syzbot


BUG: MAX_STACK_TRACE_ENTRIES too low!

Status: upstream: reported C repro on 2025/09/23 14:36
Bug presence: origin:lts-only
[Documentation on labels]
Reported-by: syzbot+e727758e2a57bcf22bcd@syzkaller.appspotmail.com
First crash: 113d, last: 20d
Fix bisection: fixed by (bisect log) [release commit]:
commit 0a805b6ea8cda0caa268b396a2e5117f3772d849
Author: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: Sun Nov 2 13:14:42 2025 +0000

  Linux 6.6.116

  
Bug presence (2)
Date Name Commit Repro Result
2025/12/25 linux-6.6.y (ToT) 5fa4793a2d2d syz [report] BUG: MAX_STACK_TRACE_ENTRIES too low!
2025/12/25 upstream (ToT) ccd1cdca5cd4 syz Didn't crash
Similar bugs (6)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream BUG: MAX_STACK_TRACE_ENTRIES too low! (3) net -1 2 1729d 1730d 20/29 fixed on 2021/11/10 00:50
upstream BUG: MAX_STACK_TRACE_ENTRIES too low! (2) -1 C done 5045 2314d 2483d 13/29 fixed on 2019/10/15 23:40
upstream BUG: MAX_STACK_TRACE_ENTRIES too low! (4) bpf -1 C done unreliable 31 298d 474d 0/29 auto-obsoleted due to no activity on 2025/08/31 03:03
linux-5.15 BUG: MAX_STACK_TRACE_ENTRIES too low! origin:lts-only -1 C done 43 12d 666d 0/3 upstream: reported C repro on 2024/03/19 07:46
upstream BUG: MAX_STACK_TRACE_ENTRIES too low! -1 C done 1725 2484d 2510d 11/29 fixed on 2019/03/28 12:00
linux-6.1 BUG: MAX_STACK_TRACE_ENTRIES too low! origin:lts-only -1 C inconclusive 4 39d 298d 0/3 upstream: reported C repro on 2025/03/22 10:39
Fix bisection attempts (2)
Created Duration User Patch Repo Result
2026/01/01 15:55 1h45m fix candidate upstream OK (0) job log
2025/11/03 02:48 5h20m bisect fix linux-6.6.y OK (1) job log

Sample crash report:
chnl_net:caif_netlink_parms(): no params data found
BUG: MAX_STACK_TRACE_ENTRIES too low!
turning off the locking correctness validator.
CPU: 0 PID: 14842 Comm: syz-executor Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106
 save_trace+0x991/0xcd0 kernel/locking/lockdep.c:578
 check_prev_add kernel/locking/lockdep.c:3195 [inline]
 check_prevs_add kernel/locking/lockdep.c:3253 [inline]
 validate_chain kernel/locking/lockdep.c:3869 [inline]
 __lock_acquire+0x4399/0x7c80 kernel/locking/lockdep.c:5137
 lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754
 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
 _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
 htab_lock_bucket+0x181/0x300 kernel/bpf/hashtab.c:166
 htab_map_delete_elem+0x1a4/0x630 kernel/bpf/hashtab.c:1443
 bpf_prog_2c29ac5cdc6b1842+0x42/0x46
 bpf_dispatcher_nop_func include/linux/bpf.h:1224 [inline]
 __bpf_prog_run include/linux/filter.h:612 [inline]
 bpf_prog_run include/linux/filter.h:619 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:2322 [inline]
 bpf_trace_run3+0x1e7/0x400 kernel/trace/bpf_trace.c:2362
 __traceiter_kmem_cache_free+0x34/0x50 include/trace/events/kmem.h:114
 trace_kmem_cache_free include/trace/events/kmem.h:114 [inline]
 kmem_cache_free+0x1e0/0x280 mm/slub.c:3851
 skb_kfree_head net/core/skbuff.c:947 [inline]
 skb_free_head net/core/skbuff.c:961 [inline]
 skb_release_data+0x60a/0x800 net/core/skbuff.c:991
 skb_release_all net/core/skbuff.c:1057 [inline]
 __kfree_skb net/core/skbuff.c:1071 [inline]
 consume_skb+0xb2/0x110 net/core/skbuff.c:1287
 netlink_broadcast_filtered+0x101c/0x1110 net/netlink/af_netlink.c:1538
 netlink_broadcast net/netlink/af_netlink.c:1560 [inline]
 nlmsg_multicast include/net/netlink.h:1090 [inline]
 nlmsg_notify+0xf0/0x1a0 net/netlink/af_netlink.c:2588
 __addrconf_sysctl_register+0x375/0x3e0 net/ipv6/addrconf.c:7193
 addrconf_sysctl_register+0x15c/0x1b0 net/ipv6/addrconf.c:7230
 ipv6_add_dev+0xc42/0x11f0 net/ipv6/addrconf.c:451
 addrconf_notify+0x67b/0x1010 net/ipv6/addrconf.c:3622
 notifier_call_chain+0x197/0x390 kernel/notifier.c:93
 call_netdevice_notifiers_extack net/core/dev.c:2064 [inline]
 call_netdevice_notifiers net/core/dev.c:2078 [inline]
 register_netdevice+0x160c/0x1ae0 net/core/dev.c:10313
 veth_newlink+0x7bb/0xc30 drivers/net/veth.c:1902
 rtnl_newlink_create net/core/rtnetlink.c:3517 [inline]
 __rtnl_newlink net/core/rtnetlink.c:3737 [inline]
 rtnl_newlink+0x14d0/0x2020 net/core/rtnetlink.c:3750
 rtnetlink_rcv_msg+0x7c7/0xf10 net/core/rtnetlink.c:6472
 netlink_rcv_skb+0x216/0x480 net/netlink/af_netlink.c:2545
 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
 netlink_unicast+0x751/0x8d0 net/netlink/af_netlink.c:1346
 netlink_sendmsg+0x8c1/0xbe0 net/netlink/af_netlink.c:1894
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg net/socket.c:745 [inline]
 __sys_sendto+0x46a/0x620 net/socket.c:2201
 __do_sys_sendto net/socket.c:2213 [inline]
 __se_sys_sendto net/socket.c:2209 [inline]
 __x64_sys_sendto+0xde/0xf0 net/socket.c:2209
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7ff95b5915dc
Code: 2a 5f 02 00 44 8b 4c 24 2c 4c 8b 44 24 20 89 c5 44 8b 54 24 28 48 8b 54 24 18 b8 2c 00 00 00 48 8b 74 24 10 8b 7c 24 08 0f 05 <48> 3d 00 f0 ff ff 77 34 89 ef 48 89 44 24 08 e8 70 5f 02 00 48 8b
RSP: 002b:00007ffda5ea13f0 EFLAGS: 00000293 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007ff95c314620 RCX: 00007ff95b5915dc
RDX: 000000000000002c RSI: 00007ff95c314670 RDI: 0000000000000003
RBP: 0000000000000000 R08: 00007ffda5ea1444 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000003
R13: 0000000000000000 R14: 00007ff95c314670 R15: 0000000000000000
 </TASK>
bridge0: port 1(bridge_slave_0) entered blocking state
bridge0: port 1(bridge_slave_0) entered disabled state
bridge_slave_0: entered allmulticast mode
bridge_slave_0: entered promiscuous mode
bridge0: port 2(bridge_slave_1) entered blocking state
bridge0: port 2(bridge_slave_1) entered disabled state
bridge_slave_1: entered allmulticast mode
bridge_slave_1: entered promiscuous mode
bond0: (slave bond_slave_0): Enslaving as an active interface with an up link
bond0: (slave bond_slave_1): Enslaving as an active interface with an up link
team0: Port device team_slave_0 added
team0: Port device team_slave_1 added
batman_adv: batadv0: Adding interface: batadv_slave_0
batman_adv: batadv0: The MTU of interface batadv_slave_0 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1560 would solve the problem.
batman_adv: batadv0: Not using interface batadv_slave_0 (retrying later): interface not active
batman_adv: batadv0: Adding interface: batadv_slave_1
batman_adv: batadv0: The MTU of interface batadv_slave_1 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1560 would solve the problem.
batman_adv: batadv0: Not using interface batadv_slave_1 (retrying later): interface not active
hsr_slave_0: entered promiscuous mode
hsr_slave_1: entered promiscuous mode
debugfs: Directory 'hsr0' with parent 'hsr' already present!
Cannot create hsr debugfs directory
netdevsim netdevsim2 netdevsim0: renamed from eth0
netdevsim netdevsim2 netdevsim1: renamed from eth1
netdevsim netdevsim2 netdevsim2: renamed from eth2
netdevsim netdevsim2 netdevsim3: renamed from eth3
8021q: adding VLAN 0 to HW filter on device bond0
8021q: adding VLAN 0 to HW filter on device team0
8021q: adding VLAN 0 to HW filter on device batadv0
veth0_vlan: entered promiscuous mode
veth1_vlan: entered promiscuous mode
veth0_macvtap: entered promiscuous mode
veth1_macvtap: entered promiscuous mode
batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3e) already exists on: batadv_slave_0
batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems!
batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3e) already exists on: batadv_slave_0
batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems!
batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3e) already exists on: batadv_slave_0
batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems!
batman_adv: batadv0: Interface activated: batadv_slave_0
batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3f) already exists on: batadv_slave_1
batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems!
batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3f) already exists on: batadv_slave_1
batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems!
batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3f) already exists on: batadv_slave_1
batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems!
batman_adv: batadv0: Interface activated: batadv_slave_1
netdevsim netdevsim2 netdevsim0: set [1, 0] type 2 family 0 port 6081 - 0
netdevsim netdevsim2 netdevsim1: set [1, 0] type 2 family 0 port 6081 - 0
netdevsim netdevsim2 netdevsim2: set [1, 0] type 2 family 0 port 6081 - 0
netdevsim netdevsim2 netdevsim3: set [1, 0] type 2 family 0 port 6081 - 0
ieee80211 phy35: Selected rate control algorithm 'minstrel_ht'
ieee80211 phy36: Selected rate control algorithm 'minstrel_ht'

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/12/06 20:03 linux-6.6.y 4791134e4aeb d6526ea3 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf BUG: MAX_STACK_TRACE_ENTRIES too low!
2025/09/23 14:35 linux-6.6.y af1544b5d072 0ac7291c .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf BUG: MAX_STACK_TRACE_ENTRIES too low!
* Struck through repros no longer work on HEAD.