netlink: 'syz.1.15': attribute type 1 has an invalid length.
netlink: 'syz.1.15': attribute type 4 has an invalid length.
netlink: 15334 bytes leftover after parsing attributes in process `syz.1.15'.
=============================
WARNING: suspicious RCU usage
6.12.0-rc3-syzkaller #0 Not tainted
-----------------------------
kernel/rcu/tree.c:4092 Illegal synchronize_rcu() in RCU read-side critical section!

other info that might help us debug this:


rcu_scheduler_active = 2, debug_locks = 1
1 lock held by syz.1.15/5054:
 #0: ffffffff84db24f0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
 #0: ffffffff84db24f0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffffffff84db24f0 (rcu_read_lock){....}-{1:2}, at: route_doit+0x1f1/0x340 net/phonet/pn_netlink.c:264

stack backtrace:
CPU: 1 UID: 0 PID: 5054 Comm: syz.1.15 Not tainted 6.12.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x12b/0x1d0 lib/dump_stack.c:120
 lockdep_rcu_suspicious+0x163/0x1b0 kernel/locking/lockdep.c:6821
 synchronize_rcu+0x90/0x190 kernel/rcu/tree.c:4089
 phonet_route_del+0x7c/0xf0 net/phonet/pn_dev.c:409
 route_doit+0x2f2/0x340 net/phonet/pn_netlink.c:275
 rtnetlink_rcv_msg+0x4e9/0x760 net/core/rtnetlink.c:6777
 netlink_rcv_skb+0xe8/0x1c0 net/netlink/af_netlink.c:2551
 netlink_unicast_kernel net/netlink/af_netlink.c:1331 [inline]
 netlink_unicast+0x497/0x560 net/netlink/af_netlink.c:1357
 netlink_sendmsg+0x4e7/0x5d0 net/netlink/af_netlink.c:1901
 sock_sendmsg_nosec net/socket.c:729 [inline]
 __sock_sendmsg+0xca/0xf0 net/socket.c:744
 sock_write_iter+0x185/0x1e0 net/socket.c:1165
 new_sync_write fs/read_write.c:590 [inline]
 vfs_write+0x4c4/0x620 fs/read_write.c:683
 ksys_write+0xc6/0x180 fs/read_write.c:736
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xa0/0x1b0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f92cf48e719
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f92cef0f038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f92cf645f80 RCX: 00007f92cf48e719
RDX: 000000000000fe33 RSI: 0000000020000000 RDI: 0000000000000004
RBP: 00007f92cf50132e R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f92cf645f80 R15: 00007fff6d56e3f8
 </TASK>

=============================
WARNING: suspicious RCU usage
6.12.0-rc3-syzkaller #0 Not tainted
-----------------------------
kernel/rcu/tree_exp.h:949 Illegal synchronize_rcu_expedited() in RCU read-side critical section!

other info that might help us debug this:


rcu_scheduler_active = 2, debug_locks = 1
1 lock held by syz.1.15/5054:
 #0: ffffffff84db24f0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
 #0: ffffffff84db24f0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffffffff84db24f0 (rcu_read_lock){....}-{1:2}, at: route_doit+0x1f1/0x340 net/phonet/pn_netlink.c:264

stack backtrace:
CPU: 1 UID: 0 PID: 5054 Comm: syz.1.15 Not tainted 6.12.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x12b/0x1d0 lib/dump_stack.c:120
 lockdep_rcu_suspicious+0x163/0x1b0 kernel/locking/lockdep.c:6821
 synchronize_rcu_expedited+0xcb/0x4d0 kernel/rcu/tree_exp.h:946
 synchronize_rcu+0xb0/0x190 kernel/rcu/tree.c:4095
 phonet_route_del+0x7c/0xf0 net/phonet/pn_dev.c:409
 route_doit+0x2f2/0x340 net/phonet/pn_netlink.c:275
 rtnetlink_rcv_msg+0x4e9/0x760 net/core/rtnetlink.c:6777
 netlink_rcv_skb+0xe8/0x1c0 net/netlink/af_netlink.c:2551
 netlink_unicast_kernel net/netlink/af_netlink.c:1331 [inline]
 netlink_unicast+0x497/0x560 net/netlink/af_netlink.c:1357
 netlink_sendmsg+0x4e7/0x5d0 net/netlink/af_netlink.c:1901
 sock_sendmsg_nosec net/socket.c:729 [inline]
 __sock_sendmsg+0xca/0xf0 net/socket.c:744
 sock_write_iter+0x185/0x1e0 net/socket.c:1165
 new_sync_write fs/read_write.c:590 [inline]
 vfs_write+0x4c4/0x620 fs/read_write.c:683
 ksys_write+0xc6/0x180 fs/read_write.c:736
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xa0/0x1b0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f92cf48e719
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f92cef0f038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f92cf645f80 RCX: 00007f92cf48e719
RDX: 000000000000fe33 RSI: 0000000020000000 RDI: 0000000000000004
RBP: 00007f92cf50132e R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f92cf645f80 R15: 00007fff6d56e3f8
 </TASK>