=============================
WARNING: suspicious RCU usage
6.15.0-rc5-syzkaller-00038-g707df3375124 #0 Not tainted
-----------------------------
net/ipv6/ip6_fib.c:1350 suspicious rcu_dereference_protected() usage!
other info that might help us debug this:
rcu_scheduler_active = 2, debug_locks = 1
3 locks held by syz.8.2474/15091:
#0: ffffffff901265a8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#0: ffffffff901265a8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
#0: ffffffff901265a8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x600/0x2000 net/core/rtnetlink.c:4064
#1: ffffffff8e3bf440 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#1: ffffffff8e3bf440 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#1: ffffffff8e3bf440 (rcu_read_lock){....}-{1:3}, at: __fib6_clean_all+0x3a/0x2d0 net/ipv6/ip6_fib.c:2263
#2: ffff88804a66a430 (&tb->tb6_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:356 [inline]
#2: ffff88804a66a430 (&tb->tb6_lock){+.-.}-{3:3}, at: __fib6_clean_all+0xeb/0x2d0 net/ipv6/ip6_fib.c:2267
stack backtrace:
CPU: 0 UID: 0 PID: 15091 Comm: syz.8.2474 Not tainted 6.15.0-rc5-syzkaller-00038-g707df3375124 #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x16c/0x1f0 lib/dump_stack.c:120
lockdep_rcu_suspicious+0x166/0x260 kernel/locking/lockdep.c:6865
__fib6_update_sernum_upto_root+0x221/0x270 net/ipv6/ip6_fib.c:1350
fib6_ifup+0x19b/0x2a0 net/ipv6/route.c:4818
fib6_clean_node+0x2a4/0x5b0 net/ipv6/ip6_fib.c:2199
fib6_walk_continue+0x44f/0x8d0 net/ipv6/ip6_fib.c:2124
fib6_walk+0x182/0x370 net/ipv6/ip6_fib.c:2172
fib6_clean_tree+0xd4/0x110 net/ipv6/ip6_fib.c:2252
__fib6_clean_all+0x107/0x2d0 net/ipv6/ip6_fib.c:2268
rt6_sync_up+0xc9/0x170 net/ipv6/route.c:4837
addrconf_notify+0x1709/0x19e0 net/ipv6/addrconf.c:3729
notifier_call_chain+0xb9/0x410 kernel/notifier.c:85
call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:2176
__dev_notify_flags+0x2a8/0x2e0 net/core/dev.c:9419
netif_change_flags+0x108/0x160 net/core/dev.c:9434
do_setlink.constprop.0+0xddf/0x44b0 net/core/rtnetlink.c:3152
rtnl_group_changelink net/core/rtnetlink.c:3783 [inline]
__rtnl_newlink net/core/rtnetlink.c:3937 [inline]
rtnl_newlink+0x18e0/0x2000 net/core/rtnetlink.c:4065
rtnetlink_rcv_msg+0x95b/0xe90 net/core/rtnetlink.c:6955
netlink_rcv_skb+0x16a/0x440 net/netlink/af_netlink.c:2534
netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline]
netlink_unicast+0x53a/0x7f0 net/netlink/af_netlink.c:1339
netlink_sendmsg+0x8d1/0xdd0 net/netlink/af_netlink.c:1883
sock_sendmsg_nosec net/socket.c:712 [inline]
__sock_sendmsg net/socket.c:727 [inline]
____sys_sendmsg+0xa95/0xc70 net/socket.c:2566
___sys_sendmsg+0x134/0x1d0 net/socket.c:2620
__sys_sendmsg+0x16d/0x220 net/socket.c:2652
do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
__do_fast_syscall_32+0x73/0x120 arch/x86/entry/syscall_32.c:306
do_fast_syscall_32+0x32/0x80 arch/x86/entry/syscall_32.c:331
entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf7f91579
Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00
RSP: 002b:00000000f50b655c EFLAGS: 00000296 ORIG_RAX: 0000000000000172
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000080000280
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000296 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
=============================
WARNING: suspicious RCU usage
6.15.0-rc5-syzkaller-00038-g707df3375124 #0 Not tainted
-----------------------------
net/ipv6/ip6_fib.c:1357 suspicious rcu_dereference_protected() usage!
other info that might help us debug this:
rcu_scheduler_active = 2, debug_locks = 1
3 locks held by syz.8.2474/15091:
#0: ffffffff901265a8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#0: ffffffff901265a8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
#0: ffffffff901265a8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x600/0x2000 net/core/rtnetlink.c:4064
#1: ffffffff8e3bf440 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#1: ffffffff8e3bf440 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#1: ffffffff8e3bf440 (rcu_read_lock){....}-{1:3}, at: __fib6_clean_all+0x3a/0x2d0 net/ipv6/ip6_fib.c:2263
#2: ffff88804a66a430 (&tb->tb6_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:356 [inline]
#2: ffff88804a66a430 (&tb->tb6_lock){+.-.}-{3:3}, at: __fib6_clean_all+0xeb/0x2d0 net/ipv6/ip6_fib.c:2267
stack backtrace:
CPU: 0 UID: 0 PID: 15091 Comm: syz.8.2474 Not tainted 6.15.0-rc5-syzkaller-00038-g707df3375124 #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x16c/0x1f0 lib/dump_stack.c:120
lockdep_rcu_suspicious+0x166/0x260 kernel/locking/lockdep.c:6865
__fib6_update_sernum_upto_root+0x16b/0x270 net/ipv6/ip6_fib.c:1357
fib6_ifup+0x19b/0x2a0 net/ipv6/route.c:4818
fib6_clean_node+0x2a4/0x5b0 net/ipv6/ip6_fib.c:2199
fib6_walk_continue+0x44f/0x8d0 net/ipv6/ip6_fib.c:2124
fib6_walk+0x182/0x370 net/ipv6/ip6_fib.c:2172
fib6_clean_tree+0xd4/0x110 net/ipv6/ip6_fib.c:2252
__fib6_clean_all+0x107/0x2d0 net/ipv6/ip6_fib.c:2268
rt6_sync_up+0xc9/0x170 net/ipv6/route.c:4837
addrconf_notify+0x1709/0x19e0 net/ipv6/addrconf.c:3729
notifier_call_chain+0xb9/0x410 kernel/notifier.c:85
call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:2176
__dev_notify_flags+0x2a8/0x2e0 net/core/dev.c:9419
netif_change_flags+0x108/0x160 net/core/dev.c:9434
do_setlink.constprop.0+0xddf/0x44b0 net/core/rtnetlink.c:3152
rtnl_group_changelink net/core/rtnetlink.c:3783 [inline]
__rtnl_newlink net/core/rtnetlink.c:3937 [inline]
rtnl_newlink+0x18e0/0x2000 net/core/rtnetlink.c:4065
rtnetlink_rcv_msg+0x95b/0xe90 net/core/rtnetlink.c:6955
netlink_rcv_skb+0x16a/0x440 net/netlink/af_netlink.c:2534
netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline]
netlink_unicast+0x53a/0x7f0 net/netlink/af_netlink.c:1339
netlink_sendmsg+0x8d1/0xdd0 net/netlink/af_netlink.c:1883
sock_sendmsg_nosec net/socket.c:712 [inline]
__sock_sendmsg net/socket.c:727 [inline]
____sys_sendmsg+0xa95/0xc70 net/socket.c:2566
___sys_sendmsg+0x134/0x1d0 net/socket.c:2620
__sys_sendmsg+0x16d/0x220 net/socket.c:2652
do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
__do_fast_syscall_32+0x73/0x120 arch/x86/entry/syscall_32.c:306
do_fast_syscall_32+0x32/0x80 arch/x86/entry/syscall_32.c:331
entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf7f91579
Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00
RSP: 002b:00000000f50b655c EFLAGS: 00000296 ORIG_RAX: 0000000000000172
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000080000280
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000296 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
IPv6: RTM_NEWROUTE with no NLM_F_CREATE or NLM_F_REPLACE
IPv6: NLM_F_CREATE should be set when creating new route
IPv6: NLM_F_CREATE should be set when creating new route
----------------
Code disassembly (best guess), 2 bytes skipped:
0: 10 06 adc %al,(%rsi)
2: 03 74 b4 01 add 0x1(%rsp,%rsi,4),%esi
6: 10 07 adc %al,(%rdi)
8: 03 74 b0 01 add 0x1(%rax,%rsi,4),%esi
c: 10 08 adc %cl,(%rax)
e: 03 74 d8 01 add 0x1(%rax,%rbx,8),%esi
1e: 00 51 52 add %dl,0x52(%rcx)
21: 55 push %rbp
22: 89 e5 mov %esp,%ebp
24: 0f 34 sysenter
26: cd 80 int $0x80
* 28: 5d pop %rbp <-- trapping instruction
29: 5a pop %rdx
2a: 59 pop %rcx
2b: c3 ret
2c: 90 nop
2d: 90 nop
2e: 90 nop
2f: 90 nop
30: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi
37: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi