====================================================== WARNING: possible circular locking dependency detected 4.16.0-rc4+ #259 Not tainted ------------------------------------------------------ syz-executor5/15215 is trying to acquire lock: (&sb->s_type->i_mutex_key#11){++++}, at: [<000000004e1ef2b6>] inode_lock include/linux/fs.h:713 [inline] (&sb->s_type->i_mutex_key#11){++++}, at: [<000000004e1ef2b6>] shmem_file_llseek+0xef/0x240 mm/shmem.c:2579 but task is already holding lock: (ashmem_mutex){+.+.}, at: [<0000000012ef7248>] ashmem_llseek+0x56/0x1f0 drivers/staging/android/ashmem.c:326 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (ashmem_mutex){+.+.}: __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 ashmem_mmap+0x53/0x410 drivers/staging/android/ashmem.c:362 call_mmap include/linux/fs.h:1786 [inline] mmap_region+0xa99/0x15a0 mm/mmap.c:1705 do_mmap+0x6c0/0xe00 mm/mmap.c:1483 do_mmap_pgoff include/linux/mm.h:2223 [inline] vm_mmap_pgoff+0x1de/0x280 mm/util.c:355 SYSC_mmap_pgoff mm/mmap.c:1533 [inline] SyS_mmap_pgoff+0x462/0x5f0 mm/mmap.c:1491 do_syscall_32_irqs_on arch/x86/entry/common.c:330 [inline] do_fast_syscall_32+0x3ec/0xf9f arch/x86/entry/common.c:392 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139 -> #1 (&mm->mmap_sem){++++}: __might_fault+0x13a/0x1d0 mm/memory.c:4571 _copy_to_user+0x2c/0xc0 lib/usercopy.c:25 copy_to_user include/linux/uaccess.h:155 [inline] filldir+0x1a7/0x320 fs/readdir.c:196 dir_emit_dot include/linux/fs.h:3370 [inline] dir_emit_dots include/linux/fs.h:3381 [inline] dcache_readdir+0x12d/0x5e0 fs/libfs.c:192 iterate_dir+0x1ca/0x530 fs/readdir.c:51 SYSC_getdents fs/readdir.c:231 [inline] SyS_getdents+0x225/0x450 fs/readdir.c:212 do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x42/0xb7 -> #0 (&sb->s_type->i_mutex_key#11){++++}: lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3920 down_write+0x87/0x120 kernel/locking/rwsem.c:70 inode_lock include/linux/fs.h:713 [inline] shmem_file_llseek+0xef/0x240 mm/shmem.c:2579 vfs_llseek+0xa2/0xd0 fs/read_write.c:300 ashmem_llseek+0xe7/0x1f0 drivers/staging/android/ashmem.c:338 vfs_llseek fs/read_write.c:300 [inline] SYSC_lseek fs/read_write.c:313 [inline] SyS_lseek fs/read_write.c:304 [inline] C_SYSC_lseek fs/read_write.c:325 [inline] compat_SyS_lseek+0xeb/0x170 fs/read_write.c:323 do_syscall_32_irqs_on arch/x86/entry/common.c:330 [inline] do_fast_syscall_32+0x3ec/0xf9f arch/x86/entry/common.c:392 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139 other info that might help us debug this: Chain exists of: &sb->s_type->i_mutex_key#11 --> &mm->mmap_sem --> ashmem_mutex Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(ashmem_mutex); lock(&mm->mmap_sem); lock(ashmem_mutex); lock(&sb->s_type->i_mutex_key#11); *** DEADLOCK *** 1 lock held by syz-executor5/15215: #0: (ashmem_mutex){+.+.}, at: [<0000000012ef7248>] ashmem_llseek+0x56/0x1f0 drivers/staging/android/ashmem.c:326 stack backtrace: CPU: 0 PID: 15215 Comm: syz-executor5 Not tainted 4.16.0-rc4+ #259 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x194/0x24d lib/dump_stack.c:53 print_circular_bug.isra.38+0x2cd/0x2dc kernel/locking/lockdep.c:1223 check_prev_add kernel/locking/lockdep.c:1863 [inline] check_prevs_add kernel/locking/lockdep.c:1976 [inline] validate_chain kernel/locking/lockdep.c:2417 [inline] __lock_acquire+0x30a8/0x3e00 kernel/locking/lockdep.c:3431 lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3920 down_write+0x87/0x120 kernel/locking/rwsem.c:70 inode_lock include/linux/fs.h:713 [inline] shmem_file_llseek+0xef/0x240 mm/shmem.c:2579 vfs_llseek+0xa2/0xd0 fs/read_write.c:300 ashmem_llseek+0xe7/0x1f0 drivers/staging/android/ashmem.c:338 vfs_llseek fs/read_write.c:300 [inline] SYSC_lseek fs/read_write.c:313 [inline] SyS_lseek fs/read_write.c:304 [inline] C_SYSC_lseek fs/read_write.c:325 [inline] compat_SyS_lseek+0xeb/0x170 fs/read_write.c:323 do_syscall_32_irqs_on arch/x86/entry/common.c:330 [inline] do_fast_syscall_32+0x3ec/0xf9f arch/x86/entry/common.c:392 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139 RIP: 0023:0xf7faac99 RSP: 002b:00000000f77a609c EFLAGS: 00000286 ORIG_RAX: 0000000000000013 RAX: ffffffffffffffda RBX: 0000000000000013 RCX: 00000000fffffffd RDX: 0000000000000003 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FAULT_INJECTION: forcing a failure. name failslab, interval 1, probability 0, space 0, times 1 CPU: 0 PID: 15412 Comm: syz-executor7 Not tainted 4.16.0-rc4+ #259 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x194/0x24d lib/dump_stack.c:53 fail_dump lib/fault-inject.c:51 [inline] should_fail+0x8c0/0xa40 lib/fault-inject.c:149 should_failslab+0xec/0x120 mm/failslab.c:32 slab_pre_alloc_hook mm/slab.h:422 [inline] slab_alloc mm/slab.c:3365 [inline] kmem_cache_alloc+0x47/0x760 mm/slab.c:3539 kmem_cache_zalloc include/linux/slab.h:691 [inline] avc_alloc_node+0x27/0x4d0 security/selinux/avc.c:549 avc_insert security/selinux/avc.c:668 [inline] avc_compute_av+0x22a/0x710 security/selinux/avc.c:974 avc_has_perm_noaudit security/selinux/avc.c:1110 [inline] avc_has_perm+0x4be/0x680 security/selinux/avc.c:1144 selinux_task_setscheduler+0x266/0x390 security/selinux/hooks.c:4022 selinux_task_movememory+0x15/0x20 include/linux/compiler.h:188 security_task_movememory+0x6d/0xa0 security/security.c:1113 SYSC_migrate_pages mm/mempolicy.c:1445 [inline] SyS_migrate_pages+0x51d/0x610 mm/mempolicy.c:1380 do_syscall_32_irqs_on arch/x86/entry/common.c:330 [inline] do_fast_syscall_32+0x3ec/0xf9f arch/x86/entry/common.c:392 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139 RIP: 0023:0xf7fefc99 RSP: 002b:00000000f77eb09c EFLAGS: 00000286 ORIG_RAX: 0000000000000126 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000000007 RDX: 0000000020000000 RSI: 0000000020000080 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 kauditd_printk_skb: 3349 callbacks suppressed audit: type=1400 audit(1520794630.643:17820): avc: denied { net_admin } for pid=4288 comm="syz-executor6" capability=12 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=cap_userns permissive=1 audit: type=1400 audit(1520794630.643:17821): avc: denied { net_admin } for pid=10363 comm="syz-executor7" capability=12 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=cap_userns permissive=1 audit: type=1400 audit(1520794630.644:17822): avc: denied { net_admin } for pid=7739 comm="syz-executor2" capability=12 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=cap_userns permissive=1 audit: type=1400 audit(1520794630.645:17823): avc: denied { net_admin } for pid=7739 comm="syz-executor2" capability=12 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=cap_userns permissive=1 audit: type=1400 audit(1520794630.647:17824): avc: denied { net_admin } for pid=7739 comm="syz-executor2" capability=12 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=cap_userns permissive=1 audit: audit_backlog=65 > audit_backlog_limit=64 audit: type=1400 audit(1520794630.648:17825): avc: denied { net_admin } for pid=4279 comm="syz-executor0" capability=12 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=cap_userns permissive=1 audit: audit_lost=2722 audit_rate_limit=0 audit_backlog_limit=64 audit: backlog limit exceeded audit: audit_backlog=65 > audit_backlog_limit=64 FAULT_INJECTION: forcing a failure. name fail_futex, interval 1, probability 0, space 0, times 1 CPU: 0 PID: 15618 Comm: syz-executor1 Not tainted 4.16.0-rc4+ #259 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x194/0x24d lib/dump_stack.c:53 fail_dump lib/fault-inject.c:51 [inline] should_fail+0x8c0/0xa40 lib/fault-inject.c:149 should_fail_futex.part.10+0x1a/0x20 kernel/futex.c:306 should_fail_futex kernel/futex.c:705 [inline] get_futex_key+0x3a7/0x1d50 kernel/futex.c:519 futex_wake+0x193/0x680 kernel/futex.c:1526 do_futex+0x11b0/0x22a0 kernel/futex.c:3531 C_SYSC_futex kernel/futex_compat.c:201 [inline] compat_SyS_futex+0x27f/0x380 kernel/futex_compat.c:175 do_syscall_32_irqs_on arch/x86/entry/common.c:330 [inline] do_fast_syscall_32+0x3ec/0xf9f arch/x86/entry/common.c:392 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139 RIP: 0023:0xf7f6cc99 RSP: 002b:00000000f774709c EFLAGS: 00000286 ORIG_RAX: 00000000000000f0 RAX: ffffffffffffffda RBX: 000000002000cffc RCX: 0000000000000001 RDX: 0000000000000000 RSI: 0000000020edfff0 RDI: 0000000020048000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FAULT_INJECTION: forcing a failure. name fail_page_alloc, interval 1, probability 0, space 0, times 1 CPU: 1 PID: 15666 Comm: syz-executor4 Not tainted 4.16.0-rc4+ #259 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x194/0x24d lib/dump_stack.c:53 fail_dump lib/fault-inject.c:51 [inline] should_fail+0x8c0/0xa40 lib/fault-inject.c:149 should_fail_alloc_page mm/page_alloc.c:2959 [inline] prepare_alloc_pages mm/page_alloc.c:4198 [inline] __alloc_pages_nodemask+0x327/0xdd0 mm/page_alloc.c:4237 alloc_pages_current+0xb6/0x1e0 mm/mempolicy.c:2055 alloc_pages include/linux/gfp.h:492 [inline] skb_page_frag_refill+0x358/0x5f0 net/core/sock.c:2208 tun_build_skb.isra.50+0x2f0/0x1840 drivers/net/tun.c:1626 tun_get_user+0x18fa/0x3810 drivers/net/tun.c:1803 tun_chr_write_iter+0xb9/0x160 drivers/net/tun.c:1989 call_write_iter include/linux/fs.h:1781 [inline] do_iter_readv_writev+0x55c/0x830 fs/read_write.c:653 do_iter_write+0x154/0x540 fs/read_write.c:932 compat_writev+0x225/0x420 fs/read_write.c:1246 do_compat_writev+0x115/0x220 fs/read_write.c:1267 C_SYSC_writev fs/read_write.c:1278 [inline] compat_SyS_writev+0x26/0x30 fs/read_write.c:1274 do_syscall_32_irqs_on arch/x86/entry/common.c:330 [inline] do_fast_syscall_32+0x3ec/0xf9f arch/x86/entry/common.c:392 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139 RIP: 0023:0xf7f27c99 RSP: 002b:00000000f7723034 EFLAGS: 00000296 ORIG_RAX: 0000000000000092 RAX: ffffffffffffffda RBX: 00000000000000fc RCX: 00000000f7723084 RDX: 0000000000000001 RSI: 000000000813af00 RDI: 0000000000000013 RBP: 00000000f7723158 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FAULT_INJECTION: forcing a failure. name failslab, interval 1, probability 0, space 0, times 0 CPU: 1 PID: 15761 Comm: syz-executor2 Not tainted 4.16.0-rc4+ #259 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x194/0x24d lib/dump_stack.c:53 fail_dump lib/fault-inject.c:51 [inline] should_fail+0x8c0/0xa40 lib/fault-inject.c:149 should_failslab+0xec/0x120 mm/failslab.c:32 slab_pre_alloc_hook mm/slab.h:422 [inline] slab_alloc mm/slab.c:3365 [inline] kmem_cache_alloc+0x47/0x760 mm/slab.c:3539 kmem_cache_zalloc include/linux/slab.h:691 [inline] avc_alloc_node+0x27/0x4d0 security/selinux/avc.c:549 avc_insert security/selinux/avc.c:668 [inline] avc_compute_av+0x22a/0x710 security/selinux/avc.c:974 avc_has_perm_noaudit security/selinux/avc.c:1110 [inline] avc_has_perm+0x4be/0x680 security/selinux/avc.c:1144 sock_has_perm+0x299/0x420 security/selinux/hooks.c:4352 selinux_socket_bind+0xd4/0xb50 security/selinux/hooks.c:4415 security_socket_bind+0x7d/0xb0 security/security.c:1350 SYSC_bind+0x13b/0x410 net/socket.c:1470 SyS_bind+0x24/0x30 net/socket.c:1460 do_syscall_32_irqs_on arch/x86/entry/common.c:330 [inline] do_fast_syscall_32+0x3ec/0xf9f arch/x86/entry/common.c:392 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139 RIP: 0023:0xf7fb6c99 RSP: 002b:00000000f77b209c EFLAGS: 00000286 ORIG_RAX: 0000000000000169 RAX: ffffffffffffffda RBX: 0000000000000013 RCX: 0000000020ad0000 RDX: 000000000000006e RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FAULT_INJECTION: forcing a failure. name failslab, interval 1, probability 0, space 0, times 0 CPU: 1 PID: 15787 Comm: syz-executor2 Not tainted 4.16.0-rc4+ #259 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x194/0x24d lib/dump_stack.c:53 fail_dump lib/fault-inject.c:51 [inline] should_fail+0x8c0/0xa40 lib/fault-inject.c:149 should_failslab+0xec/0x120 mm/failslab.c:32 slab_pre_alloc_hook mm/slab.h:422 [inline] slab_alloc mm/slab.c:3365 [inline] __do_kmalloc mm/slab.c:3703 [inline] __kmalloc+0x63/0x760 mm/slab.c:3714 kmalloc include/linux/slab.h:517 [inline] unix_bind+0x5c7/0xf90 net/unix/af_unix.c:1037 SYSC_bind+0x1c3/0x410 net/socket.c:1474 SyS_bind+0x24/0x30 net/socket.c:1460 do_syscall_32_irqs_on arch/x86/entry/common.c:330 [inline] do_fast_syscall_32+0x3ec/0xf9f arch/x86/entry/common.c:392 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139 RIP: 0023:0xf7fb6c99 RSP: 002b:00000000f77b209c EFLAGS: 00000286 ORIG_RAX: 0000000000000169 RAX: ffffffffffffffda RBX: 0000000000000013 RCX: 0000000020ad0000 RDX: 000000000000006e RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 kauditd_printk_skb: 4371 callbacks suppressed audit: type=1400 audit(1520794635.643:20794): avc: denied { net_admin } for pid=4279 comm="syz-executor0" capability=12 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=cap_userns permissive=1 audit: type=1400 audit(1520794635.643:20795): avc: denied { net_admin } for pid=4282 comm="syz-executor3" capability=12 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=cap_userns permissive=1 audit: type=1400 audit(1520794635.644:20796): avc: denied { net_admin } for pid=4279 comm="syz-executor0" capability=12 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=cap_userns permissive=1 audit: type=1400 audit(1520794635.645:20797): avc: denied { net_admin } for pid=4279 comm="syz-executor0" capability=12 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=cap_userns permissive=1 audit: type=1400 audit(1520794635.651:20798): avc: denied { net_admin } for pid=4279 comm="syz-executor0" capability=12 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=cap_userns permissive=1 audit: type=1400 audit(1520794635.651:20799): avc: denied { dac_override } for pid=15808 comm="syz-executor6" capability=1 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=cap_userns permissive=1 audit: type=1400 audit(1520794635.675:20800): avc: denied { net_admin } for pid=4281 comm="syz-executor4" capability=12 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=cap_userns permissive=1 audit: audit_backlog=65 > audit_backlog_limit=64 audit: type=1400 audit(1520794635.675:20801): avc: denied { net_admin } for pid=4290 comm="syz-executor5" capability=12 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=cap_userns permissive=1 audit: type=1400 audit(1520794635.675:20802): avc: denied { net_admin } for pid=4281 comm="syz-executor4" capability=12 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=cap_userns permissive=1