Starting mcstransd: [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [ 11.854709] random: sshd: uninitialized urandom read (32 bytes read) [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting file context maintaining daemon: restorecond[?25l[?1c7[ ok 8[?25h[?0c. [ 12.023572] random: crng init done Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added '10.128.0.129' (ECDSA) to the list of known hosts. 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 syzkaller login: [ 51.345210] ================================================================== [ 51.352619] BUG: KASAN: use-after-free in disk_unblock_events+0x51/0x60 [ 51.359370] Read of size 8 at addr ffff8801d61d6b60 by task syz-executor057/2105 [ 51.366893] [ 51.368522] CPU: 0 PID: 2105 Comm: syz-executor057 Not tainted 4.9.141+ #1 [ 51.375530] ffff8801cef776f8 ffffffff81b42e79 ffffea0007587400 ffff8801d61d6b60 [ 51.383647] 0000000000000000 ffff8801d61d6b60 0000000000000000 ffff8801cef77730 executing program executing program executing program executing program [ 51.391764] ffffffff815009b8 ffff8801d61d6b60 0000000000000008 0000000000000000 [ 51.399853] Call Trace: [ 51.402456] [] dump_stack+0xc1/0x128 [ 51.407826] [] print_address_description+0x6c/0x234 [ 51.414492] [] kasan_report.cold.6+0x242/0x2fe [ 51.420727] [] ? disk_unblock_events+0x51/0x60 [ 51.426958] [] __asan_report_load8_noabort+0x14/0x20 [ 51.433716] [] disk_unblock_events+0x51/0x60 [ 51.439775] [] __blkdev_get+0x6b6/0xd60 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 51.445402] [] ? __blkdev_put+0x840/0x840 [ 51.451208] [] blkdev_get+0x2da/0x920 [ 51.456660] [] ? debug_lockdep_rcu_enabled+0x77/0x90 [ 51.463415] [] ? bd_may_claim+0xd0/0xd0 [ 51.469055] [] ? bd_acquire+0xfc/0x250 [ 51.474593] [] ? bd_acquire+0x133/0x250 [ 51.480217] [] ? _raw_spin_unlock+0x2c/0x50 [ 51.486188] [] blkdev_open+0x1a5/0x250 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 executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 51.491724] [] do_dentry_open+0x3ef/0xc90 [ 51.497527] [] ? blkdev_get_by_dev+0x70/0x70 [ 51.503588] [] vfs_open+0x11c/0x210 [ 51.508866] [] ? may_open.isra.20+0x14f/0x2a0 [ 51.515012] [] path_openat+0x542/0x2790 [ 51.520641] [] ? path_mountpoint+0x6c0/0x6c0 [ 51.526705] [] ? trace_hardirqs_on+0x10/0x10 [ 51.532766] [] ? expand_files.part.3+0x3a9/0x6d0 [ 51.539175] [] do_filp_open+0x197/0x270 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 executing program executing program [ 51.544802] [] ? may_open_dev+0xe0/0xe0 [ 51.550436] [] ? _raw_spin_unlock+0x2c/0x50 [ 51.556412] [] ? __alloc_fd+0x1d7/0x4a0 [ 51.562052] [] do_sys_open+0x30d/0x5c0 [ 51.567608] [] ? filp_open+0x70/0x70 [ 51.572978] [] ? up_read+0x1a/0x40 [ 51.578173] [] SyS_open+0x2d/0x40 [ 51.583276] [] ? do_sys_open+0x5c0/0x5c0 [ 51.588987] [] do_syscall_64+0x19f/0x550 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 [ 51.594699] [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 51.601618] [ 51.603242] Allocated by task 2105: [ 51.607379] save_stack_trace+0x16/0x20 [ 51.611358] kasan_kmalloc.part.1+0x62/0xf0 [ 51.615678] kasan_kmalloc+0xaf/0xc0 [ 51.619391] kmem_cache_alloc_trace+0x117/0x2e0 [ 51.624071] alloc_disk_node+0x54/0x3a0 [ 51.628044] alloc_disk+0x18/0x20 [ 51.631496] loop_add+0x368/0x7a0 [ 51.634949] loop_control_ioctl+0x167/0x300 [ 51.639273] do_vfs_ioctl+0x1ac/0x11a0 [ 51.643161] SyS_ioctl+0x8f/0xc0 [ 51.646522] do_syscall_64+0x19f/0x550 [ 51.650410] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 51.655509] [ 51.657130] Freed by task 2105: [ 51.660409] save_stack_trace+0x16/0x20 [ 51.664415] kasan_slab_free+0xac/0x190 [ 51.668396] kfree+0xfb/0x310 [ 51.671509] disk_release+0x259/0x330 [ 51.675310] device_release+0x7e/0x220 [ 51.679196] kobject_put+0x148/0x250 [ 51.682910] put_disk+0x23/0x30 [ 51.686202] __blkdev_get+0x616/0xd60 [ 51.690004] blkdev_get+0x2da/0x920 [ 51.693629] blkdev_open+0x1a5/0x250 [ 51.697350] do_dentry_open+0x3ef/0xc90 [ 51.701329] vfs_open+0x11c/0x210 [ 51.704786] path_openat+0x542/0x2790 [ 51.708588] do_filp_open+0x197/0x270 [ 51.712385] do_sys_open+0x30d/0x5c0 [ 51.716098] SyS_open+0x2d/0x40 [ 51.719375] do_syscall_64+0x19f/0x550 [ 51.723262] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 51.728356] [ 51.729979] The buggy address belongs to the object at ffff8801d61d6600 [ 51.729979] which belongs to the cache kmalloc-2048 of size 2048 [ 51.742809] The buggy address is located 1376 bytes inside of [ 51.742809] 2048-byte region [ffff8801d61d6600, ffff8801d61d6e00) [ 51.754850] The buggy address belongs to the page: [ 51.759778] page:ffffea0007587400 count:1 mapcount:0 mapping: (null) index:0x0 compound_mapcount: 0 [ 51.770014] flags: 0x4000000000004080(slab|head) [ 51.774762] page dumped because: kasan: bad access detected [ 51.780480] [ 51.782099] Memory state around the buggy address: [ 51.787023] ffff8801d61d6a00: 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 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 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 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 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 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 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 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 [ 51.794378] ffff8801d61d6a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 51.801733] >ffff8801d61d6b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 51.809088] ^ [ 51.815574] ffff8801d61d6b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 51.822932] ffff8801d61d6c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 51.830285] ================================================================== [ 51.837672] Disabling lock debugging due to kernel taint 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 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 [ 51.848464] Kernel panic - not syncing: panic_on_warn set ... [ 51.848464] [ 51.855844] CPU: 0 PID: 2105 Comm: syz-executor057 Tainted: G B 4.9.141+ #1 [ 51.864076] ffff8801cef77658 ffffffff81b42e79 ffffffff82e37630 00000000ffffffff [ 51.872248] 0000000000000000 0000000000000000 0000000000000000 ffff8801cef77718 [ 51.880417] ffffffff813f7125 0000000041b58ab3 ffffffff82e2b62b ffffffff813f6f66 [ 51.888536] Call Trace: [ 51.891157] [] dump_stack+0xc1/0x128 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 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 [ 51.896551] [] panic+0x1bf/0x39f [ 51.901575] [] ? add_taint.cold.5+0x16/0x16 [ 51.907548] [] ? ___preempt_schedule+0x16/0x18 [ 51.913785] [] kasan_end_report+0x47/0x4f [ 51.919593] [] kasan_report.cold.6+0x76/0x2fe [ 51.925744] [] ? disk_unblock_events+0x51/0x60 [ 51.931977] [] __asan_report_load8_noabort+0x14/0x20 [ 51.938749] [] disk_unblock_events+0x51/0x60 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 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 [ 51.944807] [] __blkdev_get+0x6b6/0xd60 [ 51.950441] [] ? __blkdev_put+0x840/0x840 [ 51.956246] [] blkdev_get+0x2da/0x920 [ 51.961789] [] ? debug_lockdep_rcu_enabled+0x77/0x90 [ 51.968545] [] ? bd_may_claim+0xd0/0xd0 [ 51.974182] [] ? bd_acquire+0xfc/0x250 [ 51.979742] [] ? bd_acquire+0x133/0x250 [ 51.985367] [] ? _raw_spin_unlock+0x2c/0x50 [ 51.991336] [] blkdev_open+0x1a5/0x250 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 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 [ 51.996875] [] do_dentry_open+0x3ef/0xc90 [ 52.002673] [] ? blkdev_get_by_dev+0x70/0x70 [ 52.008734] [] vfs_open+0x11c/0x210 [ 52.014011] [] ? may_open.isra.20+0x14f/0x2a0 [ 52.020155] [] path_openat+0x542/0x2790 [ 52.025778] [] ? path_mountpoint+0x6c0/0x6c0 [ 52.031838] [] ? trace_hardirqs_on+0x10/0x10 [ 52.037897] [] ? expand_files.part.3+0x3a9/0x6d0 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 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 [ 52.044303] [] do_filp_open+0x197/0x270 [ 52.049927] [] ? may_open_dev+0xe0/0xe0 [ 52.055555] [] ? _raw_spin_unlock+0x2c/0x50 [ 52.061530] [] ? __alloc_fd+0x1d7/0x4a0 [ 52.067153] [] do_sys_open+0x30d/0x5c0 [ 52.072689] [] ? filp_open+0x70/0x70 [ 52.078053] [] ? up_read+0x1a/0x40 [ 52.083244] [] SyS_open+0x2d/0x40 [ 52.088348] [] ? do_sys_open+0x5c0/0x5c0 [ 52.094058] [] do_syscall_64+0x19f/0x550 executing program executing program executing program executing program executing program executing program [ 52.099770] [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 52.106958] Kernel Offset: disabled [ 52.110577] Rebooting in 86400 seconds..