BUG: soft lockup in sys_sendmsg

Status: fixed on 2024/05/22 23:36
Subsystems: tipc batman
[Documentation on labels]
Reported-by: syzbot+a6a4b5bb3da165594cff@syzkaller.appspotmail.com
Fix commit: b1f532a3b1e6 batman-adv: Avoid infinite loop trying to resize local TT
First crash: 914d, last: 869d
▶ ▼ Duplicate bugs (1)
Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
INFO: rcu detected stall in batadv_iv_send_outstanding_bat_ogm_packet (5) batman 1 syz, C 44 768d 767d 0/29 closed as dup on 2024/07/04 19:37
▶ ▼ Discussions (2)
Title Replies (including bot) Last reply
[PATCH 1/1] batman-adv: Avoid infinite loop trying to resize local TT 1 (1) 2024/04/05 08:31
[syzbot] [batman?] BUG: soft lockup in sys_sendmsg 3 (5) 2024/03/21 18:26
▶ ▼ Similar bugs (10)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-6-1 BUG: soft lockup in sys_sendmsg origin:upstream 1 syz, C 3 826d 853d 0/2 upstream: reported C repro on 2024/04/09 06:46
linux-6.1 INFO: rcu detected stall in sendmsg (5) 1 syz, C 47 5d16h 413d 0/3 upstream: reported C repro on 2025/06/23 07:43
linux-6.1 BUG: soft lockup in sys_sendmsg 1 2 1155d 1161d 0/3 auto-obsoleted due to no activity on 2023/09/20 17:26
upstream BUG: soft lockup in sys_sendmsg (2) prio:high tipc 1 syz, C error error 59 18d 431d 0/29 upstream: reported C repro on 2025/06/05 02:15
android-5-10 BUG: soft lockup in sys_sendmsg 1 syz, C error 66 67d 871d 0/2 upstream: reported C repro on 2024/03/22 10:41
android-5-15 BUG: soft lockup in sys_sendmsg origin:upstream 1 syz, C error 13 697d 871d 0/2 upstream: reported C repro on 2024/03/22 10:44
linux-5.15 INFO: rcu detected stall in sys_sendmsg origin:upstream 1 syz, C error 67 3d01h 874d 0/3 upstream: reported C repro on 2024/03/19 21:37
linux-6.1 BUG: soft lockup in sys_sendmsg (2) origin:upstream 1 syz, C done 1 856d 856d 3/3 fixed on 2024/05/15 09:17
linux-6.6 INFO: rcu detected stall in sendmsg 1 13 40d 375d 0/2 upstream: reported on 2025/07/31 17:16
linux-6.1 INFO: rcu detected stall in sys_sendmsg 1 6 681d 767d 0/3 auto-obsoleted due to no activity on 2025/01/06 11:24

Sample crash report:
watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [syz-executor389:11960]
Modules linked in:
irq event stamp: 4931
hardirqs last  enabled at (4930): [<ffff80008ad68de8>] __exit_to_kernel_mode arch/arm64/kernel/entry-common.c:85 [inline]
hardirqs last  enabled at (4930): [<ffff80008ad68de8>] exit_to_kernel_mode+0xdc/0x10c arch/arm64/kernel/entry-common.c:95
hardirqs last disabled at (4931): [<ffff80008ad66a78>] __el1_irq arch/arm64/kernel/entry-common.c:533 [inline]
hardirqs last disabled at (4931): [<ffff80008ad66a78>] el1_interrupt+0x24/0x68 arch/arm64/kernel/entry-common.c:551
softirqs last  enabled at (728): [<ffff800088e9a56c>] spin_unlock_bh include/linux/spinlock.h:396 [inline]
softirqs last  enabled at (728): [<ffff800088e9a56c>] release_sock+0x154/0x1b8 net/core/sock.c:3547
softirqs last disabled at (734): [<ffff800088eaf8bc>] spin_lock_bh include/linux/spinlock.h:356 [inline]
softirqs last disabled at (734): [<ffff800088eaf8bc>] lock_sock_nested+0x74/0x11c net/core/sock.c:3526
CPU: 0 PID: 11960 Comm: syz-executor389 Not tainted 6.8.0-rc7-syzkaller-g707081b61156 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024
pstate: 00400005 (nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : queued_spin_lock_slowpath+0x15c/0xcf8 kernel/locking/qspinlock.c:383
lr : queued_spin_lock_slowpath+0x168/0xcf8 kernel/locking/qspinlock.c:383
sp : ffff8000999776c0
x29: ffff800099977760 x28: 1fffe0001a159d93 x27: 1ffff0001332eee4
x26: dfff800000000000 x25: 1fffe0001a159d95 x24: ffff8000999776e0
x23: ffff800099977720 x22: ffff70001332eedc x21: 0000000000000001
x20: 0000000000000001 x19: ffff0000d0acec98 x18: 0000000000000000
x17: 0000000000000000 x16: ffff8000809fd934 x15: 0000000000000001
x14: 1fffe0001a159d93 x13: 0000000000000000 x12: 0000000000000000
x11: ffff60001a159d94 x10: 1fffe0001a159d93 x9 : 0000000000000000
x8 : 0000000000000001 x7 : ffff800088eaf8bc x6 : 0000000000000000
x5 : 0000000000000000 x4 : 0000000000000001 x3 : ffff80008ae5db50
x2 : 0000000000000000 x1 : 0000000000000001 x0 : 0000000000000001
Call trace:
 __cmpwait_case_8 arch/arm64/include/asm/cmpxchg.h:229 [inline]
 __cmpwait arch/arm64/include/asm/cmpxchg.h:257 [inline]
 queued_spin_lock_slowpath+0x15c/0xcf8 kernel/locking/qspinlock.c:383
 queued_spin_lock include/asm-generic/qspinlock.h:114 [inline]
 do_raw_spin_lock+0x320/0x348 kernel/locking/spinlock_debug.c:116
 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:127 [inline]
 _raw_spin_lock_bh+0x50/0x60 kernel/locking/spinlock.c:178
 spin_lock_bh include/linux/spinlock.h:356 [inline]
 lock_sock_nested+0x74/0x11c net/core/sock.c:3526
 lock_sock include/net/sock.h:1691 [inline]
 tipc_sendstream+0x50/0x84 net/tipc/socket.c:1550
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg net/socket.c:745 [inline]
 ____sys_sendmsg+0x56c/0x840 net/socket.c:2584
 ___sys_sendmsg net/socket.c:2638 [inline]
 __sys_sendmsg+0x26c/0x33c net/socket.c:2667
 __do_sys_sendmsg net/socket.c:2676 [inline]
 __se_sys_sendmsg net/socket.c:2674 [inline]
 __arm64_sys_sendmsg+0x80/0x94 net/socket.c:2674
 __invoke_syscall arch/arm64/kernel/syscall.c:34 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:48
 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:133
 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:152
 el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:712
 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:730
 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:598

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/03/24 18:43 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 707081b61156 0ea90952 .config console log report syz C [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 BUG: soft lockup in sys_sendmsg
2024/03/21 18:25 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 707081b61156 6753db5c .config console log report syz C [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 BUG: soft lockup in sys_sendmsg
2024/02/08 00:16 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 41bccc98fb79 6404acf9 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 BUG: soft lockup in sys_sendmsg
* Struck through repros no longer work on HEAD.