[ OK ] Started Getty on tty6. [ OK ] Started Getty on tty5. [ OK ] Started Getty on tty4. [ OK ] Started Getty on tty3. [ OK ] Started Serial Getty on ttyS0. [ OK ] Reached target Login Prompts. [ OK ] Reached target Multi-User System. [ OK ] Reached target Graphical Interface. Starting Update UTMP about System Runlevel Changes... [ OK ] Started Update UTMP about System Runlevel Changes. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.0.46' (ECDSA) to the list of known hosts. executing program executing program syzkaller login: [ 33.425771] ================================================================== [ 33.433264] BUG: KASAN: use-after-free in __list_add_valid+0x81/0xa0 [ 33.439782] Read of size 8 at addr ffff88808cef8980 by task syz-executor538/8116 [ 33.447362] [ 33.448976] CPU: 0 PID: 8116 Comm: syz-executor538 Not tainted 4.19.195-syzkaller #0 [ 33.456834] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 33.466168] Call Trace: [ 33.468749] dump_stack+0x1fc/0x2ef [ 33.472362] print_address_description.cold+0x54/0x219 [ 33.477630] kasan_report_error.cold+0x8a/0x1b9 [ 33.482309] ? __list_add_valid+0x81/0xa0 [ 33.486441] __asan_report_load8_noabort+0x88/0x90 [ 33.491361] ? __list_add_valid+0x81/0xa0 [ 33.495493] __list_add_valid+0x81/0xa0 [ 33.499544] chrdev_open+0x4b9/0x770 [ 33.503238] ? __register_chrdev+0x400/0x400 [ 33.507734] do_dentry_open+0x4aa/0x1160 [ 33.511777] ? __register_chrdev+0x400/0x400 [ 33.516187] ? inode_permission.part.0+0x10c/0x450 [ 33.521100] ? chown_common+0x550/0x550 [ 33.525074] ? inode_permission+0x3d/0x140 [ 33.529302] path_openat+0x793/0x2df0 [ 33.533114] ? path_lookupat+0x8d0/0x8d0 [ 33.537169] ? mark_held_locks+0xf0/0xf0 [ 33.541223] ? mark_held_locks+0xf0/0xf0 [ 33.545317] do_filp_open+0x18c/0x3f0 [ 33.549119] ? may_open_dev+0xf0/0xf0 [ 33.552935] ? lock_downgrade+0x720/0x720 [ 33.557094] ? lock_acquire+0x170/0x3c0 [ 33.561051] ? __alloc_fd+0x34/0x570 [ 33.564754] ? do_raw_spin_unlock+0x171/0x230 [ 33.569252] ? _raw_spin_unlock+0x29/0x40 [ 33.573390] ? __alloc_fd+0x28d/0x570 [ 33.577182] do_sys_open+0x3b3/0x520 [ 33.580912] ? filp_open+0x70/0x70 [ 33.584560] ? entry_SYSCALL_64_after_hwframe+0x3e/0xbe [ 33.589914] ? trace_hardirqs_off_caller+0x6e/0x210 [ 33.595010] ? do_syscall_64+0x21/0x620 [ 33.599162] do_syscall_64+0xf9/0x620 [ 33.602951] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 33.608308] RIP: 0033:0x446809 [ 33.611491] Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 41 15 00 00 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 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 [ 33.630487] RSP: 002b:00007f60b3b3c2f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 [ 33.638208] RAX: ffffffffffffffda RBX: 00000000004d0510 RCX: 0000000000446809 [ 33.645558] RDX: 0000000000000000 RSI: 0000000020002100 RDI: 00000000ffffff9c [ 33.652811] RBP: 00000000004a013c R08: 0000000000000000 R09: 0000000000000000 [ 33.660066] R10: 0000000000000000 R11: 0000000000000246 R12: 000000000049e138 [ 33.667470] R13: 2f30656c69662f2e R14: 0000000100000001 R15: 00000000004d0518 [ 33.674751] [ 33.676366] Allocated by task 8109: [ 33.679991] kmem_cache_alloc+0x122/0x370 [ 33.684165] fuse_alloc_inode+0x1d/0x3f0 [ 33.688220] alloc_inode+0x5d/0x180 [ 33.691833] iget5_locked+0x57/0xd0 [ 33.695448] fuse_iget+0x1a6/0x800 [ 33.698975] fuse_lookup_name+0x413/0x5c0 [ 33.703143] fuse_lookup+0xdf/0x410 [ 33.706754] fuse_atomic_open+0x20a/0x330 [ 33.710887] lookup_open+0x1023/0x1a20 [ 33.714760] path_openat+0x1804/0x2df0 [ 33.718638] do_filp_open+0x18c/0x3f0 [ 33.722425] do_sys_open+0x3b3/0x520 [ 33.726142] do_syscall_64+0xf9/0x620 [ 33.729948] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 33.735117] [ 33.736731] Freed by task 18: [ 33.739821] kmem_cache_free+0x7f/0x260 [ 33.743781] rcu_process_callbacks+0x8ff/0x18b0 [ 33.748522] __do_softirq+0x265/0x980 [ 33.752302] [ 33.753914] The buggy address belongs to the object at ffff88808cef8600 [ 33.753914] which belongs to the cache fuse_inode of size 1264 [ 33.766555] The buggy address is located 896 bytes inside of [ 33.766555] 1264-byte region [ffff88808cef8600, ffff88808cef8af0) [ 33.778524] The buggy address belongs to the page: [ 33.783449] page:ffffea000233be00 count:1 mapcount:0 mapping:ffff8880b0e9da80 index:0xffff88808cef8ffe [ 33.792890] flags: 0xfff00000000100(slab) [ 33.797038] raw: 00fff00000000100 ffffea000233d4c8 ffff8880b0e9eb48 ffff8880b0e9da80 [ 33.804904] raw: ffff88808cef8ffe ffff88808cef8080 0000000100000002 0000000000000000 [ 33.812806] page dumped because: kasan: bad access detected [ 33.818497] [ 33.820108] Memory state around the buggy address: [ 33.825022] ffff88808cef8880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 33.832466] ffff88808cef8900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 33.839809] >ffff88808cef8980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 33.847149] ^ [ 33.850498] ffff88808cef8a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 33.857863] ffff88808cef8a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc [ 33.865218] ================================================================== [ 33.872568] Disabling lock debugging due to kernel taint [ 33.878200] Kernel panic - not syncing: panic_on_warn set ... [ 33.878200] [ 33.885587] CPU: 0 PID: 8116 Comm: syz-executor538 Tainted: G B 4.19.195-syzkaller #0 [ 33.894860] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 33.904565] Call Trace: [ 33.907160] dump_stack+0x1fc/0x2ef [ 33.910796] panic+0x26a/0x50e [ 33.913974] ? __warn_printk+0xf3/0xf3 [ 33.917844] ? retint_kernel+0x2d/0x2d [ 33.921864] ? trace_hardirqs_on+0x55/0x210 [ 33.926181] kasan_end_report+0x43/0x49 [ 33.930148] kasan_report_error.cold+0xa7/0x1b9 [ 33.934821] ? __list_add_valid+0x81/0xa0 [ 33.938964] __asan_report_load8_noabort+0x88/0x90 [ 33.943877] ? __list_add_valid+0x81/0xa0 [ 33.948021] __list_add_valid+0x81/0xa0 [ 33.951991] chrdev_open+0x4b9/0x770 [ 33.955708] ? __register_chrdev+0x400/0x400 [ 33.960102] do_dentry_open+0x4aa/0x1160 [ 33.964146] ? __register_chrdev+0x400/0x400 [ 33.968821] ? inode_permission.part.0+0x10c/0x450 [ 33.973752] ? chown_common+0x550/0x550 [ 33.977734] ? inode_permission+0x3d/0x140 [ 33.981977] path_openat+0x793/0x2df0 [ 33.985853] ? path_lookupat+0x8d0/0x8d0 [ 33.989897] ? mark_held_locks+0xf0/0xf0 [ 33.994029] ? mark_held_locks+0xf0/0xf0 [ 33.998074] do_filp_open+0x18c/0x3f0 [ 34.001884] ? may_open_dev+0xf0/0xf0 [ 34.005775] ? lock_downgrade+0x720/0x720 [ 34.009924] ? lock_acquire+0x170/0x3c0 [ 34.013886] ? __alloc_fd+0x34/0x570 [ 34.017583] ? do_raw_spin_unlock+0x171/0x230 [ 34.022063] ? _raw_spin_unlock+0x29/0x40 [ 34.026194] ? __alloc_fd+0x28d/0x570 [ 34.029990] do_sys_open+0x3b3/0x520 [ 34.033689] ? filp_open+0x70/0x70 [ 34.037299] ? entry_SYSCALL_64_after_hwframe+0x3e/0xbe [ 34.042668] ? trace_hardirqs_off_caller+0x6e/0x210 [ 34.047668] ? do_syscall_64+0x21/0x620 [ 34.051627] do_syscall_64+0xf9/0x620 [ 34.055794] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 34.060966] RIP: 0033:0x446809 [ 34.064159] Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 41 15 00 00 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 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 [ 34.083045] RSP: 002b:00007f60b3b3c2f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 [ 34.090736] RAX: ffffffffffffffda RBX: 00000000004d0510 RCX: 0000000000446809 [ 34.098012] RDX: 0000000000000000 RSI: 0000000020002100 RDI: 00000000ffffff9c [ 34.105266] RBP: 00000000004a013c R08: 0000000000000000 R09: 0000000000000000 [ 34.112520] R10: 0000000000000000 R11: 0000000000000246 R12: 000000000049e138 [ 34.119776] R13: 2f30656c69662f2e R14: 0000000100000001 R15: 00000000004d0518 [ 34.128003] Kernel Offset: disabled [ 34.131615] Rebooting in 86400 seconds..