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| author | Eric Dumazet <edumazet@google.com> | 2019-11-07 18:29:11 -0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2019-11-07 20:07:30 -0800 |
| commit | c305c6ae79e2ce20c22660ceda94f0d86d639a82 (patch) | |
| tree | 902ad3a822aa2ed406068e90cf2cd3fcbde59c68 /drivers/firewire | |
| parent | 9dfd871481c8e9c512938e9ce632beed645363e0 (diff) | |
| download | linux-c305c6ae79e2ce20c22660ceda94f0d86d639a82.tar.gz linux-c305c6ae79e2ce20c22660ceda94f0d86d639a82.tar.bz2 linux-c305c6ae79e2ce20c22660ceda94f0d86d639a82.zip | |
net: add annotations on hh->hh_len lockless accesses
KCSAN reported a data-race [1]
While we can use READ_ONCE() on the read sides,
we need to make sure hh->hh_len is written last.
[1]
BUG: KCSAN: data-race in eth_header_cache / neigh_resolve_output
write to 0xffff8880b9dedcb8 of 4 bytes by task 29760 on cpu 0:
eth_header_cache+0xa9/0xd0 net/ethernet/eth.c:247
neigh_hh_init net/core/neighbour.c:1463 [inline]
neigh_resolve_output net/core/neighbour.c:1480 [inline]
neigh_resolve_output+0x415/0x470 net/core/neighbour.c:1470
neigh_output include/net/neighbour.h:511 [inline]
ip6_finish_output2+0x7a2/0xec0 net/ipv6/ip6_output.c:116
__ip6_finish_output net/ipv6/ip6_output.c:142 [inline]
__ip6_finish_output+0x2d7/0x330 net/ipv6/ip6_output.c:127
ip6_finish_output+0x41/0x160 net/ipv6/ip6_output.c:152
NF_HOOK_COND include/linux/netfilter.h:294 [inline]
ip6_output+0xf2/0x280 net/ipv6/ip6_output.c:175
dst_output include/net/dst.h:436 [inline]
NF_HOOK include/linux/netfilter.h:305 [inline]
ndisc_send_skb+0x459/0x5f0 net/ipv6/ndisc.c:505
ndisc_send_ns+0x207/0x430 net/ipv6/ndisc.c:647
rt6_probe_deferred+0x98/0xf0 net/ipv6/route.c:615
process_one_work+0x3d4/0x890 kernel/workqueue.c:2269
worker_thread+0xa0/0x800 kernel/workqueue.c:2415
kthread+0x1d4/0x200 drivers/block/aoe/aoecmd.c:1253
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352
read to 0xffff8880b9dedcb8 of 4 bytes by task 29572 on cpu 1:
neigh_resolve_output net/core/neighbour.c:1479 [inline]
neigh_resolve_output+0x113/0x470 net/core/neighbour.c:1470
neigh_output include/net/neighbour.h:511 [inline]
ip6_finish_output2+0x7a2/0xec0 net/ipv6/ip6_output.c:116
__ip6_finish_output net/ipv6/ip6_output.c:142 [inline]
__ip6_finish_output+0x2d7/0x330 net/ipv6/ip6_output.c:127
ip6_finish_output+0x41/0x160 net/ipv6/ip6_output.c:152
NF_HOOK_COND include/linux/netfilter.h:294 [inline]
ip6_output+0xf2/0x280 net/ipv6/ip6_output.c:175
dst_output include/net/dst.h:436 [inline]
NF_HOOK include/linux/netfilter.h:305 [inline]
ndisc_send_skb+0x459/0x5f0 net/ipv6/ndisc.c:505
ndisc_send_ns+0x207/0x430 net/ipv6/ndisc.c:647
rt6_probe_deferred+0x98/0xf0 net/ipv6/route.c:615
process_one_work+0x3d4/0x890 kernel/workqueue.c:2269
worker_thread+0xa0/0x800 kernel/workqueue.c:2415
kthread+0x1d4/0x200 drivers/block/aoe/aoecmd.c:1253
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352
Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 29572 Comm: kworker/1:4 Not tainted 5.4.0-rc6+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events rt6_probe_deferred
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/firewire')
| -rw-r--r-- | drivers/firewire/net.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/drivers/firewire/net.c b/drivers/firewire/net.c index b132ab9ad607..715e491dfbc3 100644 --- a/drivers/firewire/net.c +++ b/drivers/firewire/net.c @@ -250,7 +250,11 @@ static int fwnet_header_cache(const struct neighbour *neigh, h = (struct fwnet_header *)((u8 *)hh->hh_data + HH_DATA_OFF(sizeof(*h))); h->h_proto = type; memcpy(h->h_dest, neigh->ha, net->addr_len); - hh->hh_len = FWNET_HLEN; + + /* Pairs with the READ_ONCE() in neigh_resolve_output(), + * neigh_hh_output() and neigh_update_hhs(). + */ + smp_store_release(&hh->hh_len, FWNET_HLEN); return 0; } |