====================================================== [ INFO: possible circular locking dependency detected ] 4.4.120-gd63fdf6 #29 Not tainted ------------------------------------------------------- syz-executor7/5531 is trying to acquire lock: audit: type=1400 audit(1521594302.202:8): avc: denied { set_context_mgr } for pid=5530 comm="syz-executor1" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=binder permissive=1 (&mm->mmap_sem){++++++}, at: [ 42.628523] audit: type=1400 audit(1521594302.232:9): avc: denied { call } for pid=5530 comm="syz-executor1" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=binder permissive=1 binder: 5530:5535 got reply transaction with bad transaction stack, transaction 2 has target 5530:0 binder: 5530:5535 transaction failed 29201/-71, size 0-0 line 2936 binder: 5530:5535 ioctl c0306201 20000000 returned -14 binder: BINDER_SET_CONTEXT_MGR already set binder: 5530:5551 ioctl 40046207 0 returned -16 binder_alloc: 5530: binder_alloc_buf, no vma binder: 5530:5551 transaction failed 29189/-3, size 0-0 line 3128 binder: 5530:5554 got reply transaction with no transaction stack binder: 5530:5554 transaction failed 29201/-71, size 0-0 line 2921 binder: undelivered TRANSACTION_ERROR: 29189 binder: undelivered TRANSACTION_ERROR: 29201 binder: release 5530:5535 transaction 2 out, still active binder: undelivered TRANSACTION_COMPLETE binder: undelivered TRANSACTION_ERROR: 29201 binder: send failed reply for transaction 2, target dead [] __might_fault+0xe4/0x1d0 mm/memory.c:3809 but task is already holding lock: (ashmem_mutex){+.+.+.}, at: [] ashmem_pin_unpin drivers/staging/android/ashmem.c:701 [inline] (ashmem_mutex){+.+.+.}, at: [] ashmem_ioctl+0x367/0xfa0 drivers/staging/android/ashmem.c:778 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: [] lock_acquire+0x15e/0x460 kernel/locking/lockdep.c:3592 [] __mutex_lock_common kernel/locking/mutex.c:521 [inline] [] mutex_lock_nested+0xbb/0x850 kernel/locking/mutex.c:621 [] ashmem_mmap+0x53/0x400 drivers/staging/android/ashmem.c:366 [] mmap_region+0x94f/0x1250 mm/mmap.c:1664 [] do_mmap+0x4fd/0x9d0 mm/mmap.c:1441 [] do_mmap_pgoff include/linux/mm.h:1915 [inline] [] vm_mmap_pgoff+0x16e/0x1c0 mm/util.c:296 [] SYSC_mmap_pgoff mm/mmap.c:1491 [inline] [] SyS_mmap_pgoff+0x33f/0x560 mm/mmap.c:1449 [] do_syscall_32_irqs_on arch/x86/entry/common.c:392 [inline] [] do_fast_syscall_32+0x321/0x8a0 arch/x86/entry/common.c:459 [] sysenter_flags_fixed+0xd/0x17 [] check_prev_add kernel/locking/lockdep.c:1853 [inline] [] check_prevs_add kernel/locking/lockdep.c:1958 [inline] [] validate_chain kernel/locking/lockdep.c:2144 [inline] [] __lock_acquire+0x371f/0x4b50 kernel/locking/lockdep.c:3213 [] lock_acquire+0x15e/0x460 kernel/locking/lockdep.c:3592 [] __might_fault+0x14a/0x1d0 mm/memory.c:3810 [] copy_from_user arch/x86/include/asm/uaccess.h:724 [inline] [] ashmem_pin_unpin drivers/staging/android/ashmem.c:706 [inline] [] ashmem_ioctl+0x3b4/0xfa0 drivers/staging/android/ashmem.c:778 [] compat_ashmem_ioctl+0x3e/0x50 drivers/staging/android/ashmem.c:809 [] C_SYSC_ioctl fs/compat_ioctl.c:1592 [inline] [] compat_SyS_ioctl+0x28a/0x2540 fs/compat_ioctl.c:1544 [] do_syscall_32_irqs_on arch/x86/entry/common.c:392 [inline] [] do_fast_syscall_32+0x321/0x8a0 arch/x86/entry/common.c:459 [] sysenter_flags_fixed+0xd/0x17 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-executor7/5531: #0: (ashmem_mutex){+.+.+.}, at: [] ashmem_pin_unpin drivers/staging/android/ashmem.c:701 [inline] #0: (ashmem_mutex){+.+.+.}, at: [] ashmem_ioctl+0x367/0xfa0 drivers/staging/android/ashmem.c:778 stack backtrace: CPU: 1 PID: 5531 Comm: syz-executor7 Not tainted 4.4.120-gd63fdf6 #29 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 0000000000000000 fed173612332693d ffff8800af05f8a8 ffffffff81d0408d ffffffff851a0010 ffffffff851a0010 ffffffff851becd0 ffff8800a9dd88f8 ffff8800a9dd8000 ffff8800af05f8f0 ffffffff81233ba1 ffff8800a9dd88f8 Call Trace: [] __dump_stack lib/dump_stack.c:15 [inline] [] dump_stack+0xc1/0x124 lib/dump_stack.c:51 [] print_circular_bug+0x271/0x310 kernel/locking/lockdep.c:1226 [] check_prev_add kernel/locking/lockdep.c:1853 [inline] [] check_prevs_add kernel/locking/lockdep.c:1958 [inline] [] validate_chain kernel/locking/lockdep.c:2144 [inline] [] __lock_acquire+0x371f/0x4b50 kernel/locking/lockdep.c:3213 [] lock_acquire+0x15e/0x460 kernel/locking/lockdep.c:3592 [] __might_fault+0x14a/0x1d0 mm/memory.c:3810 [] copy_from_user arch/x86/include/asm/uaccess.h:724 [inline] [] ashmem_pin_unpin drivers/staging/android/ashmem.c:706 [inline] [] ashmem_ioctl+0x3b4/0xfa0 drivers/staging/android/ashmem.c:778 [] compat_ashmem_ioctl+0x3e/0x50 drivers/staging/android/ashmem.c:809 [] C_SYSC_ioctl fs/compat_ioctl.c:1592 [inline] [] compat_SyS_ioctl+0x28a/0x2540 fs/compat_ioctl.c:1544 [] do_syscall_32_irqs_on arch/x86/entry/common.c:392 [inline] [] do_fast_syscall_32+0x321/0x8a0 arch/x86/entry/common.c:459 [] sysenter_flags_fixed+0xd/0x17 mmap: syz-executor3 (5560) uses deprecated remap_file_pages() syscall. See Documentation/vm/remap_file_pages.txt. audit: type=1400 audit(1521594303.052:10): avc: denied { create } for pid=5611 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_generic_socket permissive=1 audit: type=1400 audit(1521594303.092:11): avc: denied { ioctl } for pid=5611 comm="syz-executor3" path="socket:[13039]" dev="sockfs" ino=13039 ioctlcmd=8946 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(1521594303.152:12): avc: denied { accept } for pid=5611 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_generic_socket permissive=1 audit: type=1400 audit(1521594303.212:13): avc: denied { write } for pid=5611 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_generic_socket permissive=1 audit_printk_skb: 3 callbacks suppressed audit: type=1400 audit(1521594304.002:15): avc: denied { set_context_mgr } for pid=5837 comm="syz-executor1" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=binder permissive=1 binder: 5837:5838 ioctl c0306201 20007000 returned -14 binder: BINDER_SET_CONTEXT_MGR already set binder: 5837:5845 ioctl 40046207 0 returned -16 binder: 5837:5845 ioctl c0306201 20007000 returned -14 binder: BINDER_SET_CONTEXT_MGR already set binder: 5856:5859 ioctl 40046207 0 returned -16 binder: 5856:5859 ioctl c0306201 20007000 returned -14 audit: type=1400 audit(1521594304.642:16): avc: denied { create } for pid=6027 comm="syz-executor7" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_netfilter_socket permissive=1 audit: type=1400 audit(1521594304.682:17): avc: denied { write } for pid=6027 comm="syz-executor7" path="socket:[13897]" dev="sockfs" ino=13897 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_netfilter_socket permissive=1 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=770 sclass=netlink_route_socket SELinux: unrecognized netlink message: protocol=0 nlmsg_type=770 sclass=netlink_route_socket SELinux: unrecognized netlink message: protocol=0 nlmsg_type=770 sclass=netlink_route_socket SELinux: unrecognized netlink message: protocol=0 nlmsg_type=770 sclass=netlink_route_socket SELinux: unrecognized netlink message: protocol=0 nlmsg_type=770 sclass=netlink_route_socket SELinux: unrecognized netlink message: protocol=0 nlmsg_type=770 sclass=netlink_route_socket SELinux: unrecognized netlink message: protocol=0 nlmsg_type=770 sclass=netlink_route_socket audit: type=1400 audit(1521594307.432:18): avc: denied { create } for pid=6799 comm="syz-executor6" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_fib_lookup_socket permissive=1 audit: type=1400 audit(1521594307.492:19): avc: denied { write } for pid=6799 comm="syz-executor6" path="socket:[16574]" dev="sockfs" ino=16574 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_fib_lookup_socket permissive=1 audit: type=1400 audit(1521594307.622:20): avc: denied { ioctl } for pid=6850 comm="syz-executor6" path="socket:[16602]" dev="sockfs" ino=16602 ioctlcmd=5420 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_netfilter_socket permissive=1 audit: type=1400 audit(1521594307.752:21): avc: denied { getopt } for pid=6897 comm="syz-executor6" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_netfilter_socket permissive=1 audit: type=1400 audit(1521594308.812:22): avc: denied { create } for pid=7181 comm="syz-executor6" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_iscsi_socket permissive=1 audit: type=1400 audit(1521594309.302:23): avc: denied { setopt } for pid=7309 comm="syz-executor6" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_netfilter_socket permissive=1 SELinux: unrecognized netlink message: protocol=4 nlmsg_type=770 sclass=netlink_tcpdiag_socket SELinux: unrecognized netlink message: protocol=4 nlmsg_type=770 sclass=netlink_tcpdiag_socket audit: type=1400 audit(1521594311.702:24): avc: denied { getattr } for pid=8083 comm="syz-executor7" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_netfilter_socket permissive=1 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=21473 sclass=netlink_route_socket SELinux: unrecognized netlink message: protocol=0 nlmsg_type=21473 sclass=netlink_route_socket