[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 58.000188][ T26] audit: type=1800 audit(1562164619.309:25): pid=8562 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2414 res=0 [ 58.045214][ T26] audit: type=1800 audit(1562164619.309:26): pid=8562 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2457 res=0 [ 58.070642][ T26] audit: type=1800 audit(1562164619.319:27): pid=8562 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 '10.128.0.251' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 69.793618][ T8718] [ 69.796118][ T8718] ====================================================== [ 69.803115][ T8718] WARNING: possible circular locking dependency detected [ 69.810209][ T8718] 5.2.0-rc7+ #40 Not tainted [ 69.814913][ T8718] ------------------------------------------------------ [ 69.822051][ T8718] syz-executor292/8718 is trying to acquire lock: [ 69.828442][ T8718] 00000000df43932d (&rp->fetch_lock){+.+.}, at: mon_bin_vma_fault+0x73/0x2d0 [ 69.837316][ T8718] [ 69.837316][ T8718] but task is already holding lock: [ 69.844853][ T8718] 00000000a168186b (&mm->mmap_sem#2){++++}, at: __mm_populate+0x270/0x380 [ 69.853355][ T8718] [ 69.853355][ T8718] which lock already depends on the new lock. [ 69.853355][ T8718] [ 69.863845][ T8718] [ 69.863845][ T8718] the existing dependency chain (in reverse order) is: [ 69.872857][ T8718] [ 69.872857][ T8718] -> #1 (&mm->mmap_sem#2){++++}: [ 69.879977][ T8718] __might_fault+0x15e/0x1e0 [ 69.885084][ T8718] _copy_to_user+0x30/0x120 [ 69.890101][ T8718] mon_bin_read+0x329/0x640 [ 69.895121][ T8718] do_iter_read+0x4a4/0x660 [ 69.900128][ T8718] compat_readv+0x18e/0x200 [ 69.905129][ T8718] do_compat_preadv64+0x190/0x1c0 [ 69.910739][ T8718] __ia32_compat_sys_preadv+0xc7/0x140 [ 69.916702][ T8718] do_fast_syscall_32+0x27b/0xd7d [ 69.922254][ T8718] entry_SYSENTER_compat+0x70/0x7f [ 69.927863][ T8718] [ 69.927863][ T8718] -> #0 (&rp->fetch_lock){+.+.}: [ 69.937234][ T8718] lock_acquire+0x16f/0x3f0 [ 69.942249][ T8718] __mutex_lock+0xf7/0x1310 [ 69.947352][ T8718] mutex_lock_nested+0x16/0x20 [ 69.952623][ T8718] mon_bin_vma_fault+0x73/0x2d0 [ 69.957994][ T8718] __do_fault+0x111/0x4d0 [ 69.962852][ T8718] __handle_mm_fault+0xf67/0x3eb0 [ 69.968410][ T8718] handle_mm_fault+0x3b7/0xa90 [ 69.973683][ T8718] __get_user_pages+0x7b6/0x1a40 [ 69.979210][ T8718] populate_vma_page_range+0x20d/0x2a0 [ 69.985277][ T8718] __mm_populate+0x204/0x380 [ 69.990374][ T8718] vm_mmap_pgoff+0x213/0x230 [ 69.995478][ T8718] ksys_mmap_pgoff+0x4aa/0x630 [ 70.000755][ T8718] __ia32_sys_mmap_pgoff+0xdd/0x1a0 [ 70.006494][ T8718] do_fast_syscall_32+0x27b/0xd7d [ 70.012242][ T8718] entry_SYSENTER_compat+0x70/0x7f [ 70.017846][ T8718] [ 70.017846][ T8718] other info that might help us debug this: [ 70.017846][ T8718] [ 70.028054][ T8718] Possible unsafe locking scenario: [ 70.028054][ T8718] [ 70.035568][ T8718] CPU0 CPU1 [ 70.040918][ T8718] ---- ---- [ 70.046269][ T8718] lock(&mm->mmap_sem#2); [ 70.050677][ T8718] lock(&rp->fetch_lock); [ 70.057618][ T8718] lock(&mm->mmap_sem#2); [ 70.064539][ T8718] lock(&rp->fetch_lock); [ 70.068944][ T8718] [ 70.068944][ T8718] *** DEADLOCK *** [ 70.068944][ T8718] [ 70.077075][ T8718] 1 lock held by syz-executor292/8718: [ 70.082516][ T8718] #0: 00000000a168186b (&mm->mmap_sem#2){++++}, at: __mm_populate+0x270/0x380 [ 70.091530][ T8718] [ 70.091530][ T8718] stack backtrace: [ 70.097663][ T8718] CPU: 0 PID: 8718 Comm: syz-executor292 Not tainted 5.2.0-rc7+ #40 [ 70.105616][ T8718] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 70.115667][ T8718] Call Trace: [ 70.118990][ T8718] dump_stack+0x172/0x1f0 [ 70.123421][ T8718] print_circular_bug.cold+0x1cc/0x28f [ 70.128997][ T8718] __lock_acquire+0x3755/0x5490 [ 70.133926][ T8718] ? lockdep_hardirqs_on+0x418/0x5d0 [ 70.151985][ T8718] ? mark_held_locks+0xf0/0xf0 [ 70.156756][ T8718] ? save_stack+0x5c/0x90 [ 70.161076][ T8718] ? save_stack+0x23/0x90 [ 70.165395][ T8718] ? __kasan_kmalloc.constprop.0+0xcf/0xe0 [ 70.171183][ T8718] ? kasan_slab_alloc+0xf/0x20 [ 70.175946][ T8718] ? kmem_cache_alloc+0x11a/0x6f0 [ 70.180958][ T8718] ? pte_alloc_one+0x6d/0x1a0 [ 70.185620][ T8718] ? __handle_mm_fault+0xf67/0x3eb0 [ 70.190801][ T8718] lock_acquire+0x16f/0x3f0 [ 70.195307][ T8718] ? mon_bin_vma_fault+0x73/0x2d0 [ 70.200316][ T8718] ? mon_bin_vma_fault+0x73/0x2d0 [ 70.205336][ T8718] __mutex_lock+0xf7/0x1310 [ 70.209828][ T8718] ? mon_bin_vma_fault+0x73/0x2d0 [ 70.214852][ T8718] ? fs_reclaim_acquire.part.0+0x30/0x30 [ 70.220478][ T8718] ? mon_bin_vma_fault+0x73/0x2d0 [ 70.225490][ T8718] ? mutex_trylock+0x1e0/0x1e0 [ 70.230265][ T8718] ? ptlock_alloc+0x20/0x70 [ 70.234752][ T8718] ? rcu_read_lock_sched_held+0x110/0x130 [ 70.240554][ T8718] ? kmem_cache_alloc+0x32b/0x6f0 [ 70.245586][ T8718] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 70.251832][ T8718] ? __sanitizer_cov_trace_const_cmp2+0x18/0x20 [ 70.258142][ T8718] mutex_lock_nested+0x16/0x20 [ 70.262888][ T8718] ? mutex_lock_nested+0x16/0x20 [ 70.267805][ T8718] mon_bin_vma_fault+0x73/0x2d0 [ 70.272638][ T8718] __do_fault+0x111/0x4d0 [ 70.276959][ T8718] ? mem_cgroup_try_charge_delay+0x6c/0xa0 [ 70.282759][ T8718] __handle_mm_fault+0xf67/0x3eb0 [ 70.287765][ T8718] ? vmf_insert_mixed_mkwrite+0x40/0x40 [ 70.293298][ T8718] ? find_held_lock+0x35/0x130 [ 70.298060][ T8718] ? handle_mm_fault+0x292/0xa90 [ 70.302999][ T8718] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 70.309231][ T8718] ? kasan_check_read+0x11/0x20 [ 70.314074][ T8718] handle_mm_fault+0x3b7/0xa90 [ 70.318817][ T8718] __get_user_pages+0x7b6/0x1a40 [ 70.323733][ T8718] ? follow_page_mask+0x19a0/0x19a0 [ 70.328907][ T8718] ? vma_set_page_prot+0x18c/0x240 [ 70.334000][ T8718] ? memset+0x32/0x40 [ 70.337992][ T8718] populate_vma_page_range+0x20d/0x2a0 [ 70.343469][ T8718] __mm_populate+0x204/0x380 [ 70.348328][ T8718] ? populate_vma_page_range+0x2a0/0x2a0 [ 70.354567][ T8718] ? kasan_check_write+0x14/0x20 [ 70.359614][ T8718] vm_mmap_pgoff+0x213/0x230 [ 70.364187][ T8718] ? vma_is_stack_for_current+0xd0/0xd0 [ 70.369744][ T8718] ? ksys_dup3+0x3e0/0x3e0 [ 70.374452][ T8718] ksys_mmap_pgoff+0x4aa/0x630 [ 70.379303][ T8718] ? find_mergeable_anon_vma+0x2e0/0x2e0 [ 70.385029][ T8718] ? rcu_read_lock_sched_held+0x110/0x130 [ 70.390748][ T8718] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 70.396973][ T8718] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 70.407881][ T8718] ? do_fast_syscall_32+0xd1/0xd7d [ 70.412980][ T8718] ? entry_SYSENTER_compat+0x70/0x7f [ 70.418245][ T8718] __ia32_sys_mmap_pgoff+0xdd/0x1a0 [ 70.423472][ T8718] do_fast_syscall_32+0x27b/0xd7d [ 70.428488][ T8718] entry_SYSENTER_compat+0x70/0x7f [ 70.433580][ T8718] RIP: 0023:0xf7fc5849 [ 70.437630][ T8718] Code: 85 d2 74 02 89 0a 5b 5d c3 8b 04 24 c3 8b 14 24 c3 8b 3c 24 c3 90 90 90 90 90 90 90 90 90 90 90 90 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 eb 0d 90 90 90 90 90 90 90 90 90 90 90 90 [ 70.457301][ T8718] RSP: 002b:00000000f7fa011c EFLAGS: 00000296 ORIG_RAX: 00000000000000c0 [ 70.465696][ T8718] RAX: ffffffffffffffda RBX: 0000000020a05000 RCX: 0000000000400000 [ 70.473662][ T8718] RDX: 0000000000000002 RSI: 0000000000008012 RDI: 0000000000000005 [ 70.481637][ T8718] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 [ 70.489594][ T8718] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 70.497545][ T8718] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 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