On Sun, May 13, 2018 at 10:26:15AM +0200, 'Dmitry Vyukov' via syzkaller-bugs wrote: > On Sun, Apr 29, 2018 at 7:00 PM, syzbot > <syzbot+549decbd1891d501b6d5@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote: > > Hello, > > > > syzbot hit the following crash on upstream commit > > cdface5209349930ae1b51338763c8e029971b97 (Sun Apr 29 03:07:21 2018 +0000) > > Merge tag 'for_linus_stable' of > > git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4 > > syzbot dashboard link: > > https://syzkaller.appspot.com/bug?extid=549decbd1891d501b6d5 > > > > So far this crash happened 8 times on upstream. > > C reproducer: https://syzkaller.appspot.com/x/repro.c?id=6647588371562496 > > syzkaller reproducer: > > https://syzkaller.appspot.com/x/repro.syz?id=4781854846615552 > > Raw console output: > > https://syzkaller.appspot.com/x/log.txt?id=4580574157078528 > > Kernel config: > > https://syzkaller.appspot.com/x/.config?id=7043958930931867332 > > compiler: gcc (GCC) 8.0.1 20180413 (experimental) > > > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > > Reported-by: syzbot+549decbd1891d501b6d5@xxxxxxxxxxxxxxxxxxxxxxxxx > > It will help syzbot understand when the bug is fixed. See footer for > > details. > > If you forward the report, please keep this part and the footer. > > > This crash was bisected as introduced by: > > commit faeb7833eee0d6afe0ecb6bdfa6042556c2c352e > Author: Roman Kagan <rkagan@xxxxxxxxxxxxx> > Date: Thu Feb 1 16:48:32 2018 +0300 > > kvm: x86: hyperv: guest->host event signaling via eventfd > > https://gist.githubusercontent.com/dvyukov/df4971d7dfd1b37bedb5bfa0c95f9ebc/raw/ee8b7804788049f80625563e0322090c798c4544/gistfile1.txt > > > > > kasan: CONFIG_KASAN_INLINE enabled > > kasan: GPF could be caused by NULL-ptr deref or user memory access > > general protection fault: 0000 [#1] SMP KASAN > > Dumping ftrace buffer: > > (ftrace buffer empty) > > Modules linked in: > > CPU: 0 PID: 4525 Comm: syz-executor786 Not tainted 4.17.0-rc2+ #23 > > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > > Google 01/01/2011 > > RIP: 0010:__read_once_size include/linux/compiler.h:188 [inline] > > RIP: 0010:__radix_tree_delete+0x74/0x230 lib/radix-tree.c:1989 > > RSP: 0018:ffff8801d9137108 EFLAGS: 00010206 > > RAX: 0000000000000003 RBX: dffffc0000000000 RCX: 1ffff1003b226e3e > > RDX: 0000000000000000 RSI: ffffffff8768eeed RDI: ffff8801a7dac168 > > RBP: ffff8801d91371a8 R08: ffff8801d962c1c0 R09: ffffed0034fb5811 > > R10: ffff8801d91372b8 R11: ffff8801a7dac08f R12: 0000000000000000 > > R13: ffff8801a7dac168 R14: 0000000000000018 R15: ffff8801d9137230 > > FS: 0000000001df3880(0000) GS:ffff8801dae00000(0000) knlGS:0000000000000000 > > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > > CR2: 0000000020000100 CR3: 00000001d9104000 CR4: 00000000001426f0 > > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > > Call Trace: > > radix_tree_delete_item+0x148/0x2d0 lib/radix-tree.c:2050 > > idr_remove+0x46/0x60 lib/idr.c:157 > > kvm_hv_eventfd_deassign arch/x86/kvm/hyperv.c:1433 [inline] > > kvm_vm_ioctl_hv_eventfd+0x1df/0x24b arch/x86/kvm/hyperv.c:1451 > > kvm_arch_vm_ioctl+0x155e/0x2690 arch/x86/kvm/x86.c:4563 > > kvm_vm_ioctl+0x246/0x1d90 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3100 > > vfs_ioctl fs/ioctl.c:46 [inline] > > file_ioctl fs/ioctl.c:500 [inline] > > do_vfs_ioctl+0x1cf/0x16a0 fs/ioctl.c:684 > > ksys_ioctl+0xa9/0xd0 fs/ioctl.c:701 > > __do_sys_ioctl fs/ioctl.c:708 [inline] > > __se_sys_ioctl fs/ioctl.c:706 [inline] > > __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:706 > > do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287 > > entry_SYSCALL_64_after_hwframe+0x49/0xbe > > RIP: 0033:0x440069 > > RSP: 002b:00007ffcf0b02cd8 EFLAGS: 00000217 ORIG_RAX: 0000000000000010 > > RAX: ffffffffffffffda RBX: 6d766b2f7665642f RCX: 0000000000440069 > > RDX: 0000000020000000 RSI: 000000004018aebd RDI: 00000000000000a9 > > RBP: 00000000006cb018 R08: 00007ffcf0b02cf0 R09: 00007ffcf0b02cf0 > > R10: 00007ffcf0b02cf0 R11: 0000000000000217 R12: 00000000004018a0 > > R13: 0000000000401930 R14: 0000000000000000 R15: 0000000000000000 > > Code: 3f 9a 88 48 c7 45 88 80 ee 68 87 c7 00 f1 f1 f1 f1 c7 40 04 00 f2 f2 > > f2 c7 40 08 f3 f3 f3 f3 e8 a3 51 10 fa 4c 89 f0 48 c1 e8 03 <80> 3c 18 00 0f > > 85 97 01 00 00 48 8d 55 d8 4c 8d 7a c0 49 8b 1e > > RIP: __read_once_size include/linux/compiler.h:188 [inline] RSP: > > ffff8801d9137108 > > RIP: __radix_tree_delete+0x74/0x230 lib/radix-tree.c:1989 RSP: > > ffff8801d9137108 > > ---[ end trace 79327005f044daef ]--- > > > > > > --- > > This bug is generated by a dumb bot. It may contain errors. > > See https://goo.gl/tpsmEJ for details. > > Direct all questions to syzkaller@xxxxxxxxxxxxxxxx. > > > > syzbot will keep track of this bug report. > > If you forgot to add the Reported-by tag, once the fix for this bug is > > merged > > into any tree, please reply to this email with: > > #syz fix: exact-commit-title This seems to have been another report of the IDR / radix tree bug now fixed by commit 7a4deea1aa8b (thanks Matthew!): #syz fix: idr: fix invalid ptr dereference on item delete - Eric
