syzbot


BUG: unable to handle kernel NULL pointer dereference in irq_bypass_register_consumer

Status: closed as dup on 2018/01/26 23:25
Subsystems: kvm
[Documentation on labels]
Reported-by: syzbot+dcff49641d63583853a5806197d79145931ac740@syzkaller.appspotmail.com
First crash: 2336d, last: 2328d
Duplicate of
Title Repro Cause bisect Fix bisect Count Last Reported
KASAN: use-after-free Write in irq_bypass_register_consumer kvm C 1632 2118d 2379d

Sample crash report:
BUG: unable to handle kernel NULL pointer dereference at 0000000000000010
IP: irq_bypass_register_consumer+0xbe/0x200 virt/lib/irqbypass.c:198
PGD 20d26c067 P4D 20d26c067 PUD 20d26f067 PMD 0 
Oops: 0000 [#1] SMP
Dumping ftrace buffer:
   (ftrace buffer empty)
Modules linked in:
CPU: 1 PID: 8627 Comm: syz-executor7 Not tainted 4.15.0-rc3-next-20171213+ #66
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:irq_bypass_register_consumer+0xbe/0x200 virt/lib/irqbypass.c:198
RSP: 0018:ffffc9000691fd50 EFLAGS: 00010293
RAX: ffff88021431e2c0 RBX: 0000000000000000 RCX: ffffffff825a774e
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc9000691fd70 R08: ffffffff825a7710 R09: 0000000000000004
R10: ffffc9000691fd40 R11: 0000000000000004 R12: ffff88020d3d5368
R13: ffff88020ef7c980 R14: ffff88020eef2768 R15: ffff88020d370000
FS:  00007f2d09cf8700(0000) GS:ffff88021fd00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000010 CR3: 00000002143f1000 CR4: 00000000001426e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 kvm_irqfd_assign arch/x86/kvm/../../../virt/kvm/eventfd.c:417 [inline]
 kvm_irqfd+0x6d4/0x860 arch/x86/kvm/../../../virt/kvm/eventfd.c:572
 kvm_vm_ioctl+0x3e2/0x9f0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3000
 vfs_ioctl fs/ioctl.c:46 [inline]
 do_vfs_ioctl+0xaf/0x840 fs/ioctl.c:686
 SYSC_ioctl fs/ioctl.c:701 [inline]
 SyS_ioctl+0x8f/0xc0 fs/ioctl.c:692
 entry_SYSCALL_64_fastpath+0x1f/0x96
RIP: 0033:0x452a39
RSP: 002b:00007f2d09cf7c58 EFLAGS: 00000212 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000758020 RCX: 0000000000452a39
RDX: 0000000020080fe0 RSI: 000000004020ae76 RDI: 0000000000000003
RBP: 0000000000000562 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000212 R12: 00000000006f61d0
R13: 00000000ffffffff R14: 00007f2d09cf86d4 R15: 0000000000000000
Code: d1 fe 4d 8b 6c 24 10 4d 39 6e 10 74 2f 4d 39 f4 74 2a 4c 89 f3 e8 33 2c d1 fe 48 8b 1b 48 81 fb 60 e1 19 83 74 43 e8 22 2c d1 fe <4c> 39 6b 10 0f 94 c2 49 39 dc 0f 94 c0 08 c2 74 d9 e8 0c 2c d1 
RIP: irq_bypass_register_consumer+0xbe/0x200 virt/lib/irqbypass.c:198 RSP: ffffc9000691fd50
CR2: 0000000000000010
---[ end trace 28b4667ba051ea9a ]---
Kernel panic - not syncing: Fatal exception
Dumping ftrace buffer:
   (ftrace buffer empty)
Kernel Offset: disabled
Rebooting in 86400 seconds..

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2017/12/13 09:16 linux-next 41d8c16909eb ce7f2399 .config console log report syz ci-upstream-next-kasan-gce
2017/12/20 11:54 linux-next 6084b576dca2 2d836b1d .config console log report ci-upstream-next-kasan-gce
2017/12/18 17:14 linux-next 6084b576dca2 1c4160ef .config console log report ci-upstream-next-kasan-gce
* Struck through repros no longer work on HEAD.