[?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[ 10.211289] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 41.616468] random: crng init done Warning: Permanently added '10.128.0.64' (ECDSA) to the list of known hosts. 2019/09/24 11:06:47 parsed 1 programs 2019/09/24 11:06:49 executed programs: 0 [ 55.488449] audit: type=1400 audit(1569323210.930:5): avc: denied { associate } for pid=2091 comm="syz-executor.2" name="syz2" scontext=unconfined_u:object_r:unlabeled_t:s0 tcontext=system_u:object_r:unlabeled_t:s0 tclass=filesystem permissive=1 [ 55.567304] audit: type=1400 audit(1569323211.010:6): avc: denied { wake_alarm } for pid=2963 comm="syz-executor.3" capability=35 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=capability2 permissive=1 [ 55.638334] hrtimer: interrupt took 35995 ns [ 57.173198] ================================================================== [ 57.180621] BUG: KASAN: use-after-free in disk_unblock_events+0x55/0x60 [ 57.187370] Read of size 8 at addr ffff8801d2deeb60 by task syz-executor.5/3287 [ 57.194907] [ 57.196532] CPU: 0 PID: 3287 Comm: syz-executor.5 Not tainted 4.9.194+ #0 [ 57.203448] ffff8801d1d7f730 ffffffff81b67001 0000000000000000 ffffea00074b7a00 [ 57.211584] ffff8801d2deeb60 0000000000000008 ffffffff81b3b4b5 ffff8801d1d7f768 [ 57.219666] ffffffff8150c4f1 0000000000000000 ffff8801d2deeb60 ffff8801d2deeb60 [ 57.227727] Call Trace: [ 57.230327] [<000000003325aa4f>] dump_stack+0xc1/0x120 [ 57.235691] [<000000009ca09013>] ? disk_unblock_events+0x55/0x60 [ 57.241931] [<00000000a001acc6>] print_address_description+0x6f/0x23a [ 57.248615] [<000000009ca09013>] ? disk_unblock_events+0x55/0x60 [ 57.254861] [<00000000b4f348cf>] kasan_report.cold+0x8c/0x2ba [ 57.260951] [<000000005ca8d76f>] __asan_report_load8_noabort+0x14/0x20 [ 57.267707] [<000000009ca09013>] disk_unblock_events+0x55/0x60 [ 57.273774] [<00000000899736a0>] __blkdev_get+0x6ba/0xeb0 [ 57.279400] [<00000000ef0c44c1>] ? __blkdev_put+0x840/0x840 [ 57.285202] [<00000000a6a7348d>] blkdev_get+0x2e8/0x920 [ 57.290656] [<00000000ecf91479>] ? debug_lockdep_rcu_enabled+0x71/0xa0 [ 57.297410] [<00000000017c35da>] ? bd_may_claim+0xd0/0xd0 [ 57.303037] [<000000006c153c57>] ? bd_acquire+0x26/0x250 [ 57.308582] [<000000007b1850fc>] ? bd_acquire+0x88/0x250 [ 57.314122] [<0000000038220b0f>] ? _raw_spin_unlock+0x2d/0x50 [ 57.320094] [<00000000837487a9>] blkdev_open+0x1aa/0x250 [ 57.325638] [<0000000071974194>] do_dentry_open+0x422/0xd20 [ 57.331435] [<0000000067bc856c>] ? blkdev_get_by_dev+0x80/0x80 [ 57.337494] [<00000000d82e678e>] vfs_open+0x105/0x230 [ 57.342775] [<000000006bfdaa3c>] ? may_open.isra.0+0x139/0x290 [ 57.348835] [<0000000091dbf68a>] path_openat+0xbf5/0x2f60 [ 57.354472] [<00000000c35bffb8>] ? path_mountpoint+0x6d0/0x6d0 [ 57.360533] [<000000007083d8fe>] do_filp_open+0x1a1/0x280 [ 57.366197] [<000000006e4fa229>] ? may_open_dev+0xe0/0xe0 [ 57.371834] [<0000000018d25b1b>] ? __alloc_fd+0x1d4/0x490 [ 57.377470] [<0000000038220b0f>] ? _raw_spin_unlock+0x2d/0x50 [ 57.383441] [<0000000018d25b1b>] ? __alloc_fd+0x1d4/0x490 [ 57.389069] [<000000007ba101c9>] do_sys_open+0x2f0/0x610 [ 57.394608] [<00000000c7f12bbe>] ? filp_open+0x70/0x70 [ 57.399975] [<0000000055d31105>] ? __might_fault+0x18e/0x1d0 [ 57.405874] [<000000004b741419>] ? __might_fault+0xe4/0x1d0 [ 57.411678] [<000000000a8543e1>] ? SyS_clock_gettime+0x118/0x1f0 [ 57.417916] [<00000000af6c3f1c>] ? SyS_clock_settime+0x230/0x230 [ 57.424152] [<000000008929f9bd>] SyS_open+0x2d/0x40 [ 57.429255] [<00000000f7607cbf>] ? do_sys_open+0x610/0x610 [ 57.434969] [<000000000fdeebe6>] do_syscall_64+0x1ad/0x5c0 [ 57.440686] [<000000008b144d0f>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 57.447634] [ 57.449258] Allocated by task 3264: [ 57.452878] save_stack_trace+0x16/0x20 [ 57.457024] kasan_kmalloc.part.0+0x62/0xf0 [ 57.461377] kasan_kmalloc+0xb7/0xd0 [ 57.465076] kmem_cache_alloc_trace+0x115/0x2d0 [ 57.469726] alloc_disk_node+0x50/0x3c0 [ 57.473682] alloc_disk+0x1b/0x20 [ 57.477114] loop_add+0x37e/0x7d0 [ 57.480546] loop_probe+0x154/0x180 [ 57.484150] kobj_lookup+0x221/0x410 [ 57.487846] get_gendisk+0x3c/0x2d0 [ 57.491451] __blkdev_get+0x356/0xeb0 [ 57.495234] blkdev_get+0x2e8/0x920 [ 57.498840] blkdev_open+0x1aa/0x250 [ 57.502537] do_dentry_open+0x422/0xd20 [ 57.506492] vfs_open+0x105/0x230 [ 57.509938] path_openat+0xbf5/0x2f60 [ 57.513781] do_filp_open+0x1a1/0x280 [ 57.520098] do_sys_open+0x2f0/0x610 [ 57.523796] SyS_open+0x2d/0x40 [ 57.527057] do_syscall_64+0x1ad/0x5c0 [ 57.530970] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 57.536058] [ 57.537675] Freed by task 3287: [ 57.540948] save_stack_trace+0x16/0x20 [ 57.544913] kasan_slab_free+0xb0/0x190 [ 57.548863] kfree+0xfc/0x310 [ 57.551946] disk_release+0x255/0x330 [ 57.555726] device_release+0x7d/0x220 [ 57.559588] kobject_put+0x150/0x260 [ 57.563288] put_disk+0x23/0x30 [ 57.566547] __blkdev_get+0x61a/0xeb0 [ 57.570324] blkdev_get+0x2e8/0x920 [ 57.573926] blkdev_open+0x1aa/0x250 [ 57.577620] do_dentry_open+0x422/0xd20 [ 57.581569] vfs_open+0x105/0x230 [ 57.585002] path_openat+0xbf5/0x2f60 [ 57.588779] do_filp_open+0x1a1/0x280 [ 57.592554] do_sys_open+0x2f0/0x610 [ 57.596244] SyS_open+0x2d/0x40 [ 57.599500] do_syscall_64+0x1ad/0x5c0 [ 57.603371] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 57.608499] [ 57.610120] The buggy address belongs to the object at ffff8801d2dee600 [ 57.610120] which belongs to the cache kmalloc-2048 of size 2048 [ 57.622926] The buggy address is located 1376 bytes inside of [ 57.622926] 2048-byte region [ffff8801d2dee600, ffff8801d2deee00) [ 57.634971] The buggy address belongs to the page: [ 57.639883] page:ffffea00074b7a00 count:1 mapcount:0 mapping: (null) index:0x0 compound_mapcount: 0 [ 57.650091] flags: 0x4000000000010200(slab|head) [ 57.654819] page dumped because: kasan: bad access detected [ 57.660523] [ 57.662126] Memory state around the buggy address: [ 57.667043] ffff8801d2deea00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 57.674380] ffff8801d2deea80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 57.681714] >ffff8801d2deeb00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 57.689046] ^ [ 57.695527] ffff8801d2deeb80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 57.702862] ffff8801d2deec00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 57.710196] ================================================================== [ 57.717555] Disabling lock debugging due to kernel taint [ 57.723805] Kernel panic - not syncing: panic_on_warn set ... [ 57.723805] [ 57.731179] CPU: 0 PID: 3287 Comm: syz-executor.5 Tainted: G B 4.9.194+ #0 [ 57.739302] ffff8801d1d7f670 ffffffff81b67001 ffff8801d1d7f700 ffffffff82e40f17 [ 57.747317] 00000000ffffffff 0000000000000000 ffffffff81b3b4b5 ffff8801d1d7f750 [ 57.755342] ffffffff813fef3a 0000000041b58ab3 ffffffff82e32f55 ffffffff813fed61 [ 57.763350] Call Trace: [ 57.765920] [<000000003325aa4f>] dump_stack+0xc1/0x120 [ 57.771263] [<000000009ca09013>] ? disk_unblock_events+0x55/0x60 [ 57.777480] [<00000000b5411800>] panic+0x1d9/0x3bd [ 57.782487] [<000000008b70c4e9>] ? add_taint.cold+0x16/0x16 [ 57.788276] [<000000002f30be6a>] ? preempt_schedule_common+0x4f/0xe0 [ 57.794833] [<000000009ca09013>] ? disk_unblock_events+0x55/0x60 [ 57.801042] [<000000003148e13b>] ? preempt_schedule+0x26/0x30 [ 57.807000] [<0000000059d25199>] ? ___preempt_schedule+0x16/0x18 [ 57.813217] [<00000000df8174df>] kasan_end_report+0x47/0x4f [ 57.818999] [<00000000e5ff916b>] kasan_report.cold+0xa9/0x2ba [ 57.824957] [<000000005ca8d76f>] __asan_report_load8_noabort+0x14/0x20 [ 57.831694] [<000000009ca09013>] disk_unblock_events+0x55/0x60 [ 57.837730] [<00000000899736a0>] __blkdev_get+0x6ba/0xeb0 [ 57.843340] [<00000000ef0c44c1>] ? __blkdev_put+0x840/0x840 [ 57.849124] [<00000000a6a7348d>] blkdev_get+0x2e8/0x920 [ 57.854575] [<00000000ecf91479>] ? debug_lockdep_rcu_enabled+0x71/0xa0 [ 57.861307] [<00000000017c35da>] ? bd_may_claim+0xd0/0xd0 [ 57.866908] [<000000006c153c57>] ? bd_acquire+0x26/0x250 [ 57.872454] [<000000007b1850fc>] ? bd_acquire+0x88/0x250 [ 57.877982] [<0000000038220b0f>] ? _raw_spin_unlock+0x2d/0x50 [ 57.883949] [<00000000837487a9>] blkdev_open+0x1aa/0x250 [ 57.889478] [<0000000071974194>] do_dentry_open+0x422/0xd20 [ 57.895256] [<0000000067bc856c>] ? blkdev_get_by_dev+0x80/0x80 [ 57.901293] [<00000000d82e678e>] vfs_open+0x105/0x230 [ 57.906549] [<000000006bfdaa3c>] ? may_open.isra.0+0x139/0x290 [ 57.912585] [<0000000091dbf68a>] path_openat+0xbf5/0x2f60 [ 57.918190] [<00000000c35bffb8>] ? path_mountpoint+0x6d0/0x6d0 [ 57.924229] [<000000007083d8fe>] do_filp_open+0x1a1/0x280 [ 57.929828] [<000000006e4fa229>] ? may_open_dev+0xe0/0xe0 [ 57.935428] [<0000000018d25b1b>] ? __alloc_fd+0x1d4/0x490 [ 57.941029] [<0000000038220b0f>] ? _raw_spin_unlock+0x2d/0x50 [ 57.946980] [<0000000018d25b1b>] ? __alloc_fd+0x1d4/0x490 [ 57.952586] [<000000007ba101c9>] do_sys_open+0x2f0/0x610 [ 57.958111] [<00000000c7f12bbe>] ? filp_open+0x70/0x70 [ 57.963451] [<0000000055d31105>] ? __might_fault+0x18e/0x1d0 [ 57.969312] [<000000004b741419>] ? __might_fault+0xe4/0x1d0 [ 57.975092] [<000000000a8543e1>] ? SyS_clock_gettime+0x118/0x1f0 [ 57.981300] [<00000000af6c3f1c>] ? SyS_clock_settime+0x230/0x230 [ 57.987510] [<000000008929f9bd>] SyS_open+0x2d/0x40 [ 57.992597] [<00000000f7607cbf>] ? do_sys_open+0x610/0x610 [ 57.998284] [<000000000fdeebe6>] do_syscall_64+0x1ad/0x5c0 [ 58.003974] [<000000008b144d0f>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 58.011519] Kernel Offset: disabled [ 58.015126] Rebooting in 86400 seconds..