====================================================== WARNING: possible circular locking dependency detected 4.16.0-rc5+ #352 Not tainted ------------------------------------------------------ syz-executor3/10122 is trying to acquire lock: (&sb->s_type->i_mutex_key#11){++++}, at: [<00000000fa6a7b97>] inode_lock include/linux/fs.h:713 [inline] (&sb->s_type->i_mutex_key#11){++++}, at: [<00000000fa6a7b97>] shmem_file_llseek+0xef/0x240 mm/shmem.c:2579 but task is already holding lock: (ashmem_mutex){+.+.}, at: [<00000000a432627b>] 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-executor3/10122: #0: (ashmem_mutex){+.+.}, at: [<00000000a432627b>] ashmem_llseek+0x56/0x1f0 drivers/staging/android/ashmem.c:326 stack backtrace: CPU: 1 PID: 10122 Comm: syz-executor3 Not tainted 4.16.0-rc5+ #352 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:00007f2888b07c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000008 RAX: ffffffffffffffda RBX: 00007f2888b086d4 RCX: 0000000000453e69 RDX: 0000000000000003 RSI: ffffffffffffffff RDI: 0000000000000013 RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000003da R14: 00000000006f5d10 R15: 0000000000000000 FAULT_INJECTION: forcing a failure. name failslab, interval 1, probability 0, space 0, times 1 CPU: 0 PID: 10411 Comm: syz-executor1 Not tainted 4.16.0-rc5+ #352 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_node mm/slab.c:3286 [inline] kmem_cache_alloc_node+0x56/0x760 mm/slab.c:3629 __alloc_skb+0xf1/0x780 net/core/skbuff.c:193 alloc_skb include/linux/skbuff.h:983 [inline] netlink_alloc_large_skb net/netlink/af_netlink.c:1180 [inline] netlink_sendmsg+0xa86/0xe60 net/netlink/af_netlink.c:1872 sock_sendmsg_nosec net/socket.c:630 [inline] sock_sendmsg+0xca/0x110 net/socket.c:640 ___sys_sendmsg+0x767/0x8b0 net/socket.c:2046 __sys_sendmsg+0xe5/0x210 net/socket.c:2080 SYSC_sendmsg net/socket.c:2091 [inline] SyS_sendmsg+0x2d/0x50 net/socket.c:2087 do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x453e69 RSP: 002b:00007f0d83cf2c68 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f0d83cf36d4 RCX: 0000000000453e69 RDX: 0000000000000000 RSI: 0000000020000000 RDI: 0000000000000013 RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000014 R13: 00000000000004c7 R14: 00000000006f7348 R15: 0000000000000000 FAULT_INJECTION: forcing a failure. name failslab, interval 1, probability 0, space 0, times 0 CPU: 1 PID: 10435 Comm: syz-executor1 Not tainted 4.16.0-rc5+ #352 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_node mm/slab.c:3286 [inline] kmem_cache_alloc_node_trace+0x5a/0x760 mm/slab.c:3648 __do_kmalloc_node mm/slab.c:3668 [inline] __kmalloc_node_track_caller+0x33/0x70 mm/slab.c:3683 __kmalloc_reserve.isra.39+0x41/0xd0 net/core/skbuff.c:137 __alloc_skb+0x13b/0x780 net/core/skbuff.c:205 alloc_skb include/linux/skbuff.h:983 [inline] netlink_alloc_large_skb net/netlink/af_netlink.c:1180 [inline] netlink_sendmsg+0xa86/0xe60 net/netlink/af_netlink.c:1872 sock_sendmsg_nosec net/socket.c:630 [inline] sock_sendmsg+0xca/0x110 net/socket.c:640 ___sys_sendmsg+0x767/0x8b0 net/socket.c:2046 __sys_sendmsg+0xe5/0x210 net/socket.c:2080 SYSC_sendmsg net/socket.c:2091 [inline] SyS_sendmsg+0x2d/0x50 net/socket.c:2087 do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x453e69 RSP: 002b:00007f0d83cf2c68 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f0d83cf36d4 RCX: 0000000000453e69 RDX: 0000000000000000 RSI: 0000000020000000 RDI: 0000000000000013 RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000014 R13: 00000000000004c7 R14: 00000000006f7348 R15: 0000000000000001 FAULT_INJECTION: forcing a failure. name failslab, interval 1, probability 0, space 0, times 0 CPU: 0 PID: 10461 Comm: syz-executor1 Not tainted 4.16.0-rc5+ #352 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_node mm/slab.c:3286 [inline] kmem_cache_alloc_node+0x56/0x760 mm/slab.c:3629 __alloc_skb+0xf1/0x780 net/core/skbuff.c:193 alloc_skb include/linux/skbuff.h:983 [inline] nlmsg_new include/net/netlink.h:511 [inline] netlink_ack+0x283/0xa10 net/netlink/af_netlink.c:2378 netlink_rcv_skb+0x2b4/0x380 net/netlink/af_netlink.c:2450 xfrm_netlink_rcv+0x6f/0x90 net/xfrm/xfrm_user.c:2603 netlink_unicast_kernel net/netlink/af_netlink.c:1308 [inline] netlink_unicast+0x4c4/0x6b0 net/netlink/af_netlink.c:1334 netlink_sendmsg+0xa4a/0xe60 net/netlink/af_netlink.c:1897 sock_sendmsg_nosec net/socket.c:630 [inline] sock_sendmsg+0xca/0x110 net/socket.c:640 ___sys_sendmsg+0x767/0x8b0 net/socket.c:2046 __sys_sendmsg+0xe5/0x210 net/socket.c:2080 SYSC_sendmsg net/socket.c:2091 [inline] SyS_sendmsg+0x2d/0x50 net/socket.c:2087 do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x453e69 RSP: 002b:00007f0d83cf2c68 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f0d83cf36d4 RCX: 0000000000453e69 RDX: 0000000000000000 RSI: 0000000020000000 RDI: 0000000000000013 RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000014 R13: 00000000000004c7 R14: 00000000006f7348 R15: 0000000000000002 binder: 10457:10465 transaction failed 29189/-22, size 40-8 line 2848 binder: BINDER_SET_CONTEXT_MGR already set binder: 10457:10465 ioctl 40046207 0 returned -16 binder_alloc: 10457: binder_alloc_buf, no vma binder: 10457:10463 transaction failed 29189/-3, size 40-8 line 2963 binder: undelivered TRANSACTION_ERROR: 29189 binder: undelivered TRANSACTION_ERROR: 29189 FAULT_INJECTION: forcing a failure. name failslab, interval 1, probability 0, space 0, times 0 CPU: 0 PID: 10484 Comm: syz-executor1 Not tainted 4.16.0-rc5+ #352 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_node mm/slab.c:3286 [inline] kmem_cache_alloc_node_trace+0x5a/0x760 mm/slab.c:3648 __do_kmalloc_node mm/slab.c:3668 [inline] __kmalloc_node_track_caller+0x33/0x70 mm/slab.c:3683 __kmalloc_reserve.isra.39+0x41/0xd0 net/core/skbuff.c:137 __alloc_skb+0x13b/0x780 net/core/skbuff.c:205 alloc_skb include/linux/skbuff.h:983 [inline] nlmsg_new include/net/netlink.h:511 [inline] netlink_ack+0x283/0xa10 net/netlink/af_netlink.c:2378 netlink_rcv_skb+0x2b4/0x380 net/netlink/af_netlink.c:2450 xfrm_netlink_rcv+0x6f/0x90 net/xfrm/xfrm_user.c:2603 netlink_unicast_kernel net/netlink/af_netlink.c:1308 [inline] netlink_unicast+0x4c4/0x6b0 net/netlink/af_netlink.c:1334 netlink_sendmsg+0xa4a/0xe60 net/netlink/af_netlink.c:1897 sock_sendmsg_nosec net/socket.c:630 [inline] sock_sendmsg+0xca/0x110 net/socket.c:640 ___sys_sendmsg+0x767/0x8b0 net/socket.c:2046 __sys_sendmsg+0xe5/0x210 net/socket.c:2080 SYSC_sendmsg net/socket.c:2091 [inline] SyS_sendmsg+0x2d/0x50 net/socket.c:2087 do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x453e69 RSP: 002b:00007f0d83cf2c68 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f0d83cf36d4 RCX: 0000000000453e69 RDX: 0000000000000000 RSI: 0000000020000000 RDI: 0000000000000013 RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000014 R13: 00000000000004c7 R14: 00000000006f7348 R15: 0000000000000003 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=2830 sclass=netlink_route_socket pig=10501 comm=syz-executor7 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=2830 sclass=netlink_route_socket pig=10501 comm=syz-executor7 SELinux: unrecognized netlink message: protocol=6 nlmsg_type=256 sclass=netlink_xfrm_socket pig=10544 comm=syz-executor1 SELinux: unrecognized netlink message: protocol=6 nlmsg_type=0 sclass=netlink_xfrm_socket pig=10645 comm=syz-executor1 binder: binder_mmap: 10656 20ffb000-20fff000 bad vm_flags failed -1 binder: binder_mmap: 10656 20ffb000-20fff000 bad vm_flags failed -1 SELinux: unrecognized netlink message: protocol=6 nlmsg_type=0 sclass=netlink_xfrm_socket pig=10916 comm=syz-executor1 SELinux: unrecognized netlink message: protocol=6 nlmsg_type=0 sclass=netlink_xfrm_socket pig=10916 comm=syz-executor1 audit: type=1400 audit(1520970846.400:70): avc: denied { map } for pid=11142 comm="syz-executor7" path="/dev/random" dev="devtmpfs" ino=1058 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=system_u:object_r:random_device_t:s0 tclass=chr_file permissive=1