[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. Starting mcstransd: [....] Starting file context maintaining daemon: restorecond[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 10.083979] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 16.409373] random: crng init done Warning: Permanently added '10.128.10.50' (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 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 32.542492] ================================================================== [ 32.550054] BUG: KASAN: use-after-free in disk_unblock_events+0x51/0x60 [ 32.556803] Read of size 8 at addr ffff8801ceab51e0 by task blkid/2153 [ 32.563449] [ 32.565063] CPU: 1 PID: 2153 Comm: blkid Not tainted 4.9.128+ #93 [ 32.571276] ffff8801ce0a76f8 ffffffff81af2469 ffffea00073aac00 ffff8801ceab51e0 [ 32.579392] 0000000000000000 ffff8801ceab51e0 0000000000000000 ffff8801ce0a7730 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 32.587492] ffffffff814e13cb ffff8801ceab51e0 0000000000000008 0000000000000000 [ 32.595542] Call Trace: [ 32.598112] [] dump_stack+0xc1/0x128 [ 32.603459] [] print_address_description+0x6c/0x234 [ 32.610108] [] kasan_report.cold.6+0x242/0x2fe [ 32.616324] [] ? disk_unblock_events+0x51/0x60 [ 32.622545] [] __asan_report_load8_noabort+0x14/0x20 [ 32.629299] [] disk_unblock_events+0x51/0x60 [ 32.635344] [] __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 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 32.640953] [] ? __blkdev_put+0x840/0x840 [ 32.646737] [] ? fsnotify+0x114/0x1100 [ 32.652337] [] blkdev_get+0x2da/0x920 [ 32.657783] [] ? debug_lockdep_rcu_enabled+0x77/0x90 [ 32.664520] [] ? bd_may_claim+0xd0/0xd0 [ 32.670126] [] ? bd_acquire+0x27/0x250 [ 32.675645] [] ? bd_acquire+0x88/0x250 [ 32.681167] [] ? _raw_spin_unlock+0x2c/0x50 [ 32.687134] [] 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 [ 32.692667] [] do_dentry_open+0x3ef/0xc90 [ 32.698444] [] ? blkdev_get_by_dev+0x70/0x70 [ 32.704484] [] vfs_open+0x11c/0x210 [ 32.709739] [] ? may_open.isra.20+0x14f/0x2a0 [ 32.716052] [] path_openat+0x542/0x2790 [ 32.721665] [] ? path_mountpoint+0x6c0/0x6c0 [ 32.727703] [] ? trace_hardirqs_on+0x10/0x10 [ 32.733747] [] ? 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 [ 32.740136] [] do_filp_open+0x197/0x270 [ 32.745751] [] ? may_open_dev+0xe0/0xe0 [ 32.751371] [] ? _raw_spin_unlock+0x2c/0x50 [ 32.757326] [] ? __alloc_fd+0x1d7/0x4a0 [ 32.762937] [] do_sys_open+0x30d/0x5c0 [ 32.768523] [] ? filp_open+0x70/0x70 [ 32.773887] [] ? up_read+0x1a/0x40 [ 32.779059] [] SyS_open+0x2d/0x40 [ 32.784142] [] ? do_sys_open+0x5c0/0x5c0 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 32.789845] [] do_syscall_64+0x19f/0x480 [ 32.795545] [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 32.802450] [ 32.804062] Allocated by task 2135: [ 32.807675] save_stack_trace+0x16/0x20 [ 32.811759] kasan_kmalloc.part.1+0x62/0xf0 [ 32.816064] kasan_kmalloc+0xaf/0xc0 [ 32.819765] kmem_cache_alloc_trace+0x117/0x2e0 [ 32.824422] alloc_disk_node+0x54/0x3a0 [ 32.828394] alloc_disk+0x18/0x20 [ 32.831829] loop_add+0x33b/0x770 [ 32.835277] loop_probe+0x14f/0x180 [ 32.838887] kobj_lookup+0x223/0x410 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 32.842626] get_gendisk+0x39/0x2d0 [ 32.846240] __blkdev_get+0x351/0xd60 [ 32.850018] blkdev_get+0x488/0x920 [ 32.853626] blkdev_open+0x1a5/0x250 [ 32.857320] do_dentry_open+0x3ef/0xc90 [ 32.861376] vfs_open+0x11c/0x210 [ 32.864814] path_openat+0x542/0x2790 [ 32.868596] do_filp_open+0x197/0x270 [ 32.872384] do_sys_open+0x30d/0x5c0 [ 32.876087] SyS_open+0x2d/0x40 [ 32.879352] do_syscall_64+0x19f/0x480 [ 32.883221] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 32.888305] [ 32.889911] Freed by task 2153: executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 32.893378] save_stack_trace+0x16/0x20 [ 32.897369] kasan_slab_free+0xac/0x190 [ 32.901337] kfree+0xfb/0x310 [ 32.904425] disk_release+0x259/0x330 [ 32.908211] device_release+0x7e/0x220 [ 32.912076] kobject_put+0x148/0x250 [ 32.915767] put_disk+0x23/0x30 [ 32.919023] __blkdev_get+0x616/0xd60 [ 32.922860] blkdev_get+0x2da/0x920 [ 32.926492] blkdev_open+0x1a5/0x250 [ 32.930207] do_dentry_open+0x3ef/0xc90 [ 32.934163] vfs_open+0x11c/0x210 [ 32.937604] path_openat+0x542/0x2790 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 32.941393] do_filp_open+0x197/0x270 [ 32.945172] do_sys_open+0x30d/0x5c0 [ 32.948888] SyS_open+0x2d/0x40 [ 32.952148] do_syscall_64+0x19f/0x480 [ 32.956022] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 32.961106] [ 32.962714] The buggy address belongs to the object at ffff8801ceab4c80 [ 32.962714] which belongs to the cache kmalloc-2048 of size 2048 [ 32.975524] The buggy address is located 1376 bytes inside of [ 32.975524] 2048-byte region [ffff8801ceab4c80, ffff8801ceab5480) [ 32.987570] The buggy address belongs to the page: executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 32.992507] page:ffffea00073aac00 count:1 mapcount:0 mapping: (null) index:0x0 compound_mapcount: 0 [ 33.002774] flags: 0x4000000000004080(slab|head) [ 33.007522] page dumped because: kasan: bad access detected [ 33.013299] [ 33.014920] Memory state around the buggy address: [ 33.019828] ffff8801ceab5080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 33.027165] ffff8801ceab5100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 33.034609] >ffff8801ceab5180: 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 [ 33.041964] ^ [ 33.048446] ffff8801ceab5200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 33.055800] ffff8801ceab5280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 33.063144] ================================================================== [ 33.070482] 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 [ 33.092824] Kernel panic - not syncing: panic_on_warn set ... [ 33.092824] [ 33.100190] CPU: 1 PID: 2153 Comm: blkid Tainted: G B 4.9.128+ #93 [ 33.107618] ffff8801ce0a7658 ffffffff81af2469 ffffffff82c34968 00000000ffffffff [ 33.115778] 0000000000000000 0000000000000001 0000000000000000 ffff8801ce0a7718 [ 33.123886] ffffffff813df985 0000000041b58ab3 ffffffff82c2896b ffffffff813df7c6 [ 33.131935] Call Trace: [ 33.134510] [] dump_stack+0xc1/0x128 [ 33.139873] [] panic+0x1bf/0x39f executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 33.144925] [] ? add_taint.cold.6+0x16/0x16 [ 33.150912] [] ? ___preempt_schedule+0x16/0x18 [ 33.157156] [] kasan_end_report+0x47/0x4f [ 33.162995] [] kasan_report.cold.6+0x76/0x2fe [ 33.169149] [] ? disk_unblock_events+0x51/0x60 [ 33.175399] [] __asan_report_load8_noabort+0x14/0x20 [ 33.182539] [] disk_unblock_events+0x51/0x60 [ 33.188610] [] __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 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 33.194243] [] ? __blkdev_put+0x840/0x840 [ 33.200055] [] ? fsnotify+0x114/0x1100 [ 33.205612] [] blkdev_get+0x2da/0x920 [ 33.211084] [] ? debug_lockdep_rcu_enabled+0x77/0x90 [ 33.217831] [] ? bd_may_claim+0xd0/0xd0 [ 33.223474] [] ? bd_acquire+0x27/0x250 [ 33.229008] [] ? bd_acquire+0x88/0x250 [ 33.234540] [] ? _raw_spin_unlock+0x2c/0x50 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 33.240530] [] blkdev_open+0x1a5/0x250 [ 33.246080] [] do_dentry_open+0x3ef/0xc90 [ 33.251901] [] ? blkdev_get_by_dev+0x70/0x70 [ 33.257970] [] vfs_open+0x11c/0x210 [ 33.263261] [] ? may_open.isra.20+0x14f/0x2a0 [ 33.269422] [] path_openat+0x542/0x2790 [ 33.275054] [] ? path_mountpoint+0x6c0/0x6c0 [ 33.281116] [] ? trace_hardirqs_on+0x10/0x10 [ 33.287202] [] ? 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 [ 33.293635] [] do_filp_open+0x197/0x270 [ 33.299262] [] ? may_open_dev+0xe0/0xe0 [ 33.304926] [] ? _raw_spin_unlock+0x2c/0x50 [ 33.310907] [] ? __alloc_fd+0x1d7/0x4a0 [ 33.316539] [] do_sys_open+0x30d/0x5c0 [ 33.322091] [] ? filp_open+0x70/0x70 [ 33.327470] [] ? up_read+0x1a/0x40 [ 33.332672] [] SyS_open+0x2d/0x40 [ 33.337786] [] ? do_sys_open+0x5c0/0x5c0 executing program executing program executing program executing program executing program executing program executing program [ 33.343504] [] do_syscall_64+0x19f/0x480 [ 33.349229] [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 33.356452] Kernel Offset: disabled [ 33.360078] Rebooting in 86400 seconds..