bisecting fixing commit since 4143d798313fffa39f05bf24dd560ace42225c26 building syzkaller on c104d4a3bfc1f83e7ed33b4dca70e099402ce39f testing commit 4143d798313fffa39f05bf24dd560ace42225c26 compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: 03039936026b4d6ded8490a8e35601a875b79493d3300ca4120b58b79b24eccf all runs: crashed: WARNING in ieee80211_free_ack_frame testing current HEAD 3f8a27f9e27bd78604c0709224cec0ec85a8b106 testing commit 3f8a27f9e27bd78604c0709224cec0ec85a8b106 compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: 3e9578343783517d9e9c8f7e130d86db19f77d0a9e04f34b63992946a7dd25e6 all runs: crashed: WARNING in ieee80211_free_ack_frame revisions tested: 2, total time: 36m12.219854277s (build: 22m52.13247889s, test: 12m51.55778056s) the crash still happens on HEAD commit msg: Linux 4.19.211 crash: WARNING in ieee80211_free_ack_frame team0: Port device team_slave_0 added ------------[ cut here ]------------ IPv6: ADDRCONF(NETDEV_UP): team_slave_1: link is not ready Have pending ack frames! team0: Port device team_slave_1 added WARNING: CPU: 0 PID: 33 at net/mac80211/main.c:1279 ieee80211_free_ack_frame+0x34/0x40 net/mac80211/main.c:1279 Kernel panic - not syncing: panic_on_warn set ... batman_adv: batadv0: Adding interface: batadv_slave_0 CPU: 0 PID: 33 Comm: kworker/u4:2 Not tainted 4.19.211-syzkaller #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. Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: netns cleanup_net batman_adv: batadv0: Not using interface batadv_slave_0 (retrying later): interface not active Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x17c/0x226 lib/dump_stack.c:118 panic+0x1cd/0x375 kernel/panic.c:186 __warn.cold.7+0x1b/0x36 kernel/panic.c:541 report_bug+0x1a1/0x200 lib/bug.c:183 fixup_bug arch/x86/kernel/traps.c:178 [inline] fixup_bug arch/x86/kernel/traps.c:173 [inline] do_error_trap+0x200/0x350 arch/x86/kernel/traps.c:296 batman_adv: batadv0: Adding interface: batadv_slave_1 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:316 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:1038 RIP: 0010:ieee80211_free_ack_frame+0x34/0x40 net/mac80211/main.c:1279 Code: f5 57 77 03 00 74 0c 48 89 f7 e8 97 7f e9 fe 31 c0 c9 c3 48 c7 c7 a0 78 f6 88 48 89 75 f8 c6 05 d5 57 77 03 01 e8 c1 3d 58 00 <0f> 0b 48 8b 75 f8 eb d5 0f 1f 40 00 55 be 04 00 00 00 48 89 e5 41 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. RSP: 0018:ffff8880b502f970 EFLAGS: 00010286 batman_adv: batadv0: Not using interface batadv_slave_1 (retrying later): interface not active RAX: 0000000000000000 RBX: dffffc0000000000 RCX: 0000000000000000 IPv6: ADDRCONF(NETDEV_UP): bridge_slave_0: link is not ready RDX: 0000000000000004 RSI: ffffffff885024a0 RDI: ffffffff8bada720 RBP: ffff8880b502f978 R08: ffffed1017444ea9 R09: ffffed1017444ea8 R10: ffffed1017444ea8 R11: ffff8880ba227547 R12: 0000000000000000 R13: ffff88808a2f6630 R14: ffffffff872a0c30 R15: ffff8880b502fa38 idr_for_each+0x114/0x250 lib/idr.c:211 ieee80211_free_hw+0x77/0x130 net/mac80211/main.c:1294 IPv6: ADDRCONF(NETDEV_UP): bridge_slave_1: link is not ready mac80211_hwsim_del_radio+0x2a7/0x360 drivers/net/wireless/mac80211_hwsim.c:2998 hwsim_exit_net+0x869/0x1200 drivers/net/wireless/mac80211_hwsim.c:3666 ops_exit_list.isra.0+0x8b/0x120 net/core/net_namespace.c:153 cleanup_net+0x368/0x850 net/core/net_namespace.c:554 process_one_work+0x7b9/0x15a0 kernel/workqueue.c:2153 worker_thread+0x85/0xb60 kernel/workqueue.c:2296 kthread+0x347/0x410 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 Kernel Offset: disabled Rebooting in 86400 seconds..