net/ipv6: slab-out-of-bounds in ip6_tnl_xmit

From: Andrey Konovalov
Date: Mon Apr 24 2017 - 11:03:12 EST

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Hi,

I've got the following error report while fuzzing the kernel with syzkaller.

On commit 5a7ad1146caa895ad718a534399e38bd2ba721b7 (4.11-rc8).

Unfortunately it's not reproducible.

The issue might be similar to this one:
https://groups.google.com/forum/#!topic/syzkaller/IDoQHFmrnRI

==================================================================
BUG: KASAN: slab-out-of-bounds in ip6_tnl_xmit+0x25dd/0x28f0
net/ipv6/ip6_tunnel.c:1078 at addr ffff88005dcc5f98
Read of size 16 by task syz-executor7/8076
CPU: 3 PID: 8076 Comm: syz-executor7 Not tainted 4.11.0-rc8+ #266
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:16 [inline]
dump_stack+0x192/0x22d lib/dump_stack.c:52
kasan_object_err+0x1c/0x70 mm/kasan/report.c:164
print_address_description mm/kasan/report.c:202 [inline]
kasan_report_error mm/kasan/report.c:291 [inline]
kasan_report+0x252/0x510 mm/kasan/report.c:347
__asan_report_load_n_noabort+0xf/0x20 mm/kasan/report.c:378
ip6_tnl_xmit+0x25dd/0x28f0 net/ipv6/ip6_tunnel.c:1078
ip4ip6_tnl_xmit net/ipv6/ip6_tunnel.c:1268 [inline]
ip6_tnl_start_xmit+0xc1e/0x1890 net/ipv6/ip6_tunnel.c:1370
__netdev_start_xmit include/linux/netdevice.h:3980 [inline]
netdev_start_xmit include/linux/netdevice.h:3989 [inline]
xmit_one net/core/dev.c:2908 [inline]
dev_hard_start_xmit+0x213/0x800 net/core/dev.c:2924
__dev_queue_xmit+0x1abc/0x2580 net/core/dev.c:3391
dev_queue_xmit+0x17/0x20 net/core/dev.c:3424
neigh_direct_output+0x15/0x20 net/core/neighbour.c:1349
neigh_output include/net/neighbour.h:478 [inline]
ip_finish_output2+0x7cd/0x1020 net/ipv4/ip_output.c:228
ip_finish_output+0x83d/0xc30 net/ipv4/ip_output.c:316
NF_HOOK_COND include/linux/netfilter.h:246 [inline]
ip_output+0x1e7/0x5d0 net/ipv4/ip_output.c:404
dst_output include/net/dst.h:486 [inline]
ip_local_out+0x82/0xb0 net/ipv4/ip_output.c:124
ip_send_skb+0x3c/0xc0 net/ipv4/ip_output.c:1492
ip_push_pending_frames+0x64/0x80 net/ipv4/ip_output.c:1512
ping_v4_push_pending_frames net/ipv4/ping.c:653 [inline]
ping_v4_sendmsg+0x1b35/0x23e0 net/ipv4/ping.c:840
inet_sendmsg+0x164/0x490 net/ipv4/af_inet.c:762
sock_sendmsg_nosec net/socket.c:633 [inline]
sock_sendmsg+0xca/0x110 net/socket.c:643
SYSC_sendto+0x660/0x810 net/socket.c:1696
SyS_sendto+0x40/0x50 net/socket.c:1664
entry_SYSCALL_64_fastpath+0x1a/0xa9
RIP: 0033:0x4458d9
RSP: 002b:00007f853159db58 EFLAGS: 00000282 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 0000000000708000 RCX: 00000000004458d9
RDX: 0000000000000008 RSI: 00000000204f9fe1 RDI: 0000000000000017
RBP: 0000000000003410 R08: 0000000020235000 R09: 0000000000000010
R10: 0000000000000000 R11: 0000000000000282 R12: 00000000006e24d0
R13: 0000000020ef8000 R14: 0000000000001000 R15: 0000000000000003
Object at ffff88005dcc5e20, in cache kmalloc-512 size: 512
Allocated:
PID = 8076
save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59
save_stack+0x43/0xd0 mm/kasan/kasan.c:513
set_track mm/kasan/kasan.c:525 [inline]
kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:616
__kmalloc+0x7c/0x1c0 mm/slub.c:3745
kmalloc include/linux/slab.h:495 [inline]
kzalloc include/linux/slab.h:663 [inline]
neigh_alloc net/core/neighbour.c:286 [inline]
__neigh_create+0x386/0x1da0 net/core/neighbour.c:458
neigh_create include/net/neighbour.h:313 [inline]
ipv4_neigh_lookup+0x4bb/0x730 net/ipv4/route.c:463
dst_neigh_lookup include/net/dst.h:447 [inline]
ip6_tnl_xmit+0x1598/0x28f0 net/ipv6/ip6_tunnel.c:1067
ip4ip6_tnl_xmit net/ipv6/ip6_tunnel.c:1268 [inline]
ip6_tnl_start_xmit+0xc1e/0x1890 net/ipv6/ip6_tunnel.c:1370
__netdev_start_xmit include/linux/netdevice.h:3980 [inline]
netdev_start_xmit include/linux/netdevice.h:3989 [inline]
xmit_one net/core/dev.c:2908 [inline]
dev_hard_start_xmit+0x213/0x800 net/core/dev.c:2924
__dev_queue_xmit+0x1abc/0x2580 net/core/dev.c:3391
dev_queue_xmit+0x17/0x20 net/core/dev.c:3424
neigh_direct_output+0x15/0x20 net/core/neighbour.c:1349
neigh_output include/net/neighbour.h:478 [inline]
ip_finish_output2+0x7cd/0x1020 net/ipv4/ip_output.c:228
ip_finish_output+0x83d/0xc30 net/ipv4/ip_output.c:316
NF_HOOK_COND include/linux/netfilter.h:246 [inline]
ip_output+0x1e7/0x5d0 net/ipv4/ip_output.c:404
dst_output include/net/dst.h:486 [inline]
ip_local_out+0x82/0xb0 net/ipv4/ip_output.c:124
ip_send_skb+0x3c/0xc0 net/ipv4/ip_output.c:1492
ip_push_pending_frames+0x64/0x80 net/ipv4/ip_output.c:1512
ping_v4_push_pending_frames net/ipv4/ping.c:653 [inline]
ping_v4_sendmsg+0x1b35/0x23e0 net/ipv4/ping.c:840
inet_sendmsg+0x164/0x490 net/ipv4/af_inet.c:762
sock_sendmsg_nosec net/socket.c:633 [inline]
sock_sendmsg+0xca/0x110 net/socket.c:643
SYSC_sendto+0x660/0x810 net/socket.c:1696
SyS_sendto+0x40/0x50 net/socket.c:1664
entry_SYSCALL_64_fastpath+0x1a/0xa9
Freed:
PID = 7604
save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59
save_stack+0x43/0xd0 mm/kasan/kasan.c:513
set_track mm/kasan/kasan.c:525 [inline]
kasan_slab_free+0x73/0xc0 mm/kasan/kasan.c:589
slab_free_hook mm/slub.c:1357 [inline]
slab_free_freelist_hook mm/slub.c:1379 [inline]
slab_free mm/slub.c:2961 [inline]
kfree+0x91/0x190 mm/slub.c:3882
skb_free_head+0x74/0xb0 net/core/skbuff.c:579
skb_release_data+0x37c/0x440 net/core/skbuff.c:610
skb_release_all+0x4a/0x60 net/core/skbuff.c:669
__kfree_skb net/core/skbuff.c:683 [inline]
consume_skb+0x130/0x2f0 net/core/skbuff.c:756
netlink_broadcast_filtered+0x5fa/0x1420 net/netlink/af_netlink.c:1473
netlink_broadcast net/netlink/af_netlink.c:1495 [inline]
nlmsg_multicast include/net/netlink.h:577 [inline]
nlmsg_notify+0x9c/0x140 net/netlink/af_netlink.c:2382
rtnl_notify+0xbb/0xe0 net/core/rtnetlink.c:674
rtmsg_fib+0x3a7/0x4b0 net/ipv4/fib_semantics.c:422
fib_table_delete+0x836/0x1140 net/ipv4/fib_trie.c:1659
fib_magic.isra.14+0x4b3/0x890 net/ipv4/fib_frontend.c:840
fib_del_ifaddr+0xb20/0xe10 net/ipv4/fib_frontend.c:1013
fib_inetaddr_event+0xaf/0x200 net/ipv4/fib_frontend.c:1150
notifier_call_chain+0x145/0x2f0 kernel/notifier.c:93
__blocking_notifier_call_chain kernel/notifier.c:317 [inline]
blocking_notifier_call_chain+0x109/0x1a0 kernel/notifier.c:328
__inet_del_ifa+0x4b5/0xb00 net/ipv4/devinet.c:402
inet_del_ifa net/ipv4/devinet.c:432 [inline]
devinet_ioctl+0xa75/0x1a10 net/ipv4/devinet.c:1073
inet_ioctl+0x117/0x1c0 net/ipv4/af_inet.c:900
sock_do_ioctl+0x65/0xb0 net/socket.c:906
sock_ioctl+0x27a/0x410 net/socket.c:1004
vfs_ioctl fs/ioctl.c:45 [inline]
do_vfs_ioctl+0x1cd/0x15a0 fs/ioctl.c:685
SYSC_ioctl fs/ioctl.c:700 [inline]
SyS_ioctl+0x8f/0xc0 fs/ioctl.c:691
entry_SYSCALL_64_fastpath+0x1a/0xa9
Memory state around the buggy address:
ffff88005dcc5e80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff88005dcc5f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88005dcc5f80: 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc
^
ffff88005dcc6000: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff88005dcc6080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================

Next message: Jan Kara: "Re: [PATCH v2 29/33] uio, libnvdimm, pmem: implement cache bypass for all copy_from_iter() operations"
Previous message: Christoph Hellwig: "Re: [RFC xfstests PATCH] xfstests: add a writeback error handling test"
Next in thread: Andrey Konovalov: "Re: net/ipv6: slab-out-of-bounds in ip6_tnl_xmit"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]