====================================================== WARNING: possible circular locking dependency detected 4.16.0-rc4+ #349 Not tainted ------------------------------------------------------ syz-executor2/8825 is trying to acquire lock: (&sb->s_type->i_mutex_key#11){++++}, at: [<0000000092041d53>] inode_lock include/linux/fs.h:713 [inline] (&sb->s_type->i_mutex_key#11){++++}, at: [<0000000092041d53>] shmem_file_llseek+0xef/0x240 mm/shmem.c:2579 but task is already holding lock: (ashmem_mutex){+.+.}, at: [<00000000dd2f456c>] 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 SYSC_mmap arch/x86/kernel/sys_x86_64.c:100 [inline] SyS_mmap+0x16/0x20 arch/x86/kernel/sys_x86_64.c:91 do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x42/0xb7 -> #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+0xeb/0x170 fs/read_write.c:304 do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x42/0xb7 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-executor2/8825: #0: (ashmem_mutex){+.+.}, at: [<00000000dd2f456c>] ashmem_llseek+0x56/0x1f0 drivers/staging/android/ashmem.c:326 stack backtrace: CPU: 0 PID: 8825 Comm: syz-executor2 Not tainted 4.16.0-rc4+ #349 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+0xeb/0x170 fs/read_write.c:304 do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x453e69 RSP: 002b:00007f3bab20bc68 EFLAGS: 00000246 ORIG_RAX: 0000000000000008 RAX: ffffffffffffffda RBX: 00007f3bab20c6d4 RCX: 0000000000453e69 RDX: 0000000000000003 RSI: ffffffffffffffff RDI: 0000000000000014 RBP: 000000000072bf58 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000003da R14: 00000000006f5d10 R15: 0000000000000001 can: request_module (can-proto-0) failed. can: request_module (can-proto-0) failed. FAULT_INJECTION: forcing a failure. name fail_page_alloc, interval 1, probability 0, space 0, times 1 CPU: 0 PID: 9308 Comm: syz-executor5 Not tainted 4.16.0-rc4+ #349 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 vfs_writev+0x18a/0x340 fs/read_write.c:977 do_writev+0xfc/0x2a0 fs/read_write.c:1012 SYSC_writev fs/read_write.c:1085 [inline] SyS_writev+0x27/0x30 fs/read_write.c:1082 do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x453d41 RSP: 002b:00007f3729d84ba0 EFLAGS: 00000293 ORIG_RAX: 0000000000000014 RAX: ffffffffffffffda RBX: 0000000000000066 RCX: 0000000000453d41 RDX: 0000000000000001 RSI: 00007f3729d84bf0 RDI: 00000000000000fc RBP: 0000000020101000 R08: 00000000000000fc R09: 0000000000000000 R10: 0000000000000066 R11: 0000000000000293 R12: 0000000000000014 R13: 0000000000000622 R14: 00000000006f93d0 R15: 0000000000000000 FAULT_INJECTION: forcing a failure. name fail_page_alloc, interval 1, probability 0, space 0, times 0 FAULT_INJECTION: forcing a failure. name failslab, interval 1, probability 0, space 0, times 1 CPU: 1 PID: 9332 Comm: syz-executor4 Not tainted 4.16.0-rc4+ #349 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 vfs_writev+0x18a/0x340 fs/read_write.c:977 do_writev+0xfc/0x2a0 fs/read_write.c:1012 SYSC_writev fs/read_write.c:1085 [inline] SyS_writev+0x27/0x30 fs/read_write.c:1082 do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x453d41 RSP: 002b:00007fe9a2d90ba0 EFLAGS: 00000293 ORIG_RAX: 0000000000000014 RAX: ffffffffffffffda RBX: 0000000000000066 RCX: 0000000000453d41 RDX: 0000000000000001 RSI: 00007fe9a2d90bf0 RDI: 00000000000000fc RBP: 0000000020101000 R08: 00000000000000fc R09: 0000000000000000 R10: 0000000000000066 R11: 0000000000000293 R12: 0000000000000013 R13: 0000000000000622 R14: 00000000006f93d0 R15: 0000000000000000 CPU: 0 PID: 9342 Comm: syz-executor2 Not tainted 4.16.0-rc4+ #349 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 anon_vma_chain_alloc mm/rmap.c:128 [inline] __anon_vma_prepare+0xbc/0x6b0 mm/rmap.c:182 anon_vma_prepare include/linux/rmap.h:153 [inline] do_huge_pmd_anonymous_page+0x1049/0x19e0 mm/huge_memory.c:678 create_huge_pmd mm/memory.c:3870 [inline] __handle_mm_fault+0x178a/0x38c0 mm/memory.c:4074 handle_mm_fault+0x44a/0xb10 mm/memory.c:4140 __do_page_fault+0x5c9/0xc90 arch/x86/mm/fault.c:1422 do_page_fault+0xee/0x730 arch/x86/mm/fault.c:1497 page_fault+0x25/0x50 arch/x86/entry/entry_64.S:1151 RIP: 0010:copy_user_generic_unrolled+0x89/0xc0 arch/x86/lib/copy_user_64.S:66 RSP: 0018:ffff8801abc07c40 EFLAGS: 00010203 RAX: ffffed0035780faa RBX: 000000000000000e RCX: 0000000000000001 RDX: 0000000000000006 RSI: ffff8801abc07d40 RDI: 00000000209dd000 RBP: ffff8801abc07c70 R08: 4cb50c5205448d60 R09: ffffed0035780faa R10: 0000000000000002 R11: ffffed0035780fa9 R12: 00000000209dd000 R13: ffff8801abc07d40 R14: 00007ffffffff000 R15: 00000000209dd00e copy_to_user include/linux/uaccess.h:155 [inline] extract_crng_user drivers/char/random.c:938 [inline] urandom_read+0x108/0x5c0 drivers/char/random.c:1782 SYSC_getrandom drivers/char/random.c:1928 [inline] SyS_getrandom+0xc3/0x120 drivers/char/random.c:1907 do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x453e69 RSP: 002b:00007f3bab22cc68 EFLAGS: 00000246 ORIG_RAX: 000000000000013e RAX: ffffffffffffffda RBX: 00007f3bab22d6d4 RCX: 0000000000453e69 RDX: 0000000000000000 RSI: 000000000000000e RDI: 00000000209dd000 RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000013 R13: 00000000000000bd R14: 00000000006f1258 R15: 0000000000000000 FAULT_INJECTION: forcing a failure. name failslab, interval 1, probability 0, space 0, times 0 CPU: 0 PID: 9419 Comm: syz-executor7 Not tainted 4.16.0-rc4+ #349 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 audit: type=1400 audit(1520744931.723:52): avc: denied { setopt } for pid=9431 comm="syz-executor5" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_generic_socket permissive=1 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 getname_flags+0xcb/0x580 fs/namei.c:138 audit: type=1400 audit(1520744931.723:53): avc: denied { name_bind } for pid=9432 comm="syz-executor3" src=20000 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=system_u:object_r:port_t:s0 tclass=dccp_socket permissive=1 getname+0x19/0x20 fs/namei.c:209 audit: type=1400 audit(1520744931.723:54): avc: denied { node_bind } for pid=9432 comm="syz-executor3" src=20000 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=system_u:object_r:node_t:s0 tclass=dccp_socket permissive=1 do_sys_open+0x2e7/0x6d0 fs/open.c:1053 SYSC_openat fs/open.c:1086 [inline] SyS_openat+0x30/0x40 fs/open.c:1080 do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x453e69 RSP: 002b:00007f3c4f868c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f3c4f8696d4 RCX: 0000000000453e69 RDX: 0000000000000000 RSI: 000000002088cff6 RDI: ffffffffffffff9c RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000014 R13: 0000000000000424 R14: 00000000006f6400 R15: 0000000000000000 audit: type=1400 audit(1520744933.156:55): avc: denied { getattr } for pid=9883 comm="syz-executor5" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_generic_socket permissive=1 lo: Invalid MTU -1 requested, hw min 0 lo: Invalid MTU -1 requested, hw min 0 QAT: Invalid ioctl QAT: Invalid ioctl QAT: Invalid ioctl QAT: Invalid ioctl SELinux: policydb magic number 0x43b10bd2 does not match expected magic number 0xf97cff8c SELinux: failed to load policy SELinux: policydb magic number 0x43b10bd2 does not match expected magic number 0xf97cff8c SELinux: failed to load policy QAT: Invalid ioctl QAT: Invalid ioctl audit: type=1400 audit(1520744936.062:56): avc: denied { bind } for pid=11050 comm="syz-executor3" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_crypto_socket permissive=1 QAT: Invalid ioctl QAT: Invalid ioctl SELinux: policydb magic number 0x43b10bd2 does not match expected magic number 0xf97cff8c SELinux: failed to load policy SELinux: policydb magic number 0x43b10bd2 does not match expected magic number 0xf97cff8c SELinux: failed to load policy SELinux: policydb magic number 0x43b10bd2 does not match expected magic number 0xf97cff8c SELinux: failed to load policy SELinux: policydb magic number 0x43b10bd2 does not match expected magic number 0xf97cff8c SELinux: failed to load policy SELinux: policydb magic number 0x43b10bd2 does not match expected magic number 0xf97cff8c SELinux: failed to load policy