[syzbot] [wpan?] WARNING in cfg802154_switch_netns (3)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 2ba9f676d0a2 Merge tag 'drm-next-2024-11-29' of https://gi..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=13b7b9e8580000
kernel config: https://syzkaller.appspot.com/x/.config?x=7903df3280dd39ea
dashboard link: https://syzkaller.appspot.com/bug?extid=bd5829ba3619f08e2341
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=17b7b9e8580000

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7feb34a89c2a/non_bootable_disk-2ba9f676.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/49a0011f6379/vmlinux-2ba9f676.xz
kernel image: https://storage.googleapis.com/syzbot-assets/ac57640f6a59/bzImage-2ba9f676.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+bd5829...@syzkaller.appspotmail.com

R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000002
R13: 0000000000000000 R14: 00007f2cedb45fa0 R15: 00007ffcd711e1d8
</TASK>
------------[ cut here ]------------
WARNING: CPU: 0 PID: 20692 at net/ieee802154/core.c:258 cfg802154_switch_netns+0x3c7/0x3d0 net/ieee802154/core.c:258
Modules linked in:
CPU: 0 UID: 0 PID: 20692 Comm: syz.3.7229 Not tainted 6.12.0-syzkaller-11677-g2ba9f676d0a2 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:cfg802154_switch_netns+0x3c7/0x3d0 net/ieee802154/core.c:258
Code: e1 07 38 c1 7c 92 48 89 ef e8 c5 74 87 f6 eb 88 e8 7e 8d 1c f6 e9 66 fe ff ff e8 74 8d 1c f6 e9 5c fe ff ff e8 6a 8d 1c f6 90 <0f> 0b 90 e9 4e fe ff ff 90 90 90 90 90 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc9000dcff3c8 EFLAGS: 00010293
RAX: ffffffff8b795426 RBX: 00000000fffffff4 RCX: ffff888000342440
RDX: 0000000000000000 RSI: 00000000fffffff4 RDI: 0000000000000000
RBP: ffff88801f128198 R08: ffffffff8b795270 R09: 1ffffffff285fb12
R10: dffffc0000000000 R11: fffffbfff285fb13 R12: ffff888032cb4db0
R13: 0000000000000000 R14: ffff88801f128078 R15: dffffc0000000000
FS: 00007f2cee7af6c0(0000) GS:ffff88801fc00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 00000000120f6000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
nl802154_wpan_phy_netns+0x13d/0x210 net/ieee802154/nl802154.c:1292
genl_family_rcv_msg_doit net/netlink/genetlink.c:1115 [inline]
genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline]
genl_rcv_msg+0xb14/0xec0 net/netlink/genetlink.c:1210
netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2542
genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219
netlink_unicast_kernel net/netlink/af_netlink.c:1321 [inline]
netlink_unicast+0x7f6/0x990 net/netlink/af_netlink.c:1347
netlink_sendmsg+0x8e4/0xcb0 net/netlink/af_netlink.c:1891
sock_sendmsg_nosec net/socket.c:711 [inline]
__sock_sendmsg+0x221/0x270 net/socket.c:726
____sys_sendmsg+0x52a/0x7e0 net/socket.c:2583
___sys_sendmsg net/socket.c:2637 [inline]
__sys_sendmsg+0x269/0x350 net/socket.c:2669
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2ced980849
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f2cee7af058 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f2cedb45fa0 RCX: 00007f2ced980849
RDX: 0000000000000000 RSI: 0000000020000f40 RDI: 0000000000000004
RBP: 00007f2cee7af0a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000002
R13: 0000000000000000 R14: 00007f2cedb45fa0 R15: 00007ffcd711e1d8
</TASK>


---
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[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit: 7b24f164cf00 Merge tag 'ipsec-next-2025-01-09' of git://gi..
git tree: net-next
console+strace: https://syzkaller.appspot.com/x/log.txt?x=168791df980000
kernel config: https://syzkaller.appspot.com/x/.config?x=28dc37e0ec0dfc41

dashboard link: https://syzkaller.appspot.com/bug?extid=bd5829ba3619f08e2341
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=122fef0f980000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16c9ccb0580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/73892b055b77/disk-7b24f164.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/d6a3f606bee9/vmlinux-7b24f164.xz
kernel image: https://storage.googleapis.com/syzbot-assets/4d3108a02573/bzImage-7b24f164.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+bd5829...@syzkaller.appspotmail.com

RSP: 002b:00007ffe8eee9248 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007ffe8eee9260 RCX: 00007f255ac67da9
RDX: 000000000004c084 RSI: 0000000020000100 RDI: 0000000000000006
RBP: 0000000000000001 R08: 00007ffe8eee8fe7 R09: 000055556b883610
R10: 0000000000000001 R11: 0000000000000246 R12: 00007f255acafe7c
R13: 00007f255acaa10f R14: 0000000000000001 R15: 0000000000000001

</TASK>
------------[ cut here ]------------

WARNING: CPU: 0 PID: 5837 at net/ieee802154/core.c:258 cfg802154_switch_netns+0x3c7/0x3d0 net/ieee802154/core.c:258
Modules linked in:
CPU: 0 UID: 0 PID: 5837 Comm: syz-executor125 Not tainted 6.13.0-rc6-syzkaller-00918-g7b24f164cf00 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024

RIP: 0010:cfg802154_switch_netns+0x3c7/0x3d0 net/ieee802154/core.c:258

Code: e1 07 38 c1 7c 92 48 89 ef e8 35 dd 86 f6 eb 88 e8 9e 79 20 f6 e9 66 fe ff ff e8 94 79 20 f6 e9 5c fe ff ff e8 8a 79 20 f6 90 <0f> 0b 90 e9 4e fe ff ff 90 90 90 90 90 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc9000406f3c8 EFLAGS: 00010293
RAX: ffffffff8b7f0a96 RBX: 00000000fffffff4 RCX: ffff88802e890000

RDX: 0000000000000000 RSI: 00000000fffffff4 RDI: 0000000000000000

RBP: ffff88814479e198 R08: ffffffff8b7f08e0 R09: 1ffffffff2858111
R10: dffffc0000000000 R11: fffffbfff2858112 R12: 0000000000000000
R13: 0000000000000000 R14: ffff88814479e078 R15: dffffc0000000000
FS: 000055556b882380(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000

CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033

CR2: 00007f255acbe5e7 CR3: 000000007e970000 CR4: 00000000003526f0

DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
nl802154_wpan_phy_netns+0x13d/0x210 net/ieee802154/nl802154.c:1292
genl_family_rcv_msg_doit net/netlink/genetlink.c:1115 [inline]
genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline]
genl_rcv_msg+0xb14/0xec0 net/netlink/genetlink.c:1210

netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2543
genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219
netlink_unicast_kernel net/netlink/af_netlink.c:1322 [inline]
netlink_unicast+0x7f6/0x990 net/netlink/af_netlink.c:1348
netlink_sendmsg+0x8e4/0xcb0 net/netlink/af_netlink.c:1892

sock_sendmsg_nosec net/socket.c:711 [inline]
__sock_sendmsg+0x221/0x270 net/socket.c:726

____sys_sendmsg+0x52a/0x7e0 net/socket.c:2594
___sys_sendmsg net/socket.c:2648 [inline]
__sys_sendmsg+0x269/0x350 net/socket.c:2680

do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f

RIP: 0033:0x7f255ac67da9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffe8eee9248 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007ffe8eee9260 RCX: 00007f255ac67da9
RDX: 000000000004c084 RSI: 0000000020000100 RDI: 0000000000000006
RBP: 0000000000000001 R08: 00007ffe8eee8fe7 R09: 000055556b883610
R10: 0000000000000001 R11: 0000000000000246 R12: 00007f255acafe7c
R13: 00007f255acaa10f R14: 0000000000000001 R15: 0000000000000001
</TASK>


---

[syzbot]

For archival purposes, forwarding an incoming command email to
linux-...@vger.kernel.org, syzkall...@googlegroups.com.

***

Subject: Re: [PATCH RFC v2] wifi: cfg80211: replace WARN_ON() with dev_err() in netns switch
Author: nog...@google.com

Debugging went 100% astray because of an strace output in the repro run results.

#syz reject

On Tue, May 19, 2026 at 12:08 AM 'syzbot' via
syzkaller-upstream-moderation
<syzkaller-upst...@googlegroups.com> wrote:
>
> The syzkaller reported a kernel panic in cfg802154_switch_netns() when
> device_rename() fails with -ENOMEM. The crash occurs because WARN_ON()
> is used to handle the memory allocation failure, which escalates into a
> kernel panic when panic_on_warn is enabled.
>
> Memory allocation failures are expected runtime events under memory
> pressure and should be handled gracefully. The WARN_ON() macro must not
> be used for conditions that can legitimately happen. Failing to rename
> the device or change the network namespace is not a fatal system error.
>
> Replace the WARN_ON() calls with dev_err() in both
> cfg802154_switch_netns() and cfg80211_switch_netns(), as well as in
> their respective pernet exit handlers (cfg802154_pernet_exit() and
> cfg80211_pernet_exit()). This ensures that memory allocation failures
> under pressure are handled gracefully, logging the error for debugging
> purposes without bringing down the entire system.
>
> Fixes: 04600794958f1833f5571c6cde40f260ab557f55 ("cfg80211: support sysfs namespaces")
> Assisted-by: Gemini:gemini-3.1-pro-preview Gemini:gemini-3-flash-preview
> Reported-by: syzbot+bd5829...@syzkaller.appspotmail.com
> Link: https://syzkaller.appspot.com/bug?extid=bd5829ba3619f08e2341
> Link: https://syzkaller.appspot.com/ai_job?id=a1cfc84c-7c0f-4340-891d-885fcee80cad
> To: <alex....@gmail.com>
> To: <da...@davemloft.net>
> To: <edum...@google.com>
> To: <ku...@kernel.org>
> To: <linux...@vger.kernel.org>
> To: <miquel...@bootlin.com>
> To: <net...@vger.kernel.org>
> To: <pab...@redhat.com>
> To: <ste...@datenfreihafen.org>
> Cc: <ho...@kernel.org>
> Cc: <joha...@sipsolutions.net>
> Cc: <linux-...@vger.kernel.org>
> Cc: <linux-w...@vger.kernel.org>
>
> ---
> v2:
> - Replaced pr_err() with dev_err() to include device details in the error messages.
>
> v1:
> https://lore.kernel.org/all/7d949fbc-9781-4428...@mail.kernel.org/T/
> ---
> diff --git a/net/ieee802154/core.c b/net/ieee802154/core.c
> index 89b671b12..07082857c 100644
> --- a/net/ieee802154/core.c
> +++ b/net/ieee802154/core.c
> @@ -245,7 +245,9 @@ int cfg802154_switch_netns(struct cfg802154_registered_device *rdev,
> wpan_dev->netdev->netns_immutable = false;
> err = dev_change_net_namespace(wpan_dev->netdev, net,
> "wpan%d");
> - WARN_ON(err);
> + if (err)
> + dev_err(&rdev->wpan_phy.dev,
> + "failed to change netns: %d\n", err);
> wpan_dev->netdev->netns_immutable = true;
> }
>
> @@ -255,7 +257,9 @@ int cfg802154_switch_netns(struct cfg802154_registered_device *rdev,
> wpan_phy_net_set(&rdev->wpan_phy, net);
>
> err = device_rename(&rdev->wpan_phy.dev, dev_name(&rdev->wpan_phy.dev));
> - WARN_ON(err);
> + if (err)
> + dev_err(&rdev->wpan_phy.dev, "failed to rename device: %d\n",
> + err);
>
> return 0;
> }
> @@ -350,8 +354,11 @@ static void __net_exit cfg802154_pernet_exit(struct net *net)
>
> rtnl_lock();
> list_for_each_entry(rdev, &cfg802154_rdev_list, list) {
> - if (net_eq(wpan_phy_net(&rdev->wpan_phy), net))
> - WARN_ON(cfg802154_switch_netns(rdev, &init_net));
> + if (net_eq(wpan_phy_net(&rdev->wpan_phy), net)) {
> + if (cfg802154_switch_netns(rdev, &init_net))
> + dev_err(&rdev->wpan_phy.dev,
> + "failed to switch netns on exit\n");
> + }
> }
> rtnl_unlock();
> }
> diff --git a/net/wireless/core.c b/net/wireless/core.c
> index 6783e0672..6badcec46 100644
> --- a/net/wireless/core.c
> +++ b/net/wireless/core.c
> @@ -184,7 +184,9 @@ int cfg80211_switch_netns(struct cfg80211_registered_device *rdev,
> wdev->netdev->netns_immutable = false;
> err = dev_change_net_namespace(wdev->netdev, net,
> "wlan%d");
> - WARN_ON(err);
> + if (err)
> + dev_err(&rdev->wiphy.dev,
> + "failed to change netns: %d\n", err);
> wdev->netdev->netns_immutable = true;
> }
>
> @@ -204,7 +206,8 @@ int cfg80211_switch_netns(struct cfg80211_registered_device *rdev,
> wiphy_net_set(&rdev->wiphy, net);
>
> err = device_rename(&rdev->wiphy.dev, dev_name(&rdev->wiphy.dev));
> - WARN_ON(err);
> + if (err)
> + dev_err(&rdev->wiphy.dev, "failed to rename device: %d\n", err);
>
> nl80211_notify_wiphy(rdev, NL80211_CMD_NEW_WIPHY);
>
> @@ -1809,8 +1812,11 @@ static void __net_exit cfg80211_pernet_exit(struct net *net)
>
> rtnl_lock();
> for_each_rdev(rdev) {
> - if (net_eq(wiphy_net(&rdev->wiphy), net))
> - WARN_ON(cfg80211_switch_netns(rdev, &init_net));
> + if (net_eq(wiphy_net(&rdev->wiphy), net)) {
> + if (cfg80211_switch_netns(rdev, &init_net))
> + dev_err(&rdev->wiphy.dev,
> + "failed to switch netns on exit\n");
> + }
> }
> rtnl_unlock();
> }
>
>
> base-commit: 5d6919055dec134de3c40167a490f33c74c12581
> --
> This is an AI-generated patch subject to moderation.
> Reply with '#syz upstream' to send it to the mailing list.
> Reply with '#syz reject' to reject it.
>
> See for more information.
>
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[Dmitry Vyukov]

On Tue, 19 May 2026 at 16:08, syzbot
<syzbot+bd5829...@syzkaller.appspotmail.com> wrote:
>
> For archival purposes, forwarding an incoming command email to
> linux-...@vger.kernel.org, syzkall...@googlegroups.com.
>
> ***
>
> Subject: Re: [PATCH RFC v2] wifi: cfg80211: replace WARN_ON() with dev_err() in netns switch
> Author: nog...@google.com
>
> Debugging went 100% astray because of an strace output in the repro run results.

The "100% astray" was related to the "WARNING: ODEBUG bug in
ieee80211_led_exit (2)" bug, not this one.

> You received this message because you are subscribed to the Google Groups "syzkaller-bugs" group.
> To unsubscribe from this group and stop receiving emails from it, send an email to syzkaller-bug...@googlegroups.com.
> To view this discussion visit https://groups.google.com/d/msgid/syzkaller-bugs/6a0c6ec4.170a0220.39a13.0003.GAE%40google.com.