On Wed, Nov 1, 2017 at 11:17 PM, syzbot <bot+9a592b2d4f3c5d4c93adef9de16ded0105530914@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote: > Hello, > > syzkaller hit the following crash on > aae4e7a8bc44722fe70d58920a36916b1043195e > git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/master > compiler: gcc (GCC) 7.1.1 20170620 > .config is attached > Raw console output is attached. > C reproducer is attached > syzkaller reproducer is attached. See https://goo.gl/kgGztJ > for information about syzkaller reproducers > > > BUG: KASAN: use-after-free in irq_bypass_register_consumer+0x4f0/0x500 > virt/lib/irqbypass.c:198 > Read of size 8 at addr ffff8801cf1d9178 by task syzkaller948360/3420 > > CPU: 1 PID: 3420 Comm: syzkaller948360 Not tainted 4.13.0-rc4+ #23 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > Google 01/01/2011 > Call Trace: > __dump_stack lib/dump_stack.c:16 [inline] > dump_stack+0x194/0x257 lib/dump_stack.c:52 > print_address_description+0x7f/0x260 mm/kasan/report.c:252 > kasan_report_error mm/kasan/report.c:351 [inline] > kasan_report+0x24e/0x340 mm/kasan/report.c:409 > __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:430 > irq_bypass_register_consumer+0x4f0/0x500 virt/lib/irqbypass.c:198 > kvm_irqfd_assign arch/x86/kvm/../../../virt/kvm/eventfd.c:417 [inline] > kvm_irqfd+0x137a/0x1d50 arch/x86/kvm/../../../virt/kvm/eventfd.c:572 > kvm_vm_ioctl+0x1079/0x1c40 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3029 > vfs_ioctl fs/ioctl.c:45 [inline] > do_vfs_ioctl+0x1b1/0x1520 fs/ioctl.c:685 > SYSC_ioctl fs/ioctl.c:700 [inline] > SyS_ioctl+0x8f/0xc0 fs/ioctl.c:691 > entry_SYSCALL_64_fastpath+0x1f/0xbe > RIP: 0033:0x4460d9 > RSP: 002b:00007f24ae19adc8 EFLAGS: 00000202 ORIG_RAX: 0000000000000010 > RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00000000004460d9 > RDX: 000000002000d000 RSI: 000000004020ae76 RDI: 000000000000002b > RBP: 0000000000000086 R08: 00007f24ae19b700 R09: 00007f24ae19b700 > R10: 00007f24ae19b700 R11: 0000000000000202 R12: 0000000000000000 > R13: 00007ffe1847ef3f R14: 00007f24ae19b9c0 R15: 0000000000000000 > > Allocated by task 3420: > save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59 > save_stack+0x43/0xd0 mm/kasan/kasan.c:447 > set_track mm/kasan/kasan.c:459 [inline] > kasan_kmalloc+0xaa/0xd0 mm/kasan/kasan.c:551 > kmem_cache_alloc_trace+0x101/0x6f0 mm/slab.c:3627 > kmalloc include/linux/slab.h:493 [inline] > kzalloc include/linux/slab.h:666 [inline] > kvm_irqfd_assign arch/x86/kvm/../../../virt/kvm/eventfd.c:296 [inline] > kvm_irqfd+0x16c/0x1d50 arch/x86/kvm/../../../virt/kvm/eventfd.c:572 > kvm_vm_ioctl+0x1079/0x1c40 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3029 > vfs_ioctl fs/ioctl.c:45 [inline] > do_vfs_ioctl+0x1b1/0x1520 fs/ioctl.c:685 > SYSC_ioctl fs/ioctl.c:700 [inline] > SyS_ioctl+0x8f/0xc0 fs/ioctl.c:691 > entry_SYSCALL_64_fastpath+0x1f/0xbe > > Freed by task 24: > save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59 > save_stack+0x43/0xd0 mm/kasan/kasan.c:447 > set_track mm/kasan/kasan.c:459 [inline] > kasan_slab_free+0x6e/0xc0 mm/kasan/kasan.c:524 > __cache_free mm/slab.c:3503 [inline] > kfree+0xd3/0x260 mm/slab.c:3820 > irqfd_shutdown+0x13c/0x1a0 arch/x86/kvm/../../../virt/kvm/eventfd.c:148 > process_one_work+0xbf3/0x1bc0 kernel/workqueue.c:2097 > worker_thread+0x223/0x1860 kernel/workqueue.c:2231 > kthread+0x35e/0x430 kernel/kthread.c:231 > ret_from_fork+0x2a/0x40 arch/x86/entry/entry_64.S:425 > > The buggy address belongs to the object at ffff8801cf1d9000 > which belongs to the cache kmalloc-512 of size 512 > The buggy address is located 376 bytes inside of > 512-byte region [ffff8801cf1d9000, ffff8801cf1d9200) > The buggy address belongs to the page: > page:ffffea000654e778 count:1 mapcount:0 mapping:ffff8801cf1d9000 index:0x0 > flags: 0x200000000000100(slab) > raw: 0200000000000100 ffff8801cf1d9000 0000000000000000 0000000100000006 > raw: ffffea000654e648 ffffea0006560c48 ffff8801dbc00600 > page dumped because: kasan: bad access detected > > Memory state around the buggy address: > ffff8801cf1d9000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > ffff8801cf1d9080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >> >> ffff8801cf1d9100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > > ^ > ffff8801cf1d9180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > ffff8801cf1d9200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc > ================================================================== Still happens on newer commits, e.g. on linux-next 36ef71cae353f88fd6e095e2aaa3e5953af1685d (Oct 19) ================================================================== BUG: KASAN: use-after-free in list_add include/linux/list.h:63 [inline] BUG: KASAN: use-after-free in irq_bypass_register_consumer+0x4e4/0x530 virt/lib/irqbypass.c:217 Write of size 8 at addr ffff880067e363e8 by task a.out/12001 CPU: 1 PID: 12001 Comm: a.out Not tainted 4.14.0-rc5-next-20171018 #15 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:16 [inline] dump_stack+0x1a8/0x272 lib/dump_stack.c:52 print_address_description+0x6c/0x204 mm/kasan/report.c:252 kasan_report_error mm/kasan/report.c:351 [inline] kasan_report+0x16e/0x270 mm/kasan/report.c:409 __asan_report_store8_noabort+0x17/0x20 mm/kasan/report.c:435 list_add include/linux/list.h:63 [inline] irq_bypass_register_consumer+0x4e4/0x530 virt/lib/irqbypass.c:217 kvm_irqfd_assign arch/x86/kvm/../../../virt/kvm/eventfd.c:417 [inline] kvm_irqfd+0x14e7/0x1e60 arch/x86/kvm/../../../virt/kvm/eventfd.c:572 kvm_vm_ioctl+0xa15/0x1dc0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2988 vfs_ioctl fs/ioctl.c:45 [inline] file_ioctl fs/ioctl.c:499 [inline] do_vfs_ioctl+0x1cf/0x16b0 fs/ioctl.c:683 SYSC_ioctl fs/ioctl.c:700 [inline] SyS_ioctl+0xb6/0xe0 fs/ioctl.c:691 entry_SYSCALL_64_fastpath+0x1f/0xbe RIP: 0033:0x44c969 RSP: 002b:00007fc56c43edb8 EFLAGS: 00000297 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000044c969 RDX: 0000000020025fe0 RSI: 000000004020ae76 RDI: 0000000000000005 RBP: 0000000000000086 R08: 00007fc56c43f700 R09: 0000000000000000 R10: 00007fc56c43f700 R11: 0000000000000297 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fc56c43f9c0 R15: 00007fc56c43f700 Allocated by task 12001: save_stack+0x43/0xd0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] kasan_kmalloc+0xc4/0xe0 mm/kasan/kasan.c:551 kmem_cache_alloc_trace+0x140/0x740 mm/slab.c:3614 kmalloc include/linux/slab.h:502 [inline] kzalloc include/linux/slab.h:691 [inline] kvm_irqfd_assign arch/x86/kvm/../../../virt/kvm/eventfd.c:296 [inline] kvm_irqfd+0x187/0x1e60 arch/x86/kvm/../../../virt/kvm/eventfd.c:572 kvm_vm_ioctl+0xa15/0x1dc0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2988 vfs_ioctl fs/ioctl.c:45 [inline] file_ioctl fs/ioctl.c:499 [inline] do_vfs_ioctl+0x1cf/0x16b0 fs/ioctl.c:683 SYSC_ioctl fs/ioctl.c:700 [inline] SyS_ioctl+0xb6/0xe0 fs/ioctl.c:691 entry_SYSCALL_64_fastpath+0x1f/0xbe Freed by task 1338: save_stack+0x43/0xd0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] kasan_slab_free+0x71/0xc0 mm/kasan/kasan.c:524 __cache_free mm/slab.c:3492 [inline] kfree+0xca/0x250 mm/slab.c:3807 irqfd_shutdown+0x13a/0x1a0 arch/x86/kvm/../../../virt/kvm/eventfd.c:148 process_one_work+0xb70/0x1ac0 kernel/workqueue.c:2112 worker_thread+0x223/0x1ac0 kernel/workqueue.c:2246 kthread+0x38f/0x470 kernel/kthread.c:242 ret_from_fork+0x2a/0x40 arch/x86/entry/entry_64.S:431 The buggy address belongs to the object at ffff880067e36280 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 360 bytes inside of 512-byte region [ffff880067e36280, ffff880067e36480) The buggy address belongs to the page: page:ffffea00019f8d80 count:1 mapcount:0 mapping:ffff880067e36000 index:0x0 flags: 0x100000000000100(slab) raw: 0100000000000100 ffff880067e36000 0000000000000000 0000000100000006 raw: ffffea0001a945e0 ffffea0001a153a0 ffff88006c400940 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff880067e36280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff880067e36300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff880067e36380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff880067e36400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff880067e36480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ================================================================== > --- > 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. > Please credit me with: Reported-by: syzbot <syzkaller@xxxxxxxxxxxxxxxx> > > syzbot will keep track of this bug report. > Once a fix for this bug is committed, please reply to this email with: > #syz fix: exact-commit-title > To mark this as a duplicate of another syzbot report, please reply with: > #syz dup: exact-subject-of-another-report > If it's a one-off invalid bug report, please reply with: > #syz invalid > Note: if the crash happens again, it will cause creation of a new bug > report. > Note: all commands must start from beginning of the line. > > -- > 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@xxxxxxxxxxxxxxxx. > To view this discussion on the web visit > https://groups.google.com/d/msgid/syzkaller-bugs/94eb2c0bfe1ee3b038055cf18dce%40google.com. > For more options, visit https://groups.google.com/d/optout.
