WARNING: suspicious RCU usage in tipc_bearer_find

[syzbot]

Hello,

syzbot hit the following crash on net-next commit
617aebe6a97efa539cc4b8a52adccd89596e6be0 (Sun Feb 4 00:25:42 2018 +0000)
Merge tag 'usercopy-v4.16-rc1' of
git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

So far this crash happened 4 times on net-next.
Unfortunately, I don't have any reproducer for this crash yet.
Raw console output is attached.
compiler: gcc (GCC) 7.1.1 20170620
.config is attached.

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+b74395...@syzkaller.appspotmail.com
It will help syzbot understand when the bug is fixed. See footer for
details.
If you forward the report, please keep this part and the footer.

netlink: 'syz-executor6': attribute type 1 has an invalid length.
sctp: [Deprecated]: syz-executor3 (pid 6217) Use of int in max_burst socket
option.
Use struct sctp_assoc_value instead

=============================
WARNING: suspicious RCU usage
4.15.0+ #221 Not tainted
sctp: [Deprecated]: syz-executor3 (pid 6225) Use of int in max_burst socket
option.
Use struct sctp_assoc_value instead
-----------------------------
net/tipc/bearer.c:177 suspicious rcu_dereference_protected() usage!

other info that might help us debug this:


rcu_scheduler_active = 2, debug_locks = 1
2 locks held by syz-executor6/6218:
#0: (
syz-executor5 (6213) used greatest stack depth: 14576 bytes left
cb_lock){++++}, at: [<000000004bdfcf78>] genl_rcv+0x19/0x40
net/netlink/genetlink.c:634
#1: (genl_mutex){+.+.}, at: [<00000000482c2989>] genl_lock
net/netlink/genetlink.c:33 [inline]
#1: (genl_mutex){+.+.}, at: [<00000000482c2989>] genl_rcv_msg+0x115/0x140
net/netlink/genetlink.c:622

stack backtrace:
CPU: 1 PID: 6218 Comm: syz-executor6 Not tainted 4.15.0+ #221
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x194/0x257 lib/dump_stack.c:53
lockdep_rcu_suspicious+0x123/0x170 kernel/locking/lockdep.c:4592
tipc_bearer_find+0x2b4/0x3b0 net/tipc/bearer.c:177
tipc_nl_compat_link_set+0x329/0x9f0 net/tipc/netlink_compat.c:729
sock: sock_set_timeout: `syz-executor4' (pid 6237) tries to set negative
timeout
__tipc_nl_compat_doit net/tipc/netlink_compat.c:288 [inline]
tipc_nl_compat_doit+0x15b/0x670 net/tipc/netlink_compat.c:335
tipc_nl_compat_handle net/tipc/netlink_compat.c:1119 [inline]
tipc_nl_compat_recv+0x1135/0x18f0 net/tipc/netlink_compat.c:1201
genl_family_rcv_msg+0x7b7/0xfb0 net/netlink/genetlink.c:599
genl_rcv_msg+0xb2/0x140 net/netlink/genetlink.c:624
netlink_rcv_skb+0x14b/0x380 net/netlink/af_netlink.c:2442
genl_rcv+0x28/0x40 net/netlink/genetlink.c:635
netlink_unicast_kernel net/netlink/af_netlink.c:1308 [inline]
netlink_unicast+0x4c4/0x6b0 net/netlink/af_netlink.c:1334
netlink_sendmsg+0xa4a/0xe60 net/netlink/af_netlink.c:1897
sock_sendmsg_nosec net/socket.c:630 [inline]
sock_sendmsg+0xca/0x110 net/socket.c:640
___sys_sendmsg+0x767/0x8b0 net/socket.c:2046
__sys_sendmsg+0xe5/0x210 net/socket.c:2080
SYSC_sendmsg net/socket.c:2091 [inline]
SyS_sendmsg+0x2d/0x50 net/socket.c:2087
entry_SYSCALL_64_fastpath+0x29/0xa0
RIP: 0033:0x4537d9
RSP: 002b:00007fa225171c58 EFLAGS: 00000212 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fa225172700 RCX: 00000000004537d9
RDX: 0000000000000000 RSI: 0000000020003000 RDI: 0000000000000013
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000212 R12: 0000000000000000
R13: 0000000000a2f09f R14: 00007fa2251729c0 R15: 0000000000000000
sctp: [Deprecated]: syz-executor1 (pid 6246) Use of struct sctp_assoc_value
in delayed_ack socket option.
Use struct sctp_sack_info instead
netlink: 'syz-executor2': attribute type 11 has an invalid length.
netlink: 'syz-executor2': attribute type 11 has an invalid length.
netlink: 8 bytes leftover after parsing attributes in process
`syz-executor0'.
netlink: 8 bytes leftover after parsing attributes in process
`syz-executor0'.
netlink: 8 bytes leftover after parsing attributes in process
`syz-executor5'.
netlink: 8 bytes leftover after parsing attributes in process
`syz-executor5'.
netlink: 8 bytes leftover after parsing attributes in process
`syz-executor5'.
netlink: 8 bytes leftover after parsing attributes in process
`syz-executor5'.
raw_sendmsg: syz-executor3 forgot to set AF_INET. Fix it!
kauditd_printk_skb: 13 callbacks suppressed
audit: type=1400 audit(1518204148.200:35): avc: denied { shutdown } for
pid=6517 comm="syz-executor5"
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
syz0: Invalid MTU -2 requested, hw min 68
syz0: Invalid MTU -2 requested, hw min 68
Cannot find set identified by id 32769 to match
TCP: request_sock_TCPv6: Possible SYN flooding on port 20010. Sending
cookies. Check SNMP counters.
audit: type=1400 audit(1518204148.699:36): avc: denied { prog_run } for
pid=6645 comm="syz-executor2"
scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023
tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=bpf
permissive=1
Cannot find set identified by id 32769 to match
audit: type=1400 audit(1518204148.973:37): avc: denied { getattr } for
pid=6698 comm="syz-executor1"
scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023
tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023
tclass=netlink_netfilter_socket permissive=1
audit: type=1400 audit(1518204149.035:38): avc: denied { write } for
pid=6705 comm="syz-executor7"
scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023
tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023
tclass=netlink_crypto_socket permissive=1
audit: type=1400 audit(1518204149.050:39): avc: denied { listen } for
pid=6705 comm="syz-executor7"
scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023
tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023
tclass=netlink_crypto_socket permissive=1
netlink: 'syz-executor5': attribute type 1 has an invalid length.
netlink: 'syz-executor5': attribute type 1 has an invalid length.
audit: type=1400 audit(1518204149.909:40): avc: denied { read } for
pid=6952 comm="syz-executor5"
scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023
tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023
tclass=netlink_netfilter_socket permissive=1
audit: type=1400 audit(1518204149.943:41): avc: denied { connect } for
pid=6952 comm="syz-executor5"
scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023
tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023
tclass=netlink_netfilter_socket permissive=1
ipt_CLUSTERIP: Please specify an interface name
netlink: 'syz-executor6': attribute type 3 has an invalid length.
netlink: 'syz-executor6': attribute type 3 has an invalid length.
validate_nla: 1 callbacks suppressed
netlink: 'syz-executor3': attribute type 33 has an invalid length.
A link change request failed with some changes committed already. Interface
syz3 may have been left with an inconsistent configuration, please check.
audit: type=1400 audit(1518204151.702:42): avc: denied { setopt } for
pid=7436 comm="syz-executor5"
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
NFQUEUE: number of total queues is 0
NFQUEUE: number of total queues is 0
netlink: 'syz-executor3': attribute type 33 has an invalid length.
A link change request failed with some changes committed already. Interface
syz3 may have been left with an inconsistent configuration, please check.
netlink: 'syz-executor6': attribute type 1 has an invalid length.
netlink: 'syz-executor6': attribute type 1 has an invalid length.
audit: type=1400 audit(1518204152.463:43): avc: denied { map } for
pid=7639 comm="syz-executor3"
path=2F616E6F6E5F6875676570616765202864656C6574656429 dev="hugetlbfs"
ino=19879 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023
tcontext=unconfined_u:object_r:hugetlbfs_t:s0 tclass=file permissive=1
atomic_op 00000000e4d3062f conn xmit_atomic (null)
atomic_op 0000000045f50105 conn xmit_atomic (null)
atomic_op 00000000272ad12c conn xmit_atomic (null)
atomic_op 0000000003371d71 conn xmit_atomic (null)
device syz6 entered promiscuous mode
device syz6 left promiscuous mode
atomic_op 000000002579eed8 conn xmit_atomic (null)
atomic_op 00000000a306f3e1 conn xmit_atomic (null)
FAULT_INJECTION: forcing a failure.
name fail_page_alloc, interval 1, probability 0, space 0, times 1
CPU: 0 PID: 7836 Comm: syz-executor4 Not tainted 4.15.0+ #221
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x194/0x257 lib/dump_stack.c:53
fail_dump lib/fault-inject.c:51 [inline]
should_fail+0x8c0/0xa40 lib/fault-inject.c:149
nla_parse: 3 callbacks suppressed
netlink: 15 bytes leftover after parsing attributes in process
`syz-executor0'.
should_fail_alloc_page mm/page_alloc.c:2955 [inline]
prepare_alloc_pages mm/page_alloc.c:4194 [inline]
__alloc_pages_nodemask+0x338/0xd80 mm/page_alloc.c:4233
audit: type=1400 audit(1518204153.249:44): avc: denied { bind } for
pid=7842 comm="syz-executor0"
scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023
tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023
tclass=netlink_crypto_socket permissive=1
netlink: 15 bytes leftover after parsing attributes in process
`syz-executor0'.
alloc_pages_current+0xb6/0x1e0 mm/mempolicy.c:2055
alloc_pages include/linux/gfp.h:492 [inline]
skb_page_frag_refill+0x358/0x5f0 net/core/sock.c:2208
tun_build_skb.isra.50+0x2f0/0x1810 drivers/net/tun.c:1630
tun_get_user+0x17d0/0x3940 drivers/net/tun.c:1800
tun_chr_write_iter+0xb9/0x160 drivers/net/tun.c:1986
call_write_iter include/linux/fs.h:1781 [inline]
do_iter_readv_writev+0x55c/0x830 fs/read_write.c:653
do_iter_write+0x154/0x540 fs/read_write.c:932
vfs_writev+0x18a/0x340 fs/read_write.c:977
do_writev+0xfc/0x2a0 fs/read_write.c:1012
SYSC_writev fs/read_write.c:1085 [inline]
SyS_writev+0x27/0x30 fs/read_write.c:1082
entry_SYSCALL_64_fastpath+0x29/0xa0
RIP: 0033:0x4536b1
RSP: 002b:00007f3d41762b80 EFLAGS: 00000293 ORIG_RAX: 0000000000000014
RAX: ffffffffffffffda RBX: 000000000000005f RCX: 00000000004536b1
RDX: 0000000000000001 RSI: 00007f3d41762bd0 RDI: 0000000000000012
RBP: 00000000200f805f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000066 R11: 0000000000000293 R12: 0000000000000066
R13: 0000000000000014 R14: 00007f3d417636d4 R15: ffffffffffffffff
atomic_op 00000000f4b2bda9 conn xmit_atomic (null)
FAULT_INJECTION: forcing a failure.
name failslab, interval 1, probability 0, space 0, times 1
CPU: 1 PID: 7886 Comm: syz-executor4 Not tainted 4.15.0+ #221
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x194/0x257 lib/dump_stack.c:53
fail_dump lib/fault-inject.c:51 [inline]
should_fail+0x8c0/0xa40 lib/fault-inject.c:149
should_failslab+0xec/0x120 mm/failslab.c:32
slab_pre_alloc_hook mm/slab.h:422 [inline]
slab_alloc mm/slab.c:3365 [inline]
kmem_cache_alloc+0x47/0x760 mm/slab.c:3539
__build_skb+0x9d/0x450 net/core/skbuff.c:281
build_skb+0x6f/0x2a0 net/core/skbuff.c:312
tun_build_skb.isra.50+0x9cb/0x1810 drivers/net/tun.c:1690
atomic_op 000000002be437ac conn xmit_atomic (null)
tun_get_user+0x17d0/0x3940 drivers/net/tun.c:1800
tun_chr_write_iter+0xb9/0x160 drivers/net/tun.c:1986
call_write_iter include/linux/fs.h:1781 [inline]
do_iter_readv_writev+0x55c/0x830 fs/read_write.c:653
do_iter_write+0x154/0x540 fs/read_write.c:932
vfs_writev+0x18a/0x340 fs/read_write.c:977
do_writev+0xfc/0x2a0 fs/read_write.c:1012
SYSC_writev fs/read_write.c:1085 [inline]
SyS_writev+0x27/0x30 fs/read_write.c:1082
entry_SYSCALL_64_fastpath+0x29/0xa0
RIP: 0033:0x4536b1
RSP: 002b:00007f3d41762b80 EFLAGS: 00000293 ORIG_RAX: 0000000000000014
RAX: ffffffffffffffda RBX: 00007f3d41762aa0 RCX: 00000000004536b1
RDX: 0000000000000001 RSI: 00007f3d41762bd0 RDI: 0000000000000012
RBP: 00007f3d41762a90 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000066 R11: 0000000000000293 R12: 00000000004b863a
R13: 00007f3d41762bc8 R14: 00000000004b863a R15: 0000000000000000
atomic_op 00000000e2fa1a71 conn xmit_atomic (null)
atomic_op 000000003a952aff conn xmit_atomic (null)
netlink: 'syz-executor6': attribute type 33 has an invalid length.
A link change request failed with some changes committed already. Interface
syz6 may have been left with an inconsistent configuration, please check.
netlink: 'syz-executor6': attribute type 33 has an invalid length.
A link change request failed with some changes committed already. Interface
syz6 may have been left with an inconsistent configuration, please check.
netlink: 40 bytes leftover after parsing attributes in process
`syz-executor5'.
audit: type=1400 audit(1518204155.198:45): avc: denied { connect } for
pid=8195 comm="syz-executor6"
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(1518204156.127:46): avc: denied { net_bind_service
} for pid=8464 comm="syz-executor7" capability=10
scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023
tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=cap_userns
permissive=1
audit: type=1400 audit(1518204156.257:47): avc: denied { create } for
pid=8493 comm="syz-executor5"
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(1518204156.286:48): avc: denied { write } for
pid=8493 comm="syz-executor5" path="socket:[20676]" dev="sockfs" ino=20676
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
netlink: 'syz-executor0': attribute type 2 has an invalid length.
audit: type=1400 audit(1518204156.414:49): avc: denied { read } for
pid=8523 comm="syz-executor6"
scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023
tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023
tclass=netlink_crypto_socket permissive=1
FAULT_INJECTION: forcing a failure.
name failslab, interval 1, probability 0, space 0, times 0
CPU: 1 PID: 8533 Comm: syz-executor3 Not tainted 4.15.0+ #221
netlink: 'syz-executor6': attribute type 2 has an invalid length.
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x194/0x257 lib/dump_stack.c:53
fail_dump lib/fault-inject.c:51 [inline]
should_fail+0x8c0/0xa40 lib/fault-inject.c:149
should_failslab+0xec/0x120 mm/failslab.c:32
slab_pre_alloc_hook mm/slab.h:422 [inline]
slab_alloc mm/slab.c:3365 [inline]
__do_kmalloc mm/slab.c:3703 [inline]
__kmalloc+0x63/0x760 mm/slab.c:3714
kmalloc include/linux/slab.h:517 [inline]
sock_kmalloc+0x112/0x190 net/core/sock.c:1986
netlink: 'syz-executor6': attribute type 2 has an invalid length.
___sys_sendmsg+0x458/0x8b0 net/socket.c:2013
__sys_sendmsg+0xe5/0x210 net/socket.c:2080
SYSC_sendmsg net/socket.c:2091 [inline]
SyS_sendmsg+0x2d/0x50 net/socket.c:2087
entry_SYSCALL_64_fastpath+0x29/0xa0
RIP: 0033:0x4537d9
RSP: 002b:00007faabf0e4c58 EFLAGS: 00000212 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007faabf0e4aa0 RCX: 00000000004537d9
RDX: 0000000000000000 RSI: 0000000020019fc8 RDI: 0000000000000013
RBP: 00007faabf0e4a90 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000212 R12: 00000000004b863a
R13: 00007faabf0e4bc8 R14: 00000000004b863a R15: 0000000000000000


---
This bug is generated by a dumb bot. It may contain errors.
See https://goo.gl/tpsmEJ for details.
Direct all questions to syzk...@googlegroups.com.

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[Dmitry Vyukov]

On Fri, Feb 9, 2018 at 8:27 PM, syzbot
<syzbot+b74395...@syzkaller.appspotmail.com> wrote:
> Hello,
>
> syzbot hit the following crash on net-next commit
> 617aebe6a97efa539cc4b8a52adccd89596e6be0 (Sun Feb 4 00:25:42 2018 +0000)
> Merge tag 'usercopy-v4.16-rc1' of
> git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
>
> So far this crash happened 4 times on net-next.
> Unfortunately, I don't have any reproducer for this crash yet.
> Raw console output is attached.
> compiler: gcc (GCC) 7.1.1 20170620
> .config is attached.

For the record, from Eric in
https://groups.google.com/d/msg/syzkaller-bugs/s0qdtBtcJb8/6CrnEixcAgAJ

> This is still happening; looks like a missing lock in tipc_nl_compat_link_set().
> Note that the reproducer isn't guaranteed to work as-is because the message it
> sends to the netlink socket assumes that the "TIPC" generic netlink family was
> assigned ID 31, when actually it is a dynamically assigned ID. But it will
> trigger if you adjust the message's ->nlmsg_type accordingly.

> --
> You received this message because you are subscribed to the Google Groups
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> To unsubscribe from this group and stop receiving emails from it, send an
> email to syzkaller-bug...@googlegroups.com.
> To view this discussion on the web visit
> https://groups.google.com/d/msgid/syzkaller-bugs/94eb2c1984003ba8ef0564cc8333%40google.com.
> For more options, visit https://groups.google.com/d/optout.

[syzbot]

syzbot has found reproducer for the following crash on net-next commit

617aebe6a97efa539cc4b8a52adccd89596e6be0 (Sun Feb 4 00:25:42 2018 +0000)
Merge tag 'usercopy-v4.16-rc1' of
git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

So far this crash happened 13 times on net-next, upstream.
C reproducer is attached.
syzkaller reproducer is attached.

Raw console output is attached.
compiler: gcc (GCC) 7.1.1 20170620
.config is attached.

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+b74395...@syzkaller.appspotmail.com
It will help syzbot understand when the bug is fixed.

audit: type=1400 audit(1518206230.395:8): avc: denied { create } for
pid=4164 comm="syzkaller756462"

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(1518206230.396:9): avc: denied { write } for
pid=4164 comm="syzkaller756462"

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

WARNING: suspicious RCU usage
4.15.0+ #221 Not tainted

-----------------------------
net/tipc/bearer.c:177 suspicious rcu_dereference_protected() usage!

other info that might help us debug this:


rcu_scheduler_active = 2, debug_locks = 1

2 locks held by syzkaller756462/4164:
#0: (cb_lock){++++}, at: [<000000003bb01113>] genl_rcv+0x19/0x40
net/netlink/genetlink.c:634
#1: (genl_mutex){+.+.}, at: [<000000002e321e71>] genl_lock
net/netlink/genetlink.c:33 [inline]
#1: (genl_mutex){+.+.}, at: [<000000002e321e71>] genl_rcv_msg+0x115/0x140
net/netlink/genetlink.c:622

stack backtrace:
CPU: 0 PID: 4164 Comm: syzkaller756462 Not tainted 4.15.0+ #221

Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x194/0x257 lib/dump_stack.c:53
lockdep_rcu_suspicious+0x123/0x170 kernel/locking/lockdep.c:4592
tipc_bearer_find+0x2b4/0x3b0 net/tipc/bearer.c:177
tipc_nl_compat_link_set+0x329/0x9f0 net/tipc/netlink_compat.c:729

__tipc_nl_compat_doit net/tipc/netlink_compat.c:288 [inline]
tipc_nl_compat_doit+0x15b/0x670 net/tipc/netlink_compat.c:335
tipc_nl_compat_handle net/tipc/netlink_compat.c:1119 [inline]
tipc_nl_compat_recv+0x1135/0x18f0 net/tipc/netlink_compat.c:1201
genl_family_rcv_msg+0x7b7/0xfb0 net/netlink/genetlink.c:599
genl_rcv_msg+0xb2/0x140 net/netlink/genetlink.c:624
netlink_rcv_skb+0x14b/0x380 net/netlink/af_netlink.c:2442
genl_rcv+0x28/0x40 net/netlink/genetlink.c:635
netlink_unicast_kernel net/netlink/af_netlink.c:1308 [inline]
netlink_unicast+0x4c4/0x6b0 net/netlink/af_netlink.c:1334
netlink_sendmsg+0xa4a/0xe60 net/netlink/af_netlink.c:1897
sock_sendmsg_nosec net/socket.c:630 [inline]
sock_sendmsg+0xca/0x110 net/socket.c:640
___sys_sendmsg+0x767/0x8b0 net/socket.c:2046
__sys_sendmsg+0xe5/0x210 net/socket.c:2080
SYSC_sendmsg net/socket.c:2091 [inline]
SyS_sendmsg+0x2d/0x50 net/socket.c:2087
entry_SYSCALL_64_fastpath+0x29/0xa0

RIP: 0033:0x43fd69
RSP: 002b:00007fff09979378 EFLAGS: 00000203 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 000000000043fd69
RDX: 0000000000000000 RSI: 0000000020003000 RDI: 0000000000000003
RBP: 00000000006ca018 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000203 R12: 0000000000401690
R13: 0000000000401720 R14: 0000000000000000 R15: 0000000

[Eric Biggers]

This was fixed by commit ed4ffdfec26df:

#syz fix: tipc: Fix missing RTNL lock protection during setting link properties

- Eric