syzkaller login: [ 332.769217] kworker/dying (38) used greatest stack depth: 15264 bytes left 2017/10/26 20:35:28 parsed 1 programs 2017/10/26 20:35:28 executed programs: 0 2017/10/26 20:35:33 executed programs: 88 2017/10/26 20:35:38 executed programs: 173 2017/10/26 20:35:43 executed programs: 255 2017/10/26 20:35:49 executed programs: 336 2017/10/26 20:35:54 executed programs: 416 2017/10/26 20:35:59 executed programs: 496 2017/10/26 20:36:04 executed programs: 576 2017/10/26 20:36:09 executed programs: 657 2017/10/26 20:36:14 executed programs: 739 2017/10/26 20:36:19 executed programs: 827 2017/10/26 20:36:24 executed programs: 910 2017/10/26 20:36:29 executed programs: 996 2017/10/26 20:36:34 executed programs: 1085 2017/10/26 20:36:39 executed programs: 1171 2017/10/26 20:36:44 executed programs: 1256 [ 629.989557] ================================================================== [ 629.990203] BUG: KASAN: use-after-free in __lock_acquire+0x3c9f/0x3d50 [ 629.990635] Read of size 8 at addr ffff88006c402de8 by task syz-executor0/8331 [ 629.991167] [ 629.991280] CPU: 3 PID: 8331 Comm: syz-executor0 Not tainted 4.14.0-rc5-next-20171018+ #8 [ 629.991801] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 [ 629.992390] Call Trace: [ 629.992603] dump_stack+0x194/0x257 [ 629.992895] ? arch_local_irq_restore+0x53/0x53 [ 629.993267] ? show_regs_print_info+0x65/0x65 [ 629.993615] ? print_irqtrace_events+0x270/0x270 [ 629.994121] ? print_irqtrace_events+0x270/0x270 [ 629.994504] ? __lock_acquire+0x3c9f/0x3d50 [ 629.994814] print_address_description+0x73/0x250 [ 629.995203] ? __lock_acquire+0x3c9f/0x3d50 [ 629.995539] kasan_report+0x25b/0x340 [ 629.995822] __asan_report_load8_noabort+0x14/0x20 [ 629.996214] __lock_acquire+0x3c9f/0x3d50 [ 629.996544] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 629.996951] ? exit_pi_state_list+0x369/0x7a0 [ 629.997314] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 629.997703] ? __lock_acquire+0x6aa/0x3d50 [ 629.998083] ? __lock_acquire+0x6aa/0x3d50 [ 629.998424] ? __lock_acquire+0x6aa/0x3d50 [ 629.998756] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 629.999163] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 629.999579] ? check_noncircular+0x20/0x20 [ 629.999913] ? osq_unlock+0x350/0x350 [ 630.000234] ? __lock_acquire+0x6aa/0x3d50 [ 630.000572] ? check_noncircular+0x20/0x20 [ 630.000909] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 630.001319] ? check_noncircular+0x20/0x20 [ 630.001658] ? pick_next_task_fair+0xee5/0x1830 [ 630.002042] ? print_irqtrace_events+0x270/0x270 [ 630.002414] ? find_held_lock+0x35/0x1d0 [ 630.002744] ? kprobe_flush_task+0x1a3/0x5d0 [ 630.003100] ? find_held_lock+0x35/0x1d0 [ 630.003427] lock_acquire+0x1d5/0x580 [ 630.003728] ? lock_acquire+0x1d5/0x580 [ 630.004050] ? exit_pi_state_list+0x369/0x7a0 [ 630.004381] ? lock_downgrade+0x990/0x990 [ 630.004716] ? lock_release+0xa40/0xa40 [ 630.005034] ? do_raw_spin_trylock+0x190/0x190 [ 630.005433] ? trace_hardirqs_on+0xd/0x10 [ 630.005811] _raw_spin_lock_irq+0x5e/0x80 [ 630.006249] ? exit_pi_state_list+0x369/0x7a0 [ 630.006639] exit_pi_state_list+0x369/0x7a0 [ 630.007096] ? futex_wait_requeue_pi.constprop.19+0x1300/0x1300 [ 630.007669] ? lock_release+0xa40/0xa40 [ 630.008358] ? trace_event_raw_event_sched_switch+0x8a0/0x8a0 [ 630.008843] ? _raw_spin_unlock_irqrestore+0x31/0xba [ 630.009172] ? __might_sleep+0x95/0x190 [ 630.009457] ? __might_fault+0x188/0x1d0 [ 630.009801] ? do_raw_spin_trylock+0x190/0x190 [ 630.010117] mm_release+0x46d/0x590 [ 630.010371] ? do_raw_spin_trylock+0x190/0x190 [ 630.010704] ? mm_access+0x140/0x140 [ 630.010975] ? _raw_spin_unlock_irq+0x27/0x70 [ 630.011308] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 630.011727] ? trace_hardirqs_on+0xd/0x10 [ 630.011986] ? _raw_spin_unlock_irq+0x27/0x70 [ 630.012335] ? acct_collect+0x637/0x800 [ 630.012626] do_exit+0x481/0x1ad0 [ 630.012918] ? mm_update_next_owner+0x930/0x930 [ 630.013217] ? trace_event_raw_event_sched_switch+0x8a0/0x8a0 [ 630.013666] ? rcu_note_context_switch+0x710/0x710 [ 630.022142] ? futex_wait_setup+0x14a/0x3d0 [ 630.022537] ? __might_sleep+0x95/0x190 [ 630.024784] ? find_held_lock+0x35/0x1d0 [ 630.025091] ? futex_wait+0x402/0x990 [ 630.025387] ? lock_downgrade+0x990/0x990 [ 630.025718] ? do_raw_spin_trylock+0x190/0x190 [ 630.026111] ? check_noncircular+0x20/0x20 [ 630.026431] ? futex_wake+0x680/0x680 [ 630.026717] ? mmdrop+0x18/0x30 [ 630.026967] ? drop_futex_key_refs.isra.13+0x63/0xa0 [ 630.027347] ? futex_wait+0x69e/0x990 [ 630.027626] ? find_held_lock+0x35/0x1d0 [ 630.027923] ? get_signal+0x7ae/0x16d0 [ 630.028206] ? lock_downgrade+0x990/0x990 [ 630.028589] do_group_exit+0x149/0x400 [ 630.028873] ? __lock_is_held+0xb6/0x140 [ 630.029174] ? SyS_exit+0x30/0x30 [ 630.029436] ? _raw_spin_unlock_irq+0x27/0x70 [ 630.029770] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 630.033447] get_signal+0x73f/0x16d0 [ 630.033947] ? ptrace_notify+0x130/0x130 [ 630.034344] ? __schedule+0x8f3/0x2060 [ 630.034714] ? exit_robust_list+0x240/0x240 [ 630.035122] ? __sched_text_start+0x8/0x8 [ 630.035509] ? find_held_lock+0x35/0x1d0 [ 630.035890] do_signal+0x94/0x1ee0 [ 630.036226] ? vm_mmap_pgoff+0x1ed/0x280 [ 630.036613] ? should_fail+0x23b/0xa40 [ 630.036974] ? fault_create_debugfs_attr+0x1f0/0x1f0 [ 630.037444] ? setup_sigcontext+0x7d0/0x7d0 [ 630.038124] ? schedule+0xf5/0x430 [ 630.038477] ? __schedule+0x2060/0x2060 [ 630.038855] ? lock_downgrade+0x990/0x990 [ 630.039270] ? down_read_killable+0x180/0x180 [ 630.039732] ? lock_release+0xa40/0xa40 [ 630.040141] ? trace_event_raw_event_sched_switch+0x8a0/0x8a0 [ 630.040765] ? vm_mmap_pgoff+0x1fc/0x280 [ 630.041146] ? exit_to_usermode_loop+0x8c/0x310 [ 630.041509] exit_to_usermode_loop+0x214/0x310 [ 630.041785] ? trace_event_raw_event_sys_exit+0x260/0x260 [ 630.042325] ? kasan_check_write+0x14/0x20 [ 630.042720] syscall_return_slowpath+0x42f/0x510 [ 630.043081] ? prepare_exit_to_usermode+0x2d0/0x2d0 [ 630.043516] ? entry_SYSCALL_64_fastpath+0x91/0xbe [ 630.043963] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 630.044405] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 630.044754] entry_SYSCALL_64_fastpath+0xbc/0xbe [ 630.045036] RIP: 0033:0x447c89 [ 630.045242] RSP: 002b:00007fe96678ace8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca [ 630.045811] RAX: fffffffffffffe00 RBX: 0000000000748048 RCX: 0000000000447c89 [ 630.046488] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000748048 [ 630.047174] RBP: 0000000000748048 R08: 0000000000000000 R09: 0000000000748020 [ 630.047830] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 [ 630.048487] R13: 0000000000000000 R14: 00007fe96678b9c0 R15: 00007fe96678b700 [ 630.049147] [ 630.049296] Allocated by task 8333: [ 630.049629] save_stack+0x43/0xd0 [ 630.055161] kasan_kmalloc+0xad/0xe0 [ 630.055504] kmem_cache_alloc_trace+0x136/0x750 [ 630.055932] refill_pi_state_cache.part.6+0xa5/0x2f0 [ 630.056425] futex_requeue+0x1887/0x2370 [ 630.056793] do_futex+0x7f5/0x20d0 [ 630.057122] SyS_futex+0x260/0x390 [ 630.057451] entry_SYSCALL_64_fastpath+0x1f/0xbe [ 630.057906] [ 630.058054] Freed by task 8332: [ 630.058406] save_stack+0x43/0xd0 [ 630.058724] kasan_slab_free+0x71/0xc0 [ 630.059078] kfree+0xca/0x250 [ 630.059361] do_exit+0x1502/0x1ad0 [ 630.059684] do_group_exit+0x149/0x400 [ 630.060065] get_signal+0x73f/0x16d0 [ 630.060409] do_signal+0x94/0x1ee0 [ 630.060720] exit_to_usermode_loop+0x214/0x310 [ 630.061056] syscall_return_slowpath+0x42f/0x510 [ 630.061491] entry_SYSCALL_64_fastpath+0xbc/0xbe [ 630.061947] [ 630.062103] The buggy address belongs to the object at ffff88006c402dc0 [ 630.062103] which belongs to the cache kmalloc-256 of size 256 [ 630.063342] The buggy address is located 40 bytes inside of [ 630.063342] 256-byte region [ffff88006c402dc0, ffff88006c402ec0) [ 630.064519] The buggy address belongs to the page: [ 630.065002] page:ffffea0001b10080 count:1 mapcount:0 mapping:ffff88006c402000 index:0xffff88006c402a00 [ 630.065918] flags: 0x500000000000100(slab) [ 630.066306] raw: 0500000000000100 ffff88006c402000 ffff88006c402a00 0000000100000009 [ 630.067032] raw: ffffea0001ad6f20 ffffea0001b281e0 ffff88003e8007c0 0000000000000000 [ 630.067761] page dumped because: kasan: bad access detected [ 630.068293] [ 630.068474] Memory state around the buggy address: [ 630.068959] ffff88006c402c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 630.069629] ffff88006c402d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 630.070348] >ffff88006c402d80: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb [ 630.071068] ^ [ 630.071717] ffff88006c402e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 630.072459] ffff88006c402e80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc [ 630.073153] ================================================================== [ 630.073828] Disabling lock debugging due to kernel taint [ 630.074296] Kernel panic - not syncing: panic_on_warn set ... [ 630.074296] [ 630.074960] CPU: 3 PID: 8331 Comm: syz-executor0 Tainted: G B 4.14.0-rc5-next-20171018+ #8 [ 630.075782] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 [ 630.076303] Call Trace: [ 630.076467] dump_stack+0x194/0x257 [ 630.076688] ? arch_local_irq_restore+0x53/0x53 [ 630.076971] ? kasan_end_report+0x32/0x50 [ 630.077223] ? lock_downgrade+0x990/0x990 [ 630.077473] ? vsnprintf+0x1ed/0x1900 [ 630.077703] ? __lock_acquire+0x3c50/0x3d50 [ 630.078027] panic+0x1e4/0x41c [ 630.078222] ? refcount_error_report+0x214/0x214 [ 630.078510] ? add_taint+0x40/0x50 [ 630.078740] ? add_taint+0x1c/0x50 [ 630.078969] ? __lock_acquire+0x3c9f/0x3d50 [ 630.079335] kasan_end_report+0x50/0x50 [ 630.079688] kasan_report+0x144/0x340 [ 630.080040] __asan_report_load8_noabort+0x14/0x20 [ 630.080384] __lock_acquire+0x3c9f/0x3d50 [ 630.080635] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 630.080950] ? exit_pi_state_list+0x369/0x7a0 [ 630.081222] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 630.081534] ? __lock_acquire+0x6aa/0x3d50 [ 630.081843] ? __lock_acquire+0x6aa/0x3d50 [ 630.082266] ? __lock_acquire+0x6aa/0x3d50 [ 630.082649] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 630.083115] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 630.083568] ? check_noncircular+0x20/0x20 [ 630.083936] ? osq_unlock+0x350/0x350 [ 630.084188] ? __lock_acquire+0x6aa/0x3d50 [ 630.084550] ? check_noncircular+0x20/0x20 [ 630.084933] ? debug_check_no_locks_freed+0x3c0/0x3c0 [ 630.085300] ? check_noncircular+0x20/0x20 [ 630.085566] ? pick_next_task_fair+0xee5/0x1830 [ 630.085854] ? print_irqtrace_events+0x270/0x270 [ 630.086146] ? find_held_lock+0x35/0x1d0 [ 630.086400] ? kprobe_flush_task+0x1a3/0x5d0 [ 630.086673] ? find_held_lock+0x35/0x1d0 [ 630.086920] lock_acquire+0x1d5/0x580 [ 630.087151] ? lock_acquire+0x1d5/0x580 [ 630.087393] ? exit_pi_state_list+0x369/0x7a0 [ 630.087666] ? lock_downgrade+0x990/0x990 [ 630.087920] ? lock_release+0xa40/0xa40 [ 630.088162] ? do_raw_spin_trylock+0x190/0x190 [ 630.088440] ? trace_hardirqs_on+0xd/0x10 [ 630.088696] _raw_spin_lock_irq+0x5e/0x80 [ 630.088977] ? exit_pi_state_list+0x369/0x7a0 [ 630.089330] exit_pi_state_list+0x369/0x7a0 [ 630.089595] ? futex_wait_requeue_pi.constprop.19+0x1300/0x1300 [ 630.090069] ? lock_release+0xa40/0xa40 [ 630.090325] ? trace_event_raw_event_sched_switch+0x8a0/0x8a0 [ 630.090707] ? _raw_spin_unlock_irqrestore+0x31/0xba [ 630.091083] ? __might_sleep+0x95/0x190 [ 630.091378] ? __might_fault+0x188/0x1d0 [ 630.091680] ? do_raw_spin_trylock+0x190/0x190 [ 630.091984] mm_release+0x46d/0x590 [ 630.092218] ? do_raw_spin_trylock+0x190/0x190 [ 630.092535] ? mm_access+0x140/0x140 [ 630.092760] ? _raw_spin_unlock_irq+0x27/0x70 [ 630.093030] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 630.093332] ? trace_hardirqs_on+0xd/0x10 [ 630.093582] ? _raw_spin_unlock_irq+0x27/0x70 [ 630.093966] ? acct_collect+0x637/0x800 [ 630.094269] do_exit+0x481/0x1ad0 [ 630.094478] ? mm_update_next_owner+0x930/0x930 [ 630.094774] ? trace_event_raw_event_sched_switch+0x8a0/0x8a0 [ 630.095189] ? rcu_note_context_switch+0x710/0x710 [ 630.095485] ? futex_wait_setup+0x14a/0x3d0 [ 630.095745] ? __might_sleep+0x95/0x190 [ 630.095986] ? find_held_lock+0x35/0x1d0 [ 630.096230] ? futex_wait+0x402/0x990 [ 630.096459] ? lock_downgrade+0x990/0x990 [ 630.096707] ? do_raw_spin_trylock+0x190/0x190 [ 630.097023] ? check_noncircular+0x20/0x20 [ 630.097291] ? futex_wake+0x680/0x680 [ 630.097520] ? mmdrop+0x18/0x30 [ 630.097746] ? drop_futex_key_refs.isra.13+0x63/0xa0 [ 630.098890] ? futex_wait+0x69e/0x990 [ 630.099214] ? find_held_lock+0x35/0x1d0 [ 630.099461] ? get_signal+0x7ae/0x16d0 [ 630.099696] ? lock_downgrade+0x990/0x990 [ 630.100003] do_group_exit+0x149/0x400 [ 630.100267] ? __lock_is_held+0xb6/0x140 [ 630.100513] ? SyS_exit+0x30/0x30 [ 630.100738] ? _raw_spin_unlock_irq+0x27/0x70 [ 630.101036] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 630.101353] get_signal+0x73f/0x16d0 [ 630.101579] ? ptrace_notify+0x130/0x130 [ 630.101961] ? __schedule+0x8f3/0x2060 [ 630.102242] ? exit_robust_list+0x240/0x240 [ 630.102513] ? __sched_text_start+0x8/0x8 [ 630.102775] ? find_held_lock+0x35/0x1d0 [ 630.103029] do_signal+0x94/0x1ee0 [ 630.103264] ? vm_mmap_pgoff+0x1ed/0x280 [ 630.103591] ? should_fail+0x23b/0xa40 [ 630.103878] ? fault_create_debugfs_attr+0x1f0/0x1f0 [ 630.104265] ? setup_sigcontext+0x7d0/0x7d0 [ 630.104576] ? schedule+0xf5/0x430 [ 630.104824] ? __schedule+0x2060/0x2060 [ 630.105087] ? lock_downgrade+0x990/0x990 [ 630.105373] ? down_read_killable+0x180/0x180 [ 630.105665] ? lock_release+0xa40/0xa40 [ 630.105968] ? trace_event_raw_event_sched_switch+0x8a0/0x8a0 [ 630.106438] ? vm_mmap_pgoff+0x1fc/0x280 [ 630.106750] ? exit_to_usermode_loop+0x8c/0x310 [ 630.107033] exit_to_usermode_loop+0x214/0x310 [ 630.107313] ? trace_event_raw_event_sys_exit+0x260/0x260 [ 630.107659] ? kasan_check_write+0x14/0x20 [ 630.107929] syscall_return_slowpath+0x42f/0x510 [ 630.108259] ? prepare_exit_to_usermode+0x2d0/0x2d0 [ 630.108612] ? entry_SYSCALL_64_fastpath+0x91/0xbe [ 630.108901] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 630.109229] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 630.109532] entry_SYSCALL_64_fastpath+0xbc/0xbe [ 630.109899] RIP: 0033:0x447c89 [ 630.110161] RSP: 002b:00007fe96678ace8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca [ 630.110623] RAX: fffffffffffffe00 RBX: 0000000000748048 RCX: 0000000000447c89 [ 630.111058] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000748048 [ 630.111492] RBP: 0000000000748048 R08: 0000000000000000 R09: 0000000000748020 [ 630.111926] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 [ 630.112360] R13: 0000000000000000 R14: 00007fe96678b9c0 R15: 00007fe96678b700 [ 630.113924] Dumping ftrace buffer: [ 630.114180] (ftrace buffer empty) [ 630.114418] Kernel Offset: disabled [ 630.114705] Rebooting in 86400 seconds..