Messages in this thread | | | From | Dmitry Vyukov <> | Date | Thu, 1 Oct 2020 12:48:52 +0200 | Subject | Re: KMSAN: uninit-value in batadv_nc_worker |
| |
On Thu, Oct 1, 2020 at 12:29 PM syzbot <syzbot+da9194708de785081f11@syzkaller.appspotmail.com> wrote: > > Hello, > > syzbot found the following issue on: > > HEAD commit: 5edb1df2 kmsan: drop the _nosanitize string functions > git tree: https://github.com/google/kmsan.git master > console output: https://syzkaller.appspot.com/x/log.txt?x=10cc55a7900000 > kernel config: https://syzkaller.appspot.com/x/.config?x=4991d22eb136035c > dashboard link: https://syzkaller.appspot.com/bug?extid=da9194708de785081f11 > compiler: clang version 10.0.0 (https://github.com/llvm/llvm-project/ c2443155a0fb245c8f17f2c1c72b6ea391e86e81) > > Unfortunately, I don't have any reproducer for this issue yet. > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+da9194708de785081f11@syzkaller.appspotmail.com
It's somewhat unobvious how this can happen (or not?).
But may be related to: INFO: rcu detected stall in batadv_nc_worker (3) https://syzkaller.appspot.com/bug?id=6dba9b6476dd536c17afa799a72f265e448ff820
which happens with low frequency for the past 300 days, 21 stalls in total.
If we imagine the list somehow ends up uninitialized, occasional infinite loops make perfect sense.
> ===================================================== > BUG: KMSAN: uninit-value in batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline] > BUG: KMSAN: uninit-value in batadv_nc_worker+0x1c0/0x1d70 net/batman-adv/network-coding.c:718 > CPU: 0 PID: 7 Comm: kworker/u4:0 Not tainted 5.9.0-rc4-syzkaller #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 > Workqueue: bat_events batadv_nc_worker > Call Trace: > __dump_stack lib/dump_stack.c:77 [inline] > dump_stack+0x21c/0x280 lib/dump_stack.c:118 > kmsan_report+0xf7/0x1e0 mm/kmsan/kmsan_report.c:122 > __msan_warning+0x58/0xa0 mm/kmsan/kmsan_instr.c:201 > batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline] > batadv_nc_worker+0x1c0/0x1d70 net/batman-adv/network-coding.c:718 > process_one_work+0x1688/0x2140 kernel/workqueue.c:2269 > worker_thread+0x10bc/0x2730 kernel/workqueue.c:2415 > kthread+0x551/0x590 kernel/kthread.c:293 > ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 > > Uninit was created at: > kmsan_save_stack_with_flags mm/kmsan/kmsan.c:143 [inline] > kmsan_internal_poison_shadow+0x66/0xd0 mm/kmsan/kmsan.c:126 > kmsan_slab_alloc+0x8a/0xe0 mm/kmsan/kmsan_hooks.c:80 > slab_alloc_node mm/slub.c:2907 [inline] > slab_alloc mm/slub.c:2916 [inline] > __kmalloc+0x2bb/0x4b0 mm/slub.c:3982 > kmalloc_array+0x90/0x140 include/linux/slab.h:594 > batadv_hash_new+0x129/0x530 net/batman-adv/hash.c:52 > batadv_originator_init+0x9b/0x370 net/batman-adv/originator.c:211 > batadv_mesh_init+0x4dc/0x9d0 net/batman-adv/main.c:204 > batadv_softif_init_late+0x6d8/0xa30 net/batman-adv/soft-interface.c:857 > register_netdevice+0xbbc/0x37d0 net/core/dev.c:9760 > __rtnl_newlink net/core/rtnetlink.c:3454 [inline] > rtnl_newlink+0x2e77/0x3ed0 net/core/rtnetlink.c:3500 > rtnetlink_rcv_msg+0x142b/0x18c0 net/core/rtnetlink.c:5563 > netlink_rcv_skb+0x6d7/0x7e0 net/netlink/af_netlink.c:2470 > rtnetlink_rcv+0x50/0x60 net/core/rtnetlink.c:5581 > netlink_unicast_kernel net/netlink/af_netlink.c:1304 [inline] > netlink_unicast+0x11c8/0x1490 net/netlink/af_netlink.c:1330 > netlink_sendmsg+0x173a/0x1840 net/netlink/af_netlink.c:1919 > sock_sendmsg_nosec net/socket.c:651 [inline] > sock_sendmsg net/socket.c:671 [inline] > __sys_sendto+0x9dc/0xc80 net/socket.c:1992 > __do_sys_sendto net/socket.c:2004 [inline] > __se_sys_sendto+0x107/0x130 net/socket.c:2000 > __x64_sys_sendto+0x6e/0x90 net/socket.c:2000 > do_syscall_64+0x9f/0x140 arch/x86/entry/common.c:48 > entry_SYSCALL_64_after_hwframe+0x44/0xa9 > ===================================================== > > > --- > This report is generated by a bot. It may contain errors. > See https://goo.gl/tpsmEJ for more information about syzbot. > syzbot engineers can be reached at syzkaller@googlegroups.com. > > syzbot will keep track of this issue. See: > https://goo.gl/tpsmEJ#status for how to communicate with syzbot. > > -- > You received this message because you are subscribed to the Google Groups "syzkaller-bugs" group. > To unsubscribe from this group and stop receiving emails from it, send an email to syzkaller-bugs+unsubscribe@googlegroups.com. > To view this discussion on the web visit https://groups.google.com/d/msgid/syzkaller-bugs/000000000000fb885a05b0997c54%40google.com.
| |