syzbot


KMSAN: uninit-value in pfifo_fast_dequeue

Status: upstream: reported C repro on 2020/05/18 18:23
Reported-by: syzbot+ae62f326a5154c4b908f@syzkaller.appspotmail.com
First crash: 1024d, last: 499d
Patch testing requests:
Created Duration User Patch Repo Result
2022/09/20 21:29 21m retest repro https://github.com/google/kmsan.git master OK log
2022/09/20 17:29 20m retest repro https://github.com/google/kmsan.git master OK log
2022/09/20 13:29 21m retest repro https://github.com/google/kmsan.git master OK log
2022/09/02 00:27 7m retest repro https://github.com/google/kmsan.git master error

Sample crash report:
=====================================================
BUG: KMSAN: uninit-value in kmsan_check_skb+0x3c/0x210 mm/kmsan/kmsan_hooks.c:299
CPU: 1 PID: 833 Comm: kworker/u4:20 Not tainted 5.6.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1c9/0x220 lib/dump_stack.c:118
 kmsan_report+0xf7/0x1e0 mm/kmsan/kmsan_report.c:118
 kmsan_internal_check_memory+0x238/0x3d0 mm/kmsan/kmsan.c:423
 kmsan_check_skb+0x3c/0x210 mm/kmsan/kmsan_hooks.c:299
 pfifo_fast_dequeue+0xdb4/0xfd0 net/sched/sch_generic.c:658
 dequeue_skb net/sched/sch_generic.c:264 [inline]
 qdisc_restart net/sched/sch_generic.c:367 [inline]
 __qdisc_run+0x3f1/0x3350 net/sched/sch_generic.c:385
 qdisc_run include/net/pkt_sched.h:126 [inline]
 __dev_xmit_skb net/core/dev.c:3668 [inline]
 __dev_queue_xmit+0x23b7/0x3b20 net/core/dev.c:4021
 dev_queue_xmit+0x4b/0x60 net/core/dev.c:4085
 batadv_send_skb_packet+0x59b/0x8c0 net/batman-adv/send.c:108
 batadv_send_broadcast_skb+0x76/0x90 net/batman-adv/send.c:127
 batadv_iv_ogm_send_to_if net/batman-adv/bat_iv_ogm.c:393 [inline]
 batadv_iv_ogm_emit net/batman-adv/bat_iv_ogm.c:419 [inline]
 batadv_iv_send_outstanding_bat_ogm_packet+0x97e/0xd50 net/batman-adv/bat_iv_ogm.c:1710
 process_one_work+0x1555/0x1f40 kernel/workqueue.c:2266
 worker_thread+0xef6/0x2450 kernel/workqueue.c:2412
 kthread+0x4b5/0x4f0 kernel/kthread.c:256
 ret_from_fork+0x35/0x40 arch/x86/entry/entry_64.S:353

Uninit was stored to memory at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:144 [inline]
 kmsan_internal_chain_origin+0xad/0x130 mm/kmsan/kmsan.c:310
 kmsan_memcpy_memmove_metadata+0x272/0x2e0 mm/kmsan/kmsan.c:247
 kmsan_memcpy_metadata+0xb/0x10 mm/kmsan/kmsan.c:267
 __msan_memcpy+0x43/0x50 mm/kmsan/kmsan_instr.c:116
 pskb_expand_head+0x38b/0x1b00 net/core/skbuff.c:1636
 __skb_cow include/linux/skbuff.h:3169 [inline]
 skb_cow_head include/linux/skbuff.h:3203 [inline]
 batadv_skb_head_push+0x234/0x350 net/batman-adv/soft-interface.c:74
 batadv_send_skb_packet+0x1a7/0x8c0 net/batman-adv/send.c:86
 batadv_send_broadcast_skb+0x76/0x90 net/batman-adv/send.c:127
 batadv_iv_ogm_send_to_if net/batman-adv/bat_iv_ogm.c:393 [inline]
 batadv_iv_ogm_emit net/batman-adv/bat_iv_ogm.c:419 [inline]
 batadv_iv_send_outstanding_bat_ogm_packet+0x97e/0xd50 net/batman-adv/bat_iv_ogm.c:1710
 process_one_work+0x1555/0x1f40 kernel/workqueue.c:2266
 worker_thread+0xef6/0x2450 kernel/workqueue.c:2412
 kthread+0x4b5/0x4f0 kernel/kthread.c:256
 ret_from_fork+0x35/0x40 arch/x86/entry/entry_64.S:353

Uninit was created at:
 kmsan_save_stack_with_flags+0x3c/0x90 mm/kmsan/kmsan.c:144
 kmsan_internal_alloc_meta_for_pages mm/kmsan/kmsan_shadow.c:307 [inline]
 kmsan_alloc_page+0x12a/0x310 mm/kmsan/kmsan_shadow.c:336
 __alloc_pages_nodemask+0x5712/0x5e80 mm/page_alloc.c:4775
 __alloc_pages include/linux/gfp.h:498 [inline]
 __alloc_pages_node include/linux/gfp.h:511 [inline]
 alloc_pages_node include/linux/gfp.h:525 [inline]
 __page_frag_cache_refill mm/page_alloc.c:4850 [inline]
 page_frag_alloc+0x3ae/0x910 mm/page_alloc.c:4880
 __napi_alloc_skb+0x193/0xa60 net/core/skbuff.c:519
 napi_alloc_skb include/linux/skbuff.h:2874 [inline]
 page_to_skb+0x19f/0x1100 drivers/net/virtio_net.c:384
 receive_mergeable drivers/net/virtio_net.c:924 [inline]
 receive_buf+0xe79/0x8b30 drivers/net/virtio_net.c:1033
 virtnet_receive drivers/net/virtio_net.c:1323 [inline]
 virtnet_poll+0x64b/0x19f0 drivers/net/virtio_net.c:1428
 napi_poll net/core/dev.c:6571 [inline]
 net_rx_action+0x786/0x1aa0 net/core/dev.c:6639
 __do_softirq+0x311/0x83d kernel/softirq.c:293

Bytes 52-53 of 146 are uninitialized
Memory access of size 146 starts at ffff9a60b51f3c40
=====================================================

Crashes (2114):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-upstream-kmsan-gce-386 2020/03/17 16:26 https://github.com/google/kmsan.git master a58741ac26cc 749688d2 .config log report syz C
ci-upstream-kmsan-gce 2020/08/21 05:33 https://github.com/google/kmsan.git master ce8056d1f79e 1d75fe45 .config log report syz C
ci-upstream-kmsan-gce 2020/07/19 09:39 https://github.com/google/kmsan.git master 14525656779e 9c812472 .config log report syz C
ci-upstream-kmsan-gce 2020/03/21 20:08 https://github.com/google/kmsan.git master a58741ac26cc 4288d95e .config log report syz C
ci-upstream-kmsan-gce 2021/07/16 04:28 https://github.com/google/kmsan.git master 57b5797c8013 f115ae98 .config log report info KMSAN: uninit-value in pfifo_fast_dequeue
ci-upstream-kmsan-gce 2021/07/16 00:24 https://github.com/google/kmsan.git master 57b5797c8013 f115ae98 .config log report info KMSAN: uninit-value in pfifo_fast_dequeue
ci-upstream-kmsan-gce 2021/07/15 15:20 https://github.com/google/kmsan.git master 57b5797c8013 b9a2f64e .config log report info KMSAN: uninit-value in pfifo_fast_dequeue
ci-upstream-kmsan-gce 2021/07/15 06:12 https://github.com/google/kmsan.git master 57b5797c8013 b9a2f64e .config log report info KMSAN: uninit-value in pfifo_fast_dequeue
ci-upstream-kmsan-gce 2021/07/12 07:26 https://github.com/google/kmsan.git master 57b5797c8013 a4869c92 .config log report info KMSAN: uninit-value in pfifo_fast_dequeue
ci-upstream-kmsan-gce 2021/07/08 02:03 https://github.com/google/kmsan.git master 57b5797c8013 95793bce .config log report info KMSAN: uninit-value in pfifo_fast_dequeue
ci-upstream-kmsan-gce 2021/07/06 17:04 https://github.com/google/kmsan.git master 57b5797c8013 6c4484eb .config log report info KMSAN: uninit-value in pfifo_fast_dequeue
ci-upstream-kmsan-gce 2021/07/06 08:54 https://github.com/google/kmsan.git master 57b5797c8013 6c4484eb .config log report info KMSAN: uninit-value in pfifo_fast_dequeue
ci-upstream-kmsan-gce 2021/07/04 22:00 https://github.com/google/kmsan.git master 57b5797c8013 55aa55c2 .config log report info KMSAN: uninit-value in pfifo_fast_dequeue
ci-upstream-kmsan-gce 2021/07/04 20:49 https://github.com/google/kmsan.git master 57b5797c8013 55aa55c2 .config log report info KMSAN: uninit-value in pfifo_fast_dequeue
ci-upstream-kmsan-gce 2021/07/03 23:21 https://github.com/google/kmsan.git master 57b5797c8013 55aa55c2 .config log report info KMSAN: uninit-value in pfifo_fast_dequeue
ci-upstream-kmsan-gce 2021/06/30 21:05 https://github.com/google/kmsan.git master 57b5797c8013 38a885d1 .config log report info KMSAN: uninit-value in pfifo_fast_dequeue
ci-upstream-kmsan-gce 2021/06/30 02:21 https://github.com/google/kmsan.git master 57b5797c8013 a4fccb01 .config log report info KMSAN: uninit-value in pfifo_fast_dequeue
ci-upstream-kmsan-gce 2021/06/29 15:33 https://github.com/google/kmsan.git master 57b5797c8013 9d2ab5df .config log report info KMSAN: uninit-value in pfifo_fast_dequeue
ci-upstream-kmsan-gce 2021/06/26 07:49 https://github.com/google/kmsan.git master 57b5797c8013 9d2ab5df .config log report info KMSAN: uninit-value in pfifo_fast_dequeue
ci-upstream-kmsan-gce 2021/06/23 20:08 https://github.com/google/kmsan.git master 31ffdb453231 fe4ab389 .config log report info KMSAN: uninit-value in pfifo_fast_dequeue
ci-upstream-kmsan-gce 2021/06/23 10:06 https://github.com/google/kmsan.git master 6a6a67f21dec aba2b2fb .config log report info KMSAN: uninit-value in pfifo_fast_dequeue
ci-upstream-kmsan-gce 2021/06/23 06:23 https://github.com/google/kmsan.git master 6a6a67f21dec aba2b2fb .config log report info KMSAN: uninit-value in pfifo_fast_dequeue
ci-upstream-kmsan-gce 2021/06/23 02:30 https://github.com/google/kmsan.git master 6a6a67f21dec aba2b2fb .config log report info KMSAN: uninit-value in pfifo_fast_dequeue
ci-upstream-kmsan-gce 2021/06/21 11:45 https://github.com/google/kmsan.git master 6a6a67f21dec aba2b2fb .config log report info KMSAN: uninit-value in pfifo_fast_dequeue
ci-upstream-kmsan-gce 2021/06/20 19:08 https://github.com/google/kmsan.git master 6a6a67f21dec aba2b2fb .config log report info KMSAN: uninit-value in pfifo_fast_dequeue
ci-upstream-kmsan-gce 2021/06/20 12:48 https://github.com/google/kmsan.git master 6a6a67f21dec aba2b2fb .config log report info KMSAN: uninit-value in pfifo_fast_dequeue
ci-upstream-kmsan-gce 2021/06/18 07:29 https://github.com/google/kmsan.git master bfeba8b4c158 aba2b2fb .config log report info KMSAN: uninit-value in pfifo_fast_dequeue
ci-upstream-kmsan-gce 2021/06/17 07:25 https://github.com/google/kmsan.git master 89a0faf20faa aba2b2fb .config log report info KMSAN: uninit-value in pfifo_fast_dequeue
ci-upstream-kmsan-gce 2021/06/15 19:30 https://github.com/google/kmsan.git master 7bcc9a7be76b 58636922 .config log report info KMSAN: uninit-value in pfifo_fast_dequeue
ci-upstream-kmsan-gce 2021/06/12 07:28 https://github.com/google/kmsan.git master 6099c9da2f7d 1ba81399 .config log report info KMSAN: uninit-value in pfifo_fast_dequeue
ci-upstream-kmsan-gce-386 2021/07/25 16:13 https://github.com/google/kmsan.git master a43e029dee89 4d1b57d4 .config log report info KMSAN: uninit-value in pfifo_fast_dequeue
ci-upstream-kmsan-gce-386 2021/07/14 03:04 https://github.com/google/kmsan.git master 57b5797c8013 fa0594c3 .config log report info KMSAN: uninit-value in pfifo_fast_dequeue
ci-upstream-kmsan-gce-386 2021/07/13 07:40 https://github.com/google/kmsan.git master 57b5797c8013 f415556d .config log report info KMSAN: uninit-value in pfifo_fast_dequeue
ci-upstream-kmsan-gce-386 2021/07/11 12:52 https://github.com/google/kmsan.git master 57b5797c8013 8f5a7b8c .config log report info KMSAN: uninit-value in pfifo_fast_dequeue
ci-upstream-kmsan-gce-386 2021/07/10 19:55 https://github.com/google/kmsan.git master 57b5797c8013 8f5a7b8c .config log report info KMSAN: uninit-value in pfifo_fast_dequeue
ci-upstream-kmsan-gce-386 2021/07/10 16:36 https://github.com/google/kmsan.git master 57b5797c8013 8f5a7b8c .config log report info KMSAN: uninit-value in pfifo_fast_dequeue
ci-upstream-kmsan-gce-386 2021/07/07 14:49 https://github.com/google/kmsan.git master 57b5797c8013 4846d5c1 .config log report info KMSAN: uninit-value in pfifo_fast_dequeue
ci-upstream-kmsan-gce-386 2021/07/04 13:55 https://github.com/google/kmsan.git master 57b5797c8013 55aa55c2 .config log report info KMSAN: uninit-value in pfifo_fast_dequeue
ci-upstream-kmsan-gce-386 2021/07/03 04:01 https://github.com/google/kmsan.git master 57b5797c8013 55aa55c2 .config log report info KMSAN: uninit-value in pfifo_fast_dequeue
ci-upstream-kmsan-gce-386 2021/07/01 22:07 https://github.com/google/kmsan.git master 57b5797c8013 658ebc66 .config log report info KMSAN: uninit-value in pfifo_fast_dequeue
ci-upstream-kmsan-gce-386 2021/07/01 15:54 https://github.com/google/kmsan.git master 57b5797c8013 658ebc66 .config log report info KMSAN: uninit-value in pfifo_fast_dequeue
ci-upstream-kmsan-gce-386 2021/06/30 07:28 https://github.com/google/kmsan.git master 57b5797c8013 a4fccb01 .config log report info KMSAN: uninit-value in pfifo_fast_dequeue
ci-upstream-kmsan-gce-386 2021/06/26 00:14 https://github.com/google/kmsan.git master 57b5797c8013 ae6bf8dd .config log report info KMSAN: uninit-value in pfifo_fast_dequeue
ci-upstream-kmsan-gce-386 2021/06/24 08:04 https://github.com/google/kmsan.git master 31ffdb453231 ec865f6a .config log report info KMSAN: uninit-value in pfifo_fast_dequeue
ci-upstream-kmsan-gce-386 2021/06/21 04:25 https://github.com/google/kmsan.git master 6a6a67f21dec aba2b2fb .config log report info KMSAN: uninit-value in pfifo_fast_dequeue
ci-upstream-kmsan-gce-386 2021/06/20 17:00 https://github.com/google/kmsan.git master 6a6a67f21dec aba2b2fb .config log report info KMSAN: uninit-value in pfifo_fast_dequeue
ci-upstream-kmsan-gce-386 2021/06/18 01:08 https://github.com/google/kmsan.git master bfeba8b4c158 aba2b2fb .config log report info KMSAN: uninit-value in pfifo_fast_dequeue
ci-upstream-kmsan-gce-386 2021/06/16 08:21 https://github.com/google/kmsan.git master 7bcc9a7be76b 990d3cbe .config log report info KMSAN: uninit-value in pfifo_fast_dequeue
ci-upstream-kmsan-gce-386 2021/06/13 16:05 https://github.com/google/kmsan.git master 6099c9da2f7d 1ba81399 .config log report info KMSAN: uninit-value in pfifo_fast_dequeue
ci-upstream-kmsan-gce-386 2021/06/12 14:56 https://github.com/google/kmsan.git master 6099c9da2f7d 1ba81399 .config log report info KMSAN: uninit-value in pfifo_fast_dequeue
ci-upstream-net-kasan-gce 2021/04/23 20:58 net-next cad4162a90ae 17f0b706 .config log report info general protection fault in pfifo_fast_dequeue
ci-upstream-linux-next-kasan-gce-root 2021/05/04 01:29 linux-next e3d35712f85a ad61f371 .config log report info general protection fault in pfifo_fast_dequeue
ci-upstream-linux-next-kasan-gce-root 2021/05/03 07:20 linux-next e3d35712f85a 77e2b668 .config log report info general protection fault in pfifo_fast_dequeue
ci-upstream-kmsan-gce 2020/02/16 22:02 https://github.com/google/kmsan.git master 686a4f77cb0c 1f448cd6 .config log report
ci-upstream-kmsan-gce-386 2021/01/17 07:47 https://github.com/google/kmsan.git master 73d62e81b476 65a7a854 .config log report info
* Struck through repros no longer work on HEAD.