[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 87.264640][ T27] audit: type=1800 audit(1582972994.607:25): pid=9457 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2414 res=0 [ 87.284525][ T27] audit: type=1800 audit(1582972994.607:26): pid=9457 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2457 res=0 [ 87.336472][ T27] audit: type=1800 audit(1582972994.607:27): pid=9457 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 '10.128.0.175' (ECDSA) to the list of known hosts. syzkaller login: [ 97.028810][ T9613] IPVS: ftp: loaded support on port[0] = 21 [ 97.034038][ T9619] IPVS: ftp: loaded support on port[0] = 21 [ 97.038236][ T9617] IPVS: ftp: loaded support on port[0] = 21 [ 97.044769][ T9618] IPVS: ftp: loaded support on port[0] = 21 [ 97.055194][ T9620] IPVS: ftp: loaded support on port[0] = 21 [ 97.060365][ T9621] IPVS: ftp: loaded support on port[0] = 21 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 97.201817][ T3165] ================================================================== [ 97.210055][ T3165] BUG: KASAN: use-after-free in l2cap_chan_close+0x661/0xa10 [ 97.217433][ T3165] Read of size 1 at addr ffff8880936ee020 by task kworker/1:123/3165 [ 97.225592][ T3165] [ 97.227939][ T3165] CPU: 1 PID: 3165 Comm: kworker/1:123 Not tainted 5.6.0-rc3-syzkaller #0 [ 97.236639][ T3165] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 97.246699][ T3165] Workqueue: events do_enable_set [ 97.251715][ T3165] Call Trace: [ 97.255013][ T3165] dump_stack+0x197/0x210 [ 97.259339][ T3165] ? l2cap_chan_close+0x661/0xa10 [ 97.264561][ T3165] print_address_description.constprop.0.cold+0xd4/0x30b [ 97.271584][ T3165] ? l2cap_chan_close+0x661/0xa10 [ 97.276609][ T3165] ? l2cap_chan_close+0x661/0xa10 [ 97.281637][ T3165] __kasan_report.cold+0x1b/0x32 [ 97.286587][ T3165] ? l2cap_chan_close+0x661/0xa10 [ 97.291704][ T3165] kasan_report+0x12/0x20 [ 97.296033][ T3165] __asan_report_load1_noabort+0x14/0x20 [ 97.301664][ T3165] l2cap_chan_close+0x661/0xa10 [ 97.306514][ T3165] ? __kasan_check_read+0x11/0x20 [ 97.311584][ T3165] ? l2cap_send_i_or_rr_or_rnr+0x330/0x330 [ 97.317400][ T3165] do_enable_set+0x53f/0x960 [ 97.322004][ T3165] ? rcu_lockdep_current_cpu_online+0xe3/0x130 [ 97.328157][ T3165] ? lowpan_control_write+0x4b0/0x4b0 [ 97.333545][ T3165] ? rcu_read_lock_sched_held+0x9c/0xd0 [ 97.339081][ T3165] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 97.345064][ T3165] ? trace_hardirqs_on+0x67/0x240 [ 97.350099][ T3165] process_one_work+0xa05/0x17a0 [ 97.355473][ T3165] ? mark_held_locks+0xf0/0xf0 [ 97.360251][ T3165] ? pwq_dec_nr_in_flight+0x320/0x320 [ 97.365623][ T3165] ? lock_acquire+0x190/0x410 [ 97.370313][ T3165] worker_thread+0x98/0xe40 [ 97.374831][ T3165] ? trace_hardirqs_on+0x67/0x240 [ 97.379862][ T3165] kthread+0x361/0x430 [ 97.383932][ T3165] ? process_one_work+0x17a0/0x17a0 [ 97.389388][ T3165] ? kthread_mod_delayed_work+0x1f0/0x1f0 [ 97.395113][ T3165] ret_from_fork+0x24/0x30 [ 97.399539][ T3165] [ 97.401864][ T3165] Allocated by task 2822: [ 97.406182][ T3165] save_stack+0x23/0x90 [ 97.410337][ T3165] __kasan_kmalloc.constprop.0+0xcf/0xe0 [ 97.415968][ T3165] kasan_kmalloc+0x9/0x10 [ 97.420295][ T3165] kmem_cache_alloc_trace+0x158/0x790 [ 97.425661][ T3165] l2cap_chan_create+0x45/0x3a0 [ 97.430508][ T3165] chan_create+0x10/0xe0 [ 97.434828][ T3165] do_enable_set+0x583/0x960 [ 97.439418][ T3165] process_one_work+0xa05/0x17a0 [ 97.444351][ T3165] worker_thread+0x98/0xe40 [ 97.448846][ T3165] kthread+0x361/0x430 [ 97.452924][ T3165] ret_from_fork+0x24/0x30 [ 97.457334][ T3165] [ 97.459649][ T3165] Freed by task 2822: [ 97.463631][ T3165] save_stack+0x23/0x90 [ 97.467780][ T3165] __kasan_slab_free+0x102/0x150 [ 97.472805][ T3165] kasan_slab_free+0xe/0x10 [ 97.477337][ T3165] kfree+0x10a/0x2c0 [ 97.481227][ T3165] l2cap_chan_put+0x1b7/0x240 [ 97.485914][ T3165] do_enable_set+0x54b/0x960 [ 97.490501][ T3165] process_one_work+0xa05/0x17a0 [ 97.495693][ T3165] worker_thread+0x98/0xe40 [ 97.500199][ T3165] kthread+0x361/0x430 [ 97.504262][ T3165] ret_from_fork+0x24/0x30 [ 97.508686][ T3165] [ 97.511009][ T3165] The buggy address belongs to the object at ffff8880936ee000 [ 97.511009][ T3165] which belongs to the cache kmalloc-2k of size 2048 [ 97.525060][ T3165] The buggy address is located 32 bytes inside of [ 97.525060][ T3165] 2048-byte region [ffff8880936ee000, ffff8880936ee800) [ 97.538409][ T3165] The buggy address belongs to the page: [ 97.544044][ T3165] page:ffffea00024dbb80 refcount:1 mapcount:0 mapping:ffff8880aa400e00 index:0x0 [ 97.553268][ T3165] flags: 0xfffe0000000200(slab) [ 97.558211][ T3165] raw: 00fffe0000000200 ffffea000288d708 ffffea000286ba88 ffff8880aa400e00 [ 97.566795][ T3165] raw: 0000000000000000 ffff8880936ee000 0000000100000001 0000000000000000 [ 97.575372][ T3165] page dumped because: kasan: bad access detected [ 97.582293][ T3165] [ 97.588545][ T3165] Memory state around the buggy address: [ 97.594175][ T3165] ffff8880936edf00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc executing program executing program executing program executing program executing program [ 97.602237][ T3165] ffff8880936edf80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 97.610299][ T3165] >ffff8880936ee000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 97.618353][ T3165] ^ [ 97.623565][ T3165] ffff8880936ee080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 97.631619][ T3165] ffff8880936ee100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 97.639672][ T3165] ================================================================== [ 97.647721][ T3165] 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 [ 97.716702][ T3165] Kernel panic - not syncing: panic_on_warn set ... [ 97.723356][ T3165] CPU: 1 PID: 3165 Comm: kworker/1:123 Tainted: G B 5.6.0-rc3-syzkaller #0 [ 97.733262][ T3165] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 97.743335][ T3165] Workqueue: events do_enable_set [ 97.748477][ T3165] Call Trace: [ 97.751783][ T3165] dump_stack+0x197/0x210 [ 97.756257][ T3165] panic+0x2e3/0x75c [ 97.760163][ T3165] ? add_taint.cold+0x16/0x16 [ 97.764857][ T3165] ? l2cap_chan_close+0x661/0xa10 [ 97.770000][ T3165] ? preempt_schedule+0x4b/0x60 [ 97.774858][ T3165] ? ___preempt_schedule+0x16/0x18 [ 97.780097][ T3165] ? trace_hardirqs_on+0x5e/0x240 [ 97.785224][ T3165] ? l2cap_chan_close+0x661/0xa10 [ 97.790260][ T3165] end_report+0x47/0x4f [ 97.794580][ T3165] ? l2cap_chan_close+0x661/0xa10 [ 97.799633][ T3165] __kasan_report.cold+0xe/0x32 [ 97.804498][ T3165] ? l2cap_chan_close+0x661/0xa10 [ 97.809535][ T3165] kasan_report+0x12/0x20 [ 97.813874][ T3165] __asan_report_load1_noabort+0x14/0x20 [ 97.819514][ T3165] l2cap_chan_close+0x661/0xa10 [ 97.824498][ T3165] ? __kasan_check_read+0x11/0x20 [ 97.829529][ T3165] ? l2cap_send_i_or_rr_or_rnr+0x330/0x330 [ 97.835613][ T3165] do_enable_set+0x53f/0x960 [ 97.840214][ T3165] ? rcu_lockdep_current_cpu_online+0xe3/0x130 [ 97.846379][ T3165] ? lowpan_control_write+0x4b0/0x4b0 [ 97.851766][ T3165] ? rcu_read_lock_sched_held+0x9c/0xd0 [ 97.857319][ T3165] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 97.863428][ T3165] ? trace_hardirqs_on+0x67/0x240 [ 97.868466][ T3165] process_one_work+0xa05/0x17a0 [ 97.873411][ T3165] ? mark_held_locks+0xf0/0xf0 [ 97.878288][ T3165] ? pwq_dec_nr_in_flight+0x320/0x320 [ 97.883668][ T3165] ? lock_acquire+0x190/0x410 [ 97.888366][ T3165] worker_thread+0x98/0xe40 [ 97.892881][ T3165] ? trace_hardirqs_on+0x67/0x240 [ 97.897954][ T3165] kthread+0x361/0x430 [ 97.902039][ T3165] ? process_one_work+0x17a0/0x17a0 [ 97.907245][ T3165] ? kthread_mod_delayed_work+0x1f0/0x1f0 [ 97.913017][ T3165] ret_from_fork+0x24/0x30 [ 97.918981][ T3165] Kernel Offset: disabled [ 97.923311][ T3165] Rebooting in 86400 seconds..