====================================================== WARNING: possible circular locking dependency detected 4.18.0+ #195 Not tainted ------------------------------------------------------ syz-executor7/8968 is trying to acquire lock: 0000000083e699ba (sb_writers#3){.+.+}, at: file_start_write include/linux/fs.h:2755 [inline] 0000000083e699ba (sb_writers#3){.+.+}, at: vfs_fallocate+0x5be/0x8d0 fs/open.c:318 but task is already holding lock: 0000000068481303 (ashmem_mutex){+.+.}, at: ashmem_shrink_scan+0xb4/0x580 drivers/staging/android/ashmem.c:442 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (ashmem_mutex){+.+.}: __mutex_lock_common kernel/locking/mutex.c:925 [inline] __mutex_lock+0x171/0x1700 kernel/locking/mutex.c:1073 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1088 ashmem_mmap+0x53/0x4a0 drivers/staging/android/ashmem.c:361 call_mmap include/linux/fs.h:1816 [inline] mmap_region+0xf27/0x1c50 mm/mmap.c:1762 do_mmap+0xa06/0x1320 mm/mmap.c:1535 do_mmap_pgoff include/linux/mm.h:2306 [inline] vm_mmap_pgoff+0x213/0x2c0 mm/util.c:357 ksys_mmap_pgoff+0x4da/0x660 mm/mmap.c:1585 __do_sys_mmap arch/x86/kernel/sys_x86_64.c:100 [inline] __se_sys_mmap arch/x86/kernel/sys_x86_64.c:91 [inline] __x64_sys_mmap+0xe9/0x1b0 arch/x86/kernel/sys_x86_64.c:91 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #2 (&mm->mmap_sem){++++}: __might_fault+0x155/0x1e0 mm/memory.c:4583 _copy_to_user+0x30/0x110 lib/usercopy.c:25 copy_to_user include/linux/uaccess.h:155 [inline] filldir+0x1ea/0x3a0 fs/readdir.c:196 dir_emit_dot include/linux/fs.h:3420 [inline] dir_emit_dots include/linux/fs.h:3431 [inline] dcache_readdir+0x13a/0x620 fs/libfs.c:192 iterate_dir+0x4b0/0x5d0 fs/readdir.c:51 __do_sys_getdents fs/readdir.c:231 [inline] __se_sys_getdents fs/readdir.c:212 [inline] __x64_sys_getdents+0x29f/0x510 fs/readdir.c:212 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #1 (&sb->s_type->i_mutex_key#10){++++}: down_write+0x8f/0x130 kernel/locking/rwsem.c:70 inode_lock include/linux/fs.h:733 [inline] generic_file_write_iter+0xed/0x870 mm/filemap.c:3289 call_write_iter include/linux/fs.h:1811 [inline] new_sync_write fs/read_write.c:474 [inline] __vfs_write+0x6af/0x9d0 fs/read_write.c:487 vfs_write+0x1f8/0x560 fs/read_write.c:549 kernel_write+0xab/0x120 fs/read_write.c:526 fork_usermode_blob+0x11c/0x1b0 kernel/umh.c:493 load_umh+0x2b/0xbd net/bpfilter/bpfilter_kern.c:93 do_one_initcall+0x127/0x913 init/main.c:884 do_initcall_level init/main.c:952 [inline] do_initcalls init/main.c:960 [inline] do_basic_setup init/main.c:978 [inline] kernel_init_freeable+0x49b/0x58e init/main.c:1142 kernel_init+0x11/0x1b3 init/main.c:1061 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:413 -> #0 (sb_writers#3){.+.+}: lock_acquire+0x1e4/0x540 kernel/locking/lockdep.c:3924 percpu_down_read_preempt_disable include/linux/percpu-rwsem.h:36 [inline] percpu_down_read include/linux/percpu-rwsem.h:59 [inline] __sb_start_write+0x1e9/0x300 fs/super.c:1406 file_start_write include/linux/fs.h:2755 [inline] vfs_fallocate+0x5be/0x8d0 fs/open.c:318 ashmem_shrink_scan+0x1f9/0x580 drivers/staging/android/ashmem.c:449 ashmem_ioctl+0x3dd/0x13c0 drivers/staging/android/ashmem.c:791 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x1de/0x1720 fs/ioctl.c:684 ksys_ioctl+0xa9/0xd0 fs/ioctl.c:701 __do_sys_ioctl fs/ioctl.c:708 [inline] __se_sys_ioctl fs/ioctl.c:706 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:706 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe other info that might help us debug this: Chain exists of: sb_writers#3 --> &mm->mmap_sem --> ashmem_mutex Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(ashmem_mutex); lock(&mm->mmap_sem); lock(ashmem_mutex); lock(sb_writers#3); *** DEADLOCK *** 1 lock held by syz-executor7/8968: #0: 0000000068481303 (ashmem_mutex){+.+.}, at: ashmem_shrink_scan+0xb4/0x580 drivers/staging/android/ashmem.c:442 stack backtrace: CPU: 1 PID: 8968 Comm: syz-executor7 Not tainted 4.18.0+ #195 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1c9/0x2b4 lib/dump_stack.c:113 print_circular_bug.isra.37.cold.58+0x1bd/0x27d kernel/locking/lockdep.c:1227 check_prev_add kernel/locking/lockdep.c:1867 [inline] check_prevs_add kernel/locking/lockdep.c:1980 [inline] validate_chain kernel/locking/lockdep.c:2421 [inline] __lock_acquire+0x3449/0x5020 kernel/locking/lockdep.c:3435 lock_acquire+0x1e4/0x540 kernel/locking/lockdep.c:3924 percpu_down_read_preempt_disable include/linux/percpu-rwsem.h:36 [inline] percpu_down_read include/linux/percpu-rwsem.h:59 [inline] __sb_start_write+0x1e9/0x300 fs/super.c:1406 file_start_write include/linux/fs.h:2755 [inline] vfs_fallocate+0x5be/0x8d0 fs/open.c:318 ashmem_shrink_scan+0x1f9/0x580 drivers/staging/android/ashmem.c:449 ashmem_ioctl+0x3dd/0x13c0 drivers/staging/android/ashmem.c:791 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x1de/0x1720 fs/ioctl.c:684 ksys_ioctl+0xa9/0xd0 fs/ioctl.c:701 __do_sys_ioctl fs/ioctl.c:708 [inline] __se_sys_ioctl fs/ioctl.c:706 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:706 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457089 Code: fd b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 cb b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fa7593f1c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fa7593f26d4 RCX: 0000000000457089 RDX: 0000000000000000 RSI: 000000000000770a RDI: 0000000000000003 RBP: 00000000009300a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000004cd2f0 R14: 00000000004c3dca R15: 0000000000000000 netlink: 2 bytes leftover after parsing attributes in process `syz-executor0'. netlink: 2 bytes leftover after parsing attributes in process `syz-executor0'. FAULT_INJECTION: forcing a failure. name failslab, interval 1, probability 0, space 0, times 0 CPU: 1 PID: 9863 Comm: syz-executor0 Not tainted 4.18.0+ #195 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1c9/0x2b4 lib/dump_stack.c:113 fail_dump lib/fault-inject.c:51 [inline] should_fail.cold.4+0xa/0x11 lib/fault-inject.c:149 __should_failslab+0x124/0x180 mm/failslab.c:32 should_failslab+0x9/0x14 mm/slab_common.c:1557 slab_pre_alloc_hook mm/slab.h:423 [inline] slab_alloc_node mm/slab.c:3299 [inline] kmem_cache_alloc_node_trace+0x26f/0x770 mm/slab.c:3661 kmalloc_node include/linux/slab.h:551 [inline] kzalloc_node include/linux/slab.h:718 [inline] __get_vm_area_node+0x12d/0x390 mm/vmalloc.c:1389 __vmalloc_node_range+0xc4/0x760 mm/vmalloc.c:1741 __vmalloc_node mm/vmalloc.c:1791 [inline] __vmalloc_node_flags mm/vmalloc.c:1805 [inline] vzalloc+0x6f/0x80 mm/vmalloc.c:1844 vmx_vm_alloc+0x13/0x20 arch/x86/kvm/vmx.c:10496 kvm_arch_alloc_vm arch/x86/include/asm/kvm_host.h:1117 [inline] kvm_create_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:623 [inline] kvm_dev_ioctl_create_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:3179 [inline] kvm_dev_ioctl+0x291/0x1b10 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3231 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x1de/0x1720 fs/ioctl.c:684 ksys_ioctl+0xa9/0xd0 fs/ioctl.c:701 __do_sys_ioctl fs/ioctl.c:708 [inline] __se_sys_ioctl fs/ioctl.c:706 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:706 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457089 Code: fd b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 cb b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f97ed150c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f97ed1516d4 RCX: 0000000000457089 RDX: 000000000000004c RSI: 000000000000ae01 RDI: 0000000000000003 RBP: 00000000009300a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000004 R13: 00000000004ce9b8 R14: 00000000004c50d7 R15: 0000000000000000 syz-executor0: vmalloc: allocation failure: 41928 bytes, mode:0x6080c0(GFP_KERNEL|__GFP_ZERO), nodemask=(null) syz-executor0 cpuset=syz0 mems_allowed=0 CPU: 1 PID: 9863 Comm: syz-executor0 Not tainted 4.18.0+ #195 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1c9/0x2b4 lib/dump_stack.c:113 warn_alloc.cold.117+0xb7/0x1bd mm/page_alloc.c:3427 __vmalloc_node_range+0x472/0x760 mm/vmalloc.c:1762 __vmalloc_node mm/vmalloc.c:1791 [inline] __vmalloc_node_flags mm/vmalloc.c:1805 [inline] vzalloc+0x6f/0x80 mm/vmalloc.c:1844 vmx_vm_alloc+0x13/0x20 arch/x86/kvm/vmx.c:10496 kvm_arch_alloc_vm arch/x86/include/asm/kvm_host.h:1117 [inline] kvm_create_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:623 [inline] kvm_dev_ioctl_create_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:3179 [inline] kvm_dev_ioctl+0x291/0x1b10 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3231 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x1de/0x1720 fs/ioctl.c:684 ksys_ioctl+0xa9/0xd0 fs/ioctl.c:701 __do_sys_ioctl fs/ioctl.c:708 [inline] __se_sys_ioctl fs/ioctl.c:706 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:706 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457089 Code: fd b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 cb b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f97ed150c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f97ed1516d4 RCX: 0000000000457089 RDX: 000000000000004c RSI: 000000000000ae01 RDI: 0000000000000003 RBP: 00000000009300a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000004 R13: 00000000004ce9b8 R14: 00000000004c50d7 R15: 0000000000000000 Mem-Info: active_anon:84423 inactive_anon:359 isolated_anon:0 active_file:29165 inactive_file:11899 isolated_file:0 unevictable:0 dirty:114 writeback:0 unstable:0 slab_reclaimable:12841 slab_unreclaimable:107601 mapped:71676 shmem:452 pagetables:1100 bounce:0 free:559173 free_pcp:1018 free_cma:0 Node 0 active_anon:335652kB inactive_anon:2336kB active_file:116660kB inactive_file:47596kB unevictable:0kB isolated(anon):0kB isolated(file):0kB mapped:287604kB dirty:456kB writeback:0kB shmem:2608kB shmem_thp: 0kB shmem_pmdmapped: 0kB anon_thp: 311296kB writeback_tmp:0kB unstable:0kB all_unreclaimable? no Node 0 DMA free:15908kB min:164kB low:204kB high:244kB active_anon:0kB inactive_anon:0kB active_file:0kB inactive_file:0kB unevictable:0kB writepending:0kB present:15992kB managed:15908kB mlocked:0kB kernel_stack:0kB pagetables:0kB bounce:0kB free_pcp:0kB local_pcp:0kB free_cma:0kB lowmem_reserve[]: 0 2844 6351 6351 Node 0 DMA32 free:911384kB min:30192kB low:37740kB high:45288kB active_anon:22536kB inactive_anon:0kB active_file:28464kB inactive_file:80kB unevictable:0kB writepending:0kB present:3129292kB managed:2916616kB mlocked:0kB kernel_stack:32kB pagetables:0kB bounce:0kB free_pcp:2256kB local_pcp:868kB free_cma:0kB lowmem_reserve[]: 0 0 3507 3507 Node 0 Normal free:1310144kB min:37224kB low:46528kB high:55832kB active_anon:313244kB inactive_anon:3336kB active_file:88196kB inactive_file:47516kB unevictable:0kB writepending:456kB present:4718592kB managed:3591172kB mlocked:0kB kernel_stack:5920kB pagetables:4696kB bounce:0kB free_pcp:764kB local_pcp:376kB free_cma:0kB lowmem_reserve[]: 0 0 0 0 Node 0 DMA: 1*4kB (U) 0*8kB 0*16kB 1*32kB (U) 2*64kB (U) 1*128kB (U) 1*256kB (U) 0*512kB 1*1024kB (U) 1*2048kB (M) 3*4096kB (M) = 15908kB Node 0 DMA32: 190*4kB (UME) 420*8kB (UME) 359*16kB (UME) 299*32kB (UME) 221*64kB (UME) 186*128kB (UM) 136*256kB (UME) 106*512kB (UME) 79*1024kB (UM) 50*2048kB (UME) 142*4096kB (UM) = 911400kB Node 0 Normal: 1736*4kB (UME) 678*8kB (UME) 163*16kB (UM) 1124*32kB (UM) 335*64kB (UM) 265*128kB (UM) 130*256kB (UME) 110*512kB (UME) 772*1024kB (UME) 63*2048kB (UME) 47*4096kB (UM) = 1307968kB Node 0 hugepages_total=0 hugepages_free=0 hugepages_surp=0 hugepages_size=2048kB 42413 total pagecache pages 0 pages in swap cache Swap cache stats: add 0, delete 0, find 0/0 Free swap = 0kB Total swap = 0kB 1965969 pages RAM 0 pages HighMem/MovableOnly 335045 pages reserved