BUG: soft lockup in sys_sendmsg (2)

Status: fixed on 2024/05/15 09:17
Bug presence: origin:upstream
[Documentation on labels]
Fix commit: 3fe79b2c8346 batman-adv: Avoid infinite loop trying to resize local TT
First crash: 99d, last: 99d
Fix bisection: fixed by (bisect log) :
commit 3fe79b2c83461edbbf86ed8a6f3924820ff89259
Author: Sven Eckelmann <>
Date: Mon Feb 12 12:58:33 2024 +0000

  batman-adv: Avoid infinite loop trying to resize local TT

Bug presence (1)
Date Name Commit Repro Result
2024/04/07 upstream (ToT) f2f80ac80987 C [report] BUG: soft lockup in batadv_iv_send_outstanding_bat_ogm_packet
Similar bugs (7)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-6-1 BUG: soft lockup in sys_sendmsg origin:upstream C 3 69d 97d 0/2 upstream: reported C repro on 2024/04/09 06:46
linux-6.1 BUG: soft lockup in sys_sendmsg 2 398d 404d 0/3 auto-obsoleted due to no activity on 2023/09/20 17:26
android-5-10 BUG: soft lockup in sys_sendmsg C 32 1d03h 114d 0/2 upstream: reported C repro on 2024/03/22 10:41
upstream BUG: soft lockup in sys_sendmsg tipc batman C 3 112d 153d 26/27 fixed on 2024/05/22 23:36
android-5-15 BUG: soft lockup in sys_sendmsg origin:upstream C 11 40d 114d 0/2 upstream: reported C repro on 2024/03/22 10:44
linux-6.1 INFO: rcu detected stall in sys_sendmsg 1 11d 11d 0/3 upstream: reported on 2024/07/04 07:16
linux-5.15 INFO: rcu detected stall in sys_sendmsg origin:upstream C 3 17d 117d 0/3 upstream: reported C repro on 2024/03/19 21:37

Sample crash report:
watchdog: BUG: soft lockup - CPU#0 stuck for 27s! [syz-executor327:4299]
Modules linked in:
irq event stamp: 35843731
hardirqs last  enabled at (35843730): [<ffff8000081c784c>] __local_bh_enable_ip+0x230/0x470 kernel/softirq.c:401
hardirqs last disabled at (35843731): [<ffff800012151f7c>] __el1_irq arch/arm64/kernel/entry-common.c:468 [inline]
hardirqs last disabled at (35843731): [<ffff800012151f7c>] el1_interrupt+0x24/0x68 arch/arm64/kernel/entry-common.c:486
softirqs last  enabled at (740): [<ffff800011efa314>] spin_unlock_bh include/linux/spinlock.h:396 [inline]
softirqs last  enabled at (740): [<ffff800011efa314>] batadv_tvlv_container_register+0x1fc/0x368 net/batman-adv/tvlv.c:258
softirqs last disabled at (744): [<ffff800011ef1d44>] spin_lock_bh include/linux/spinlock.h:356 [inline]
softirqs last disabled at (744): [<ffff800011ef1d44>] batadv_tt_local_resize_to_mtu+0x60/0x150 net/batman-adv/translation-table.c:3949
CPU: 0 PID: 4299 Comm: syz-executor327 Not tainted 6.1.84-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : should_resched arch/arm64/include/asm/preempt.h:79 [inline]
pc : __local_bh_enable_ip+0x238/0x470 kernel/softirq.c:403
lr : __local_bh_enable_ip+0x230/0x470 kernel/softirq.c:401
sp : ffff80001e117110
x29: ffff80001e117120 x28: ffff700003c22e68 x27: ffff80001e117450
x26: ffff0000d61a0640 x25: ffff0000c33ab308 x24: 0000000000000001
x23: 1fffe00019067001 x22: dfff800000000000 x21: ffff800011ef2098
x20: 0000000000000202 x19: ffff0000c8338008 x18: ffff80001e116780
x17: 77656e2074696620 x16: ffff800008305ec4 x15: 0000000000000000
x14: 1ffff00002b080b0 x13: dfff800000000000 x12: 0000000000000003
x11: 0000000000ff0100 x10: 0000000000000003 x9 : 0000000000000000
x8 : 00000000000000e0 x7 : ffff800011ef1f30 x6 : 0000000000000000
x5 : 0000000000000000 x4 : 0000000000000001 x3 : 0000000000000000
x2 : 0000000000000002 x1 : ffff8000122ac6e0 x0 : ffff80019ebc9000
Call trace:
 arch_local_irq_enable arch/arm64/include/asm/irqflags.h:35 [inline]
 __local_bh_enable_ip+0x238/0x470 kernel/softirq.c:401
 __raw_spin_unlock_bh include/linux/spinlock_api_smp.h:167 [inline]
 _raw_spin_unlock_bh+0x48/0x58 kernel/locking/spinlock.c:210
 spin_unlock_bh include/linux/spinlock.h:396 [inline]
 batadv_tt_local_purge+0x264/0x2e8 net/batman-adv/translation-table.c:1356
 batadv_tt_local_resize_to_mtu+0x9c/0x150 net/batman-adv/translation-table.c:3956
 batadv_update_min_mtu+0x74/0xa4 net/batman-adv/hard-interface.c:650
 batadv_netlink_set_mesh+0x50c/0xf3c net/batman-adv/netlink.c:500
 genl_family_rcv_msg_doit net/netlink/genetlink.c:756 [inline]
 genl_family_rcv_msg net/netlink/genetlink.c:833 [inline]
 genl_rcv_msg+0x948/0xc2c net/netlink/genetlink.c:850
 netlink_rcv_skb+0x20c/0x3b8 net/netlink/af_netlink.c:2508
 genl_rcv+0x38/0x50 net/netlink/genetlink.c:861
 netlink_unicast_kernel net/netlink/af_netlink.c:1326 [inline]
 netlink_unicast+0x65c/0x898 net/netlink/af_netlink.c:1352
 netlink_sendmsg+0x834/0xb18 net/netlink/af_netlink.c:1874
 sock_sendmsg_nosec net/socket.c:718 [inline]
 __sock_sendmsg net/socket.c:730 [inline]
 ____sys_sendmsg+0x55c/0x848 net/socket.c:2514
 ___sys_sendmsg net/socket.c:2568 [inline]
 __sys_sendmsg+0x26c/0x33c net/socket.c:2597
 __do_sys_sendmsg net/socket.c:2606 [inline]
 __se_sys_sendmsg net/socket.c:2604 [inline]
 __arm64_sys_sendmsg+0x80/0x94 net/socket.c:2604
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x64/0x218 arch/arm64/kernel/syscall.c:206
 el0_svc+0x58/0x168 arch/arm64/kernel/entry-common.c:637
 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/04/06 21:28 linux-6.1.y 347385861c50 ca620dd8 .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 BUG: soft lockup in sys_sendmsg
* Struck through repros no longer work on HEAD.