno code 2021-06-03 15:13:56 -07:00
filter.c Networking changes for 5.14. 2021-06-30 15:51:09 -07:00
flow_dissector.c net: flow_dissector: fix RPS on DSA masters 2021-06-14 13:15:22 -07:00
flow_offload.c net: flow_offload: Fix memory leak for indirect flow block 2020-12-09 16:08:33 -08:00
gen_estimator.c net_sched: gen_estimator: support large ewma log 2021-01-15 18:11:06 -08:00
gen_stats.c
gro_cells.c gro_cells: reduce number of synchronize_net() calls 2020-11-25 11:28:12 -08:00
hwbm.c
link_watch.c
lwt_bpf.c lwt_bpf: Replace preempt_disable() with migrate_disable() 2020-12-07 11:53:40 -08:00
lwtunnel.c
Makefile net: selftest: fix build issue if INET is disabled 2021-04-28 14:06:45 -07:00
neighbour.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2021-06-18 19:47:02 -07:00
net_namespace.c net: inline function get_net_ns_by_fd if NET_NS is disabled 2021-06-15 11:00:45 -07:00
net-procfs.c net: move the ptype_all and ptype_base declarations to include/linux/netdevice.h 2021-03-22 13:14:45 -07:00
net-sysfs.c net-sysfs: remove possible sleep from an RCU read-side critical section 2021-03-22 13:28:13 -07:00
net-sysfs.h
net-traces.c tcp: add tracepoint for checksum errors 2021-05-14 15:26:03 -07:00
netclassid_cgroup.c net: Remove the err argument from sock_from_file 2020-12-04 22:32:40 +01:00
netevent.c net: core: Correct function name netevent_unregister_notifier() in the kerneldoc 2021-03-28 17:56:56 -07:00
netpoll.c asm-generic/unaligned: Unify asm/unaligned.h around struct helper 2021-07-02 12:43:40 -07:00
netprio_cgroup.c net: Remove the err argument from sock_from_file 2020-12-04 22:32:40 +01:00
page_pool.c page_pool: Allow drivers to hint on SKB recycling 2021-06-07 14:11:47 -07:00
pktgen.c pktgen: add pktgen_handle_all_threads() for the same code 2021-06-07 13:15:31 -07:00
ptp_classifier.c ptp: Add generic ptp v2 header parsing function 2020-08-19 16:07:49 -07:00
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 scm: fix a typo in put_cmsg() 2021-04-16 11:41:07 -07:00
secure_seq.c
selftests.c net: add generic selftest support 2021-04-20 16:08:02 -07:00
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_diag.c bpf, net: Rework cookie generator as per-cpu one 2020-09-30 11:50:35 -07:00
sock_map.c bpf: Fix integer overflow in argument calculation for bpf_map_area_alloc 2021-06-22 10:14:29 -07:00
sock_reuseport.c tcp: Add stats for socket migration. 2021-06-23 12:56:08 -07:00
sock.c sock: unlock on error in sock_setsockopt() 2021-07-07 20:49:12 -07:00
stream.c
sysctl_net_core.c net: change netdev_unregister_timeout_secs min value to 1 2021-03-25 17:24:06 -07:00
timestamping.c
tso.c net: tso: add UDP segmentation support 2020-06-18 20:46:23 -07:00
utils.c
xdp.c xdp: Move the rxq_info.mem clearing to unreg_mem_model() 2021-06-28 23:07:59 +02:00