====================================================== [ INFO: possible circular locking dependency detected ] 4.4.120-gd63fdf6 #29 Not tainted ------------------------------------------------------- syz-executor3/9731 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 [] 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 [] 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 fs/read_write.c:276 [inline] [] C_SYSC_lseek fs/read_write.c:297 [inline] [] compat_SyS_lseek+0xeb/0x170 fs/read_write.c:295 [] 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: 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-executor3/9731: #0: (ashmem_mutex){+.+.+.}, at: [] ashmem_llseek+0x56/0x1f0 drivers/staging/android/ashmem.c:330 stack backtrace: CPU: 0 PID: 9731 Comm: syz-executor3 Not tainted 4.4.120-gd63fdf6 #29 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 0000000000000000 dfb89ce5c4151acd ffff8801d2d1fa58 ffffffff81d0408d ffffffff8519fe60 ffffffff851a99a0 ffffffff851be7c0 ffff8800aa3dd0f8 ffff8800aa3dc800 ffff8801d2d1faa0 ffffffff81233ba1 ffff8800aa3dd0f8 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 fs/read_write.c:276 [inline] [] C_SYSC_lseek fs/read_write.c:297 [inline] [] compat_SyS_lseek+0xeb/0x170 fs/read_write.c:295 [] 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 binder: 9784:9790 unknown command 1074029320 binder: 9784:9790 ioctl c0306201 20fed000 returned -22 binder: 9784:9801 ioctl 4b3a 3 returned -22 rfkill: input handler disabled binder: BINDER_SET_CONTEXT_MGR already set binder: 9784:9790 ioctl 40046207 0 returned -16 binder: 9784:9801 BC_REQUEST_DEATH_NOTIFICATION invalid ref 0 binder: 9784:9790 unknown command 1074029320 binder: 9784:9790 ioctl c0306201 20fed000 returned -22 rfkill: input handler enabled 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 audit: type=1400 audit(1521639348.859:37): avc: denied { ioctl } for pid=9945 comm="syz-executor3" path="socket:[22008]" dev="sockfs" ino=22008 ioctlcmd=64 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(1521639348.949:38): avc: denied { connect } for pid=9961 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 IPVS: set_ctl: invalid protocol: 13703 39.52.93.236:60696 Ætpm¹`x/.©HÝ¼ÁÞ„ÞDBíCý°+ò ¸½ß IPVS: set_ctl: invalid protocol: 13703 39.52.93.236:60696 Ætpm¹`x/.©HÝ¼ÁÞ„ÞDBíCý°+ò ¸½ß SELinux: unrecognized netlink message: protocol=6 nlmsg_type=7488 sclass=netlink_xfrm_socket SELinux: unrecognized netlink message: protocol=6 nlmsg_type=7488 sclass=netlink_xfrm_socket binder: 10155:10164 got reply transaction with no transaction stack binder: 10155:10164 transaction failed 29201/-71, size 72-56 line 2921 binder: 10155:10175 got reply transaction with no transaction stack binder: 10155:10175 transaction failed 29201/-71, size 72-56 line 2921 binder: undelivered TRANSACTION_ERROR: 29201 binder: undelivered TRANSACTION_ERROR: 29201 binder: 10223:10229 transaction failed 29189/-22, size 0-0 line 3005 binder: undelivered TRANSACTION_ERROR: 29189 binder: 10223:10232 transaction failed 29189/-22, size 0-0 line 3005 binder: 10223:10229 BC_CLEAR_DEATH_NOTIFICATION invalid ref 2 binder: undelivered TRANSACTION_ERROR: 29189 device syz_tun entered promiscuous mode SELinux: unrecognized netlink message: protocol=9 nlmsg_type=19 sclass=netlink_audit_socket SELinux: unrecognized netlink message: protocol=9 nlmsg_type=19 sclass=netlink_audit_socket TCP: request_sock_TCPv6: Possible SYN flooding on port 20002. Sending cookies. Check SNMP counters. TCP: request_sock_TCPv6: Possible SYN flooding on port 20002. Sending cookies. Check SNMP counters. TCP: request_sock_TCPv6: Possible SYN flooding on port 20002. Sending cookies. Check SNMP counters. binder: 10463:10480 unknown command 25197735 binder: 10463:10480 ioctl c0306201 2000dfd0 returned -22 TCP: request_sock_TCPv6: Possible SYN flooding on port 20002. Sending cookies. Check SNMP counters. audit: type=1400 audit(1521639351.119:39): avc: denied { create } for pid=10518 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_scsitransport_socket permissive=1 audit: type=1400 audit(1521639351.469:40): avc: denied { create } for pid=10624 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=netlink_fib_lookup_socket permissive=1 audit: type=1400 audit(1521639351.529:41): avc: denied { write } for pid=10624 comm="syz-executor5" path="socket:[23411]" dev="sockfs" ino=23411 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 netlink: 25 bytes leftover after parsing attributes in process `syz-executor5'. SELinux: unrecognized netlink message: protocol=0 nlmsg_type=6 sclass=netlink_route_socket audit: type=1400 audit(1521639352.919:42): avc: denied { create } for pid=11041 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 audit: type=1400 audit(1521639353.759:43): avc: denied { execute } for pid=11300 comm="syz-executor1" path="/proc/869/fdinfo" dev="proc" ino=25606 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=dir permissive=1 audit: type=1400 audit(1521639354.599:44): avc: denied { getopt } for pid=11503 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=netlink_netfilter_socket permissive=1 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=26757 sclass=netlink_route_socket