As far as I know, this one's still unresolved. I can't see the bug from code inspection, and we don't have a reproducer. If anyone else sees this or has an idea what might be going wrong, I'd be interested.--b. On Sun, May 17, 2020 at 11:59:12PM -0700, syzbot wrote: > Hello, > > syzbot found the following crash on: > > HEAD commit: 9b1f2cbd Merge tag 'clk-fixes-for-linus' of git://git.kern.. > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=15dfdeaa100000 > kernel config: https://syzkaller.appspot.com/x/.config?x=c14212794ed9ad24 > dashboard link: https://syzkaller.appspot.com/bug?extid=0e37e9d19bded16b8ab9 > compiler: gcc (GCC) 9.0.0 20181231 (experimental) > > Unfortunately, I don't have any reproducer for this crash yet. > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+0e37e9d19bded16b8ab9@xxxxxxxxxxxxxxxxxxxxxxxxx > > BUG: unable to handle page fault for address: ffff887ffffffff0 > #PF: supervisor read access in kernel mode > #PF: error_code(0x0000) - not-present page > PGD 0 P4D 0 > Oops: 0000 [#1] PREEMPT SMP KASAN > CPU: 1 PID: 8682 Comm: syz-executor.3 Not tainted 5.7.0-rc5-syzkaller #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 > RIP: 0010:__rb_erase_augmented include/linux/rbtree_augmented.h:201 [inline] > RIP: 0010:rb_erase+0x37/0x18d0 lib/rbtree.c:443 > Code: 89 f7 41 56 41 55 49 89 fd 48 83 c7 08 48 89 fa 41 54 48 c1 ea 03 55 53 48 83 ec 18 80 3c 02 00 0f 85 89 10 00 00 49 8d 7d 10 <4d> 8b 75 08 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 80 > RSP: 0018:ffffc900178ffb58 EFLAGS: 00010246 > RAX: dffffc0000000000 RBX: ffff8880354d0000 RCX: ffffc9000fb6d000 > RDX: 1ffff10ffffffffe RSI: ffff88800011dfe0 RDI: ffff887ffffffff8 > RBP: ffff887fffffffb0 R08: ffff888057284280 R09: fffffbfff185d12e > R10: ffffffff8c2e896f R11: fffffbfff185d12d R12: ffff88800011dfe0 > R13: ffff887fffffffe8 R14: 000000000001dfe0 R15: ffff88800011dfe0 > FS: 00007fa002d21700(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: ffff887ffffffff0 CR3: 00000000a2164000 CR4: 00000000001426e0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > Call Trace: > nfsd_reply_cache_free_locked+0x198/0x380 fs/nfsd/nfscache.c:127 > nfsd_reply_cache_shutdown+0x150/0x350 fs/nfsd/nfscache.c:203 > nfsd_exit_net+0x189/0x4c0 fs/nfsd/nfsctl.c:1504 > ops_exit_list.isra.0+0xa8/0x150 net/core/net_namespace.c:186 > setup_net+0x50c/0x860 net/core/net_namespace.c:364 > copy_net_ns+0x293/0x590 net/core/net_namespace.c:482 > create_new_namespaces+0x3fb/0xb30 kernel/nsproxy.c:108 > unshare_nsproxy_namespaces+0xbd/0x1f0 kernel/nsproxy.c:229 > ksys_unshare+0x43d/0x8e0 kernel/fork.c:2970 > __do_sys_unshare kernel/fork.c:3038 [inline] > __se_sys_unshare kernel/fork.c:3036 [inline] > __x64_sys_unshare+0x2d/0x40 kernel/fork.c:3036 > do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 > entry_SYSCALL_64_after_hwframe+0x49/0xb3 > RIP: 0033:0x45ca29 > Code: 0d b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 db b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 > RSP: 002b:00007fa002d20c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000110 > RAX: ffffffffffffffda RBX: 000000000050a1c0 RCX: 000000000045ca29 > RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040000000 > RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff > R13: 0000000000000c4e R14: 00000000004ce9bd R15: 00007fa002d216d4 > Modules linked in: > CR2: ffff887ffffffff0 > ---[ end trace f929dcba0362906a ]--- > RIP: 0010:__rb_erase_augmented include/linux/rbtree_augmented.h:201 [inline] > RIP: 0010:rb_erase+0x37/0x18d0 lib/rbtree.c:443 > Code: 89 f7 41 56 41 55 49 89 fd 48 83 c7 08 48 89 fa 41 54 48 c1 ea 03 55 53 48 83 ec 18 80 3c 02 00 0f 85 89 10 00 00 49 8d 7d 10 <4d> 8b 75 08 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 80 > RSP: 0018:ffffc900178ffb58 EFLAGS: 00010246 > RAX: dffffc0000000000 RBX: ffff8880354d0000 RCX: ffffc9000fb6d000 > RDX: 1ffff10ffffffffe RSI: ffff88800011dfe0 RDI: ffff887ffffffff8 > RBP: ffff887fffffffb0 R08: ffff888057284280 R09: fffffbfff185d12e > R10: ffffffff8c2e896f R11: fffffbfff185d12d R12: ffff88800011dfe0 > R13: ffff887fffffffe8 R14: 000000000001dfe0 R15: ffff88800011dfe0 > FS: 00007fa002d21700(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: ffff887ffffffff0 CR3: 00000000a2164000 CR4: 00000000001426e0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > > > --- > This bug 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@xxxxxxxxxxxxxxxx. > > syzbot will keep track of this bug report. See: > https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
