From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ed1-f46.google.com (mail-ed1-f46.google.com [209.85.208.46]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1CB2A2AD20 for ; Mon, 2 Feb 2026 08:26:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.208.46 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770020787; cv=none; b=TKbDsm9OaNPt7znAlM6BGwj0ufE1p1BnHyoqBiyCzSBMl66e1T9/mfjak+kWoFveGacF0wl53EwbRfjquOrxhhswUa4cyeJExCUNFCRc1K+HsBRanGKzJz9Hzd+zZ+J3yEAzrcU0QSwHdzsY5EHYGRSPcZPkiPo4JrOXnhItOpk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770020787; c=relaxed/simple; bh=Xfe+LUjYPkIVPnjdezGMhleYeV+zBg+jzR6SxUPHLjk=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=uKu3FnzpmkHRU0uNj3dceZy/ahGconCCAbqzEneUm7vIlicM9PPKr1nA7yNkwNHyGgrInYeB3Sx5Vt2Ldt3GN8K+VC37SPx7LNwQSNzXhO1vEKmQL7smH0HSmqLvZ28dzxqJ3473oqtcNVlRbrOeKEBDQ3eUoMgsSd8FPlno0TE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=openvpn.net; spf=pass smtp.mailfrom=openvpn.com; dkim=pass (2048-bit key) header.d=openvpn.net header.i=@openvpn.net header.b=PCE2ugDQ; arc=none smtp.client-ip=209.85.208.46 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=openvpn.net Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=openvpn.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=openvpn.net header.i=@openvpn.net header.b="PCE2ugDQ" Received: by mail-ed1-f46.google.com with SMTP id 4fb4d7f45d1cf-64bea6c5819so5965372a12.3 for ; Mon, 02 Feb 2026 00:26:23 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=openvpn.net; s=google; t=1770020781; x=1770625581; darn=vger.kernel.org; h=content-transfer-encoding:in-reply-to:organization:autocrypt:from :content-language:references:cc:to:subject:user-agent:mime-version :date:message-id:from:to:cc:subject:date:message-id:reply-to; bh=/m2nZmu5HncF4943JHZWQhVJ3Ajven2N+nDxeVmCb8E=; b=PCE2ugDQAe6AqE19MNIrr48lvChCIE96FaxXokCnPC66Ue6ZnDsSjNx7htftgdjwfw ayIhTIy0qdtRXby7eacfFHohtIyOMWWhmBTYHTPt02nq6RB1gDnEqJRzmJhyDe7Wb5XK 4WY8xmZU1O4lJ7CD2Qd9g7aZ0wQeQzXLARplrs3iakmcpRTRrV80azKz5e93EQVEiIgr q52bb0JR4EUfPZZ/5ij1gW+W1ioCDQ7NJ05nLDw6fLNefkde0yTjAf/iSqZeJEmpYJMm 8j1YItrTDN0gJ5D4vRWLT2jvNnkQdtHxgnGXRVza3LQb54x3WXyf2t6cj66Jc3P+IXvt xwEw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1770020781; x=1770625581; h=content-transfer-encoding:in-reply-to:organization:autocrypt:from :content-language:references:cc:to:subject:user-agent:mime-version :date:message-id:x-gm-gg:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=/m2nZmu5HncF4943JHZWQhVJ3Ajven2N+nDxeVmCb8E=; b=hZ7WFEn0Fa5y7uL4+W55M3SiE/UZYW8gbCsUfwqtN8D0S5I579v8HHVuWXYkh7XGgp 8tOU+pBYejf2WbjuhybauwoeSm2fFi9HUkB9LVscyXYXZiaZ1fEBfRilXQgwN26hFew1 MPeg7B67m8UWaI8KP10LtJ7pNNS4Gb7fce1+RvyX/ZQHdxr8cvZO45tA+xEdVDupYt1G PWehMp6yfTQ5ATFiV3GKSxRRN0K/X+SGwNR0ES05wIpSIcJiQNuzVHVVyakB2Pwk1QqE 4B8IMSS+hLtX8Ny/gW0YYGxad298uxzyg6PblTeNdv/TUwh6GXCjaVu1hzZHpA9eNq7u 6GdQ== X-Forwarded-Encrypted: i=1; AJvYcCVxIEUBToiPftEdhfX89wy3LIgFCTg6bvXHRprUb+kx1+7l5hFapUgFkceYe6gb/CYrQr2ELw5p1SklJBw=@vger.kernel.org X-Gm-Message-State: AOJu0YzS7h+5Alpb/PPLjfxL3yNOsWgSJ0yiiS3TWgXucKQkJfjP3wse D5i8/mk5sDVAvHk+Z2IPC1mXEp6/6eASwL59smeIhBZwGKaTGt/X/1CNQEMCfXMhrp7Sh/B5Ie1 ARMyiNA3ULEsSYX3mp9jAqdan5/9KwP0/ki0X+VmQE+l044GpxVAPxsYl9uA= X-Gm-Gg: AZuq6aLcnC1MiHqJ2uggSH0uqlXhEKmi0CPww3q908yAYgGmcTG977qFPzMlzIdKcMW 4TNSwy72L3OkEv02hnft9xMIrg7vikqBqnSksP2h6WjgWH5faNx93C+0cZm4K84whxUjwyUtSu0 fZ04TuSiYlFnbCU8pr6SslJ1ucry6m98Qu2q5/L1AVrcQdYCdcJXjYclM91RrvUInr6JCtzn7hX XLXFWE28QItHzWiXYQ9T6BRTANLOPcAIxEepxebkwu2VmdcsOKBaKjkYn5RJjZV2MzmQXnLDmMO HvTRZwjEHtXhaiQyaOUswuOefG9cklPdiK9ur8xlDjfAG8cvO+p7cFYdYRVtt9tFzq/71hqFIWp AZQpM/dhiNxwNfB/3DWwxxwPhwDy+eCbJDwEnRQEbW/2aHy1nplcKMSi1k8TMCCldcdl1b7juAe fplfykWRY5cz0J9CfK+KY805RaIf7TQEmAkt3ARL9MTk+sF68vwQ== X-Received: by 2002:a17:907:e113:b0:b8e:14cc:917f with SMTP id a640c23a62f3a-b8e14ccaa2emr304754966b.27.1770020780514; Mon, 02 Feb 2026 00:26:20 -0800 (PST) Received: from ?IPV6:2001:67c:2fbc:1:97a0:6795:ea33:334a? ([2001:67c:2fbc:1:97a0:6795:ea33:334a]) by smtp.gmail.com with ESMTPSA id 4fb4d7f45d1cf-658b469e80fsm7015176a12.25.2026.02.02.00.26.18 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 02 Feb 2026 00:26:19 -0800 (PST) Message-ID: Date: Mon, 2 Feb 2026 09:26:16 +0100 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: Bug#1126499: linux-image-6.17.13+deb14-amd64: ovpn NULL pointer dereference and lockup under heavy load To: Salvatore Bonaccorso , Jon Penn , Sabrina Dubroca Cc: 1126499@bugs.debian.org, Andrew Lunn , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , netdev@vger.kernel.org, linux-kernel@vger.kernel.org References: <4be2e796-77ba-4864-a288-e6edf3b7de12@bentonvillek12.org> <176996279620.3109699.15382994681575380467@eldamar.lan> Content-Language: en-US From: Antonio Quartulli Autocrypt: addr=antonio@openvpn.net; keydata= xsFNBFN3k+ABEADEvXdJZVUfqxGOKByfkExNpKzFzAwHYjhOb3MTlzSLlVKLRIHxe/Etj13I X6tcViNYiIiJxmeHAH7FUj/yAISW56lynAEt7OdkGpZf3HGXRQz1Xi0PWuUINa4QW+ipaKmv voR4b1wZQ9cZ787KLmu10VF1duHW/IewDx9GUQIzChqQVI3lSHRCo90Z/NQ75ZL/rbR3UHB+ EWLIh8Lz1cdE47VaVyX6f0yr3Itx0ZuyIWPrctlHwV5bUdA4JnyY3QvJh4yJPYh9I69HZWsj qplU2WxEfM6+OlaM9iKOUhVxjpkFXheD57EGdVkuG0YhizVF4p9MKGB42D70pfS3EiYdTaKf WzbiFUunOHLJ4hyAi75d4ugxU02DsUjw/0t0kfHtj2V0x1169Hp/NTW1jkqgPWtIsjn+dkde dG9mXk5QrvbpihgpcmNbtloSdkRZ02lsxkUzpG8U64X8WK6LuRz7BZ7p5t/WzaR/hCdOiQCG RNup2UTNDrZpWxpwadXMnJsyJcVX4BAKaWGsm5IQyXXBUdguHVa7To/JIBlhjlKackKWoBnI Ojl8VQhVLcD551iJ61w4aQH6bHxdTjz65MT2OrW/mFZbtIwWSeif6axrYpVCyERIDEKrX5AV rOmGEaUGsCd16FueoaM2Hf96BH3SI3/q2w+g058RedLOZVZtyQARAQABzSdBbnRvbmlvIFF1 YXJ0dWxsaSA8YW50b25pb0BvcGVudnBuLm5ldD7Cwa0EEwEIAFcCGwMFCwkIBwMFFQoJCAsF FgIDAQACHgECF4AYGGhrcHM6Ly9rZXlzLm9wZW5wZ3Aub3JnFiEEyr2hKCAXwmchmIXHSPDM to9Z0UwFAmj3PEoFCShLq0sACgkQSPDMto9Z0Uw7/BAAtMIP/wzpiYn+Di0TWwNAEqDUcGnv JQ0CrFu8WzdtNo1TvEh5oqSLyO0xWaiGeDcC5bQOAAumN+0Aa8NPqhCH5O0eKslzP69cz247 4Yfx/lpNejqDaeu0Gh3kybbT84M+yFJWwbjeT9zPwfSDyoyDfBHbSb46FGoTqXR+YBp9t/CV MuXryL/vn+RmH/R8+s1T/wF2cXpQr3uXuV3e0ccKw33CugxQJsS4pqbaCmYKilLmwNBSHNrD 77BnGkml15Hd6XFFvbmxIAJVnH9ZceLln1DpjVvg5pg4BRPeWiZwf5/7UwOw+tksSIoNllUH 4z/VgsIcRw/5QyjVpUQLPY5kdr57ywieSh0agJ160fP8s/okUqqn6UQV5fE8/HBIloIbf7yW LDE5mYqmcxDzTUqdstKZzIi91QRVLgXgoi7WOeLF2WjITCWd1YcrmX/SEPnOWkK0oNr5ykb0 4XuLLzK9l9MzFkwTOwOWiQNFcxXZ9CdW2sC7G+uxhQ+x8AQW+WoLkKJF2vbREMjLqctPU1A4 557A9xZBI2xg0xWVaaOWr4eyd4vpfKY3VFlxLT7zMy/IKtsm6N01ekXwui1Zb9oWtsP3OaRx gZ5bmW8qwhk5XnNgbSfjehOO7EphsyCBgKkQZtjFyQqQZaDdQ+GTo1t6xnfBB6/TwS7pNpf2 ZvLulFbOOARoRsrsEgorBgEEAZdVAQUBAQdAyD3gsxqcxX256G9lLJ+NFhi7BQpchUat6mSA Pb+1yCQDAQgHwsF8BBgBCAAmFiEEyr2hKCAXwmchmIXHSPDMto9Z0UwFAmhGyuwCGwwFCQHh M4AACgkQSPDMto9Z0UwymQ//Z1tIZaaJM7CH8npDlnbzrI938cE0Ry5acrw2EWd0aGGUaW+L +lu6N1kTOVZiU6rnkjib+9FXwW1LhAUiLYYn2OlVpVT1kBSniR00L3oE62UpFgZbD3hr5S/i o4+ZB8fffAfD6llKxbRWNED9UrfiVh02EgYYS2Jmy+V4BT8+KJGyxNFv0LFSJjwb8zQZ5vVZ 5FPYsSQ5JQdAzYNmA99cbLlNpyHbzbHr2bXr4t8b/ri04Swn+Kzpo+811W/rkq/mI1v+yM/6 o7+0586l1MQ9m0LMj6vLXrBDN0ioGa1/97GhP8LtLE4Hlh+S8jPSDn+8BkSB4+4IpijQKtrA qVTaiP4v3Y6faqJArPch5FHKgu+rn7bMqoipKjVzKGUXroGoUHwjzeaOnnnwYMvkDIwHiAW6 XgzE5ZREn2ffEsSnVPzA4QkjP+QX/5RZoH1983gb7eOXbP/KQhiH6SO1UBAmgPKSKQGRAYYt cJX1bHWYQHTtefBGoKrbkzksL5ZvTdNRcC44/Z5u4yhNmAsq4K6wDQu0JbADv69J56jPaCM+ gg9NWuSR3XNVOui/0JRVx4qd3SnsnwsuF5xy+fD0ocYBLuksVmHa4FsJq9113Or2fM+10t1m yBIZwIDEBLu9zxGUYLenla/gHde+UnSs+mycN0sya9ahOBTG/57k7w/aQLc= Organization: OpenVPN Inc. In-Reply-To: <176996279620.3109699.15382994681575380467@eldamar.lan> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 01/02/2026 17:23, Salvatore Bonaccorso wrote: > Control: forwarded -1 https://lore.kernel.org/netdev/176996279620.3109699.15382994681575380467@eldamar.lan > > Hi Antonio and all, > > In Debian we got the following report from Jon Penn using ovpn, > reported at https://bugs.debian.org/1126499 Hi all, Thanks a lot for the report! We have a fix for this issue in our pipe already - I'll forward it to net ASAP. Best Regards, > > On Tue, Jan 27, 2026 at 10:37:40AM -0600, Jon Penn wrote: >> Package: src:linux >> Version: 6.17.13-1 >> Severity: normal >> >> Dear Maintainer, >> >> This is an OpenVPN server serving primarially TCP clients (but also some UDP >> clients). As I write this there are 1161 TCP clients and 74 UDP clients. It >> is running debian testing in order to have ovpn-dco-offload functionality >> for TCP connections. We observe that under hevy load (in terms of >> connections count, not really under much load in terms of bandwidth) this >> server will become locked up from time to time and the graphical console >> will become completely non-responsive. When this happens we reset the VM and >> things continue running normally. I attempted to monitor the system using >> dmesg and notice that I am getting some interesting messages about "BUG: >> kernel NULL pointer dereference" that mention the ovpn module, leading me to >> believe that this is a kernel bug in that module. Unfortunatly this issue >> only occours when the server has many connections, and that is only >> happening because most of my users are working from home today due to >> weather. This gives me a rather small window of reproducability but if there >> is any additional information I can provide let me know. >> -- Package-specific info: >> ** Version: >> Linux version 6.17.13+deb14-amd64 (debian-kernel@lists.debian.org) >> (x86_64-linux-gnu-gcc-15 (Debian 15.2.0-12) 15.2.0, GNU ld (GNU Binutils for >> Debian) 2.45.50.20251209) #1 SMP PREEMPT_DYNAMIC Debian 6.17.13-1 >> (2025-12-20) >> >> ** Command line: >> BOOT_IMAGE=/boot/vmlinuz-6.17.13+deb14-amd64 >> root=UUID=f00f1200-b8d8-4432-bb0b-593a5ab9075a ro quiet >> >> ** Tainted: D (128) >> * kernel died recently, i.e. there was an OOPS or BUG >> >> ** Kernel log: >> [ 709.018150] tun1: deleting peer with id 719, reason 1 >> [ 709.056997] tun1: deleting peer with id 1055, reason 1 >> [ 711.054524] tun1: deleting peer with id 201, reason 2 >> [ 711.055070] BUG: kernel NULL pointer dereference, address: >> 0000000000000020 >> [ 711.055096] #PF: supervisor write access in kernel mode >> [ 711.055429] #PF: error_code(0x0002) - not-present page >> [ 711.055656] PGD 0 P4D 0 >> [ 711.055824] Oops: Oops: 0002 [#1] SMP NOPTI >> [ 711.055991] CPU: 12 UID: 0 PID: 527 Comm: kworker/12:2 Not tainted >> 6.17.13+deb14-amd64 #1 PREEMPT(lazy) Debian 6.17.13-1 >> [ 711.056154] Hardware name: Red Hat KVM, BIOS >> edk2-20221207gitfff6d81270b5-9.el9_2 12/07/2022 >> [ 711.056333] Workqueue: events ovpn_peer_keepalive_work [ovpn] >> [ 711.056524] RIP: 0010:ovpn_tcp_socket_detach+0x61/0x80 [ovpn] >> [ 711.056695] Code: 01 00 00 48 8b 83 b8 01 00 00 48 89 85 c0 02 00 00 48 8b >> 83 c0 01 00 00 48 89 45 28 48 8b 85 20 01 00 00 48 8b 93 c8 01 00 00 <48> 89 >> 50 20 48 c7 85 98 02 00 00 00 00 00 00 5b 5d c3 cc cc cc cc >> [ 711.056986] RSP: 0018:ffffd3988153fdb8 EFLAGS: 00010246 >> [ 711.057136] RAX: 0000000000000000 RBX: ffff8e65873a5400 RCX: >> 0000000000000004 >> [ 711.057314] RDX: ffffffff92d6d660 RSI: 0000000000000068 RDI: >> ffff8e65873a5568 >> [ 711.057475] RBP: ffff8e6590fb4280 R08: 0000000000000000 R09: >> 0000000000000101 >> [ 711.057644] R10: 0000000000000000 R11: ffffffff93a080e0 R12: >> 000000006978de32 >> [ 711.057794] R13: 0000000000000001 R14: ffff8e65839c1aa8 R15: >> 0000000000000000 >> [ 711.057940] FS: 0000000000000000(0000) GS:ffff8e695b708000(0000) >> knlGS:0000000000000000 >> [ 711.058087] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 >> [ 711.058246] CR2: 0000000000000020 CR3: 000000010862d001 CR4: >> 00000000007726f0 >> [ 711.058412] PKRU: 55555554 >> [ 711.058584] Call Trace: >> [ 711.058739] >> [ 711.058892] ovpn_socket_release+0x165/0x1a0 [ovpn] >> [ 711.059048] unlock_ovpn+0x48/0x80 [ovpn] >> [ 711.059199] ovpn_peer_keepalive_work+0xf3/0x1b0 [ovpn] >> [ 711.059360] ? __schedule+0x464/0xd20 >> [ 711.059557] process_one_work+0x18f/0x350 >> [ 711.059740] worker_thread+0x25a/0x3a0 >> [ 711.059889] ? __pfx_worker_thread+0x10/0x10 >> [ 711.060046] kthread+0xfc/0x240 >> [ 711.060203] ? __pfx_kthread+0x10/0x10 >> [ 711.060358] ? __pfx_kthread+0x10/0x10 >> [ 711.060559] ret_from_fork+0x194/0x1c0 >> [ 711.060801] ? __pfx_kthread+0x10/0x10 >> [ 711.061019] ret_from_fork_asm+0x1a/0x30 >> [ 711.061269] >> [ 711.061494] Modules linked in: intel_rapl_msr intel_rapl_common >> intel_uncore_frequency_common isst_if_mbox_msr isst_if_common ovpn >> ip6_udp_tunnel udp_tunnel skx_edac_common nfit libnvdimm kvm_intel kvm >> binfmt_misc irqbypass ghash_clmulni_intel aesni_intel rapl nls_ascii >> nls_cp437 vfat fat qxl drm_ttm_helper ttm drm_exec pcspkr drm_client_lib sg >> drm_kms_helper button evdev joydev drm configfs efi_pstore nfnetlink >> vsock_loopback vmw_vsock_virtio_transport_common vmw_vsock_vmci_transport >> vsock vmw_vmci efivarfs qemu_fw_cfg autofs4 ext4 crc16 mbcache jbd2 >> crc32c_cryptoapi hid_generic usbhid hid sr_mod sd_mod cdrom ahci libahci >> xhci_pci libata xhci_hcd iTCO_wdt intel_pmc_bxt iTCO_vendor_support watchdog >> psmouse usbcore scsi_mod e1000 serio_raw i2c_i801 lpc_ich scsi_common >> usb_common i2c_smbus >> [ 711.062827] CR2: 0000000000000020 >> [ 711.063051] ---[ end trace 0000000000000000 ]--- >> [ 711.600092] RIP: 0010:ovpn_tcp_socket_detach+0x61/0x80 [ovpn] >> [ 711.602044] Code: 01 00 00 48 8b 83 b8 01 00 00 48 89 85 c0 02 00 00 48 8b >> 83 c0 01 00 00 48 89 45 28 48 8b 85 20 01 00 00 48 8b 93 c8 01 00 00 <48> 89 >> 50 20 48 c7 85 98 02 00 00 00 00 00 00 5b 5d c3 cc cc cc cc >> [ 711.602680] RSP: 0018:ffffd3988153fdb8 EFLAGS: 00010246 >> [ 711.602951] RAX: 0000000000000000 RBX: ffff8e65873a5400 RCX: >> 0000000000000004 >> [ 711.603218] RDX: ffffffff92d6d660 RSI: 0000000000000068 RDI: >> ffff8e65873a5568 >> [ 711.603487] RBP: ffff8e6590fb4280 R08: 0000000000000000 R09: >> 0000000000000101 >> [ 711.603739] R10: 0000000000000000 R11: ffffffff93a080e0 R12: >> 000000006978de32 >> [ 711.603990] R13: 0000000000000001 R14: ffff8e65839c1aa8 R15: >> 0000000000000000 >> [ 711.604231] FS: 0000000000000000(0000) GS:ffff8e695b708000(0000) >> knlGS:0000000000000000 >> [ 711.604483] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 >> [ 711.604723] CR2: 0000000000000020 CR3: 000000019ce2c006 CR4: >> 00000000007726f0 >> [ 711.604958] PKRU: 55555554 >> [ 711.605202] note: kworker/12:2[527] exited with irqs disabled >> [ 711.967459] tun1: deleting peer with id 201, reason 1 >> [ 718.617453] tun1: deleting peer with id 1057, reason 1 >> [ 719.779198] tun1: deleting peer with id 176, reason 1 >> [ 733.398723] tun1: deleting peer with id 1059, reason 1 >> [ 733.926421] tun1: deleting peer with id 154, reason 1 > > Is there anything Jon can do providing more information help > indentifying the problem? > > FWIW, I have not asked Jon yet to test mainline or 6.18.8-1 (but > afaics there were no relevant changes since to drivers/net/ovpn/). > John in Debian you should soon available 6.18.8-1 and please do test > as well 6.19~rc6-1~exp1 from experimental (or 6.19~rc7-1~exp1 once it > passes). > > Regards, > Salvatore -- Antonio Quartulli OpenVPN Inc.