syzbot


possible deadlock in dev_uc_sync

Status: auto-closed as invalid on 2020/12/19 23:00
Reported-by: syzbot+d434977d25e8a23f3cc6@syzkaller.appspotmail.com
First crash: 676d, last: 676d
similar bugs (2):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.19 possible deadlock in dev_uc_sync 1 694d 694d 0/1 auto-closed as invalid on 2020/12/02 10:24
upstream possible deadlock in dev_uc_sync C done 3 625d 723d 17/22 fixed on 2020/11/16 12:12

Sample crash report:
device team0 entered promiscuous mode
device team_slave_0 entered promiscuous mode
device team_slave_1 entered promiscuous mode
======================================================
WARNING: possible circular locking dependency detected
4.14.194-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor.3/13020 is trying to acquire lock:
 (&dev_addr_list_lock_key#2/1){+...}, at: [<ffffffff8514e54b>] netif_addr_lock_nested include/linux/netdevice.h:3699 [inline]
 (&dev_addr_list_lock_key#2/1){+...}, at: [<ffffffff8514e54b>] dev_uc_sync+0x10b/0x1c0 net/core/dev_addr_lists.c:544

but task is already holding lock:
 (&macvlan_netdev_addr_lock_key#2/2){+...}, at: [<ffffffff8513d92b>] spin_lock_bh include/linux/spinlock.h:322 [inline]
 (&macvlan_netdev_addr_lock_key#2/2){+...}, at: [<ffffffff8513d92b>] netif_addr_lock_bh include/linux/netdevice.h:3704 [inline]
 (&macvlan_netdev_addr_lock_key#2/2){+...}, at: [<ffffffff8513d92b>] dev_set_rx_mode net/core/dev.c:6720 [inline]
 (&macvlan_netdev_addr_lock_key#2/2){+...}, at: [<ffffffff8513d92b>] __dev_open+0x21b/0x310 net/core/dev.c:1375

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&macvlan_netdev_addr_lock_key#2/2){+...}:
       _raw_spin_lock_nested+0x30/0x40 kernel/locking/spinlock.c:362
       netif_addr_lock_nested include/linux/netdevice.h:3699 [inline]
       dev_uc_sync_multiple+0x10b/0x1c0 net/core/dev_addr_lists.c:574
       team_set_rx_mode+0xb8/0x1e0 drivers/net/team/team.c:1781
       __dev_set_rx_mode+0x191/0x2a0 net/core/dev.c:6715
       dev_uc_sync+0x17a/0x1c0 net/core/dev_addr_lists.c:547
       macvlan_set_mac_lists+0x55/0x110 drivers/net/macvlan.c:808
       __dev_set_rx_mode+0x191/0x2a0 net/core/dev.c:6715
       dev_set_rx_mode net/core/dev.c:6721 [inline]
       __dev_open+0x223/0x310 net/core/dev.c:1375
       __dev_change_flags+0x43f/0x540 net/core/dev.c:6793
       rtnl_configure_link+0xd9/0x200 net/core/rtnetlink.c:2421
       rtnl_newlink+0xfa4/0x1830 net/core/rtnetlink.c:2748
       rtnetlink_rcv_msg+0x3be/0xb10 net/core/rtnetlink.c:4316
       netlink_rcv_skb+0x125/0x390 net/netlink/af_netlink.c:2433
       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

-> #0 (&dev_addr_list_lock_key#2/1){+...}:
       lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998
       _raw_spin_lock_nested+0x30/0x40 kernel/locking/spinlock.c:362
       netif_addr_lock_nested include/linux/netdevice.h:3699 [inline]
       dev_uc_sync+0x10b/0x1c0 net/core/dev_addr_lists.c:544
       macvlan_set_mac_lists+0x55/0x110 drivers/net/macvlan.c:808
       __dev_set_rx_mode+0x191/0x2a0 net/core/dev.c:6715
       dev_set_rx_mode net/core/dev.c:6721 [inline]
       __dev_open+0x223/0x310 net/core/dev.c:1375
       __dev_change_flags+0x43f/0x540 net/core/dev.c:6793
       rtnl_configure_link+0xd9/0x200 net/core/rtnetlink.c:2421
       rtnl_newlink+0xfa4/0x1830 net/core/rtnetlink.c:2748
       rtnetlink_rcv_msg+0x3be/0xb10 net/core/rtnetlink.c:4316
       netlink_rcv_skb+0x125/0x390 net/netlink/af_netlink.c:2433
       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:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&macvlan_netdev_addr_lock_key#2/2);
                               lock(&dev_addr_list_lock_key#2/1);
                               lock(&macvlan_netdev_addr_lock_key#2/2);
  lock(&dev_addr_list_lock_key#2/1);

 *** DEADLOCK ***

2 locks held by syz-executor.3/13020:
 #0:  (rtnl_mutex){+.+.}, at: [<ffffffff85175d2d>] rtnl_lock net/core/rtnetlink.c:72 [inline]
 #0:  (rtnl_mutex){+.+.}, at: [<ffffffff85175d2d>] rtnetlink_rcv_msg+0x31d/0xb10 net/core/rtnetlink.c:4311
 #1:  (&macvlan_netdev_addr_lock_key#2/2){+...}, at: [<ffffffff8513d92b>] spin_lock_bh include/linux/spinlock.h:322 [inline]
 #1:  (&macvlan_netdev_addr_lock_key#2/2){+...}, at: [<ffffffff8513d92b>] netif_addr_lock_bh include/linux/netdevice.h:3704 [inline]
 #1:  (&macvlan_netdev_addr_lock_key#2/2){+...}, at: [<ffffffff8513d92b>] dev_set_rx_mode net/core/dev.c:6720 [inline]
 #1:  (&macvlan_netdev_addr_lock_key#2/2){+...}, at: [<ffffffff8513d92b>] __dev_open+0x21b/0x310 net/core/dev.c:1375

stack backtrace:
CPU: 1 PID: 13020 Comm: syz-executor.3 Not tainted 4.14.194-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+0x1b2/0x283 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
 _raw_spin_lock_nested+0x30/0x40 kernel/locking/spinlock.c:362
 netif_addr_lock_nested include/linux/netdevice.h:3699 [inline]
 dev_uc_sync+0x10b/0x1c0 net/core/dev_addr_lists.c:544
 macvlan_set_mac_lists+0x55/0x110 drivers/net/macvlan.c:808
 __dev_set_rx_mode+0x191/0x2a0 net/core/dev.c:6715
 dev_set_rx_mode net/core/dev.c:6721 [inline]
 __dev_open+0x223/0x310 net/core/dev.c:1375
 __dev_change_flags+0x43f/0x540 net/core/dev.c:6793
 rtnl_configure_link+0xd9/0x200 net/core/rtnetlink.c:2421
 rtnl_newlink+0xfa4/0x1830 net/core/rtnetlink.c:2748
 rtnetlink_rcv_msg+0x3be/0xb10 net/core/rtnetlink.c:4316
 netlink_rcv_skb+0x125/0x390 net/netlink/af_netlink.c:2433
 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: 0033:0x45d4d9
RSP: 002b:00007fb22209fc78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 000000000002cd80 RCX: 000000000045d4d9
RDX: 0000000000000000 RSI: 0000000020000040 RDI: 0000000000000007
RBP: 000000000118cf80 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118cf4c
R13: 00007ffe2da6fddf R14: 00007fb2220a09c0 R15: 000000000118cf4c
device macvlan2 entered promiscuous mode
8021q: adding VLAN 0 to HW filter on device macvlan2
net_ratelimit: 7931 callbacks suppressed
GRED: Unable to relocate VQ 0x0 after dequeue, screwing up backlog
GRED: Unable to relocate VQ 0x0 after dequeue, screwing up backlog
GRED: Unable to relocate VQ 0x0 after dequeue, screwing up backlog
GRED: Unable to relocate VQ 0x0 after dequeue, screwing up backlog
GRED: Unable to relocate VQ 0x0 after dequeue, screwing up backlog
GRED: Unable to relocate VQ 0x0 after dequeue, screwing up backlog
GRED: Unable to relocate VQ 0x0 after dequeue, screwing up backlog
GRED: Unable to relocate VQ 0x0 after dequeue, screwing up backlog
GRED: Unable to relocate VQ 0x0 after dequeue, screwing up backlog
GRED: Unable to relocate VQ 0x0 after dequeue, screwing up backlog
net_ratelimit: 8429 callbacks suppressed
GRED: Unable to relocate VQ 0x0 after dequeue, screwing up backlog
GRED: Unable to relocate VQ 0x0 after dequeue, screwing up backlog
GRED: Unable to relocate VQ 0x0 after dequeue, screwing up backlog
GRED: Unable to relocate VQ 0x0 after dequeue, screwing up backlog
GRED: Unable to relocate VQ 0x0 after dequeue, screwing up backlog
GRED: Unable to relocate VQ 0x0 after dequeue, screwing up backlog
GRED: Unable to relocate VQ 0x0 after dequeue, screwing up backlog
GRED: Unable to relocate VQ 0x0 after dequeue, screwing up backlog
GRED: Unable to relocate VQ 0x0 after dequeue, screwing up backlog
GRED: Unable to relocate VQ 0x0 after dequeue, screwing up backlog

Crashes (1):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-linux-4-14 2020/08/21 22:59 linux-4.14.y 6a24ca2506d6 6436ce4b .config log report