[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. [ 28.929506] kauditd_printk_skb: 7 callbacks suppressed [ 28.929518] audit: type=1800 audit(1543151244.938:29): pid=5875 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="rc.local" dev="sda1" ino=2432 res=0 [ 28.961069] audit: type=1800 audit(1543151244.938:30): pid=5875 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="rmnologin" dev="sda1" ino=2423 res=0 Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added '10.128.0.50' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 40.053167] ================================================================== [ 40.060614] BUG: KASAN: slab-out-of-bounds in queue_stack_map_push_elem+0x185/0x290 [ 40.068395] Write of size 262146 at addr ffff8881be5e48c8 by task syz-executor486/6030 [ 40.076569] [ 40.078191] CPU: 1 PID: 6030 Comm: syz-executor486 Not tainted 4.20.0-rc3+ #348 [ 40.085621] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 40.094962] Call Trace: [ 40.097549] dump_stack+0x244/0x39d [ 40.101163] ? dump_stack_print_info.cold.1+0x20/0x20 [ 40.106461] ? printk+0xa7/0xcf [ 40.109729] ? kmsg_dump_rewind_nolock+0xe4/0xe4 [ 40.114533] print_address_description.cold.7+0x9/0x1ff [ 40.119893] kasan_report.cold.8+0x242/0x309 [ 40.124288] ? queue_stack_map_push_elem+0x185/0x290 [ 40.129379] check_memory_region+0x13e/0x1b0 [ 40.133770] memcpy+0x37/0x50 [ 40.136869] queue_stack_map_push_elem+0x185/0x290 [ 40.141787] ? queue_map_pop_elem+0x30/0x30 [ 40.146195] map_update_elem+0x605/0xf60 [ 40.150248] __x64_sys_bpf+0x32d/0x520 [ 40.154127] ? bpf_prog_get+0x20/0x20 [ 40.157927] do_syscall_64+0x1b9/0x820 [ 40.161906] ? entry_SYSCALL_64_after_hwframe+0x3e/0xbe [ 40.167262] ? syscall_return_slowpath+0x5e0/0x5e0 [ 40.172176] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 40.177010] ? trace_hardirqs_on_caller+0x310/0x310 [ 40.182022] ? prepare_exit_to_usermode+0x3b0/0x3b0 [ 40.187031] ? prepare_exit_to_usermode+0x291/0x3b0 [ 40.192047] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 40.196991] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 40.202164] RIP: 0033:0x4400e9 [ 40.205347] Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 fb 13 fc ff c3 66 2e 0f 1f 84 00 00 00 00 [ 40.224355] RSP: 002b:00007ffc9cbf8ad8 EFLAGS: 00000213 ORIG_RAX: 0000000000000141 [ 40.232052] RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 00000000004400e9 [ 40.239303] RDX: 0000000000000020 RSI: 0000000020000040 RDI: 0000000000000002 [ 40.246552] RBP: 00000000006ca018 R08: 0000000000000000 R09: 00000000004002c8 [ 40.253802] R10: 0000000000000000 R11: 0000000000000213 R12: 0000000000401970 [ 40.261174] R13: 0000000000401a00 R14: 0000000000000000 R15: 0000000000000000 [ 40.268437] [ 40.270050] Allocated by task 6030: [ 40.273666] save_stack+0x43/0xd0 [ 40.277099] kasan_kmalloc+0xc7/0xe0 [ 40.280794] __kmalloc_node+0x50/0x70 [ 40.284591] bpf_map_area_alloc+0x3f/0x90 [ 40.288734] queue_stack_map_alloc+0x192/0x290 [ 40.293303] map_create+0x3bd/0x1110 [ 40.296997] __x64_sys_bpf+0x303/0x520 [ 40.300905] do_syscall_64+0x1b9/0x820 [ 40.304783] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 40.309952] [ 40.311563] Freed by task 3753: [ 40.314837] save_stack+0x43/0xd0 [ 40.318381] __kasan_slab_free+0x102/0x150 [ 40.322663] kasan_slab_free+0xe/0x10 [ 40.326529] kfree+0xcf/0x230 [ 40.329626] kernfs_fop_release+0x12b/0x1a0 [ 40.333932] __fput+0x385/0xa30 [ 40.337202] ____fput+0x15/0x20 [ 40.340470] task_work_run+0x1e8/0x2a0 [ 40.344344] exit_to_usermode_loop+0x318/0x380 [ 40.348909] do_syscall_64+0x6be/0x820 [ 40.352777] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 40.357940] [ 40.359551] The buggy address belongs to the object at ffff8881be5e4780 [ 40.359551] which belongs to the cache kmalloc-512 of size 512 [ 40.372312] The buggy address is located 328 bytes inside of [ 40.372312] 512-byte region [ffff8881be5e4780, ffff8881be5e4980) [ 40.384171] The buggy address belongs to the page: [ 40.389088] page:ffffea0006f97900 count:1 mapcount:0 mapping:ffff8881da800940 index:0x0 [ 40.397211] flags: 0x2fffc0000000200(slab) [ 40.401429] raw: 02fffc0000000200 ffffea0006fc1508 ffffea0006f879c8 ffff8881da800940 [ 40.409439] raw: 0000000000000000 ffff8881be5e4000 0000000100000006 0000000000000000 [ 40.417304] page dumped because: kasan: bad access detected [ 40.422996] [ 40.424646] Memory state around the buggy address: [ 40.429572] ffff8881be5e4800: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 40.436916] ffff8881be5e4880: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 40.444488] >ffff8881be5e4900: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 40.451836] ^ [ 40.455188] ffff8881be5e4980: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 40.462535] ffff8881be5e4a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 40.469895] ================================================================== [ 40.477290] Disabling lock debugging due to kernel taint [ 40.482750] Kernel panic - not syncing: panic_on_warn set ... [ 40.488616] CPU: 1 PID: 6030 Comm: syz-executor486 Tainted: G B 4.20.0-rc3+ #348 [ 40.497433] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 40.506772] Call Trace: [ 40.509361] dump_stack+0x244/0x39d [ 40.513075] ? dump_stack_print_info.cold.1+0x20/0x20 [ 40.518269] panic+0x2ad/0x55c [ 40.521459] ? add_taint.cold.5+0x16/0x16 [ 40.525596] ? add_taint.cold.5+0x5/0x16 [ 40.529757] ? trace_hardirqs_off+0xaf/0x310 [ 40.534156] kasan_end_report+0x47/0x4f [ 40.538116] kasan_report.cold.8+0x76/0x309 [ 40.542421] ? queue_stack_map_push_elem+0x185/0x290 [ 40.547506] check_memory_region+0x13e/0x1b0 [ 40.551895] memcpy+0x37/0x50 [ 40.554986] queue_stack_map_push_elem+0x185/0x290 [ 40.559900] ? queue_map_pop_elem+0x30/0x30 [ 40.564232] map_update_elem+0x605/0xf60 [ 40.568283] __x64_sys_bpf+0x32d/0x520 [ 40.572153] ? bpf_prog_get+0x20/0x20 [ 40.575963] do_syscall_64+0x1b9/0x820 [ 40.579839] ? entry_SYSCALL_64_after_hwframe+0x3e/0xbe [ 40.585347] ? syscall_return_slowpath+0x5e0/0x5e0 [ 40.590262] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 40.595088] ? trace_hardirqs_on_caller+0x310/0x310 [ 40.600161] ? prepare_exit_to_usermode+0x3b0/0x3b0 [ 40.605171] ? prepare_exit_to_usermode+0x291/0x3b0 [ 40.610176] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 40.615005] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 40.620279] RIP: 0033:0x4400e9 [ 40.623467] Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 fb 13 fc ff c3 66 2e 0f 1f 84 00 00 00 00 [ 40.642356] RSP: 002b:00007ffc9cbf8ad8 EFLAGS: 00000213 ORIG_RAX: 0000000000000141 [ 40.650056] RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 00000000004400e9 [ 40.657449] RDX: 0000000000000020 RSI: 0000000020000040 RDI: 0000000000000002 [ 40.664746] RBP: 00000000006ca018 R08: 0000000000000000 R09: 00000000004002c8 [ 40.672117] R10: 0000000000000000 R11: 0000000000000213 R12: 0000000000401970 [ 40.679372] R13: 0000000000401a00 R14: 0000000000000000 R15: 0000000000000000 [ 40.687714] Kernel Offset: disabled [ 40.691340] Rebooting in 86400 seconds..