[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. Starting mcstransd: [....] Starting file context maintaining daemon: restorecond[ 10.595188] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. [ 11.317097] random: crng init done Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added '10.128.0.42' (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 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program 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: [ 24.800046] ================================================================== [ 24.802691] BUG: KASAN: use-after-free in disk_unblock_events+0x55/0x60 [ 24.804787] Read of size 8 at addr ffff8801c5bb0560 by task blkid/2381 [ 24.806939] [ 24.807590] CPU: 1 PID: 2381 Comm: blkid Not tainted 4.9.194+ #0 [ 24.809310] ffff8801c91ff730 ffffffff81b67001 0000000000000000 ffffea000716ec00 [ 24.811559] ffff8801c5bb0560 0000000000000008 ffffffff81b3b4b5 ffff8801c91ff768 [ 24.813849] ffffffff8150c4f1 0000000000000000 ffff8801c5bb0560 ffff8801c5bb0560 [ 24.816126] Call Trace: [ 24.816981] [<000000008a45bb9a>] dump_stack+0xc1/0x120 [ 24.818844] [<0000000047a3d189>] ? disk_unblock_events+0x55/0x60 [ 24.820922] [<00000000412b4002>] print_address_description+0x6f/0x23a [ 24.827598] [<0000000047a3d189>] ? disk_unblock_events+0x55/0x60 [ 24.833838] [<000000008b8811cd>] kasan_report.cold+0x8c/0x2ba [ 24.839939] [<0000000065cd7325>] __asan_report_load8_noabort+0x14/0x20 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 24.846697] [<0000000047a3d189>] disk_unblock_events+0x55/0x60 [ 24.852755] [<000000004220f0e3>] __blkdev_get+0x6ba/0xeb0 [ 24.858385] [<000000005e0d367c>] ? __blkdev_put+0x840/0x840 [ 24.864188] [<000000003d174a7f>] blkdev_get+0x2e8/0x920 [ 24.869645] [<000000009a2e8408>] ? debug_lockdep_rcu_enabled+0x71/0xa0 [ 24.876516] [<000000002b02bd72>] ? bd_may_claim+0xd0/0xd0 [ 24.882149] [<000000007c1f4d26>] ? bd_acquire+0x26/0x250 [ 24.887691] [<000000008be78088>] ? bd_acquire+0x88/0x250 [ 24.893233] [<000000002a340a0e>] ? _raw_spin_unlock+0x2d/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 executing program [ 24.899331] [<0000000069856456>] blkdev_open+0x1aa/0x250 [ 24.904879] [<0000000075e1378a>] do_dentry_open+0x422/0xd20 [ 24.910682] [<00000000ad9f572e>] ? blkdev_get_by_dev+0x80/0x80 [ 24.916745] [<00000000f44537d4>] vfs_open+0x105/0x230 [ 24.922116] [<00000000ff8de06f>] ? may_open.isra.0+0x139/0x290 [ 24.928188] [<000000008dbca49e>] path_openat+0xbf5/0x2f60 [ 24.933818] [<00000000e0712265>] ? path_mountpoint+0x6d0/0x6d0 [ 24.939882] [<00000000297890fe>] do_filp_open+0x1a1/0x280 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 24.945523] [<00000000bd727b18>] ? may_open_dev+0xe0/0xe0 [ 24.951167] [<00000000f6387d84>] ? __alloc_fd+0x1d4/0x490 [ 24.956915] [<000000002a340a0e>] ? _raw_spin_unlock+0x2d/0x50 [ 24.962896] [<00000000f6387d84>] ? __alloc_fd+0x1d4/0x490 [ 24.968527] [<00000000bef1367e>] do_sys_open+0x2f0/0x610 [ 24.974071] [<00000000db9b3c8e>] ? filp_open+0x70/0x70 [ 24.979571] [<000000001eaf56d5>] ? __do_page_fault+0x545/0xa60 [ 24.985636] [<0000000012e345b9>] SyS_open+0x2d/0x40 [ 24.990739] [<00000000cd8c7885>] ? do_sys_open+0x610/0x610 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 24.996601] [<000000003f55834e>] do_syscall_64+0x1ad/0x5c0 [ 25.002320] [<00000000a386bb98>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 25.009241] [ 25.010870] Allocated by task 2371: [ 25.014499] save_stack_trace+0x16/0x20 [ 25.018476] kasan_kmalloc.part.0+0x62/0xf0 [ 25.022801] kasan_kmalloc+0xb7/0xd0 [ 25.026516] kmem_cache_alloc_trace+0x115/0x2d0 [ 25.031186] alloc_disk_node+0x50/0x3c0 [ 25.035161] alloc_disk+0x1b/0x20 [ 25.038613] loop_add+0x37e/0x7d0 [ 25.042065] loop_control_ioctl+0x138/0x320 [ 25.046388] do_vfs_ioctl+0xb87/0x11d0 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 25.050282] SyS_ioctl+0x8f/0xc0 [ 25.053651] do_syscall_64+0x1ad/0x5c0 [ 25.057693] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 25.062787] [ 25.064424] Freed by task 2381: [ 25.067704] save_stack_trace+0x16/0x20 [ 25.071685] kasan_slab_free+0xb0/0x190 [ 25.075675] kfree+0xfc/0x310 [ 25.078906] disk_release+0x255/0x330 [ 25.082833] device_release+0x7d/0x220 [ 25.086725] kobject_put+0x150/0x260 [ 25.090440] put_disk+0x23/0x30 [ 25.093725] __blkdev_get+0x61a/0xeb0 [ 25.097672] blkdev_get+0x2e8/0x920 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 25.101297] blkdev_open+0x1aa/0x250 [ 25.105014] do_dentry_open+0x422/0xd20 [ 25.108989] vfs_open+0x105/0x230 [ 25.112444] path_openat+0xbf5/0x2f60 [ 25.116244] do_filp_open+0x1a1/0x280 [ 25.120176] do_sys_open+0x2f0/0x610 [ 25.123897] SyS_open+0x2d/0x40 [ 25.127198] do_syscall_64+0x1ad/0x5c0 [ 25.131091] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 25.136191] [ 25.137823] The buggy address belongs to the object at ffff8801c5bb0000 [ 25.137823] which belongs to the cache kmalloc-2048 of size 2048 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 25.150658] The buggy address is located 1376 bytes inside of [ 25.150658] 2048-byte region [ffff8801c5bb0000, ffff8801c5bb0800) [ 25.162797] The buggy address belongs to the page: [ 25.167737] page:ffffea000716ec00 count:1 mapcount:0 mapping: (null) index:0x0 compound_mapcount: 0 [ 25.178001] flags: 0x4000000000010200(slab|head) [ 25.182759] page dumped because: kasan: bad access detected [ 25.188477] [ 25.190103] Memory state around the buggy address: executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 25.195036] ffff8801c5bb0400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 25.202760] ffff8801c5bb0480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 25.210127] >ffff8801c5bb0500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 25.217486] ^ [ 25.223983] ffff8801c5bb0580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 25.231489] ffff8801c5bb0600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 25.238974] ================================================================== [ 25.246332] 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 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 25.255006] Kernel panic - not syncing: panic_on_warn set ... [ 25.255006] [ 25.262518] CPU: 1 PID: 2381 Comm: blkid Tainted: G B 4.9.194+ #0 [ 25.269876] ffff8801c91ff670 ffffffff81b67001 ffff8801c91ff700 ffffffff82e40f17 [ 25.277984] 00000000ffffffff 0000000000000001 ffffffff81b3b4b5 ffff8801c91ff750 [ 25.286086] ffffffff813fef3a 0000000041b58ab3 ffffffff82e32f55 ffffffff813fed61 [ 25.294247] Call Trace: [ 25.296837] [<000000008a45bb9a>] dump_stack+0xc1/0x120 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 25.302339] [<0000000047a3d189>] ? disk_unblock_events+0x55/0x60 [ 25.308575] [<000000008f298615>] panic+0x1d9/0x3bd [ 25.313610] [<00000000d5b91cd8>] ? add_taint.cold+0x16/0x16 [ 25.319518] [<00000000602fbaa5>] ? preempt_schedule_common+0x4f/0xe0 [ 25.326189] [<0000000047a3d189>] ? disk_unblock_events+0x55/0x60 [ 25.332724] [<00000000e5c66cbc>] ? preempt_schedule+0x26/0x30 [ 25.338708] [<00000000b96ecd89>] ? ___preempt_schedule+0x16/0x18 [ 25.345093] [<00000000ac5ab9c9>] kasan_end_report+0x47/0x4f executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 25.350900] [<00000000118429bb>] kasan_report.cold+0xa9/0x2ba [ 25.357010] [<0000000065cd7325>] __asan_report_load8_noabort+0x14/0x20 [ 25.363770] [<0000000047a3d189>] disk_unblock_events+0x55/0x60 [ 25.369838] [<000000004220f0e3>] __blkdev_get+0x6ba/0xeb0 [ 25.375563] [<000000005e0d367c>] ? __blkdev_put+0x840/0x840 [ 25.381396] [<000000003d174a7f>] blkdev_get+0x2e8/0x920 [ 25.386855] [<000000009a2e8408>] ? debug_lockdep_rcu_enabled+0x71/0xa0 [ 25.393622] [<000000002b02bd72>] ? bd_may_claim+0xd0/0xd0 [ 25.399388] [<000000007c1f4d26>] ? bd_acquire+0x26/0x250 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 executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 25.404928] [<000000008be78088>] ? bd_acquire+0x88/0x250 [ 25.410473] [<000000002a340a0e>] ? _raw_spin_unlock+0x2d/0x50 [ 25.416487] [<0000000069856456>] blkdev_open+0x1aa/0x250 [ 25.422028] [<0000000075e1378a>] do_dentry_open+0x422/0xd20 [ 25.427830] [<00000000ad9f572e>] ? blkdev_get_by_dev+0x80/0x80 [ 25.433900] [<00000000f44537d4>] vfs_open+0x105/0x230 [ 25.439179] [<00000000ff8de06f>] ? may_open.isra.0+0x139/0x290 [ 25.445245] [<000000008dbca49e>] path_openat+0xbf5/0x2f60 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 25.450879] [<00000000e0712265>] ? path_mountpoint+0x6d0/0x6d0 [ 25.456946] [<00000000297890fe>] do_filp_open+0x1a1/0x280 [ 25.462573] [<00000000bd727b18>] ? may_open_dev+0xe0/0xe0 [ 25.468207] [<00000000f6387d84>] ? __alloc_fd+0x1d4/0x490 [ 25.473835] [<000000002a340a0e>] ? _raw_spin_unlock+0x2d/0x50 [ 25.479821] [<00000000f6387d84>] ? __alloc_fd+0x1d4/0x490 [ 25.490493] [<00000000bef1367e>] do_sys_open+0x2f0/0x610 [ 25.496216] [<00000000db9b3c8e>] ? filp_open+0x70/0x70 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 25.501711] [<000000001eaf56d5>] ? __do_page_fault+0x545/0xa60 [ 25.507776] [<0000000012e345b9>] SyS_open+0x2d/0x40 [ 25.512885] [<00000000cd8c7885>] ? do_sys_open+0x610/0x610 [ 25.518602] [<000000003f55834e>] do_syscall_64+0x1ad/0x5c0 [ 25.524318] [<00000000a386bb98>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 25.532097] Kernel Offset: disabled [ 25.535731] Rebooting in 86400 seconds..