Hello,
syzbot found the following issue on:
HEAD commit: cb83ddcd Linux 4.14.226
git tree: linux-4.14.y
console output:
https://syzkaller.appspot.com/x/log.txt?x=100f55ecd00000
kernel config:
https://syzkaller.appspot.com/x/.config?x=124f4e6b89b71fac
dashboard link:
https://syzkaller.appspot.com/bug?extid=5ada7cef22db1e5045a9
Unfortunately, I don't have any reproducer for this issue yet.
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by:
syzbot+5ada7c...@syzkaller.appspotmail.com
======================================================
WARNING: possible circular locking dependency detected
4.14.226-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor.5/19475 is trying to acquire lock:
(&xt[i].mutex){+.+.}, at: [<ffffffff85ef55e3>] target_revfn+0x43/0x210 net/netfilter/x_tables.c:354
but task is already holding lock:
(&table[i].mutex){+.+.}, at: [<ffffffff85e219e6>] nfnl_lock net/netfilter/nfnetlink.c:61 [inline]
(&table[i].mutex){+.+.}, at: [<ffffffff85e219e6>] nfnetlink_rcv_msg+0x726/0xc00 net/netfilter/nfnetlink.c:209
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #2 (&table[i].mutex){+.+.}:
__mutex_lock_common kernel/locking/mutex.c:756 [inline]
__mutex_lock+0xc4/0x1310 kernel/locking/mutex.c:893
nf_tables_netdev_event+0x10d/0x4d0 net/netfilter/nf_tables_netdev.c:122
notifier_call_chain+0x108/0x1a0 kernel/notifier.c:93
call_netdevice_notifiers_info net/core/dev.c:1667 [inline]
call_netdevice_notifiers net/core/dev.c:1683 [inline]
rollback_registered_many+0x765/0xba0 net/core/dev.c:7203
rollback_registered+0xca/0x170 net/core/dev.c:7245
unregister_netdevice_queue+0x1b4/0x360 net/core/dev.c:8266
br_del_bridge+0xa9/0xe0 net/bridge/br_if.c:419
br_ioctl_deviceless_stub+0x1ff/0x5f0 net/bridge/br_ioctl.c:380
sock_ioctl+0x254/0x4c0 net/socket.c:1038
vfs_ioctl fs/ioctl.c:46 [inline]
file_ioctl fs/ioctl.c:500 [inline]
do_vfs_ioctl+0x75a/0xff0 fs/ioctl.c:684
SYSC_ioctl fs/ioctl.c:701 [inline]
SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692
do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x46/0xbb
-> #1 (rtnl_mutex){+.+.}:
__mutex_lock_common kernel/locking/mutex.c:756 [inline]
__mutex_lock+0xc4/0x1310 kernel/locking/mutex.c:893
unregister_netdevice_notifier+0x5e/0x2b0 net/core/dev.c:1630
tee_tg_destroy+0x5c/0xb0 net/netfilter/xt_TEE.c:123
cleanup_entry+0x232/0x310 net/ipv6/netfilter/ip6_tables.c:684
__do_replace+0x38d/0x580 net/ipv6/netfilter/ip6_tables.c:1105
do_replace net/ipv6/netfilter/ip6_tables.c:1161 [inline]
do_ip6t_set_ctl+0x256/0x3b0 net/ipv6/netfilter/ip6_tables.c:1685
nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
nf_setsockopt+0x5f/0xb0 net/netfilter/nf_sockopt.c:115
ipv6_setsockopt+0xc0/0x120 net/ipv6/ipv6_sockglue.c:937
tcp_setsockopt+0x7b/0xc0 net/ipv4/tcp.c:2828
SYSC_setsockopt net/socket.c:1865 [inline]
SyS_setsockopt+0x110/0x1e0 net/socket.c:1844
do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x46/0xbb
-> #0 (&xt[i].mutex){+.+.}:
lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998
__mutex_lock_common kernel/locking/mutex.c:756 [inline]
__mutex_lock+0xc4/0x1310 kernel/locking/mutex.c:893
target_revfn+0x43/0x210 net/netfilter/x_tables.c:354
xt_find_revision+0x15e/0x1d0 net/netfilter/x_tables.c:378
nfnl_compat_get+0x1f7/0x870 net/netfilter/nft_compat.c:678
nfnetlink_rcv_msg+0x9bb/0xc00 net/netfilter/nfnetlink.c:214
netlink_rcv_skb+0x125/0x390 net/netlink/af_netlink.c:2433
nfnetlink_rcv+0x1ab/0x1da0 net/netfilter/nfnetlink.c:515
netlink_unicast_kernel net/netlink/af_netlink.c:1287 [inline]
netlink_unicast+0x437/0x610 net/netlink/af_netlink.c:1313
netlink_sendmsg+0x62e/0xb80 net/netlink/af_netlink.c:1878
sock_sendmsg_nosec net/socket.c:646 [inline]
sock_sendmsg+0xb5/0x100 net/socket.c:656
___sys_sendmsg+0x6c8/0x800 net/socket.c:2062
__sys_sendmsg+0xa3/0x120 net/socket.c:2096
SYSC_sendmsg net/socket.c:2107 [inline]
SyS_sendmsg+0x27/0x40 net/socket.c:2103
do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x46/0xbb
other info that might help us debug this:
Chain exists of:
&xt[i].mutex --> rtnl_mutex --> &table[i].mutex
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&table[i].mutex);
lock(rtnl_mutex);
lock(&table[i].mutex);
lock(&xt[i].mutex);
*** DEADLOCK ***
1 lock held by syz-executor.5/19475:
#0: (&table[i].mutex){+.+.}, at: [<ffffffff85e219e6>] nfnl_lock net/netfilter/nfnetlink.c:61 [inline]
#0: (&table[i].mutex){+.+.}, at: [<ffffffff85e219e6>] nfnetlink_rcv_msg+0x726/0xc00 net/netfilter/nfnetlink.c:209
stack backtrace:
CPU: 0 PID: 19475 Comm: syz-executor.5 Not tainted 4.14.226-syzkaller #0
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+0x1b2/0x281 lib/dump_stack.c:58
print_circular_bug.constprop.0.cold+0x2d7/0x41e kernel/locking/lockdep.c:1258
check_prev_add kernel/locking/lockdep.c:1905 [inline]
check_prevs_add kernel/locking/lockdep.c:2022 [inline]
validate_chain kernel/locking/lockdep.c:2464 [inline]
__lock_acquire+0x2e0e/0x3f20 kernel/locking/lockdep.c:3491
lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998
__mutex_lock_common kernel/locking/mutex.c:756 [inline]
__mutex_lock+0xc4/0x1310 kernel/locking/mutex.c:893
target_revfn+0x43/0x210 net/netfilter/x_tables.c:354
xt_find_revision+0x15e/0x1d0 net/netfilter/x_tables.c:378
nfnl_compat_get+0x1f7/0x870 net/netfilter/nft_compat.c:678
nfnetlink_rcv_msg+0x9bb/0xc00 net/netfilter/nfnetlink.c:214
netlink_rcv_skb+0x125/0x390 net/netlink/af_netlink.c:2433
nfnetlink_rcv+0x1ab/0x1da0 net/netfilter/nfnetlink.c:515
netlink_unicast_kernel net/netlink/af_netlink.c:1287 [inline]
netlink_unicast+0x437/0x610 net/netlink/af_netlink.c:1313
netlink_sendmsg+0x62e/0xb80 net/netlink/af_netlink.c:1878
sock_sendmsg_nosec net/socket.c:646 [inline]
sock_sendmsg+0xb5/0x100 net/socket.c:656
___sys_sendmsg+0x6c8/0x800 net/socket.c:2062
__sys_sendmsg+0xa3/0x120 net/socket.c:2096
SYSC_sendmsg net/socket.c:2107 [inline]
SyS_sendmsg+0x27/0x40 net/socket.c:2103
do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x465f69
RSP: 002b:00007f901f4be188 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 0000000000465f69
RDX: 0000000000000000 RSI: 0000000020000100 RDI: 0000000000000004
RBP: 00000000004bfa8f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf60
R13: 00007ffcc56bb04f R14: 00007f901f4be300 R15: 0000000000022000
overlayfs: workdir and upperdir must be separate subtrees
overlayfs: workdir and upperdir must be separate subtrees
sctp: [Deprecated]: syz-executor.0 (pid 19530) Use of int in max_burst socket option deprecated.
Use struct sctp_assoc_value instead
overlayfs: workdir and upperdir must be separate subtrees
hfsplus: unable to find HFS+ superblock
hfsplus: unable to find HFS+ superblock
hfsplus: unable to find HFS+ superblock
hfsplus: unable to find HFS+ superblock
hfsplus: unable to find HFS+ superblock
print_req_error: I/O error, dev loop3, sector 0
print_req_error: I/O error, dev loop3, sector 0
print_req_error: I/O error, dev loop3, sector 0
---
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