====================================================== [ INFO: possible circular locking dependency detected ] 4.4.118-g5f7f76a #24 Not tainted ------------------------------------------------------- syz-executor3/5616 is trying to acquire lock: (&mm->mmap_sem){++++++}, at: [] __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. binder: 5635:5639 ioctl c018620b 20000040 returned -14 binder: 5635:5639 ioctl c018620b 20000080 returned -14 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 [] SYSC_mmap arch/x86/kernel/sys_x86_64.c:95 [inline] [] SyS_mmap+0x16/0x20 arch/x86/kernel/sys_x86_64.c:86 [] entry_SYSCALL_64_fastpath+0x1c/0x98 [] 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 [] vfs_ioctl fs/ioctl.c:43 [inline] [] do_vfs_ioctl+0x7aa/0xee0 fs/ioctl.c:607 [] SYSC_ioctl fs/ioctl.c:622 [inline] [] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:613 [] entry_SYSCALL_64_fastpath+0x1c/0x98 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-executor3/5616: #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: 0 PID: 5616 Comm: syz-executor3 Not tainted 4.4.118-g5f7f76a #24 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 0000000000000000 082402b6ced332a5 ffff8800b8c479b8 ffffffff81d0402d ffffffff851a0010 ffffffff851a0010 ffffffff851beb20 ffff8800ab9f68f8 ffff8800ab9f6000 ffff8800b8c47a00 ffffffff81233ba1 ffff8800ab9f68f8 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 [] vfs_ioctl fs/ioctl.c:43 [inline] [] do_vfs_ioctl+0x7aa/0xee0 fs/ioctl.c:607 [] SYSC_ioctl fs/ioctl.c:622 [inline] [] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:613 [] entry_SYSCALL_64_fastpath+0x1c/0x98 binder: 5667:5671 got transaction to invalid handle binder: 5667:5671 transaction failed 29201/-22, size 64-0 line 3005 binder: 5667:5683 unknown command 1073310154 binder: 5667:5671 BC_REQUEST_DEATH_NOTIFICATION invalid ref 0 binder: BINDER_SET_CONTEXT_MGR already set binder: 5667:5683 ioctl c0306201 20007000 returned -22 binder: 5667:5704 got transaction to invalid handle binder: 5667:5708 unknown command 1073310154 binder: 5667:5671 ioctl 40046207 0 returned -16 binder: 5667:5708 ioctl c0306201 20007000 returned -22 binder: 5667:5683 BC_REQUEST_DEATH_NOTIFICATION invalid ref 0 binder: 5667:5704 transaction failed 29201/-22, size 64-0 line 3005 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=55524 sclass=netlink_route_socket SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0 sclass=netlink_route_socket SELinux: unrecognized netlink message: protocol=0 nlmsg_type=55524 sclass=netlink_route_socket SELinux: unrecognized netlink message: protocol=0 nlmsg_type=55524 sclass=netlink_route_socket SELinux: unrecognized netlink message: protocol=0 nlmsg_type=55524 sclass=netlink_route_socket TCP: request_sock_TCPv6: Possible SYN flooding on port 20018. Sending cookies. Check SNMP counters. SELinux: unrecognized netlink message: protocol=0 nlmsg_type=55524 sclass=netlink_route_socket SELinux: unrecognized netlink message: protocol=0 nlmsg_type=55524 sclass=netlink_route_socket SELinux: unrecognized netlink message: protocol=0 nlmsg_type=55524 sclass=netlink_route_socket SELinux: unrecognized netlink message: protocol=0 nlmsg_type=55524 sclass=netlink_route_socket SELinux: unrecognized netlink message: protocol=0 nlmsg_type=55524 sclass=netlink_route_socket SELinux: unrecognized netlink message: protocol=0 nlmsg_type=55524 sclass=netlink_route_socket SELinux: unrecognized netlink message: protocol=0 nlmsg_type=55524 sclass=netlink_route_socket SELinux: unrecognized netlink message: protocol=0 nlmsg_type=55524 sclass=netlink_route_socket SELinux: unrecognized netlink message: protocol=0 nlmsg_type=55524 sclass=netlink_route_socket audit: type=1400 audit(1519665846.194:13): avc: denied { ioctl } for pid=7012 comm="syz-executor2" path="socket:[15955]" dev="sockfs" ino=15955 ioctlcmd=8904 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=28095 sclass=netlink_route_socket SELinux: unrecognized netlink message: protocol=0 nlmsg_type=28095 sclass=netlink_route_socket SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0 sclass=netlink_route_socket audit: type=1400 audit(1519665847.374:14): avc: denied { create } for pid=7533 comm="syz-executor2" 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 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=17218 sclass=netlink_route_socket SELinux: unrecognized netlink message: protocol=0 nlmsg_type=26691 sclass=netlink_route_socket syz-executor3 uses obsolete (PF_INET,SOCK_PACKET) SELinux: unrecognized netlink message: protocol=0 nlmsg_type=17218 sclass=netlink_route_socket SELinux: unrecognized netlink message: protocol=0 nlmsg_type=26691 sclass=netlink_route_socket IPVS: Creating netns size=2552 id=9 pktgen: kernel_thread() failed for cpu 0 pktgen: Cannot create thread for cpu 0 (-4) pktgen: kernel_thread() failed for cpu 1 pktgen: Cannot create thread for cpu 1 (-4) pktgen: Initialization failed for all threads SELinux: unrecognized netlink message: protocol=0 nlmsg_type=65293 sclass=netlink_route_socket SELinux: unrecognized netlink message: protocol=0 nlmsg_type=65293 sclass=netlink_route_socket SELinux: unrecognized netlink message: protocol=0 nlmsg_type=27891 sclass=netlink_route_socket SELinux: unrecognized netlink message: protocol=0 nlmsg_type=27891 sclass=netlink_route_socket SELinux: unrecognized netlink message: protocol=0 nlmsg_type=776 sclass=netlink_route_socket SELinux: unrecognized netlink message: protocol=0 nlmsg_type=776 sclass=netlink_route_socket SELinux: unrecognized netlink message: protocol=0 nlmsg_type=1 sclass=netlink_route_socket SELinux: unrecognized netlink message: protocol=0 nlmsg_type=1 sclass=netlink_route_socket SELinux: unrecognized netlink message: protocol=0 nlmsg_type=4890 sclass=netlink_route_socket SELinux: unrecognized netlink message: protocol=0 nlmsg_type=61726 sclass=netlink_route_socket SELinux: unrecognized netlink message: protocol=0 nlmsg_type=61726 sclass=netlink_route_socket SELinux: unrecognized netlink message: protocol=0 nlmsg_type=64026 sclass=netlink_route_socket