[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [ 11.916122] random: crng init done Starting mcstransd: [....] Starting file context maintaining daemon: restorecond[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added '10.128.0.230' (ECDSA) to the list of known hosts. 2019/10/26 19:44:15 parsed 1 programs 2019/10/26 19:44:17 executed programs: 0 syzkaller login: [ 27.564738] audit: type=1400 audit(1572119059.351:5): avc: denied { associate } for pid=2087 comm="syz-executor.3" name="syz3" scontext=unconfined_u:object_r:unlabeled_t:s0 tcontext=system_u:object_r:unlabeled_t:s0 tclass=filesystem permissive=1 [ 27.975510] ================================================================== [ 27.984691] BUG: KASAN: use-after-free in disk_unblock_events+0x55/0x60 [ 27.993391] Read of size 8 at addr ffff8801d69362e0 by task syz-executor.0/2081 [ 28.002405] [ 28.004054] CPU: 0 PID: 2081 Comm: syz-executor.0 Not tainted 4.9.194+ #0 [ 28.010998] ffff8801ce697730 ffffffff81b67001 0000000000000000 ffffea00075a4c00 [ 28.019111] ffff8801d69362e0 0000000000000008 ffffffff81b3b4b5 ffff8801ce697768 [ 28.027752] ffffffff8150c4f1 0000000000000000 ffff8801d69362e0 ffff8801d69362e0 [ 28.036040] Call Trace: [ 28.038668] [<000000005a4955a1>] dump_stack+0xc1/0x120 [ 28.044052] [<00000000a3f4b270>] ? disk_unblock_events+0x55/0x60 [ 28.050315] [<00000000d2f20722>] print_address_description+0x6f/0x23a [ 28.057111] [<00000000a3f4b270>] ? disk_unblock_events+0x55/0x60 [ 28.063379] [<00000000dccef32b>] kasan_report.cold+0x8c/0x2ba [ 28.069547] [<00000000a6d0656d>] __asan_report_load8_noabort+0x14/0x20 [ 28.076613] [<00000000a3f4b270>] disk_unblock_events+0x55/0x60 [ 28.083214] [<000000003722ef34>] __blkdev_get+0x6ba/0xeb0 [ 28.089024] [<00000000e866eefa>] ? __blkdev_put+0x840/0x840 [ 28.094938] [<0000000041c56228>] blkdev_get+0x2e8/0x920 [ 28.100493] [<00000000dd8a25fc>] ? debug_lockdep_rcu_enabled+0x71/0xa0 [ 28.107441] [<00000000e30273bf>] ? bd_may_claim+0xd0/0xd0 [ 28.113275] [<0000000041b1f94c>] ? bd_acquire+0x26/0x250 [ 28.119302] [<00000000c0cfa80e>] ? bd_acquire+0x88/0x250 [ 28.125294] [<0000000018063809>] ? _raw_spin_unlock+0x2d/0x50 [ 28.131399] [<00000000489ee90a>] blkdev_open+0x1aa/0x250 [ 28.136966] [<000000005f9c4880>] do_dentry_open+0x422/0xd20 [ 28.142913] [<0000000059ff746f>] ? blkdev_get_by_dev+0x80/0x80 [ 28.149111] [<00000000209eeb47>] vfs_open+0x105/0x230 [ 28.154402] [<00000000e3fbd664>] ? may_open.isra.0+0x139/0x290 [ 28.162138] [<00000000bb950d82>] path_openat+0xbf5/0x2f60 [ 28.168344] [<000000004e4b5d41>] ? path_mountpoint+0x6d0/0x6d0 [ 28.174988] [<00000000bc2b125a>] do_filp_open+0x1a1/0x280 [ 28.182052] [<00000000074915f9>] ? may_open_dev+0xe0/0xe0 [ 28.188823] [<000000002bf98aba>] ? __alloc_fd+0x1d4/0x490 [ 28.195378] [<0000000018063809>] ? _raw_spin_unlock+0x2d/0x50 [ 28.201816] [<000000002bf98aba>] ? __alloc_fd+0x1d4/0x490 [ 28.207949] [<000000009dd74d65>] do_sys_open+0x2f0/0x610 [ 28.213605] [<000000006ba86fff>] ? filp_open+0x70/0x70 [ 28.220471] [<0000000029bac209>] ? SyS_mkdirat+0x164/0x250 [ 28.226296] [<00000000f4207a0b>] ? SyS_mknod+0x40/0x40 [ 28.233020] [<00000000fc3cc8cf>] SyS_open+0x2d/0x40 [ 28.238583] [<0000000016d98608>] ? do_sys_open+0x610/0x610 [ 28.245421] [<00000000b5d4871d>] do_syscall_64+0x1ad/0x5c0 [ 28.251847] [<000000005de93085>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 28.259286] [ 28.260970] Allocated by task 2081: [ 28.266611] save_stack_trace+0x16/0x20 [ 28.273469] kasan_kmalloc.part.0+0x62/0xf0 [ 28.278938] kasan_kmalloc+0xb7/0xd0 [ 28.283065] kmem_cache_alloc_trace+0x115/0x2d0 [ 28.288321] alloc_disk_node+0x50/0x3c0 [ 28.292532] alloc_disk+0x1b/0x20 [ 28.295983] loop_add+0x37e/0x7d0 [ 28.299689] loop_probe+0x154/0x180 [ 28.303302] kobj_lookup+0x221/0x410 [ 28.307235] get_gendisk+0x3c/0x2d0 [ 28.310997] __blkdev_get+0x356/0xeb0 [ 28.314973] blkdev_get+0x2e8/0x920 [ 28.318687] blkdev_open+0x1aa/0x250 [ 28.322431] do_dentry_open+0x422/0xd20 [ 28.327231] vfs_open+0x105/0x230 [ 28.330703] path_openat+0xbf5/0x2f60 [ 28.335212] do_filp_open+0x1a1/0x280 [ 28.339192] do_sys_open+0x2f0/0x610 [ 28.343910] SyS_open+0x2d/0x40 [ 28.348014] do_syscall_64+0x1ad/0x5c0 [ 28.354006] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 28.359188] [ 28.360887] Freed by task 2081: [ 28.364679] save_stack_trace+0x16/0x20 [ 28.370490] kasan_slab_free+0xb0/0x190 [ 28.374542] kfree+0xfc/0x310 [ 28.377697] disk_release+0x255/0x330 [ 28.381898] device_release+0x7d/0x220 [ 28.385787] kobject_put+0x150/0x260 [ 28.389790] put_disk+0x23/0x30 [ 28.393143] __blkdev_get+0x61a/0xeb0 [ 28.398089] blkdev_get+0x2e8/0x920 [ 28.401823] blkdev_open+0x1aa/0x250 [ 28.405688] do_dentry_open+0x422/0xd20 [ 28.409827] vfs_open+0x105/0x230 [ 28.413371] path_openat+0xbf5/0x2f60 [ 28.417430] do_filp_open+0x1a1/0x280 [ 28.421232] do_sys_open+0x2f0/0x610 [ 28.425045] SyS_open+0x2d/0x40 [ 28.428503] do_syscall_64+0x1ad/0x5c0 [ 28.432379] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 28.437947] [ 28.439560] The buggy address belongs to the object at ffff8801d6935d80 [ 28.439560] which belongs to the cache kmalloc-2048 of size 2048 [ 28.452391] The buggy address is located 1376 bytes inside of [ 28.452391] 2048-byte region [ffff8801d6935d80, ffff8801d6936580) [ 28.464942] The buggy address belongs to the page: [ 28.469877] page:ffffea00075a4c00 count:1 mapcount:0 mapping: (null) index:0xffff8801d6930880 compound_mapcount: 0 [ 28.481515] flags: 0x4000000000010200(slab|head) [ 28.486314] page dumped because: kasan: bad access detected [ 28.492482] [ 28.494208] Memory state around the buggy address: [ 28.499142] ffff8801d6936180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 28.506610] ffff8801d6936200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 28.513969] >ffff8801d6936280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 28.521332] ^ [ 28.527866] ffff8801d6936300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 28.535215] ffff8801d6936380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 28.542558] ================================================================== [ 28.550062] Disabling lock debugging due to kernel taint [ 28.555978] Kernel panic - not syncing: panic_on_warn set ... [ 28.555978] [ 28.563444] CPU: 0 PID: 2081 Comm: syz-executor.0 Tainted: G B 4.9.194+ #0 [ 28.571585] ffff8801ce697670 ffffffff81b67001 ffff8801ce697700 ffffffff82e40f17 [ 28.579619] 00000000ffffffff 0000000000000000 ffffffff81b3b4b5 ffff8801ce697750 [ 28.587630] ffffffff813fef3a 0000000041b58ab3 ffffffff82e32f55 ffffffff813fed61 [ 28.595831] Call Trace: [ 28.598495] [<000000005a4955a1>] dump_stack+0xc1/0x120 [ 28.603965] [<00000000a3f4b270>] ? disk_unblock_events+0x55/0x60 [ 28.610209] [<000000009e0ae49c>] panic+0x1d9/0x3bd [ 28.615246] [<00000000633ee3a1>] ? add_taint.cold+0x16/0x16 [ 28.621342] [<00000000ec8e20cb>] ? preempt_schedule_common+0x4f/0xe0 [ 28.628331] [<00000000a3f4b270>] ? disk_unblock_events+0x55/0x60 [ 28.634559] [<00000000d6bcbb92>] ? preempt_schedule+0x26/0x30 [ 28.640627] [<00000000779f0a6d>] ? ___preempt_schedule+0x16/0x18 [ 28.646877] [<0000000021010dcc>] kasan_end_report+0x47/0x4f [ 28.652923] [<00000000f4d60c5b>] kasan_report.cold+0xa9/0x2ba [ 28.658920] [<00000000a6d0656d>] __asan_report_load8_noabort+0x14/0x20 [ 28.665668] [<00000000a3f4b270>] disk_unblock_events+0x55/0x60 [ 28.671839] [<000000003722ef34>] __blkdev_get+0x6ba/0xeb0 [ 28.677477] [<00000000e866eefa>] ? __blkdev_put+0x840/0x840 [ 28.683521] [<0000000041c56228>] blkdev_get+0x2e8/0x920 [ 28.688996] [<00000000dd8a25fc>] ? debug_lockdep_rcu_enabled+0x71/0xa0 [ 28.695941] [<00000000e30273bf>] ? bd_may_claim+0xd0/0xd0 [ 28.701762] [<0000000041b1f94c>] ? bd_acquire+0x26/0x250 [ 28.707465] [<00000000c0cfa80e>] ? bd_acquire+0x88/0x250 [ 28.713151] [<0000000018063809>] ? _raw_spin_unlock+0x2d/0x50 [ 28.719367] [<00000000489ee90a>] blkdev_open+0x1aa/0x250 [ 28.725094] [<000000005f9c4880>] do_dentry_open+0x422/0xd20 [ 28.731161] [<0000000059ff746f>] ? blkdev_get_by_dev+0x80/0x80 [ 28.738061] [<00000000209eeb47>] vfs_open+0x105/0x230 [ 28.745078] [<00000000e3fbd664>] ? may_open.isra.0+0x139/0x290 [ 28.751469] [<00000000bb950d82>] path_openat+0xbf5/0x2f60 [ 28.759671] [<000000004e4b5d41>] ? path_mountpoint+0x6d0/0x6d0 [ 28.766230] [<00000000bc2b125a>] do_filp_open+0x1a1/0x280 [ 28.772139] [<00000000074915f9>] ? may_open_dev+0xe0/0xe0 [ 28.779171] [<000000002bf98aba>] ? __alloc_fd+0x1d4/0x490 [ 28.785757] [<0000000018063809>] ? _raw_spin_unlock+0x2d/0x50 [ 28.792636] [<000000002bf98aba>] ? __alloc_fd+0x1d4/0x490 [ 28.798589] [<000000009dd74d65>] do_sys_open+0x2f0/0x610 [ 28.804980] [<000000006ba86fff>] ? filp_open+0x70/0x70 [ 28.811311] [<0000000029bac209>] ? SyS_mkdirat+0x164/0x250 [ 28.819171] [<00000000f4207a0b>] ? SyS_mknod+0x40/0x40 [ 28.826310] [<00000000fc3cc8cf>] SyS_open+0x2d/0x40 [ 28.831892] [<0000000016d98608>] ? do_sys_open+0x610/0x610 [ 28.838514] [<00000000b5d4871d>] do_syscall_64+0x1ad/0x5c0 [ 28.844518] [<000000005de93085>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 28.852707] Kernel Offset: disabled [ 28.857480] Rebooting in 86400 seconds..