====================================================== [ INFO: possible circular locking dependency detected ] 4.4.120-gd63fdf6 #28 Not tainted ------------------------------------------------------- syz-executor0/5312 is trying to acquire lock: (&sb->s_type->i_mutex_key#10){+.+.+.}, at: [] shmem_file_llseek+0xf1/0x240 mm/shmem.c:1816 but task is already holding lock: (ashmem_mutex){+.+.+.}, at: [] ashmem_llseek+0x56/0x1f0 drivers/staging/android/ashmem.c:330 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 [] 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 [] lock_acquire+0x15e/0x460 kernel/locking/lockdep.c:3592 [] __might_fault+0x14a/0x1d0 mm/memory.c:3810 [] copy_to_user arch/x86/include/asm/uaccess.h:760 [inline] [] filldir+0x162/0x2d0 fs/readdir.c:180 [] dir_emit_dot include/linux/fs.h:3070 [inline] [] dir_emit_dots include/linux/fs.h:3081 [inline] [] dcache_readdir+0x11e/0x7b0 fs/libfs.c:150 [] iterate_dir+0x1c8/0x420 fs/readdir.c:42 [] SYSC_getdents fs/readdir.c:215 [inline] [] SyS_getdents+0x14a/0x270 fs/readdir.c:196 [] 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 [] __mutex_lock_common kernel/locking/mutex.c:521 [inline] [] mutex_lock_nested+0xbb/0x850 kernel/locking/mutex.c:621 [] shmem_file_llseek+0xf1/0x240 mm/shmem.c:1816 [] vfs_llseek+0xa2/0xd0 fs/read_write.c:260 [] ashmem_llseek+0xe7/0x1f0 drivers/staging/android/ashmem.c:342 [] vfs_llseek fs/read_write.c:260 [inline] [] SYSC_lseek fs/read_write.c:285 [inline] [] SyS_lseek+0xeb/0x170 fs/read_write.c:276 [] entry_SYSCALL_64_fastpath+0x1c/0x98 other info that might help us debug this: Chain exists of: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(ashmem_mutex); lock(&mm->mmap_sem); lock(ashmem_mutex); lock(&sb->s_type->i_mutex_key#10); *** DEADLOCK *** 1 lock held by syz-executor0/5312: #0: (ashmem_mutex){+.+.+.}, at: [] ashmem_llseek+0x56/0x1f0 drivers/staging/android/ashmem.c:330 stack backtrace: CPU: 0 PID: 5312 Comm: syz-executor0 Not tainted 4.4.120-gd63fdf6 #28 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 0000000000000000 fcc69319de107a25 ffff8800aaa5fad8 ffffffff81d0408d ffffffff851a0010 ffffffff851a9d00 ffffffff851be2b0 ffff8801c55f50f8 ffff8801c55f4800 ffff8800aaa5fb20 ffffffff81233ba1 ffff8801c55f50f8 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 [] __mutex_lock_common kernel/locking/mutex.c:521 [inline] [] mutex_lock_nested+0xbb/0x850 kernel/locking/mutex.c:621 [] shmem_file_llseek+0xf1/0x240 mm/shmem.c:1816 [] vfs_llseek+0xa2/0xd0 fs/read_write.c:260 [] ashmem_llseek+0xe7/0x1f0 drivers/staging/android/ashmem.c:342 [] vfs_llseek fs/read_write.c:260 [inline] [] SYSC_lseek fs/read_write.c:285 [inline] [] SyS_lseek+0xeb/0x170 fs/read_write.c:276 [] entry_SYSCALL_64_fastpath+0x1c/0x98 capability: warning: `syz-executor1' uses 32-bit capabilities (legacy support in use) syz-executor5 uses obsolete (PF_INET,SOCK_PACKET) audit: type=1400 audit(1521861006.066:9): avc: denied { ioctl } for pid=5582 comm="syz-executor3" path="socket:[13779]" dev="sockfs" ino=13779 ioctlcmd=8917 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(1521861006.316:10): avc: denied { create } for pid=5626 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 mmap: syz-executor5 (5644) uses deprecated remap_file_pages() syscall. See Documentation/vm/remap_file_pages.txt. binder: 5663:5665 ERROR: BC_REGISTER_LOOPER called without request audit: type=1400 audit(1521861006.516:11): avc: denied { write } for pid=5672 comm="syz-executor6" path="socket:[13919]" dev="sockfs" ino=13919 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 binder: 5663:5689 ioctl c0306201 203e0fd0 returned -14 binder: BINDER_SET_CONTEXT_MGR already set binder: 5663:5700 ioctl 40046207 0 returned -16 binder: 5663:5689 ERROR: BC_REGISTER_LOOPER called without request IPVS: Creating netns size=2552 id=9 binder: 5663:5707 ioctl c0306201 203e0fd0 returned -14 pktgen: kernel_thread() failed for cpu 1 pktgen: Cannot create thread for cpu 1 (-4) IPVS: Creating netns size=2552 id=10 netlink: 80 bytes leftover after parsing attributes in process `syz-executor2'. IPVS: Creating netns size=2552 id=11 binder: 6060:6064 transaction failed 29189/-22, size -8514425539733225472--7023847082660345939 line 3005 binder: 6060:6079 transaction failed 29189/-22, size -8514425539733225472--7023847082660345939 line 3005 binder: undelivered TRANSACTION_ERROR: 29189 binder: undelivered TRANSACTION_ERROR: 29189 audit: type=1400 audit(1521861009.096:12): avc: denied { getopt } for pid=6116 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_generic_socket permissive=1 netlink: 44 bytes leftover after parsing attributes in process `syz-executor5'. netlink: 44 bytes leftover after parsing attributes in process `syz-executor5'. netlink: 44 bytes leftover after parsing attributes in process `syz-executor5'. audit: type=1400 audit(1521861009.346:13): avc: denied { getattr } for pid=6187 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=netlink_generic_socket permissive=1 netlink: 44 bytes leftover after parsing attributes in process `syz-executor5'. TCP: request_sock_TCPv6: Possible SYN flooding on port 20002. Sending cookies. Check SNMP counters. binder: 6188:6193 transaction failed 29189/-22, size 0-0 line 3005 binder: 6188:6193 ioctl c0306201 20004000 returned -14 netlink: 44 bytes leftover after parsing attributes in process `syz-executor5'. binder: 6188:6219 transaction failed 29189/-22, size 0-0 line 3005 binder: undelivered TRANSACTION_ERROR: 29189 binder: undelivered TRANSACTION_ERROR: 29189 TCP: request_sock_TCPv6: Possible SYN flooding on port 20002. Sending cookies. Check SNMP counters. SELinux: unrecognized netlink message: protocol=0 nlmsg_type=24280 sclass=netlink_route_socket SELinux: unrecognized netlink message: protocol=0 nlmsg_type=24280 sclass=netlink_route_socket binder: 6452:6455 ioctl 8916 20000100 returned -22 binder: 6452:6455 ioctl 8916 20000100 returned -22 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0 sclass=netlink_route_socket SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0 sclass=netlink_route_socket TCP: request_sock_TCPv6: Possible SYN flooding on port 20002. Sending cookies. Check SNMP counters. audit: type=1400 audit(1521861011.036:14): avc: denied { create } for pid=6666 comm="syz-executor4" 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 netlink: 12 bytes leftover after parsing attributes in process `syz-executor1'. netlink: 12 bytes leftover after parsing attributes in process `syz-executor1'. audit: type=1400 audit(1521861011.546:15): avc: denied { create } for pid=6848 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(1521861011.586:16): avc: denied { write } for pid=6848 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(1521861011.586:17): avc: denied { read } for pid=6848 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(1521861011.956:18): avc: denied { set_context_mgr } for pid=6938 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=binder permissive=1 audit: type=1400 audit(1521861011.996:19): avc: denied { call } for pid=6938 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=binder permissive=1 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=257 sclass=netlink_route_socket SELinux: unrecognized netlink message: protocol=0 nlmsg_type=257 sclass=netlink_route_socket audit: type=1400 audit(1521861012.056:20): avc: denied { create } for pid=6992 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_netfilter_socket permissive=1 binder: BINDER_SET_CONTEXT_MGR already set binder: 6938:6941 ioctl 40046207 0 returned -16 binder_alloc: 6938: binder_alloc_buf, no vma binder: 6938:6954 transaction failed 29189/-3, size 0-0 line 3128 binder: undelivered TRANSACTION_ERROR: 29189 binder: undelivered TRANSACTION_COMPLETE binder: undelivered transaction 17, process died. audit: type=1400 audit(1521861012.546:21): avc: denied { write } for pid=7026 comm="syz-executor4" 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 binder: BINDER_SET_CONTEXT_MGR already set binder: 7118:7130 ioctl 40046207 0 returned -16 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0 sclass=netlink_route_socket SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0 sclass=netlink_route_socket device syz_tun entered promiscuous mode device syz_tun left promiscuous mode keychord: Insufficient bytes present for keycount 3 keychord: Insufficient bytes present for keycount 3 TCP: request_sock_TCP: Possible SYN flooding on port 20000. Sending cookies. Check SNMP counters. netlink: 4 bytes leftover after parsing attributes in process `syz-executor1'. audit_printk_skb: 13 callbacks suppressed audit: type=1400 audit(1521861014.686:26): avc: denied { transfer } for pid=7560 comm="syz-executor5" 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_alloc: binder_alloc_mmap_handler: 7560 20000000-20002000 already mapped failed -16 binder: BINDER_SET_CONTEXT_MGR already set binder: 7560:7566 ioctl 40046207 0 returned -16 binder_alloc: 7560: binder_alloc_buf, no vma binder: 7560:7572 transaction failed 29189/-3, size 40-8 line 3128 binder: send failed reply for transaction 22 to 7560:7566 binder: undelivered TRANSACTION_ERROR: 29189 netlink: 4 bytes leftover after parsing attributes in process `syz-executor1'. netlink: 4 bytes leftover after parsing attributes in process `syz-executor1'. netlink: 4 bytes leftover after parsing attributes in process `syz-executor1'.