====================================================== [ INFO: possible circular locking dependency detected ] 4.4.120-gd63fdf6 #29 Not tainted ------------------------------------------------------- syz-executor5/7521 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 TCP: request_sock_TCPv6: Possible SYN flooding on port 20002. Sending cookies. Check SNMP counters. [] 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-executor5/7521: #0: (ashmem_mutex){+.+.+.}, at: [] ashmem_llseek+0x56/0x1f0 drivers/staging/android/ashmem.c:330 stack backtrace: CPU: 0 PID: 7521 Comm: syz-executor5 Not tainted 4.4.120-gd63fdf6 #29 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 0000000000000000 105383b53fd2a314 ffff8800b600fa58 ffffffff81d0408d ffffffff8519fcb0 ffffffff851a99a0 ffffffff851bee80 ffff8800b62408f8 ffff8800b6240000 ffff8800b600faa0 ffffffff81233ba1 ffff8800b62408f8 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 audit: type=1400 audit(1521487330.402:70): avc: denied { set_context_mgr } for pid=7557 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=binder permissive=1 audit: type=1400 audit(1521487330.442:72): avc: denied { set_context_mgr } for pid=7562 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: tried to use weak ref as strong ref audit: type=1400 audit(1521487330.432:71): avc: denied { create } for pid=7553 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_netfilter_socket permissive=1 audit: type=1400 audit(1521487330.492:73): avc: denied { write } for pid=7553 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_netfilter_socket permissive=1 binder: BINDER_SET_CONTEXT_MGR already set binder: 7562:7575 ioctl 40046207 0 returned -16 binder: 7557:7577 Release 1 refcount change on invalid ref 0 ret -22 binder: BINDER_SET_CONTEXT_MGR already set binder: 7557:7560 ioctl 40046207 0 returned -16 binder: 7557:7572 Release 1 refcount change on invalid ref 0 ret -22 audit: type=1400 audit(1521487330.522:74): avc: denied { create } for pid=7553 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_netfilter_socket permissive=1 audit: type=1400 audit(1521487330.622:75): avc: denied { set_context_mgr } for pid=7603 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=binder permissive=1 binder_alloc: 7603: binder_alloc_buf, no vma binder: 7603:7604 transaction failed 29189/-3, size 0-0 line 3128 binder: BINDER_SET_CONTEXT_MGR already set binder: 7603:7618 ioctl 40046207 0 returned -16 binder: 7659:7660 ioctl c0306201 20008fd0 returned -14 binder: 7659:7660 ioctl c0306201 2000a000 returned -14 binder: 7659:7660 ioctl c0306201 20008fd0 returned -14 syz-executor4 uses obsolete (PF_INET,SOCK_PACKET) binder: send failed reply for transaction 31 to 7746:7753 binder: BINDER_SET_CONTEXT_MGR already set binder: 7746:7755 ioctl 40046207 0 returned -16 binder_alloc: 7746: binder_alloc_buf, no vma binder: 7746:7755 transaction failed 29189/-3, size 0-0 line 3128 binder: undelivered TRANSACTION_ERROR: 29189 binder: undelivered TRANSACTION_COMPLETE binder: undelivered TRANSACTION_ERROR: 29189 binder: BINDER_SET_CONTEXT_MGR already set binder: 7787:7795 ioctl 40046207 0 returned -16 mmap: syz-executor0 (7933) uses deprecated remap_file_pages() syscall. See Documentation/vm/remap_file_pages.txt. TCP: request_sock_TCPv6: Possible SYN flooding on port 20002. Sending cookies. Check SNMP counters. netlink: 3 bytes leftover after parsing attributes in process `syz-executor2'. netlink: 3 bytes leftover after parsing attributes in process `syz-executor2'. netlink: 3 bytes leftover after parsing attributes in process `syz-executor2'. netlink: 3 bytes leftover after parsing attributes in process `syz-executor2'. netlink: 28 bytes leftover after parsing attributes in process `syz-executor1'. TCP: request_sock_TCPv6: Possible SYN flooding on port 20002. Sending cookies. Check SNMP counters. binder: 8156:8158 ioctl c0306201 200001c0 returned -11 binder: BINDER_SET_CONTEXT_MGR already set binder: 8156:8168 ioctl 40046207 0 returned -16 tmpfs: No value for mount option '‚p†ÿOœß…' tmpfs: No value for mount option '‚p†ÿOœß…' audit_printk_skb: 102 callbacks suppressed audit: type=1400 audit(1521487334.242:110): avc: denied { set_context_mgr } for pid=8320 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=binder permissive=1 binder: 8320:8326 ioctl c0306201 204edfd0 returned -14 audit: type=1400 audit(1521487334.322:111): avc: denied { call } for pid=8320 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=binder permissive=1 binder: 8320:8351 got reply transaction with no transaction stack binder: 8320:8351 transaction failed 29201/-71, size 32-0 line 2921 binder: BINDER_SET_CONTEXT_MGR already set binder: 8320:8339 ioctl c0306201 204edfd0 returned -14 binder: 8320:8326 ioctl 40046207 0 returned -16 audit: type=1400 audit(1521487334.412:112): avc: denied { call } for pid=8320 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=binder permissive=1 binder_alloc: 8320: binder_alloc_buf, no vma binder: 8320:8351 transaction failed 29189/-3, size 0-0 line 3128 binder: release 8320:8339 transaction 36 out, still active binder: undelivered TRANSACTION_COMPLETE binder: undelivered TRANSACTION_ERROR: 29201 binder: send failed reply for transaction 36, target dead binder: undelivered TRANSACTION_ERROR: 29189 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=142 sclass=netlink_route_socket SELinux: unrecognized netlink message: protocol=0 nlmsg_type=142 sclass=netlink_route_socket audit: type=1400 audit(1521487335.742:113): avc: denied { create } for pid=8625 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(1521487335.772:114): avc: denied { create } for pid=8625 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(1521487335.802:115): avc: denied { write } for pid=8625 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 TCP: request_sock_TCP: Possible SYN flooding on port 20000. Sending cookies. Check SNMP counters. audit: type=1400 audit(1521487336.432:116): avc: denied { create } for pid=8808 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 audit: type=1400 audit(1521487336.492:117): avc: denied { create } for pid=8808 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 audit: type=1400 audit(1521487336.692:118): avc: denied { create } for pid=8869 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(1521487336.782:119): avc: denied { create } for pid=8869 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 binder_alloc: 9212: binder_alloc_buf, no vma binder: 9212:9216 transaction failed 29189/-3, size 0-0 line 3128 binder: 9212:9222 got reply transaction with no transaction stack binder: 9212:9222 transaction failed 29201/-71, size 0-0 line 2921 binder: 9212:9222 ioctl 4b34 4 returned -22 binder: BINDER_SET_CONTEXT_MGR already set binder: 9212:9222 ioctl 40046207 0 returned -16 binder: 9212:9227 got reply transaction with bad transaction stack, transaction 42 has target 9212:0 binder: 9212:9227 transaction failed 29201/-71, size 0-0 line 2936 binder: release 9212:9227 transaction 42 out, still active binder: undelivered TRANSACTION_COMPLETE binder: undelivered TRANSACTION_ERROR: 29201 SELinux: unknown mount option SELinux: unknown mount option binder: 9243:9247 transaction failed 29189/-22, size 40--2161727821137838072 line 3005 binder: undelivered TRANSACTION_ERROR: 29189 binder: undelivered TRANSACTION_ERROR: 29201 binder: send failed reply for transaction 42, target dead binder: 9243:9247 transaction failed 29189/-22, size 40--2161727821137838072 line 3005 SELinux: unknown mount option