syzbot

 sign-in | mailing list | source | docs
🐞 Open [1223]
≡ Subsystems
🐞 Fixed [5620]
🐞 Invalid [13551]
⬇ Missing Backports [98]
Kernel Health Bugs/Month Bug Lifetimes Fuzzing Crashes
Total Repo Heatmap Subsystems Heatmap
💬 Send us feedback

KASAN: use-after-free Read in dev_queue_xmit_nit

Status: fixed on 2017/11/06 08:47
Fix commit: 008ba2a13f2d packet: hold bind lock when rebinding to fanout hook
First crash: 2562d, last: 2544d
▶ ▼ Similar bugs (6)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-414 KASAN: use-after-free Read in dev_queue_xmit_nit 1 1764d 1764d 0/1 auto-closed as invalid on 2020/03/12 11:34
upstream KASAN: use-after-free Read in dev_queue_xmit_nit (3) net 3 2182d 2193d 0/27 closed as invalid on 2018/12/05 17:50
upstream KASAN: use-after-free Read in dev_queue_xmit_nit (2) net syz 2 2483d 2485d 0/27 closed as invalid on 2018/01/22 17:57
linux-4.19 KASAN: use-after-free Read in dev_queue_xmit_nit C error 90 585d 1786d 0/1 upstream: reported C repro on 2019/10/22 19:23
linux-4.14 KASAN: use-after-free Read in dev_queue_xmit_nit (2) syz error 18 772d 1562d 0/1 upstream: reported syz repro on 2020/06/02 08:57
linux-4.14 KASAN: use-after-free Read in dev_queue_xmit_nit 5 1798d 1908d 0/1 auto-closed as invalid on 2020/02/08 07:01

Sample crash report:
==================================================================
BUG: KASAN: use-after-free in skb_loop_sk net/core/dev.c:1882 [inline]
BUG: KASAN: use-after-free in dev_queue_xmit_nit+0xa0c/0xae0 net/core/dev.c:1911
Read of size 8 at addr ffff8801cb068c20 by task sshd/2983

CPU: 1 PID: 2983 Comm: sshd Not tainted 4.13.0+ #43
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:16 [inline]
 dump_stack+0x194/0x257 lib/dump_stack.c:52
 print_address_description+0x73/0x250 mm/kasan/report.c:252
 kasan_report_error mm/kasan/report.c:351 [inline]
 kasan_report+0x24e/0x340 mm/kasan/report.c:409
 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:430
 skb_loop_sk net/core/dev.c:1882 [inline]
 dev_queue_xmit_nit+0xa0c/0xae0 net/core/dev.c:1911
 xmit_one net/core/dev.c:2971 [inline]
 dev_hard_start_xmit+0x16b/0xac0 net/core/dev.c:2991
 sch_direct_xmit+0x31d/0x6d0 net/sched/sch_generic.c:186
 __dev_xmit_skb net/core/dev.c:3173 [inline]
 __dev_queue_xmit+0x15fe/0x1e40 net/core/dev.c:3440
 dev_queue_xmit+0x17/0x20 net/core/dev.c:3505
 neigh_hh_output include/net/neighbour.h:471 [inline]
 neigh_output include/net/neighbour.h:479 [inline]
 ip_finish_output2+0xece/0x1460 net/ipv4/ip_output.c:229
 ip_finish_output+0x85e/0xd10 net/ipv4/ip_output.c:317
 NF_HOOK_COND include/linux/netfilter.h:238 [inline]
 ip_output+0x1cc/0x860 net/ipv4/ip_output.c:405
 dst_output include/net/dst.h:472 [inline]
 ip_local_out+0x95/0x160 net/ipv4/ip_output.c:124
 ip_queue_xmit+0x8c6/0x18e0 net/ipv4/ip_output.c:504
 tcp_transmit_skb+0x1947/0x3300 net/ipv4/tcp_output.c:1123
 tcp_write_xmit+0x5fc/0x4960 net/ipv4/tcp_output.c:2341
 __tcp_push_pending_frames+0xa0/0x250 net/ipv4/tcp_output.c:2516
 tcp_push+0x4e0/0x760 net/ipv4/tcp.c:715
 tcp_sendmsg_locked+0x17ad/0x3bc0 net/ipv4/tcp.c:1408
 tcp_sendmsg+0x2f/0x50 net/ipv4/tcp.c:1445
 inet_sendmsg+0x11f/0x5e0 net/ipv4/af_inet.c:762
 sock_sendmsg_nosec net/socket.c:633 [inline]
 sock_sendmsg+0xca/0x110 net/socket.c:643
 sock_write_iter+0x320/0x5e0 net/socket.c:912
 call_write_iter include/linux/fs.h:1743 [inline]
 new_sync_write fs/read_write.c:457 [inline]
 __vfs_write+0x68a/0x970 fs/read_write.c:470
 vfs_write+0x18f/0x510 fs/read_write.c:518
 SYSC_write fs/read_write.c:565 [inline]
 SyS_write+0xef/0x220 fs/read_write.c:557
 entry_SYSCALL_64_fastpath+0x1f/0xbe
RIP: 0033:0x7fe9a9ab4370
RSP: 002b:00007ffede8a76b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000038 RCX: 00007fe9a9ab4370
RDX: 0000000000000038 RSI: 000055f6a4564440 RDI: 0000000000000003
RBP: 0000000000000082 R08: 0000000000000001 R09: 0101010101010101
R10: 0000000000000008 R11: 0000000000000246 R12: 00007ffede8a771c
R13: 000055f6a4458fb4 R14: 0000000000000028 R15: 000055f6a445aca0

Allocated by task 11343:
 save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59
 save_stack+0x43/0xd0 mm/kasan/kasan.c:447
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:551
 kmem_cache_alloc_trace+0x136/0x750 mm/slab.c:3627
 kmalloc include/linux/slab.h:493 [inline]
 kzalloc include/linux/slab.h:666 [inline]
 fanout_add+0xa50/0x1190 net/packet/af_packet.c:1733
 packet_setsockopt+0xfdc/0x1e80 net/packet/af_packet.c:3795
 SYSC_setsockopt net/socket.c:1852 [inline]
 SyS_setsockopt+0x189/0x360 net/socket.c:1831
 entry_SYSCALL_64_fastpath+0x1f/0xbe

Freed by task 11321:
 save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59
 save_stack+0x43/0xd0 mm/kasan/kasan.c:447
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_slab_free+0x71/0xc0 mm/kasan/kasan.c:524
 __cache_free mm/slab.c:3503 [inline]
 kfree+0xca/0x250 mm/slab.c:3820
 packet_release+0xa8f/0xd70 net/packet/af_packet.c:3033
 sock_release+0x8d/0x1e0 net/socket.c:597
 sock_close+0x16/0x20 net/socket.c:1126
 __fput+0x333/0x7f0 fs/file_table.c:210
 ____fput+0x15/0x20 fs/file_table.c:246
 task_work_run+0x199/0x270 kernel/task_work.c:112
 exit_task_work include/linux/task_work.h:21 [inline]
 do_exit+0xa52/0x1b40 kernel/exit.c:865
 do_group_exit+0x149/0x400 kernel/exit.c:968
 SYSC_exit_group kernel/exit.c:979 [inline]
 SyS_exit_group+0x1d/0x20 kernel/exit.c:977
 entry_SYSCALL_64_fastpath+0x1f/0xbe

The buggy address belongs to the object at ffff8801cb068380
 which belongs to the cache kmalloc-4096 of size 4096
The buggy address is located 2208 bytes inside of
 4096-byte region [ffff8801cb068380, ffff8801cb069380)
The buggy address belongs to the page:
page:ffffea00072c1a00 count:1 mapcount:0 mapping:ffff8801cb068380 index:0x0 compound_mapcount: 0
flags: 0x200000000008100(slab|head)
raw: 0200000000008100 ffff8801cb068380 0000000000000000 0000000100000001
raw: ffffea00072c09a0 ffffea00072e9420 ffff8801dac00dc0 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801cb068b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8801cb068b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8801cb068c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                               ^
 ffff8801cb068c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8801cb068d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

Crashes (13):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2017/09/15 10:32 net-next-old ad9a19d00370 96b8e399 .config console log report syz C ci-upstream-net-kasan-gce
2017/09/15 10:32 linux-next 1f183459b514 da1873aa .config console log report syz C skylake-linux-next-kasan-qemu
2017/09/22 11:23 upstream 6e80ecdddf4e c26ea367 .config console log report ci-upstream-kasan-gce
2017/09/21 19:02 upstream 4a704d6db0ee c26ea367 .config console log report ci-upstream-kasan-gce-386
2017/09/13 18:35 net-next-old ad9a19d00370 96b8e399 .config console log report ci-upstream-net-kasan-gce
2017/09/13 16:34 net-next-old ad9a19d00370 96b8e399 .config console log report ci-upstream-net-kasan-gce
2017/09/13 06:14 net-next-old ad9a19d00370 96b8e399 .config console log report ci-upstream-net-kasan-gce
2017/09/11 22:34 net-next-old ad9a19d00370 96b8e399 .config console log report ci-upstream-net-kasan-gce
2017/09/09 20:50 net-next-old 80cee03bf1d6 d18bfda0 .config console log report ci-upstream-net-kasan-gce
2017/09/07 03:54 net-next-old 80cee03bf1d6 d18bfda0 .config console log report ci-upstream-net-kasan-gce
2017/09/25 00:44 mmots 720bbe532b7c c26ea367 .config console log report ci-upstream-mmots-kasan-gce
2017/09/20 03:54 linux-next 840cc455c5f5 92f543f0 .config console log report ci-upstream-next-kasan-gce
2017/09/11 12:52 linux-next a31cc455c512 449b6f15 .config console log report ci-upstream-next-kasan-gce
* Struck through repros no longer work on HEAD.