[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 36.248287] audit: type=1800 audit(1538663881.764:25): pid=5662 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2414 res=0 [ 36.271167] audit: type=1800 audit(1538663881.764:26): pid=5662 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2457 res=0 [ 36.299396] audit: type=1800 audit(1538663881.764:27): pid=5662 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="restorecond" dev="sda1" ino=2436 res=0 [....] Starting periodic command scheduler: cron[?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 '10.128.10.58' (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 syzkaller login: [ 47.077347] ================================================================== [ 47.084752] BUG: KASAN: use-after-free in sha512_ctx_mgr_resubmit.part.3+0x3b1/0x4a0 [ 47.092631] Read of size 4 at addr ffff8801d4870578 by task kworker/1:1/24 [ 47.099634] [ 47.101245] CPU: 1 PID: 24 Comm: kworker/1:1 Not tainted 4.19.0-rc6+ #266 [ 47.108156] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 47.117533] Workqueue: crypto mcryptd_flusher [ 47.122032] Call Trace: executing program executing program executing program executing program executing program executing program executing program [ 47.124635] dump_stack+0x1c4/0x2b4 [ 47.128277] ? dump_stack_print_info.cold.2+0x52/0x52 [ 47.133474] ? printk+0xa7/0xcf [ 47.136768] ? kmsg_dump_rewind_nolock+0xe4/0xe4 [ 47.141548] print_address_description.cold.8+0x9/0x1ff [ 47.146912] kasan_report.cold.9+0x242/0x309 [ 47.151315] ? sha512_ctx_mgr_resubmit.part.3+0x3b1/0x4a0 [ 47.156853] __asan_report_load4_noabort+0x14/0x20 [ 47.161783] sha512_ctx_mgr_resubmit.part.3+0x3b1/0x4a0 [ 47.167156] sha512_ctx_mgr_flush+0x5c/0xb0 [ 47.171489] sha512_mb_flusher+0x27b/0x610 executing program executing program executing program [ 47.175755] ? lock_downgrade+0x900/0x900 [ 47.179905] ? sha512_mb_update+0x570/0x570 [ 47.184215] ? trace_hardirqs_off+0xb8/0x310 [ 47.188615] ? kasan_check_read+0x11/0x20 [ 47.192762] ? do_raw_spin_unlock+0xa7/0x2f0 [ 47.197172] mcryptd_flusher+0x340/0x4b0 [ 47.201241] ? kasan_check_read+0x11/0x20 [ 47.205385] ? process_one_work+0xb6c/0x1b90 [ 47.209801] ? mcryptd_ahash_desc+0x20/0x20 [ 47.214131] ? dequeue_entity+0x1770/0x1770 [ 47.218451] process_one_work+0xc90/0x1b90 [ 47.222682] ? mark_held_locks+0x130/0x130 executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 47.226932] ? pwq_dec_nr_in_flight+0x4a0/0x4a0 [ 47.231615] ? __switch_to_asm+0x40/0x70 [ 47.235684] ? __switch_to_asm+0x34/0x70 [ 47.239755] ? __switch_to_asm+0x40/0x70 [ 47.243825] ? __switch_to_asm+0x34/0x70 [ 47.247894] ? __switch_to_asm+0x40/0x70 [ 47.251957] ? __switch_to_asm+0x34/0x70 [ 47.256033] ? __switch_to_asm+0x40/0x70 [ 47.260100] ? __switch_to_asm+0x34/0x70 [ 47.264170] ? __switch_to_asm+0x40/0x70 [ 47.268247] ? __schedule+0x874/0x1ed0 [ 47.272148] ? __sched_text_start+0x8/0x8 executing program executing program executing program executing program [ 47.276304] ? lock_downgrade+0x900/0x900 [ 47.280465] ? graph_lock+0x170/0x170 [ 47.284291] ? find_held_lock+0x36/0x1c0 [ 47.288366] ? lock_acquire+0x1ed/0x520 [ 47.292343] ? worker_thread+0x3e0/0x1390 [ 47.296478] ? lock_downgrade+0x900/0x900 [ 47.300629] ? lock_release+0x970/0x970 [ 47.304602] ? trace_hardirqs_off+0xb8/0x310 [ 47.309001] ? kasan_check_read+0x11/0x20 [ 47.313159] ? worker_thread+0x3e0/0x1390 [ 47.317313] ? trace_hardirqs_on+0x310/0x310 [ 47.321721] ? kasan_check_write+0x14/0x20 executing program executing program executing program [ 47.325969] ? do_raw_spin_lock+0xc1/0x200 [ 47.330203] worker_thread+0x17f/0x1390 [ 47.334190] ? __switch_to_asm+0x34/0x70 [ 47.338254] ? process_one_work+0x1b90/0x1b90 [ 47.342733] ? graph_lock+0x170/0x170 [ 47.346530] ? graph_lock+0x170/0x170 [ 47.350340] ? find_held_lock+0x36/0x1c0 [ 47.354411] ? find_held_lock+0x36/0x1c0 [ 47.358475] ? __kthread_parkme+0xce/0x1a0 [ 47.362713] ? _raw_spin_unlock_irqrestore+0x82/0xd0 [ 47.367813] ? _raw_spin_unlock_irqrestore+0x82/0xd0 [ 47.372912] ? lockdep_hardirqs_on+0x421/0x5c0 executing program executing program executing program executing program executing program executing program [ 47.377493] ? trace_hardirqs_on+0xbd/0x310 [ 47.381829] ? kasan_check_read+0x11/0x20 [ 47.385980] ? __kthread_parkme+0xce/0x1a0 [ 47.390214] ? __bpf_trace_preemptirq_template+0x30/0x30 [ 47.395674] ? kasan_check_write+0x14/0x20 [ 47.399921] ? do_raw_spin_lock+0xc1/0x200 [ 47.404171] ? _raw_spin_unlock_irqrestore+0x6d/0xd0 [ 47.409276] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 47.414821] ? __kthread_parkme+0xfb/0x1a0 [ 47.419066] kthread+0x35a/0x420 [ 47.422438] ? process_one_work+0x1b90/0x1b90 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 47.426939] ? kthread_bind+0x40/0x40 [ 47.430751] ret_from_fork+0x3a/0x50 [ 47.434472] [ 47.436108] Allocated by task 6003: [ 47.439738] save_stack+0x43/0xd0 [ 47.443189] kasan_kmalloc+0xc7/0xe0 [ 47.446908] __kmalloc+0x14e/0x760 [ 47.450455] sock_kmalloc+0x15a/0x1f0 [ 47.454266] hash_accept_parent_nokey+0x58/0x2e0 [ 47.459032] hash_accept_parent+0x5b/0x80 [ 47.463180] af_alg_accept+0x127/0x7d0 [ 47.467071] alg_accept+0x46/0x60 [ 47.470536] __sys_accept4+0x3b2/0x8a0 [ 47.474432] __x64_sys_accept4+0x97/0xf0 executing program executing program executing program executing program executing program executing program executing program executing program [ 47.478516] do_syscall_64+0x1b9/0x820 [ 47.482421] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 47.487608] [ 47.489237] Freed by task 6002: [ 47.492532] save_stack+0x43/0xd0 [ 47.495993] __kasan_slab_free+0x102/0x150 [ 47.500243] kasan_slab_free+0xe/0x10 [ 47.504054] kfree+0xcf/0x230 [ 47.507173] sock_kfree_s+0x29/0x60 [ 47.510810] hash_sock_destruct+0x157/0x1c0 [ 47.515137] __sk_destruct+0x107/0xa80 [ 47.519034] sk_destruct+0x78/0x90 [ 47.522577] __sk_free+0xcf/0x300 [ 47.526041] sk_free+0x42/0x50 executing program executing program executing program executing program [ 47.529238] af_alg_release+0x6e/0x90 [ 47.533044] __sock_release+0xd7/0x250 [ 47.536933] sock_close+0x19/0x20 [ 47.540396] __fput+0x385/0xa30 [ 47.543677] ____fput+0x15/0x20 [ 47.546965] task_work_run+0x1e8/0x2a0 [ 47.550852] exit_to_usermode_loop+0x318/0x380 [ 47.555424] do_syscall_64+0x6be/0x820 [ 47.559310] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 47.564490] [ 47.566122] The buggy address belongs to the object at ffff8801d4870080 [ 47.566122] which belongs to the cache kmalloc-2048 of size 2048 executing program executing program executing program executing program executing program [ 47.578945] The buggy address is located 1272 bytes inside of [ 47.578945] 2048-byte region [ffff8801d4870080, ffff8801d4870880) [ 47.590989] The buggy address belongs to the page: [ 47.595918] page:ffffea0007521c00 count:1 mapcount:0 mapping:ffff8801da800c40 index:0x0 compound_mapcount: 0 [ 47.605893] flags: 0x2fffc0000008100(slab|head) [ 47.610566] raw: 02fffc0000008100 ffffea0007526108 ffffea0007528008 ffff8801da800c40 [ 47.618440] raw: 0000000000000000 ffff8801d4870080 0000000100000003 0000000000000000 executing program executing program executing program [ 47.626327] page dumped because: kasan: bad access detected [ 47.632028] [ 47.633644] Memory state around the buggy address: [ 47.638575] ffff8801d4870400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 47.645932] ffff8801d4870480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 47.653281] >ffff8801d4870500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 47.660631] ^ [ 47.667897] ffff8801d4870580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb executing program executing program executing program [ 47.675243] ffff8801d4870600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 47.682584] ================================================================== [ 47.689947] Kernel panic - not syncing: panic_on_warn set ... [ 47.689947] [ 47.697316] CPU: 1 PID: 24 Comm: kworker/1:1 Tainted: G B 4.19.0-rc6+ #266 [ 47.705632] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 47.714994] Workqueue: crypto mcryptd_flusher [ 47.719475] Call Trace: [ 47.722059] dump_stack+0x1c4/0x2b4 executing program executing program executing program [ 47.725683] ? dump_stack_print_info.cold.2+0x52/0x52 [ 47.730885] ? lock_downgrade+0x900/0x900 [ 47.735032] panic+0x238/0x4e7 [ 47.738214] ? add_taint.cold.5+0x16/0x16 [ 47.742373] ? print_shadow_for_address+0xb6/0x116 [ 47.747312] ? trace_hardirqs_off+0xaf/0x310 [ 47.751720] kasan_end_report+0x47/0x4f [ 47.755758] kasan_report.cold.9+0x76/0x309 [ 47.760093] ? sha512_ctx_mgr_resubmit.part.3+0x3b1/0x4a0 [ 47.765640] __asan_report_load4_noabort+0x14/0x20 [ 47.770579] sha512_ctx_mgr_resubmit.part.3+0x3b1/0x4a0 [ 47.775945] sha512_ctx_mgr_flush+0x5c/0xb0 executing program executing program executing program executing program [ 47.780253] sha512_mb_flusher+0x27b/0x610 [ 47.784479] ? lock_downgrade+0x900/0x900 [ 47.788631] ? sha512_mb_update+0x570/0x570 [ 47.792974] ? trace_hardirqs_off+0xb8/0x310 [ 47.797380] ? kasan_check_read+0x11/0x20 [ 47.801540] ? do_raw_spin_unlock+0xa7/0x2f0 [ 47.805970] mcryptd_flusher+0x340/0x4b0 [ 47.810035] ? kasan_check_read+0x11/0x20 [ 47.814181] ? process_one_work+0xb6c/0x1b90 [ 47.818581] ? mcryptd_ahash_desc+0x20/0x20 [ 47.822909] ? dequeue_entity+0x1770/0x1770 executing program executing program executing program [ 47.827253] process_one_work+0xc90/0x1b90 [ 47.831490] ? mark_held_locks+0x130/0x130 [ 47.835731] ? pwq_dec_nr_in_flight+0x4a0/0x4a0 [ 47.840387] ? __switch_to_asm+0x40/0x70 [ 47.844436] ? __switch_to_asm+0x34/0x70 [ 47.848489] ? __switch_to_asm+0x40/0x70 [ 47.852552] ? __switch_to_asm+0x34/0x70 [ 47.856695] ? __switch_to_asm+0x40/0x70 [ 47.860752] ? __switch_to_asm+0x34/0x70 [ 47.864822] ? __switch_to_asm+0x40/0x70 [ 47.868891] ? __switch_to_asm+0x34/0x70 [ 47.872953] ? __switch_to_asm+0x40/0x70 [ 47.877002] ? __schedule+0x874/0x1ed0 executing program executing program executing program [ 47.880876] ? __sched_text_start+0x8/0x8 [ 47.885013] ? lock_downgrade+0x900/0x900 [ 47.889155] ? graph_lock+0x170/0x170 [ 47.892962] ? find_held_lock+0x36/0x1c0 [ 47.897133] ? lock_acquire+0x1ed/0x520 [ 47.901142] ? worker_thread+0x3e0/0x1390 [ 47.905273] ? lock_downgrade+0x900/0x900 [ 47.909414] ? lock_release+0x970/0x970 [ 47.913387] ? trace_hardirqs_off+0xb8/0x310 [ 47.917788] ? kasan_check_read+0x11/0x20 [ 47.921935] ? worker_thread+0x3e0/0x1390 [ 47.926078] ? trace_hardirqs_on+0x310/0x310 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 47.930494] ? kasan_check_write+0x14/0x20 [ 47.934749] ? do_raw_spin_lock+0xc1/0x200 [ 47.938994] worker_thread+0x17f/0x1390 [ 47.942976] ? __switch_to_asm+0x34/0x70 [ 47.947137] ? process_one_work+0x1b90/0x1b90 [ 47.951642] ? graph_lock+0x170/0x170 [ 47.955452] ? graph_lock+0x170/0x170 [ 47.959266] ? find_held_lock+0x36/0x1c0 [ 47.963337] ? find_held_lock+0x36/0x1c0 [ 47.967408] ? __kthread_parkme+0xce/0x1a0 [ 47.971656] ? _raw_spin_unlock_irqrestore+0x82/0xd0 executing program executing program executing program executing program executing program executing program executing program [ 47.976762] ? _raw_spin_unlock_irqrestore+0x82/0xd0 [ 47.981880] ? lockdep_hardirqs_on+0x421/0x5c0 [ 47.986489] ? trace_hardirqs_on+0xbd/0x310 [ 47.990825] ? kasan_check_read+0x11/0x20 [ 47.994981] ? __kthread_parkme+0xce/0x1a0 [ 47.999225] ? __bpf_trace_preemptirq_template+0x30/0x30 [ 48.004688] ? kasan_check_write+0x14/0x20 [ 48.008946] ? do_raw_spin_lock+0xc1/0x200 [ 48.013190] ? _raw_spin_unlock_irqrestore+0x6d/0xd0 [ 48.018301] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 48.023844] ? __kthread_parkme+0xfb/0x1a0 [ 48.028089] kthread+0x35a/0x420 executing program executing program [ 48.031467] ? process_one_work+0x1b90/0x1b90 [ 48.035975] ? kthread_bind+0x40/0x40 [ 48.039795] ret_from_fork+0x3a/0x50 [ 48.044468] Kernel Offset: disabled [ 48.048101] Rebooting in 86400 seconds..