audit: type=1400 audit(1574876608.365:357): avc: denied { create } for pid=14513 comm="syz-executor.1" 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
======================================================
[ INFO: possible circular locking dependency detected ]
4.9.203-syzkaller #0 Not tainted
-------------------------------------------------------
syz-executor.4/14529 is trying to acquire lock:
(&mm->mmap_sem){++++++}, at: [<0000000080872b6a>] __do_page_fault+0x7bd/0xa60 arch/x86/mm/fault.c:1337
but task is already holding lock:
(&sb->s_type->i_mutex_key#10){+.+.+.}, at: [<0000000082d5cc11>] inode_lock include/linux/fs.h:771 [inline]
(&sb->s_type->i_mutex_key#10){+.+.+.}, at: [<0000000082d5cc11>] generic_file_write_iter+0x9a/0x630 mm/filemap.c:3090
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
lock_acquire+0x133/0x3d0 kernel/locking/lockdep.c:3759
down_write+0x41/0xa0 kernel/locking/rwsem.c:52
inode_lock include/linux/fs.h:771 [inline]
shmem_fallocate+0x143/0xab0 mm/shmem.c:2683
ashmem_shrink_scan drivers/staging/android/ashmem.c:462 [inline]
ashmem_shrink_scan+0x1c3/0x4c0 drivers/staging/android/ashmem.c:446
ashmem_ioctl+0x29b/0xdd0 drivers/staging/android/ashmem.c:804
vfs_ioctl fs/ioctl.c:43 [inline]
file_ioctl fs/ioctl.c:493 [inline]
do_vfs_ioctl+0xb87/0x11d0 fs/ioctl.c:677
SYSC_ioctl fs/ioctl.c:694 [inline]
SyS_ioctl+0x8f/0xc0 fs/ioctl.c:685
do_syscall_64+0x1ad/0x5c0 arch/x86/entry/common.c:288
entry_SYSCALL_64_after_swapgs+0x5d/0xdb
lock_acquire+0x133/0x3d0 kernel/locking/lockdep.c:3759
__mutex_lock_common kernel/locking/mutex.c:521 [inline]
mutex_lock_nested+0xc7/0x920 kernel/locking/mutex.c:621
ashmem_mmap+0x53/0x470 drivers/staging/android/ashmem.c:378
mmap_region+0x7e7/0xfa0 mm/mmap.c:1726
do_mmap+0x539/0xbc0 mm/mmap.c:1505
do_mmap_pgoff include/linux/mm.h:2066 [inline]
vm_mmap_pgoff+0x179/0x1c0 mm/util.c:329
SYSC_mmap_pgoff mm/mmap.c:1555 [inline]
SyS_mmap_pgoff+0xfa/0x1b0 mm/mmap.c:1513
SYSC_mmap arch/x86/kernel/sys_x86_64.c:96 [inline]
SyS_mmap+0x16/0x20 arch/x86/kernel/sys_x86_64.c:87
do_syscall_64+0x1ad/0x5c0 arch/x86/entry/common.c:288
entry_SYSCALL_64_after_swapgs+0x5d/0xdb
check_prev_add kernel/locking/lockdep.c:1828 [inline]
check_prevs_add kernel/locking/lockdep.c:1938 [inline]
validate_chain kernel/locking/lockdep.c:2265 [inline]
__lock_acquire+0x2d22/0x4390 kernel/locking/lockdep.c:3345
lock_acquire+0x133/0x3d0 kernel/locking/lockdep.c:3759
down_read+0x44/0xb0 kernel/locking/rwsem.c:22
__do_page_fault+0x7bd/0xa60 arch/x86/mm/fault.c:1337
do_page_fault+0x28/0x30 arch/x86/mm/fault.c:1464
page_fault+0x25/0x30 arch/x86/entry/entry_64.S:956
generic_perform_write+0x1b6/0x500 mm/filemap.c:2930
__generic_file_write_iter+0x340/0x530 mm/filemap.c:3065
generic_file_write_iter+0x38a/0x630 mm/filemap.c:3093
new_sync_write fs/read_write.c:498 [inline]
__vfs_write+0x3c1/0x560 fs/read_write.c:511
vfs_write+0x185/0x520 fs/read_write.c:559
SYSC_write fs/read_write.c:607 [inline]
SyS_write+0x121/0x270 fs/read_write.c:599
do_syscall_64+0x1ad/0x5c0 arch/x86/entry/common.c:288
entry_SYSCALL_64_after_swapgs+0x5d/0xdb
other info that might help us debug this:
Chain exists of:
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&sb->s_type->i_mutex_key#10);
lock(ashmem_mutex);
lock(&sb->s_type->i_mutex_key#10);
lock(&mm->mmap_sem);
*** DEADLOCK ***
2 locks held by syz-executor.4/14529:
#0: (sb_writers#6){.+.+.+}, at: [<0000000091f17e5d>] file_start_write include/linux/fs.h:2645 [inline]
#0: (sb_writers#6){.+.+.+}, at: [<0000000091f17e5d>] vfs_write+0x3e9/0x520 fs/read_write.c:558
#1: (&sb->s_type->i_mutex_key#10){+.+.+.}, at: [<0000000082d5cc11>] inode_lock include/linux/fs.h:771 [inline]
#1: (&sb->s_type->i_mutex_key#10){+.+.+.}, at: [<0000000082d5cc11>] generic_file_write_iter+0x9a/0x630 mm/filemap.c:3090
stack backtrace:
CPU: 1 PID: 14529 Comm: syz-executor.4 Not tainted 4.9.203-syzkaller #0
ffff8801c90775d8 ffffffff81b55f6b ffffffff83cae9d0 ffffffff83cb7e50
ffffffff83cd1350 ffffffff8424ff40 ffff8801c3f70000 ffff8801c9077630
ffffffff81406eaa dffffc0000000000 ffffffff8403c4c0 ffff8801c3f70900
Call Trace:
[<000000000e95782a>] __dump_stack lib/dump_stack.c:15 [inline]
[<000000000e95782a>] dump_stack+0xcb/0x130 lib/dump_stack.c:56
[<000000003dde1cf1>] print_circular_bug.cold+0x2f6/0x454 kernel/locking/lockdep.c:1202
[<000000002ac58544>] check_prev_add kernel/locking/lockdep.c:1828 [inline]
[<000000002ac58544>] check_prevs_add kernel/locking/lockdep.c:1938 [inline]
[<000000002ac58544>] validate_chain kernel/locking/lockdep.c:2265 [inline]
[<000000002ac58544>] __lock_acquire+0x2d22/0x4390 kernel/locking/lockdep.c:3345
[<00000000e4986716>] lock_acquire+0x133/0x3d0 kernel/locking/lockdep.c:3759
[<0000000039ee4969>] down_read+0x44/0xb0 kernel/locking/rwsem.c:22
[<0000000080872b6a>] __do_page_fault+0x7bd/0xa60 arch/x86/mm/fault.c:1337
[<0000000087c1a69e>] do_page_fault+0x28/0x30 arch/x86/mm/fault.c:1464
[<00000000c5d945e4>] page_fault+0x25/0x30 arch/x86/entry/entry_64.S:956
[<000000007029a3e9>] generic_perform_write+0x1b6/0x500 mm/filemap.c:2930
[<00000000030b0849>] __generic_file_write_iter+0x340/0x530 mm/filemap.c:3065
[<00000000e07341b2>] generic_file_write_iter+0x38a/0x630 mm/filemap.c:3093
[<00000000e4c6e7ee>] new_sync_write fs/read_write.c:498 [inline]
[<00000000e4c6e7ee>] __vfs_write+0x3c1/0x560 fs/read_write.c:511
[<000000004e936070>] vfs_write+0x185/0x520 fs/read_write.c:559
[<000000005cfef751>] SYSC_write fs/read_write.c:607 [inline]
[<000000005cfef751>] SyS_write+0x121/0x270 fs/read_write.c:599
[<00000000a85919cd>] do_syscall_64+0x1ad/0x5c0 arch/x86/entry/common.c:288
[<00000000a4e124c9>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb
audit_printk_skb: 96 callbacks suppressed
audit: type=1400 audit(1574876613.705:390): avc: denied { create } for pid=14621 comm="syz-executor.1" 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(1574876613.735:391): avc: denied { create } for pid=14619 comm="syz-executor.5" 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(1574876613.735:392): avc: denied { write } for pid=14619 comm="syz-executor.5" path="socket:[35018]" dev="sockfs" ino=35018 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(1574876613.835:393): avc: denied { create } for pid=14642 comm="syz-executor.5" 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(1574876613.845:394): avc: denied { write } for pid=14642 comm="syz-executor.5" path="socket:[35036]" dev="sockfs" ino=35036 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(1574876613.895:395): avc: denied { create } for pid=14622 comm="syz-executor.3" 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(1574876613.895:396): avc: denied { write } for pid=14622 comm="syz-executor.3" 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(1574876613.905:397): avc: denied { read } for pid=14622 comm="syz-executor.3" 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(1574876614.275:398): avc: denied { set_context_mgr } for pid=14684 comm="syz-executor.4" 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(1574876614.325:399): avc: denied { call } for pid=14684 comm="syz-executor.4" 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: 14684:14688 BC_FREE_BUFFER u0000000000000000 no match
binder: release 14684:14688 transaction 28 out, still active
binder: undelivered TRANSACTION_COMPLETE
binder: BINDER_SET_CONTEXT_MGR already set
binder: 14684:14698 ioctl 40046207 0 returned -16
binder: send failed reply for transaction 28, target dead
binder: 14705:14708 BC_FREE_BUFFER u0000000000000000 no match
binder: release 14705:14708 transaction 30 out, still active
binder: 14717:14720 BC_FREE_BUFFER u0000000000000000 no match
binder: undelivered TRANSACTION_COMPLETE
binder: send failed reply for transaction 30, target dead
binder: release 14717:14720 transaction 32 out, still active
binder: BINDER_SET_CONTEXT_MGR already set
binder: 14722:14724 ioctl 40046207 0 returned -16
binder: undelivered TRANSACTION_COMPLETE
binder: send failed reply for transaction 32, target dead
binder: 14727:14729 BC_FREE_BUFFER u0000000000000000 no match
binder: release 14727:14729 transaction 34 out, still active
binder: undelivered TRANSACTION_COMPLETE
binder: send failed reply for transaction 34, target dead
binder: 14722:14731 BC_FREE_BUFFER u0000000000000000 no match
binder: 14733:14737 BC_FREE_BUFFER u0000000000000000 no match
binder: release 14733:14737 transaction 36 out, still active
binder: undelivered TRANSACTION_COMPLETE
binder: send failed reply for transaction 36, target dead
binder: 14739:14740 BC_FREE_BUFFER u0000000000000000 no match
binder: BINDER_SET_CONTEXT_MGR already set
binder: 14743:14746 ioctl 40046207 0 returned -16
binder_alloc: 14739: binder_alloc_buf, no vma
binder: 14743:14746 transaction failed 29189/-3, size 0-0 line 3284
binder: 14743:14746 BC_FREE_BUFFER u0000000000000000 no match
binder: 14742:14744 BC_FREE_BUFFER u0000000000000000 no match
binder: release 14742:14744 transaction 41 out, still active
binder: undelivered TRANSACTION_COMPLETE
binder: send failed reply for transaction 41, target dead
binder: undelivered TRANSACTION_ERROR: 29189
binder: release 14739:14740 transaction 38 out, still active
binder: undelivered TRANSACTION_COMPLETE
binder: send failed reply for transaction 38, target dead