====================================================== [ INFO: possible circular locking dependency detected ] 4.4.120-gd63fdf6 #28 Not tainted ------------------------------------------------------- syz-executor6/6029 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-executor6/6029: #0: (ashmem_mutex){+.+.+.}, at: [] ashmem_llseek+0x56/0x1f0 drivers/staging/android/ashmem.c:330 stack backtrace: CPU: 1 PID: 6029 Comm: syz-executor6 Not tainted 4.4.120-gd63fdf6 #28 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 0000000000000000 68374f6e44fea710 ffff8801d8c0fad8 ffffffff81d0408d ffffffff851a0010 ffffffff851a9d00 ffffffff851be7c0 ffff8801d98ed0f8 ffff8801d98ec800 ffff8801d8c0fb20 ffffffff81233ba1 ffff8801d98ed0f8 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 audit: type=1400 audit(1521491626.071:11): avc: denied { create } for pid=6165 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 netlink: 8 bytes leftover after parsing attributes in process `syz-executor1'. binder: 6309:6314 got transaction to invalid handle netlink: 8 bytes leftover after parsing attributes in process `syz-executor1'. binder: 6309:6314 transaction failed 29201/-22, size 0-0 line 3005 binder: 6309:6326 got transaction to invalid handle binder: 6309:6326 transaction failed 29201/-22, size 0-0 line 3005 binder_alloc: binder_alloc_mmap_handler: 6330 20000000-20002000 already mapped failed -16 binder_alloc: binder_alloc_mmap_handler: 6330 20000000-20002000 already mapped failed -16 binder: undelivered TRANSACTION_ERROR: 29201 binder: undelivered TRANSACTION_ERROR: 29201 capability: warning: `syz-executor5' uses deprecated v2 capabilities in a way that may be insecure audit: type=1400 audit(1521491627.481:12): avc: denied { set_context_mgr } for pid=6598 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=binder permissive=1 audit: type=1400 audit(1521491627.511:13): avc: denied { call } for pid=6598 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=binder permissive=1 binder: 6598:6603 transaction failed 29201/-28, size 38184079975251968-0 line 3128 binder: BINDER_SET_CONTEXT_MGR already set binder: 6598:6630 ioctl 40046207 0 returned -16 binder_alloc: 6598: binder_alloc_buf, no vma binder: 6598:6603 transaction failed 29189/-3, size 38184079975251968-0 line 3128 binder_alloc: 6598: binder_alloc_buf, no vma binder: 6598:6630 transaction failed 29189/-3, size 0-0 line 3128 binder: undelivered TRANSACTION_ERROR: 29189 binder: undelivered TRANSACTION_ERROR: 29189 binder: undelivered TRANSACTION_ERROR: 29201 binder: BINDER_SET_CONTEXT_MGR already set binder: 6653:6656 ioctl 40046207 0 returned -16 binder: undelivered TRANSACTION_COMPLETE netlink: 100 bytes leftover after parsing attributes in process `syz-executor7'. binder: undelivered transaction 5, process died. binder: 6653:6656 unknown command 0 binder: 6653:6656 ioctl c0306201 200002c0 returned -22 binder: 6653:6672 tried to acquire reference to desc 0, got 1 instead binder_alloc: binder_alloc_mmap_handler: 6772 20ffd000-21000000 already mapped failed -16 binder_alloc: binder_alloc_mmap_handler: 6772 20ffd000-21000000 already mapped failed -16 netlink: 8 bytes leftover after parsing attributes in process `syz-executor1'. netlink: 8 bytes leftover after parsing attributes in process `syz-executor1'. netlink: 8 bytes leftover after parsing attributes in process `syz-executor1'. netlink: 8 bytes leftover after parsing attributes in process `syz-executor1'. netlink: 8 bytes leftover after parsing attributes in process `syz-executor1'. netlink: 8 bytes leftover after parsing attributes in process `syz-executor1'. capability: warning: `syz-executor3' uses 32-bit capabilities (legacy support in use) netlink: 12 bytes leftover after parsing attributes in process `syz-executor6'. netlink: 3 bytes leftover after parsing attributes in process `syz-executor6'. netlink: 12 bytes leftover after parsing attributes in process `syz-executor6'. audit: type=1400 audit(1521491629.801:14): avc: denied { create } for pid=7077 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_crypto_socket permissive=1 FAULT_FLAG_ALLOW_RETRY missing 30 CPU: 0 PID: 7116 Comm: syz-executor7 Not tainted 4.4.120-gd63fdf6 #28 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 0000000000000000 00f5ec6a3910bfea ffff8801d607f970 ffffffff81d0408d ffff8801cc076900 1ffff1003ac0ff3b ffff8801d607faf8 0000000000000000 0000000000000000 ffff8801d607fb20 ffffffff81607305 ffffffff81237410 Call Trace: [] __dump_stack lib/dump_stack.c:15 [inline] [] dump_stack+0xc1/0x124 lib/dump_stack.c:51 [] handle_userfault+0x715/0xf50 fs/userfaultfd.c:316 [] do_anonymous_page mm/memory.c:2731 [inline] [] handle_pte_fault mm/memory.c:3295 [inline] [] __handle_mm_fault mm/memory.c:3426 [inline] [] handle_mm_fault+0x2938/0x3190 mm/memory.c:3455 [] __do_page_fault+0x35b/0xa00 arch/x86/mm/fault.c:1245 [] do_page_fault+0x27/0x30 arch/x86/mm/fault.c:1308 [] page_fault+0x28/0x30 arch/x86/entry/entry_64.S:1033 [] entry_SYSCALL_64_fastpath+0x1c/0x98 binder: 7131:7146 Release 1 refcount change on invalid ref 0 ret -22 audit: type=1400 audit(1521491630.681:15): avc: denied { ioctl } for pid=7315 comm="syz-executor2" path="socket:[17084]" dev="sockfs" ino=17084 ioctlcmd=8946 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 binder: 7368:7369 transaction failed 29189/-22, size 0-0 line 3005 binder: 7368:7369 transaction failed 29189/-22, size 0-0 line 3005 binder: undelivered TRANSACTION_ERROR: 29189 binder: undelivered TRANSACTION_ERROR: 29189 audit: type=1401 audit(1521491631.311:16): op=fscreate invalid_context=40030020000000006600000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000002F73656C696E75782F6176632F63616368655F737461747300000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000[ 52.928642] audit: type=1400 audit(1521491631.491:17): avc: denied { getopt } for pid=7607 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_generic_socket permissive=1 audit: type=1400 audit(1521491631.521:18): avc: denied { write } for pid=7607 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_generic_socket permissive=1 SELinux: unknown mount option proc: unrecognized mount option "./file0/file0" or missing value proc: unrecognized mount option "./file0/file0" or missing value proc: unrecognized mount option "./file0/file0" or missing value audit: type=1400 audit(1521491632.541:19): avc: denied { create } for pid=7870 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_rdma_socket permissive=1 ALSA: seq fatal error: cannot create timer (-19) ALSA: seq fatal error: cannot create timer (-19) binder_alloc: binder_alloc_mmap_handler: 8104 20000000-20002000 already mapped failed -16 binder_alloc: binder_alloc_mmap_handler: 8104 20000000-20002000 already mapped failed -16 IPv4: Oversized IP packet from 127.0.0.1 IPv4: Oversized IP packet from 127.0.0.1 skbuff: bad partial csum: csum=65535/65535 len=20 binder: 8630:8633 ioctl c018620b 200001c0 returned -14 binder: 8630:8641 ioctl c018620b 200001c0 returned -14