syzbot


possible deadlock in dev_mc_sync

Status: auto-closed as invalid on 2022/05/28 09:02
Reported-by: syzbot+fca3254245333fced25c@syzkaller.appspotmail.com
First crash: 1040d, last: 1040d
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream possible deadlock in dev_mc_sync net 5 1545d 1620d 0/28 auto-closed as invalid on 2021/01/08 21:25
linux-4.19 possible deadlock in dev_mc_sync (2) 2 810d 828d 0/1 auto-obsoleted due to no activity on 2023/01/14 06:46

Sample crash report:
netlink: 24 bytes leftover after parsing attributes in process `syz-executor.0'.
netlink: 24 bytes leftover after parsing attributes in process `syz-executor.4'.
IPv6: ADDRCONF(NETDEV_UP): vlan88: link is not ready
============================================
WARNING: possible recursive locking detected
4.19.211-syzkaller #0 Not tainted
--------------------------------------------
syz-executor.4/7598 is trying to acquire lock:
000000009320d211 (&vlan_netdev_addr_lock_key#2/2){+...}, at: netif_addr_lock_nested include/linux/netdevice.h:4007 [inline]
000000009320d211 (&vlan_netdev_addr_lock_key#2/2){+...}, at: dev_mc_sync+0x11a/0x1e0 net/core/dev_addr_lists.c:765

but task is already holding lock:
00000000b280aa70 (&vlan_netdev_addr_lock_key#2/2){+...}, at: spin_lock_bh include/linux/spinlock.h:334 [inline]
00000000b280aa70 (&vlan_netdev_addr_lock_key#2/2){+...}, at: netif_addr_lock_bh include/linux/netdevice.h:4012 [inline]
00000000b280aa70 (&vlan_netdev_addr_lock_key#2/2){+...}, at: dev_set_rx_mode net/core/dev.c:7606 [inline]
00000000b280aa70 (&vlan_netdev_addr_lock_key#2/2){+...}, at: __dev_open+0x264/0x3a0 net/core/dev.c:1410

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(&vlan_netdev_addr_lock_key#2/2);
  lock(&vlan_netdev_addr_lock_key#2/2);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

2 locks held by syz-executor.4/7598:
 #0: 0000000054255175 (rtnl_mutex){+.+.}, at: rtnl_lock net/core/rtnetlink.c:77 [inline]
 #0: 0000000054255175 (rtnl_mutex){+.+.}, at: rtnetlink_rcv_msg+0x3fe/0xb80 net/core/rtnetlink.c:4779
 #1: 00000000b280aa70 (&vlan_netdev_addr_lock_key#2/2){+...}, at: spin_lock_bh include/linux/spinlock.h:334 [inline]
 #1: 00000000b280aa70 (&vlan_netdev_addr_lock_key#2/2){+...}, at: netif_addr_lock_bh include/linux/netdevice.h:4012 [inline]
 #1: 00000000b280aa70 (&vlan_netdev_addr_lock_key#2/2){+...}, at: dev_set_rx_mode net/core/dev.c:7606 [inline]
 #1: 00000000b280aa70 (&vlan_netdev_addr_lock_key#2/2){+...}, at: __dev_open+0x264/0x3a0 net/core/dev.c:1410

stack backtrace:
CPU: 1 PID: 7598 Comm: syz-executor.4 Not tainted 4.19.211-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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
 lock_acquire+0x170/0x3c0 kernel/locking/lockdep.c:3908
 _raw_spin_lock_nested+0x30/0x40 kernel/locking/spinlock.c:354
 netif_addr_lock_nested include/linux/netdevice.h:4007 [inline]
 dev_mc_sync+0x11a/0x1e0 net/core/dev_addr_lists.c:765
 vlan_dev_set_rx_mode+0x38/0x80 net/8021q/vlan_dev.c:488
 __dev_set_rx_mode+0x1d9/0x2f0 net/core/dev.c:7601
 dev_set_rx_mode net/core/dev.c:7607 [inline]
 __dev_open+0x26c/0x3a0 net/core/dev.c:1410
 __dev_change_flags+0x501/0x660 net/core/dev.c:7679
 rtnl_configure_link+0xec/0x230 net/core/rtnetlink.c:2830
 rtnl_newlink+0x1057/0x15c0 net/core/rtnetlink.c:3161
 rtnetlink_rcv_msg+0x453/0xb80 net/core/rtnetlink.c:4782
 netlink_rcv_skb+0x160/0x440 net/netlink/af_netlink.c:2463
 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
 __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: 0033:0x7fd317a1f059
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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fd316373168 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fd317b32030 RCX: 00007fd317a1f059
RDX: 0000000000000000 RSI: 0000000020000140 RDI: 0000000000000004
RBP: 00007fd317a7908d R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffede4861cf R14: 00007fd316373300 R15: 0000000000022000
IPv6: ADDRCONF(NETDEV_UP): vlan0: link is not ready
IPv6: ADDRCONF(NETDEV_UP): vlan4: link is not ready
FAT-fs (loop3): error, fat_get_cluster: detected the cluster chain loop (i_pos 131)
FAT-fs (loop3): error, fat_free_clusters: deleting FAT entry beyond EOF
FAT-fs (loop2): error, fat_get_cluster: detected the cluster chain loop (i_pos 131)
FAT-fs (loop2): error, fat_free_clusters: deleting FAT entry beyond EOF
netlink: 24 bytes leftover after parsing attributes in process `syz-executor.5'.
netlink: 24 bytes leftover after parsing attributes in process `syz-executor.0'.
FAT-fs (loop3): error, clusters badly computed (1 != 0)
FAT-fs (loop3): Filesystem has been set read-only
netlink: 24 bytes leftover after parsing attributes in process `syz-executor.4'.
IPv6: ADDRCONF(NETDEV_UP): vlan88: link is not ready
IPv6: ADDRCONF(NETDEV_UP): vlan89: link is not ready
FAT-fs (loop2): error, invalid access to FAT (entry 0x0000068f)
FAT-fs (loop2): Filesystem has been set read-only
FAT-fs (loop2): error, invalid access to FAT (entry 0x0000068f)
FAT-fs (loop2): error, invalid access to FAT (entry 0x0000068f)
FAT-fs (loop2): Filesystem has been set read-only
FAT-fs (loop2): error, invalid access to FAT (entry 0x0000068f)
IPv6: ADDRCONF(NETDEV_UP): vlan0: link is not ready
IPv6: ADDRCONF(NETDEV_UP): vlan2: link is not ready
Bluetooth: hci1: command 0x0406 tx timeout
Bluetooth: hci3: command 0x0406 tx timeout
Bluetooth: hci4: command 0x0406 tx timeout
netlink: 24 bytes leftover after parsing attributes in process `syz-executor.5'.
netlink: 24 bytes leftover after parsing attributes in process `syz-executor.4'.
IPv6: ADDRCONF(NETDEV_UP): vlan0: link is not ready
IPv6: ADDRCONF(NETDEV_UP): vlan2: link is not ready
FAT-fs (loop3): error, fat_get_cluster: detected the cluster chain loop (i_pos 131)
FAT-fs (loop3): error, fat_free_clusters: deleting FAT entry beyond EOF
netlink: 24 bytes leftover after parsing attributes in process `syz-executor.0'.
netlink: 24 bytes leftover after parsing attributes in process `syz-executor.5'.
netlink: 24 bytes leftover after parsing attributes in process `syz-executor.1'.
FAT-fs (loop3): error, clusters badly computed (1 != 0)
FAT-fs (loop3): Filesystem has been set read-only
netlink: 24 bytes leftover after parsing attributes in process `syz-executor.4'.
IPv6: ADDRCONF(NETDEV_UP): vlan88: link is not ready
IPv6: ADDRCONF(NETDEV_UP): vlan1: link is not ready
IPv6: ADDRCONF(NETDEV_UP): vlan0: link is not ready
IPv6: ADDRCONF(NETDEV_UP): vlan2: link is not ready
IPv6: ADDRCONF(NETDEV_UP): vlan89: link is not ready
IPv6: ADDRCONF(NETDEV_UP): vlan2: link is not ready
FAT-fs (loop2): error, clusters badly computed (1 != 0)
FAT-fs (loop2): Filesystem has been set read-only

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2022/01/28 09:01 linux-4.19.y 3f8a27f9e27b 495e00c5 .config console log report info ci2-linux-4-19 possible deadlock in dev_mc_sync
* Struck through repros no longer work on HEAD.