====================================================== WARNING: possible circular locking dependency detected 4.16.0-rc3+ #336 Not tainted ------------------------------------------------------ syz-executor7/9584 is trying to acquire lock: (&mm->mmap_sem){++++}, at: [<00000000f160019d>] __might_fault+0xe0/0x1d0 mm/memory.c:4570 but task is already holding lock: (ashmem_mutex){+.+.}, at: [<0000000098aec447>] ashmem_pin_unpin drivers/staging/android/ashmem.c:705 [inline] (ashmem_mutex){+.+.}, at: [<0000000098aec447>] ashmem_ioctl+0x3db/0x11b0 drivers/staging/android/ashmem.c:782 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (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 -> #0 (&mm->mmap_sem){++++}: lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3920 __might_fault+0x13a/0x1d0 mm/memory.c:4571 _copy_from_user+0x2c/0x110 lib/usercopy.c:10 copy_from_user include/linux/uaccess.h:147 [inline] ashmem_pin_unpin drivers/staging/android/ashmem.c:710 [inline] ashmem_ioctl+0x438/0x11b0 drivers/staging/android/ashmem.c:782 vfs_ioctl fs/ioctl.c:46 [inline] do_vfs_ioctl+0x1b1/0x1520 fs/ioctl.c:686 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:692 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: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(ashmem_mutex); lock(&mm->mmap_sem); lock(ashmem_mutex); lock(&mm->mmap_sem); *** DEADLOCK *** 1 lock held by syz-executor7/9584: #0: (ashmem_mutex){+.+.}, at: [<0000000098aec447>] ashmem_pin_unpin drivers/staging/android/ashmem.c:705 [inline] #0: (ashmem_mutex){+.+.}, at: [<0000000098aec447>] ashmem_ioctl+0x3db/0x11b0 drivers/staging/android/ashmem.c:782 stack backtrace: CPU: 1 PID: 9584 Comm: syz-executor7 Not tainted 4.16.0-rc3+ #336 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 __might_fault+0x13a/0x1d0 mm/memory.c:4571 _copy_from_user+0x2c/0x110 lib/usercopy.c:10 copy_from_user include/linux/uaccess.h:147 [inline] ashmem_pin_unpin drivers/staging/android/ashmem.c:710 [inline] ashmem_ioctl+0x438/0x11b0 drivers/staging/android/ashmem.c:782 vfs_ioctl fs/ioctl.c:46 [inline] do_vfs_ioctl+0x1b1/0x1520 fs/ioctl.c:686 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:692 do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x453d69 RSP: 002b:00007f91c5d5ac68 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f91c5d5b6d4 RCX: 0000000000453d69 RDX: 0000000000000000 RSI: 0000000000007709 RDI: 0000000000000014 RBP: 000000000072bf58 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000189 R14: 00000000006f2578 R15: 0000000000000001 FAULT_INJECTION: forcing a failure. name failslab, interval 1, probability 0, space 0, times 1 CPU: 0 PID: 10224 Comm: syz-executor7 Not tainted 4.16.0-rc3+ #336 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 getname_flags+0xcb/0x580 fs/namei.c:138 getname+0x19/0x20 fs/namei.c:209 do_sys_open+0x2e7/0x6d0 fs/open.c:1053 SYSC_open fs/open.c:1077 [inline] SyS_open+0x2d/0x40 fs/open.c:1072 do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x40e061 RSP: 002b:00007f91c5d7bbb0 EFLAGS: 00000293 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 00007f91c5d7c6d4 RCX: 000000000040e061 RDX: 00007f91c5d7bbec RSI: 0000000000000002 RDI: 00007f91c5d7bbd0 RBP: 000000000072bea0 R08: 0000000000000000 R09: 000000000000001c R10: 0000000000000011 R11: 0000000000000293 R12: 0000000000000013 R13: 000000000000064f R14: 00000000006f9808 R15: 0000000000000000 FAULT_INJECTION: forcing a failure. name failslab, interval 1, probability 0, space 0, times 0 CPU: 0 PID: 10228 Comm: syz-executor0 Not tainted 4.16.0-rc3+ #336 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 getname_flags+0xcb/0x580 fs/namei.c:138 getname+0x19/0x20 fs/namei.c:209 do_sys_open+0x2e7/0x6d0 fs/open.c:1053 SYSC_open fs/open.c:1077 [inline] SyS_open+0x2d/0x40 fs/open.c:1072 do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x40e061 RSP: 002b:00007f65f4a9abb0 EFLAGS: 00000293 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 00007f65f4a9b6d4 RCX: 000000000040e061 RDX: 00007f65f4a9abec RSI: 0000000000000002 RDI: 00007f65f4a9abd0 RBP: 000000000072bea0 R08: 0000000000000000 R09: 000000000000001c R10: 0000000000000011 R11: 0000000000000293 R12: 0000000000000013 R13: 000000000000064f R14: 00000000006f9808 R15: 0000000000000000 FAULT_INJECTION: forcing a failure. name fail_page_alloc, interval 1, probability 0, space 0, times 1 CPU: 1 PID: 10250 Comm: syz-executor7 Not tainted 4.16.0-rc3+ #336 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 include/linux/gfp.h:456 [inline] __alloc_pages_node include/linux/gfp.h:469 [inline] kmem_getpages mm/slab.c:1410 [inline] cache_grow_begin+0x72/0x640 mm/slab.c:2665 cache_alloc_refill mm/slab.c:3032 [inline] ____cache_alloc mm/slab.c:3114 [inline] __do_cache_alloc mm/slab.c:3336 [inline] slab_alloc mm/slab.c:3371 [inline] kmem_cache_alloc+0x400/0x760 mm/slab.c:3539 getname_flags+0xcb/0x580 fs/namei.c:138 getname+0x19/0x20 fs/namei.c:209 do_sys_open+0x2e7/0x6d0 fs/open.c:1053 SYSC_open fs/open.c:1077 [inline] SyS_open+0x2d/0x40 fs/open.c:1072 do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x40e061 RSP: 002b:00007f91c5d7bbb0 EFLAGS: 00000293 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 00007f91c5d7c6d4 RCX: 000000000040e061 RDX: 00007f91c5d7bbec RSI: 0000000000000002 RDI: 00007f91c5d7bbd0 RBP: 000000000072bea0 R08: 0000000000000000 R09: 000000000000001c R10: 0000000000000011 R11: 0000000000000293 R12: 0000000000000013 R13: 000000000000064f R14: 00000000006f9808 R15: 0000000000000001 FAULT_INJECTION: forcing a failure. name failslab, interval 1, probability 0, space 0, times 0 CPU: 0 PID: 10269 Comm: syz-executor7 Not tainted 4.16.0-rc3+ #336 FAULT_INJECTION: forcing a failure. name failslab, interval 1, probability 0, space 0, times 0 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] get_empty_filp+0xfb/0x4f0 fs/file_table.c:122 path_openat+0xed/0x3530 fs/namei.c:3495 do_filp_open+0x25b/0x3b0 fs/namei.c:3553 do_sys_open+0x502/0x6d0 fs/open.c:1059 SYSC_open fs/open.c:1077 [inline] SyS_open+0x2d/0x40 fs/open.c:1072 do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x40e061 RSP: 002b:00007f91c5d7bbb0 EFLAGS: 00000293 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 00007f91c5d7c6d4 RCX: 000000000040e061 RDX: 00007f91c5d7bbec RSI: 0000000000000002 RDI: 00007f91c5d7bbd0 RBP: 000000000072bea0 R08: 0000000000000000 R09: 000000000000001c R10: 0000000000000011 R11: 0000000000000293 R12: 0000000000000013 R13: 000000000000064f R14: 00000000006f9808 R15: 0000000000000002 CPU: 1 PID: 10275 Comm: syz-executor4 Not tainted 4.16.0-rc3+ #336 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 fcntl_dirnotify+0x170/0xc10 fs/notify/dnotify/dnotify.c:291 do_fcntl+0x5a4/0x1150 fs/fcntl.c:413 SYSC_fcntl fs/fcntl.c:463 [inline] SyS_fcntl+0xd6/0x110 fs/fcntl.c:448 do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x453d69 RSP: 002b:00007f0e6f10ec68 EFLAGS: 00000246 ORIG_RAX: 0000000000000048 RAX: ffffffffffffffda RBX: 00007f0e6f10f6d4 RCX: 0000000000453d69 RDX: 0000002000000003 RSI: 0000000000000402 RDI: 0000000000000013 RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000014 R13: 000000000000008f R14: 00000000006f0e08 R15: 0000000000000000 kauditd_printk_skb: 21 callbacks suppressed audit: type=1400 audit(1520009753.021:94): avc: denied { create } for pid=11156 comm="syz-executor0" 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 audit: type=1400 audit(1520009753.052:95): avc: denied { setopt } for pid=11156 comm="syz-executor0" 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 capability: warning: `syz-executor4' uses deprecated v2 capabilities in a way that may be insecure