IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_batadv: link becomes ready audit: type=1400 audit(1583758497.384:41): avc: denied { associate } for pid=8053 comm="syz-executor.3" name="syz3" scontext=unconfined_u:object_r:unlabeled_t:s0 tcontext=system_u:object_r:unlabeled_t:s0 tclass=filesystem permissive=1 ====================================================== WARNING: possible circular locking dependency detected 4.19.108-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.4/8246 is trying to acquire lock: 0000000004acf6d7 (sb_writers#4){.+.+}, at: file_start_write include/linux/fs.h:2775 [inline] 0000000004acf6d7 (sb_writers#4){.+.+}, at: ovl_write_iter+0x91b/0xc20 fs/overlayfs/file.c:280 but task is already holding lock: 00000000dddfd189 (&ovl_i_mutex_key[depth]){+.+.}, at: inode_lock include/linux/fs.h:747 [inline] 00000000dddfd189 (&ovl_i_mutex_key[depth]){+.+.}, at: ovl_write_iter+0x148/0xc20 fs/overlayfs/file.c:268 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&ovl_i_mutex_key[depth]){+.+.}: inode_lock include/linux/fs.h:747 [inline] ovl_write_iter+0x148/0xc20 fs/overlayfs/file.c:268 call_write_iter include/linux/fs.h:1820 [inline] new_sync_write fs/read_write.c:474 [inline] __vfs_write+0x512/0x760 fs/read_write.c:487 __kernel_write+0x109/0x370 fs/read_write.c:506 write_pipe_buf+0x153/0x1e0 fs/splice.c:798 splice_from_pipe_feed fs/splice.c:503 [inline] __splice_from_pipe+0x38f/0x7a0 fs/splice.c:627 splice_from_pipe+0xd9/0x140 fs/splice.c:662 default_file_splice_write+0x37/0x90 fs/splice.c:810 do_splice_from fs/splice.c:852 [inline] do_splice+0x5ea/0x1250 fs/splice.c:1154 __do_sys_splice fs/splice.c:1428 [inline] __se_sys_splice fs/splice.c:1408 [inline] __x64_sys_splice+0x2b5/0x320 fs/splice.c:1408 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #1 (&pipe->mutex/1){+.+.}: pipe_lock_nested fs/pipe.c:62 [inline] pipe_lock+0x63/0x80 fs/pipe.c:70 iter_file_splice_write+0x183/0xb30 fs/splice.c:700 do_splice_from fs/splice.c:852 [inline] do_splice+0x5ea/0x1250 fs/splice.c:1154 __do_sys_splice fs/splice.c:1428 [inline] __se_sys_splice fs/splice.c:1408 [inline] __x64_sys_splice+0x2b5/0x320 fs/splice.c:1408 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #0 (sb_writers#4){.+.+}: percpu_down_read_preempt_disable include/linux/percpu-rwsem.h:36 [inline] percpu_down_read include/linux/percpu-rwsem.h:59 [inline] __sb_start_write+0x1e6/0x340 fs/super.c:1387 file_start_write include/linux/fs.h:2775 [inline] ovl_write_iter+0x91b/0xc20 fs/overlayfs/file.c:280 call_write_iter include/linux/fs.h:1820 [inline] new_sync_write fs/read_write.c:474 [inline] __vfs_write+0x512/0x760 fs/read_write.c:487 __kernel_write+0x109/0x370 fs/read_write.c:506 write_pipe_buf+0x153/0x1e0 fs/splice.c:798 splice_from_pipe_feed fs/splice.c:503 [inline] __splice_from_pipe+0x38f/0x7a0 fs/splice.c:627 splice_from_pipe+0xd9/0x140 fs/splice.c:662 default_file_splice_write+0x37/0x90 fs/splice.c:810 do_splice_from fs/splice.c:852 [inline] do_splice+0x5ea/0x1250 fs/splice.c:1154 __do_sys_splice fs/splice.c:1428 [inline] __se_sys_splice fs/splice.c:1408 [inline] __x64_sys_splice+0x2b5/0x320 fs/splice.c:1408 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe other info that might help us debug this: Chain exists of: sb_writers#4 --> &pipe->mutex/1 --> &ovl_i_mutex_key[depth] Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&ovl_i_mutex_key[depth]); lock(&pipe->mutex/1); lock(&ovl_i_mutex_key[depth]); lock(sb_writers#4); *** DEADLOCK *** 3 locks held by syz-executor.4/8246: #0: 00000000e414fcde (sb_writers#13){.+.+}, at: file_start_write include/linux/fs.h:2775 [inline] #0: 00000000e414fcde (sb_writers#13){.+.+}, at: do_splice+0xc91/0x1250 fs/splice.c:1153 #1: 000000004215a967 (&pipe->mutex/1){+.+.}, at: pipe_lock_nested fs/pipe.c:62 [inline] #1: 000000004215a967 (&pipe->mutex/1){+.+.}, at: pipe_lock+0x63/0x80 fs/pipe.c:70 #2: 00000000dddfd189 (&ovl_i_mutex_key[depth]){+.+.}, at: inode_lock include/linux/fs.h:747 [inline] #2: 00000000dddfd189 (&ovl_i_mutex_key[depth]){+.+.}, at: ovl_write_iter+0x148/0xc20 fs/overlayfs/file.c:268 stack backtrace: CPU: 0 PID: 8246 Comm: syz-executor.4 Not tainted 4.19.108-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x188/0x20d lib/dump_stack.c:118 print_circular_bug.isra.0.cold+0x1c4/0x282 kernel/locking/lockdep.c:1221 overlayfs: unrecognized mount option "Ił gro[¬¬d=18446744073709551615" or missing value check_prev_add kernel/locking/lockdep.c:1861 [inline] check_prevs_add kernel/locking/lockdep.c:1974 [inline] validate_chain kernel/locking/lockdep.c:2415 [inline] __lock_acquire+0x2e19/0x49c0 kernel/locking/lockdep.c:3411 lock_acquire+0x170/0x400 kernel/locking/lockdep.c:3903 percpu_down_read_preempt_disable include/linux/percpu-rwsem.h:36 [inline] percpu_down_read include/linux/percpu-rwsem.h:59 [inline] __sb_start_write+0x1e6/0x340 fs/super.c:1387 file_start_write include/linux/fs.h:2775 [inline] ovl_write_iter+0x91b/0xc20 fs/overlayfs/file.c:280 call_write_iter include/linux/fs.h:1820 [inline] new_sync_write fs/read_write.c:474 [inline] __vfs_write+0x512/0x760 fs/read_write.c:487 __kernel_write+0x109/0x370 fs/read_write.c:506 write_pipe_buf+0x153/0x1e0 fs/splice.c:798 splice_from_pipe_feed fs/splice.c:503 [inline] __splice_from_pipe+0x38f/0x7a0 fs/splice.c:627 splice_from_pipe+0xd9/0x140 fs/splice.c:662 default_file_splice_write+0x37/0x90 fs/splice.c:810 do_splice_from fs/splice.c:852 [inline] do_splice+0x5ea/0x1250 fs/splice.c:1154 __do_sys_splice fs/splice.c:1428 [inline] __se_sys_splice fs/splice.c:1408 [inline] __x64_sys_splice+0x2b5/0x320 fs/splice.c:1408 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45c4a9 Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f425f909c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000113 RAX: ffffffffffffffda RBX: 00007f425f90a6d4 RCX: 000000000045c4a9 RDX: 0000000000000005 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 000000000076bfc0 R08: 000000000004ffe0 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000b9f R14: 00000000004ce2bc R15: 000000000076bfcc