INIT: Entering runlevel: 2 [info] Using makefile-style concurrent boot in runlevel 2. [....] 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. Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added 'ci-upstream-mmots-kasan-gce-0,10.128.0.48' (ECDSA) to the list of known hosts. executing program executing program syzkaller login: [ 50.010573] ================================================================== [ 50.018176] BUG: KASAN: use-after-free in __internal_add_timer+0x275/0x2d0 [ 50.025252] Write of size 8 at addr ffff8801ce52b688 by task syzkaller367658/2983 [ 50.032959] [ 50.034588] CPU: 1 PID: 2983 Comm: syzkaller367658 Not tainted 4.14.0-rc4-mm1+ #16 [ 50.042294] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 50.051639] Call Trace: [ 50.054216] dump_stack+0x194/0x257 [ 50.057834] ? arch_local_irq_restore+0x53/0x53 [ 50.062508] ? show_regs_print_info+0x65/0x65 [ 50.067089] ? __kernel_text_address+0xd/0x40 [ 50.071568] ? __internal_add_timer+0x275/0x2d0 [ 50.076389] print_address_description+0x73/0x250 [ 50.081212] ? __internal_add_timer+0x275/0x2d0 [ 50.085855] kasan_report+0x25b/0x340 [ 50.089633] __asan_report_store8_noabort+0x17/0x20 [ 50.094624] __internal_add_timer+0x275/0x2d0 [ 50.099093] ? calc_wheel_index+0x200/0x200 [ 50.103405] mod_timer+0x622/0x15b0 [ 50.107048] ? mod_timer_pending+0x14e0/0x14e0 [ 50.111612] ? __lock_is_held+0xbc/0x140 [ 50.115674] ? __lock_is_held+0xbc/0x140 [ 50.119711] ? __lockdep_init_map+0xe4/0x650 [ 50.124094] ? lockdep_init_map+0x3d/0x70 [ 50.128526] ? rcu_read_lock_sched_held+0x108/0x120 [ 50.133529] ? init_timer_key+0x126/0x3b0 [ 50.137651] ? try_to_del_timer_sync+0x120/0x120 [ 50.142468] ? round_jiffies_up+0xce/0x100 [ 50.146675] ? __round_jiffies_up_relative+0x150/0x150 [ 50.151932] ? debug_lockdep_rcu_enabled+0x77/0x90 [ 50.156847] ? selinux_tun_dev_alloc_security+0x124/0x170 [ 50.162364] __tun_chr_ioctl+0x1beb/0x3e40 [ 50.166842] ? tun_chr_read_iter+0x1e0/0x1e0 [ 50.171313] ? lock_downgrade+0x990/0x990 [ 50.175828] ? handle_mm_fault+0x410/0x8d0 [ 50.180061] ? __do_page_fault+0x31e/0xd60 [ 50.184544] ? check_same_owner+0x320/0x320 [ 50.188865] ? up_read+0x1a/0x40 [ 50.192224] ? __do_page_fault+0x3d6/0xd60 [ 50.196451] ? tun_chr_compat_ioctl+0x30/0x30 [ 50.201019] tun_chr_ioctl+0x2a/0x40 [ 50.205235] ? tun_chr_ioctl+0x2a/0x40 [ 50.209119] do_vfs_ioctl+0x1b1/0x1530 [ 50.213092] ? ioctl_preallocate+0x2b0/0x2b0 [ 50.217486] ? selinux_capable+0x40/0x40 [ 50.221524] ? putname+0xf3/0x130 [ 50.224957] ? do_sys_open+0x320/0x6d0 [ 50.228840] ? security_file_ioctl+0x89/0xb0 [ 50.233234] SyS_ioctl+0x8f/0xc0 [ 50.236580] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 50.241320] RIP: 0033:0x443d79 [ 50.244828] RSP: 002b:00007fff93348218 EFLAGS: 00000206 ORIG_RAX: 0000000000000010 [ 50.252527] RAX: ffffffffffffffda RBX: 0f1c35cd67fe3811 RCX: 0000000000443d79 [ 50.259771] RDX: 0000000020fd4fd8 RSI: 00000000400454ca RDI: 0000000000000004 [ 50.267032] RBP: 0000000000000082 R08: 0000000000000000 R09: 0000000000000000 [ 50.274304] R10: 0000000000000000 R11: 0000000000000206 R12: c23c83788a2ba035 [ 50.281563] R13: 74656e2f7665642f R14: 0000000000000000 R15: 0000000000000000 [ 50.288835] [ 50.290441] Allocated by task 2983: [ 50.294058] save_stack+0x43/0xd0 [ 50.297493] kasan_kmalloc+0xad/0xe0 [ 50.301826] __kmalloc_node+0x47/0x70 [ 50.305615] kvmalloc_node+0x64/0xd0 [ 50.309302] alloc_netdev_mqs+0x16d/0xed0 [ 50.313518] __tun_chr_ioctl+0x1386/0x3e40 [ 50.317733] tun_chr_ioctl+0x2a/0x40 [ 50.321420] do_vfs_ioctl+0x1b1/0x1530 [ 50.325365] SyS_ioctl+0x8f/0xc0 [ 50.328702] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 50.333425] [ 50.335024] Freed by task 2983: [ 50.338276] save_stack+0x43/0xd0 [ 50.341698] kasan_slab_free+0x71/0xc0 [ 50.345553] kfree+0xca/0x250 [ 50.348627] kvfree+0x36/0x60 [ 50.351703] free_netdev+0x2cf/0x360 [ 50.355386] __tun_chr_ioctl+0x2df6/0x3e40 [ 50.359590] tun_chr_ioctl+0x2a/0x40 [ 50.363278] do_vfs_ioctl+0x1b1/0x1530 [ 50.367149] SyS_ioctl+0x8f/0xc0 [ 50.370491] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 50.375218] [ 50.376828] The buggy address belongs to the object at ffff8801ce528280 [ 50.376828] which belongs to the cache kmalloc-16384 of size 16384 [ 50.389818] The buggy address is located 13320 bytes inside of [ 50.389818] 16384-byte region [ffff8801ce528280, ffff8801ce52c280) [ 50.402029] The buggy address belongs to the page: [ 50.406929] page:ffffea0007394a00 count:1 mapcount:0 mapping:ffff8801ce528280 index:0x0 compound_mapcount: 0 [ 50.416877] flags: 0x200000000008100(slab|head) [ 50.421519] raw: 0200000000008100 ffff8801ce528280 0000000000000000 0000000100000001 [ 50.429369] raw: ffffea000701a820 ffffea00073a5e20 ffff8801dac02200 0000000000000000 [ 50.437217] page dumped because: kasan: bad access detected [ 50.442895] [ 50.444492] Memory state around the buggy address: [ 50.449390] ffff8801ce52b580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 50.456723] ffff8801ce52b600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 50.464057] >ffff8801ce52b680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 50.471385] ^ [ 50.474981] ffff8801ce52b700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 50.482314] ffff8801ce52b780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 50.489645] ================================================================== [ 50.496970] Disabling lock debugging due to kernel taint [ 50.502383] Kernel panic - not syncing: panic_on_warn set ... [ 50.502383] [ 50.510507] CPU: 1 PID: 2983 Comm: syzkaller367658 Tainted: G B 4.14.0-rc4-mm1+ #16 [ 50.519484] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 50.529505] Call Trace: [ 50.532064] dump_stack+0x194/0x257 [ 50.535661] ? arch_local_irq_restore+0x53/0x53 [ 50.540308] ? vprintk_default+0x28/0x30 [ 50.544348] ? __internal_add_timer+0x1f0/0x2d0 [ 50.550382] panic+0x1e4/0x41c [ 50.553552] ? refcount_error_report+0x214/0x214 [ 50.558282] ? __internal_add_timer+0x275/0x2d0 [ 50.562925] kasan_end_report+0x50/0x50 [ 50.566961] kasan_report+0x144/0x340 [ 50.570735] __asan_report_store8_noabort+0x17/0x20 [ 50.575726] __internal_add_timer+0x275/0x2d0 [ 50.580210] ? calc_wheel_index+0x200/0x200 [ 50.584513] mod_timer+0x622/0x15b0 [ 50.588222] ? mod_timer_pending+0x14e0/0x14e0 [ 50.592773] ? __lock_is_held+0xbc/0x140 [ 50.596807] ? __lock_is_held+0xbc/0x140 [ 50.600838] ? __lockdep_init_map+0xe4/0x650 [ 50.605224] ? lockdep_init_map+0x3d/0x70 [ 50.609351] ? rcu_read_lock_sched_held+0x108/0x120 [ 50.614346] ? init_timer_key+0x126/0x3b0 [ 50.618474] ? try_to_del_timer_sync+0x120/0x120 [ 50.623198] ? round_jiffies_up+0xce/0x100 [ 50.627409] ? __round_jiffies_up_relative+0x150/0x150 [ 50.632660] ? debug_lockdep_rcu_enabled+0x77/0x90 [ 50.637559] ? selinux_tun_dev_alloc_security+0x124/0x170 [ 50.643153] __tun_chr_ioctl+0x1beb/0x3e40 [ 50.647357] ? tun_chr_read_iter+0x1e0/0x1e0 [ 50.651743] ? lock_downgrade+0x990/0x990 [ 50.655872] ? handle_mm_fault+0x410/0x8d0 [ 50.660071] ? __do_page_fault+0x31e/0xd60 [ 50.664278] ? check_same_owner+0x320/0x320 [ 50.668561] ? up_read+0x1a/0x40 [ 50.671905] ? __do_page_fault+0x3d6/0xd60 [ 50.676108] ? tun_chr_compat_ioctl+0x30/0x30 [ 50.680566] tun_chr_ioctl+0x2a/0x40 [ 50.684247] ? tun_chr_ioctl+0x2a/0x40 [ 50.688188] do_vfs_ioctl+0x1b1/0x1530 [ 50.692043] ? ioctl_preallocate+0x2b0/0x2b0 [ 50.696421] ? selinux_capable+0x40/0x40 [ 50.700449] ? putname+0xf3/0x130 [ 50.703872] ? do_sys_open+0x320/0x6d0 [ 50.707738] ? security_file_ioctl+0x89/0xb0 [ 50.712123] SyS_ioctl+0x8f/0xc0 [ 50.715458] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 50.720186] RIP: 0033:0x443d79 [ 50.723341] RSP: 002b:00007fff93348218 EFLAGS: 00000206 ORIG_RAX: 0000000000000010 [ 50.731104] RAX: ffffffffffffffda RBX: 0f1c35cd67fe3811 RCX: 0000000000443d79 [ 50.738610] RDX: 0000000020fd4fd8 RSI: 00000000400454ca RDI: 0000000000000004 [ 50.745846] RBP: 0000000000000082 R08: 0000000000000000 R09: 0000000000000000 [ 50.753176] R10: 0000000000000000 R11: 0000000000000206 R12: c23c83788a2ba035 [ 50.760417] R13: 74656e2f7665642f R14: 0000000000000000 R15: 0000000000000000 [ 50.768097] Dumping ftrace buffer: [ 50.771614] (ftrace buffer empty) [ 50.775291] Kernel Offset: disabled [ 50.778890] Rebooting in 86400 seconds..