netlink: 24 bytes leftover after parsing attributes in process `syz-executor.5'. ============================================ WARNING: possible recursive locking detected 4.19.211-syzkaller #0 Not tainted -------------------------------------------- syz-executor.5/1066 is trying to acquire lock: 00000000cc4d9456 (rtnl_mutex){+.+.}, at: hsr_dev_destroy+0x1b/0xb0 net/hsr/hsr_device.c:373 ubi0: attached mtd0 (name "mtdram test device", size 0 MiB) but task is already holding lock: 00000000cc4d9456 (rtnl_mutex){+.+.}, at: rtnl_lock net/core/rtnetlink.c:77 [inline] 00000000cc4d9456 (rtnl_mutex){+.+.}, at: rtnetlink_rcv_msg+0x3fe/0xb80 net/core/rtnetlink.c:4779 ubi0: PEB size: 4096 bytes (4 KiB), LEB size: 3968 bytes other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(rtnl_mutex); lock(rtnl_mutex); *** DEADLOCK *** May be due to missing lock nesting notation 1 lock held by syz-executor.5/1066: #0: 00000000cc4d9456 (rtnl_mutex){+.+.}, at: rtnl_lock net/core/rtnetlink.c:77 [inline] #0: 00000000cc4d9456 (rtnl_mutex){+.+.}, at: rtnetlink_rcv_msg+0x3fe/0xb80 net/core/rtnetlink.c:4779 stack backtrace: CPU: 1 PID: 1066 Comm: syz-executor.5 Not tainted 4.19.211-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1fc/0x2ef lib/dump_stack.c:118 print_deadlock_bug kernel/locking/lockdep.c:1764 [inline] check_deadlock kernel/locking/lockdep.c:1808 [inline] validate_chain kernel/locking/lockdep.c:2404 [inline] __lock_acquire.cold+0x121/0x57e kernel/locking/lockdep.c:3416 ubi0: min./max. I/O unit sizes: 1/64, sub-page size 1 ubi0: VID header offset: 64 (aligned 64), data offset: 128 lock_acquire+0x170/0x3c0 kernel/locking/lockdep.c:3908 __mutex_lock_common kernel/locking/mutex.c:937 [inline] __mutex_lock+0xd7/0x1190 kernel/locking/mutex.c:1078 ubi0: good PEBs: 32, bad PEBs: 0, corrupted PEBs: 0 hsr_dev_destroy+0x1b/0xb0 net/hsr/hsr_device.c:373 ubi0: user volume: 0, internal volumes: 1, max. volumes count: 23 register_netdevice+0x901/0x10f0 net/core/dev.c:8791 ubi0: max/mean erase counter: 1/1, WL threshold: 4096, image sequence number: 1878034059 hsr_dev_finalize+0x4f5/0x770 net/hsr/hsr_device.c:491 hsr_newlink+0x27d/0x3e0 net/hsr/hsr_netlink.c:78 rtnl_newlink+0x1030/0x15c0 net/core/rtnetlink.c:3141 ubi0: available PEBs: 28, total reserved PEBs: 4, PEBs reserved for bad PEB handling: 0 ubi0: background thread "ubi_bgt0d" started, PID 1073 rtnetlink_rcv_msg+0x453/0xb80 net/core/rtnetlink.c:4782 ubi0: detaching mtd0 ubi0: mtd0 is detached netlink_rcv_skb+0x160/0x440 net/netlink/af_netlink.c:2463 ubi0: attaching mtd0 netlink_unicast_kernel net/netlink/af_netlink.c:1325 [inline] netlink_unicast+0x4d5/0x690 net/netlink/af_netlink.c:1351 netlink_sendmsg+0x6c3/0xc50 net/netlink/af_netlink.c:1917 sock_sendmsg_nosec net/socket.c:651 [inline] sock_sendmsg+0xc3/0x120 net/socket.c:661 ___sys_sendmsg+0x7bb/0x8e0 net/socket.c:2227 ubi0: scanning is finished __sys_sendmsg net/socket.c:2265 [inline] __do_sys_sendmsg net/socket.c:2274 [inline] __se_sys_sendmsg net/socket.c:2272 [inline] __x64_sys_sendmsg+0x132/0x220 net/socket.c:2272 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f77af9d30c9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 00 00 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 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f77adf24168 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f77afaf3050 RCX: 00007f77af9d30c9 RDX: 0000000000000000 RSI: 00000000200000c0 RDI: 0000000000000004 RBP: 00007f77afa2eae9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffc228c8ddf R14: 00007f77adf24300 R15: 0000000000022000 ubi0 error: ubi_attach_mtd_dev: cannot spawn "ubi_bgt0d", error -4 ubi0: attaching mtd0 ubi0: scanning is finished ubi0: attached mtd0 (name "mtdram test device", size 0 MiB) ubi0: PEB size: 4096 bytes (4 KiB), LEB size: 3968 bytes ubi0: min./max. I/O unit sizes: 1/64, sub-page size 1 ubi0: VID header offset: 64 (aligned 64), data offset: 128 ubi0: good PEBs: 32, bad PEBs: 0, corrupted PEBs: 0 ubi0: user volume: 0, internal volumes: 1, max. volumes count: 23 ubi0: max/mean erase counter: 1/1, WL threshold: 4096, image sequence number: 1878034059 ubi0: available PEBs: 28, total reserved PEBs: 4, PEBs reserved for bad PEB handling: 0 ubi0: background thread "ubi_bgt0d" started, PID 1114 ubi0: detaching mtd0 ubi0: mtd0 is detached ubi0: attaching mtd0 ubi0: scanning is finished ubi0: attached mtd0 (name "mtdram test device", size 0 MiB) ubi0: PEB size: 4096 bytes (4 KiB), LEB size: 3968 bytes ubi0: min./max. I/O unit sizes: 1/64, sub-page size 1 ubi0: VID header offset: 64 (aligned 64), data offset: 128 ubi0: good PEBs: 32, bad PEBs: 0, corrupted PEBs: 0 ubi0: user volume: 0, internal volumes: 1, max. volumes count: 23 ubi0: max/mean erase counter: 1/1, WL threshold: 4096, image sequence number: 1878034059 ubi0: available PEBs: 28, total reserved PEBs: 4, PEBs reserved for bad PEB handling: 0 ubi0: background thread "ubi_bgt0d" started, PID 1126 ubi0: detaching mtd0 ubi0: mtd0 is detached