====================================================== [ INFO: possible circular locking dependency detected ] 4.4.120-gd63fdf6 #29 Not tainted ------------------------------------------------------- syz-executor0/11007 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-executor0/11007: #0: (ashmem_mutex){+.+.+.}, at: [] ashmem_llseek+0x56/0x1f0 drivers/staging/android/ashmem.c:330 stack backtrace: CPU: 0 PID: 11007 Comm: syz-executor0 Not tainted 4.4.120-gd63fdf6 #29 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 0000000000000000 fbcf159c6493bbf6 ffff8800b765fa58 ffffffff81d0408d ffffffff8519fcb0 ffffffff851a9d00 ffffffff851be610 ffff8800a75da0f8 ffff8800a75d9800 ffff8800b765faa0 ffffffff81233ba1 ffff8800a75da0f8 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: 11147:11164 got transaction with invalid offset (4, min 0 max 40) or object. binder: BINDER_SET_CONTEXT_MGR already set binder: 11153:11169 ioctl 40046207 0 returned -16 binder: release 11153:11160 transaction 62 out, still active binder: unexpected work type, 4, not freed binder: undelivered TRANSACTION_COMPLETE binder: send failed reply for transaction 62, target dead binder: 11147:11164 transaction failed 29201/-22, size 40-8 line 3191 binder: 11147:11172 Release 1 refcount change on invalid ref 1 ret -22 binder: 11147:11172 got transaction with invalid parent offset or type binder: 11147:11172 transaction failed 29201/-22, size 56-8 line 3251 binder: BINDER_SET_CONTEXT_MGR already set binder: 11147:11172 ioctl 40046207 0 returned -16 binder_alloc: 11147: binder_alloc_buf, no vma binder: 11147:11191 Release 1 refcount change on invalid ref 1 ret -22 binder_alloc: 11147: binder_alloc_buf, no vma binder: 11147:11191 transaction failed 29189/-3, size 56-8 line 3128 binder: 11147:11164 transaction failed 29189/-3, size 40-8 line 3128 binder: undelivered TRANSACTION_ERROR: 29189 binder: undelivered TRANSACTION_ERROR: 29189 binder: undelivered TRANSACTION_ERROR: 29201 binder: undelivered TRANSACTION_ERROR: 29201 sock: process `syz-executor2' is using obsolete getsockopt SO_BSDCOMPAT rfkill: input handler disabled rfkill: input handler enabled binder: 11328:11330 BC_CLEAR_DEATH_NOTIFICATION invalid ref 0 binder: BINDER_SET_CONTEXT_MGR already set binder: 11328:11353 ioctl 40046207 0 returned -16 binder_alloc: 11328: binder_alloc_buf, no vma binder: 11328:11348 BC_CLEAR_DEATH_NOTIFICATION invalid ref 0 binder: 11328:11330 transaction failed 29189/-3, size 40-8 line 3128 binder: undelivered TRANSACTION_ERROR: 29189 binder: release 11328:11330 transaction 70 out, still active binder: unexpected work type, 4, not freed binder: undelivered TRANSACTION_COMPLETE binder: send failed reply for transaction 70, target dead l2tp_core: tunl 2: sockfd_lookup(fd=19) returned -88 l2tp_core: tunl 2: sockfd_lookup(fd=23) returned -88 IPVS: length: 570 != 8 IPVS: length: 570 != 8 binder_alloc: 11624: binder_alloc_buf, no vma binder: 11624:11626 transaction failed 29189/-3, size 0-40 line 3128 binder: BINDER_SET_CONTEXT_MGR already set binder: 11624:11643 ioctl 40046207 0 returned -16 binder: undelivered TRANSACTION_ERROR: 29189 TCP: request_sock_TCPv6: Possible SYN flooding on port 20002. Sending cookies. Check SNMP counters. audit: type=1400 audit(1521423926.295:42): avc: denied { create } for pid=11659 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_fib_lookup_socket permissive=1 TCP: request_sock_TCPv6: Possible SYN flooding on port 20002. Sending cookies. Check SNMP counters. audit: type=1400 audit(1521423926.485:43): avc: denied { write } for pid=11659 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_fib_lookup_socket permissive=1 audit: type=1400 audit(1521423926.535:44): avc: denied { getopt } for pid=11659 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_fib_lookup_socket permissive=1 keychord: invalid keycode count 0 keychord: invalid keycode count 0 audit: type=1400 audit(1521423927.145:45): avc: denied { getopt } for pid=11849 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_netfilter_socket permissive=1 audit: type=1400 audit(1521423927.365:46): avc: denied { ioctl } for pid=11884 comm="syz-executor6" path="socket:[26189]" dev="sockfs" ino=26189 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_generic_socket permissive=1 audit: type=1400 audit(1521423927.425:47): avc: denied { accept } for pid=11884 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_generic_socket permissive=1 sd 0:0:1:0: [sg0] tag#167 FAILED Result: hostbyte=DID_ABORT driverbyte=DRIVER_OK sd 0:0:1:0: [sg0] tag#167 CDB: Test Unit Ready sd 0:0:1:0: [sg0] tag#167 CDB[00]: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 sd 0:0:1:0: [sg0] tag#167 CDB[10]: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 sd 0:0:1:0: [sg0] tag#167 CDB[20]: 00 00 00 sd 0:0:1:0: [sg0] tag#124 FAILED Result: hostbyte=DID_ABORT driverbyte=DRIVER_OK sd 0:0:1:0: [sg0] tag#124 CDB: Verify(10) sd 0:0:1:0: [sg0] tag#124 CDB[00]: 2f 64 65 76 2f 75 73 62 6d 6f 6e 23 00 00 00 00 sd 0:0:1:0: [sg0] tag#124 CDB[10]: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 sd 0:0:1:0: [sg0] tag#124 CDB[20]: 00 00 00 device lo entered promiscuous mode device lo left promiscuous mode SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0 sclass=netlink_route_socket device lo entered promiscuous mode device lo left promiscuous mode sg_write: data in/out 701760104/97 bytes for SCSI command 0x1-- guessing data in; program syz-executor7 not setting count and/or reply_len properly SELinux: unrecognized netlink message: protocol=0 nlmsg_type=65535 sclass=netlink_route_socket SELinux: unrecognized netlink message: protocol=0 nlmsg_type=65535 sclass=netlink_route_socket TCP: request_sock_TCP: Possible SYN flooding on port 20000. Sending cookies. Check SNMP counters. netlink: 20 bytes leftover after parsing attributes in process `syz-executor4'. netlink: 20 bytes leftover after parsing attributes in process `syz-executor4'. binder: 12848:12856 unknown command 0 binder: 12852:12859 BC_DEAD_BINDER_DONE 0002000000000002 not found binder: 12852:12859 BC_DEAD_BINDER_DONE 0000000000000000 not found binder: 12848:12856 ioctl c0306201 20000000 returned -22 binder_alloc: 12852: binder_alloc_buf, no vma pktgen: kernel_thread() failed for cpu 0 pktgen: Cannot create thread for cpu 0 (-4) binder: 12852:12881 transaction failed 29189/-3, size 0-0 line 3128 pktgen: kernel_thread() failed for cpu 1 pktgen: Cannot create thread for cpu 1 (-4) pktgen: Initialization failed for all threads binder: 12852:12909 BC_DEAD_BINDER_DONE 0002000000000002 not found binder: 12852:12909 BC_DEAD_BINDER_DONE 0000000000000000 not found binder: BINDER_SET_CONTEXT_MGR already set binder: 12852:12898 ioctl 40046207 0 returned -16 binder_alloc: 12852: binder_alloc_buf, no vma binder: 12852:12898 transaction failed 29189/-3, size 0-0 line 3128 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 binder: BINDER_SET_CONTEXT_MGR already set binder: 12990:12998 ioctl 40046207 0 returned -16 binder: BINDER_SET_CONTEXT_MGR already set binder: 13002:13004 ioctl 40046207 0 returned -16 binder: 13002:13004 transaction failed 29189/-22, size 0-0 line 3005 binder_alloc: 13002: binder_alloc_buf, no vma binder: 13002:13013 transaction failed 29189/-3, size 0-0 line 3128 binder: 13002:13004 got transaction with invalid offset (40, min 0 max 0) or object. binder: 13002:13004 transaction failed 29201/-22, size 0-8 line 3191 binder: undelivered TRANSACTION_ERROR: 29201 binder: undelivered TRANSACTION_ERROR: 29189 binder: undelivered TRANSACTION_ERROR: 29189 TCP: request_sock_TCP: Possible SYN flooding on port 20002. Sending cookies. Check SNMP counters. IPVS: Creating netns size=2552 id=10 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 binder: 13136:13152 ERROR: BC_REGISTER_LOOPER called without request binder: 13136:13162 ERROR: BC_REGISTER_LOOPER called without request binder_alloc: 13136: binder_alloc_buf, no vma binder: 13136:13162 transaction failed 29189/-3, size 0-0 line 3128 binder: undelivered TRANSACTION_ERROR: 29189 binder: 13221:13226 transaction failed 29189/-22, size 0-0 line 3005 binder: 13221:13226 transaction failed 29189/-22, size 0-0 line 3005