[ 31.585656] audit: type=1800 audit(1555885193.421:33): pid=6851 uid=0 auid=4294967295 ses=4294967295 subj=system_u:system_r:kernel_t:s0 op="collect_data" cause="failed(directio)" comm="startpar" name="rc.local" dev="sda1" ino=2465 res=0 [ 31.612397] audit: type=1800 audit(1555885193.421:34): pid=6851 uid=0 auid=4294967295 ses=4294967295 subj=system_u:system_r:kernel_t:s0 op="collect_data" cause="failed(directio)" comm="startpar" name="rmnologin" dev="sda1" ino=2456 res=0 Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 35.048277] random: sshd: uninitialized urandom read (32 bytes read) [ 35.250341] audit: type=1400 audit(1555885197.081:35): avc: denied { map } for pid=7025 comm="bash" path="/bin/bash" dev="sda1" ino=1457 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=system_u:object_r:file_t:s0 tclass=file permissive=1 [ 35.307499] random: sshd: uninitialized urandom read (32 bytes read) [ 35.854067] random: sshd: uninitialized urandom read (32 bytes read) [ 458.302101] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.0.83' (ECDSA) to the list of known hosts. [ 464.160876] random: sshd: uninitialized urandom read (32 bytes read) executing program executing program executing program executing program executing program executing program [ 464.283530] audit: type=1400 audit(1555885626.121:36): avc: denied { map } for pid=7037 comm="syz-executor688" path="/root/syz-executor688670550" dev="sda1" ino=1426 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1 executing program executing program executing program executing program [ 464.421522] ================================================================== [ 464.428971] BUG: KASAN: use-after-free in disk_unblock_events+0x55/0x60 [ 464.435699] Read of size 8 at addr ffff8880a48d2648 by task syz-executor688/7067 [ 464.443200] [ 464.444801] CPU: 1 PID: 7067 Comm: syz-executor688 Not tainted 4.14.113 #3 [ 464.451783] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 464.461121] Call Trace: [ 464.463699] dump_stack+0x138/0x19c [ 464.467311] ? disk_unblock_events+0x55/0x60 [ 464.471695] print_address_description.cold+0x7c/0x1dc [ 464.476992] ? disk_unblock_events+0x55/0x60 [ 464.481375] kasan_report.cold+0xaf/0x2b5 [ 464.485528] __asan_report_load8_noabort+0x14/0x20 [ 464.490430] disk_unblock_events+0x55/0x60 [ 464.494641] __blkdev_get+0x7d8/0x1120 [ 464.498507] ? __blkdev_put+0x7f0/0x7f0 [ 464.502469] ? bd_acquire+0x178/0x2c0 [ 464.506249] ? find_held_lock+0x35/0x130 [ 464.510291] blkdev_get+0xa8/0x8e0 [ 464.513821] ? bd_may_claim+0xd0/0xd0 [ 464.517618] ? _raw_spin_unlock+0x2d/0x50 [ 464.521743] blkdev_open+0x1d1/0x260 [ 464.525442] ? security_file_open+0x8f/0x1a0 [ 464.529834] do_dentry_open+0x73e/0xeb0 [ 464.533815] ? bd_acquire+0x2c0/0x2c0 [ 464.537609] vfs_open+0x105/0x230 [ 464.541045] path_openat+0x8bd/0x3f70 [ 464.544829] ? trace_hardirqs_on+0x10/0x10 [ 464.549055] ? path_lookupat.isra.0+0x7b0/0x7b0 [ 464.553705] ? find_held_lock+0x35/0x130 [ 464.557752] ? __alloc_fd+0x1d4/0x4a0 [ 464.561530] do_filp_open+0x18e/0x250 [ 464.565306] ? may_open_dev+0xe0/0xe0 [ 464.569128] ? _raw_spin_unlock+0x2d/0x50 [ 464.573252] ? __alloc_fd+0x1d4/0x4a0 [ 464.577033] do_sys_open+0x2c5/0x430 [ 464.580733] ? filp_open+0x70/0x70 [ 464.584253] SyS_open+0x2d/0x40 [ 464.587649] ? do_sys_open+0x430/0x430 [ 464.591607] do_syscall_64+0x1eb/0x630 [ 464.595517] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 464.600351] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 464.605517] RIP: 0033:0x405771 [ 464.608691] RSP: 002b:00007ff570326980 EFLAGS: 00000293 ORIG_RAX: 0000000000000002 [ 464.616387] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000405771 [ 464.623633] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00007ff570326990 [ 464.630878] RBP: 6666666666666667 R08: 000000000000000f R09: 00007ff570327700 [ 464.638130] R10: 00007ff5703279d0 R11: 0000000000000293 R12: 00000000006dbc4c [ 464.645378] R13: 00007ffc187ec75f R14: 00007ff5703279c0 R15: 000000000000002d [ 464.652636] [ 464.654242] Allocated by task 1: [ 464.657584] save_stack_trace+0x16/0x20 [ 464.661536] save_stack+0x45/0xd0 [ 464.664965] kasan_kmalloc+0xce/0xf0 [ 464.668655] kmem_cache_alloc_node_trace+0x153/0x770 [ 464.673731] alloc_disk_node+0x64/0x3e0 [ 464.677678] alloc_disk+0x1b/0x20 [ 464.681104] loop_add+0x3f4/0x8d0 [ 464.684532] loop_init+0x19d/0x1e5 [ 464.688046] do_one_initcall+0xa0/0x220 [ 464.691994] kernel_init_freeable+0x474/0x538 [ 464.696470] kernel_init+0x12/0x162 [ 464.700075] ret_from_fork+0x3a/0x50 [ 464.703764] [ 464.705366] Freed by task 7067: [ 464.708630] save_stack_trace+0x16/0x20 [ 464.712583] save_stack+0x45/0xd0 [ 464.716010] kasan_slab_free+0x75/0xc0 [ 464.719869] kfree+0xcc/0x270 [ 464.722958] disk_release+0x24b/0x2d0 [ 464.726737] device_release+0xfa/0x1b0 [ 464.730626] kobject_put.cold+0x26f/0x2ff [ 464.734792] put_disk+0x23/0x30 [ 464.738068] __blkdev_get+0x73e/0x1120 [ 464.741939] blkdev_get+0xa8/0x8e0 [ 464.745453] blkdev_open+0x1d1/0x260 [ 464.749140] do_dentry_open+0x73e/0xeb0 [ 464.753090] vfs_open+0x105/0x230 [ 464.756530] path_openat+0x8bd/0x3f70 [ 464.760307] do_filp_open+0x18e/0x250 [ 464.764087] do_sys_open+0x2c5/0x430 [ 464.767779] SyS_open+0x2d/0x40 [ 464.771036] do_syscall_64+0x1eb/0x630 [ 464.774907] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 464.780107] [ 464.781717] The buggy address belongs to the object at ffff8880a48d20c0 [ 464.781717] which belongs to the cache kmalloc-2048 of size 2048 [ 464.794525] The buggy address is located 1416 bytes inside of [ 464.794525] 2048-byte region [ffff8880a48d20c0, ffff8880a48d28c0) [ 464.806546] The buggy address belongs to the page: [ 464.811470] page:ffffea0002923480 count:1 mapcount:0 mapping:ffff8880a48d20c0 index:0x0 compound_mapcount: 0 [ 464.821435] flags: 0x1fffc0000008100(slab|head) [ 464.826085] raw: 01fffc0000008100 ffff8880a48d20c0 0000000000000000 0000000100000003 [ 464.833947] raw: ffffea0002921da0 ffffea00029244a0 ffff8880aa800c40 0000000000000000 [ 464.841880] page dumped because: kasan: bad access detected [ 464.847578] [ 464.849178] Memory state around the buggy address: [ 464.854143] ffff8880a48d2500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 464.861484] ffff8880a48d2580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 464.868826] >ffff8880a48d2600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 464.876164] ^ [ 464.881853] ffff8880a48d2680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 464.889211] ffff8880a48d2700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 464.896645] ================================================================== [ 464.903999] Disabling lock debugging due to kernel taint [ 464.917143] Kernel panic - not syncing: panic_on_warn set ... executing program executing program executing program executing program executing program executing program executing program [ 464.917143] [ 464.924522] CPU: 1 PID: 7067 Comm: syz-executor688 Tainted: G B 4.14.113 #3 [ 464.932724] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 464.942055] Call Trace: [ 464.944634] dump_stack+0x138/0x19c [ 464.948241] ? disk_unblock_events+0x55/0x60 [ 464.952637] panic+0x1f2/0x438 [ 464.955806] ? add_taint.cold+0x16/0x16 [ 464.959757] ? ___preempt_schedule+0x16/0x18 [ 464.964144] kasan_end_report+0x47/0x4f [ 464.968092] kasan_report.cold+0x136/0x2b5 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 464.972312] __asan_report_load8_noabort+0x14/0x20 [ 464.977218] disk_unblock_events+0x55/0x60 [ 464.981446] __blkdev_get+0x7d8/0x1120 [ 464.985308] ? __blkdev_put+0x7f0/0x7f0 [ 464.989326] ? bd_acquire+0x178/0x2c0 [ 464.993117] ? find_held_lock+0x35/0x130 [ 464.997158] blkdev_get+0xa8/0x8e0 [ 465.000676] ? bd_may_claim+0xd0/0xd0 [ 465.004452] ? _raw_spin_unlock+0x2d/0x50 [ 465.008587] blkdev_open+0x1d1/0x260 [ 465.012276] ? security_file_open+0x8f/0x1a0 [ 465.016656] do_dentry_open+0x73e/0xeb0 [ 465.020682] ? bd_acquire+0x2c0/0x2c0 [ 465.024467] vfs_open+0x105/0x230 [ 465.027929] path_openat+0x8bd/0x3f70 [ 465.031720] ? trace_hardirqs_on+0x10/0x10 [ 465.035930] ? path_lookupat.isra.0+0x7b0/0x7b0 [ 465.040694] ? find_held_lock+0x35/0x130 [ 465.044848] ? __alloc_fd+0x1d4/0x4a0 [ 465.048653] do_filp_open+0x18e/0x250 [ 465.052435] ? may_open_dev+0xe0/0xe0 [ 465.056222] ? _raw_spin_unlock+0x2d/0x50 [ 465.060349] ? __alloc_fd+0x1d4/0x4a0 [ 465.064153] do_sys_open+0x2c5/0x430 [ 465.067844] ? filp_open+0x70/0x70 [ 465.071515] SyS_open+0x2d/0x40 [ 465.074768] ? do_sys_open+0x430/0x430 [ 465.078631] do_syscall_64+0x1eb/0x630 [ 465.082492] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 465.087328] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 465.092545] RIP: 0033:0x405771 [ 465.095731] RSP: 002b:00007ff570326980 EFLAGS: 00000293 ORIG_RAX: 0000000000000002 [ 465.103480] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000405771 [ 465.110744] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00007ff570326990 [ 465.117999] RBP: 6666666666666667 R08: 000000000000000f R09: 00007ff570327700 [ 465.125360] R10: 00007ff5703279d0 R11: 0000000000000293 R12: 00000000006dbc4c [ 465.132613] R13: 00007ffc187ec75f R14: 00007ff5703279c0 R15: 000000000000002d [ 465.140574] Kernel Offset: disabled [ 465.144190] Rebooting in 86400 seconds..