--- id: CVE-2025-21865 title: |- In the Linux kernel, the following vulnerability has been resolved: gtp: Suppress list corruption splat in gtp_net_exit_batch_rtnl(). Brad Spengler reported the list_del() corruption splat in gtp_net_exit_batch_rtnl() summary: |- In the Linux kernel, the following vulnerability has been resolved: gtp: Suppress list corruption splat in gtp_net_exit_batch_rtnl(). Brad Spengler reported the list_del() corruption splat in gtp_net_exit_batch_rtnl(). [0] Commit eb28… severity: medium cvss: 5.5 cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H' cwe: - CWE-787 vendor: linux product: linux_kernel affected: - 'linux_kernel >= 6.1.127, < 6.1.130' - 'linux_kernel >= 6.6.74, < 6.6.80' - 'linux_kernel >= 6.12.11, < 6.12.17' - 'linux_kernel >= 6.13, < 6.13.5' - linux_kernel = 5.4.290 - linux_kernel = 5.10.234 - linux_kernel = 5.15.177 - linux_kernel = 6.14 patched: - linux_kernel 6.13.5 published: '2025-03-12' updated: '2026-10-15' sourceUpdated: '2026-10-15T02:17:40.350' source: NVD sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2025-21865' references: - url: 'https://git.kernel.org/stable/c/33eb925c0c26e86ca540a08254806512bf911f22' label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 - url: 'https://git.kernel.org/stable/c/37e7644b961600ef0beb01d3970c3034a62913af' label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 - url: 'https://git.kernel.org/stable/c/4ccacf86491d33d2486b62d4d44864d7101b299d' label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 - url: 'https://git.kernel.org/stable/c/7f86fb07db65a470d0c11f79da551bd9466357dc' label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 - url: 'https://git.kernel.org/stable/c/9d03e7e37187ae140e716377599493987fb20c5b' label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 - url: 'https://git.kernel.org/stable/c/b70fa591b066d52b141fc430ffdee35b6cc87a66' label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 - url: 'https://git.kernel.org/stable/c/cb15bb1bde0ba97cbbed9508e45210dcafec3657' label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 - url: 'https://git.kernel.org/stable/c/ff81b14010362f6188ca26fec22ff05e4da45595' label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 - url: 'https://lists.debian.org/debian-lts-announce/2025/05/msg00045.html' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://cert-portal.siemens.com/productcert/html/ssa-082556.html' label: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e - url: 'https://cert-portal.siemens.com/productcert/html/ssa-265688.html' label: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e - url: 'https://cert-portal.siemens.com/productcert/html/ssa-784472.html' label: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e tags: - nvd - cve.org epss: 0.00252 epssPercentile: 0.16793 ingestedAt: '2026-10-15T03:30:12.807Z' ssvc: exploitation: none automatable: 'no' technicalImpact: partial timestamp: '2025-10-01T19:25:29.794279Z' --- ## Overview In the Linux kernel, the following vulnerability has been resolved: gtp: Suppress list corruption splat in gtp_net_exit_batch_rtnl(). Brad Spengler reported the list_del() corruption splat in gtp_net_exit_batch_rtnl(). [0] Commit eb28fd76c0a0 ("gtp: Destroy device along with udp socket's netns dismantle.") added the for_each_netdev() loop in gtp_net_exit_batch_rtnl() to destroy devices in each netns as done in geneve and ip tunnels. However, this could trigger ->dellink() twice for the same device during ->exit_batch_rtnl(). Say we have two netns A & B and gtp device B that resides in netns B but whose UDP socket is in netns A. 1. cleanup_net() processes netns A and then B. 2. gtp_net_exit_batch_rtnl() finds the device B while iterating netns A's gn->gtp_dev_list and calls ->dellink(). [ device B is not yet unlinked from netns B as unregister_netdevice_many() has not been called. ] 3. gtp_net_exit_batch_rtnl() finds the device B while iterating netns B's for_each_netdev() and calls ->dellink(). gtp_dellink() cleans up the device's hash table, unlinks the dev from gn->gtp_dev_list, and calls unregister_netdevice_queue(). Basically, calling gtp_dellink() multiple times is fine unless CONFIG_DEBUG_LIST is enabled. Let's remove for_each_netdev() in gtp_net_exit_batch_rtnl() and delegate the destruction to default_device_exit_batch() as done in bareudp. [0]: list_del corruption, ffff8880aaa62c00->next (autoslab_size_M_dev_P_net_core_dev_11127_8_1328_8_S_4096_A_64_n_139+0xc00/0x1000 [slab object]) is LIST_POISON1 (ffffffffffffff02) (prev is 0xffffffffffffff04) kernel BUG at lib/list_debug.c:58! Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN CPU: 1 UID: 0 PID: 1804 Comm: kworker/u8:7 Tainted: G T 6.12.13-grsec-full-20250211091339 #1 Tainted: [T]=RANDSTRUCT Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 Workqueue: netns cleanup_net RIP: 0010:[] __list_del_entry_valid_or_report+0x141/0x200 lib/list_debug.c:58 Code: c2 76 91 31 c0 e8 9f b1 f7 fc 0f 0b 4d 89 f0 48 c7 c1 02 ff ff ff 48 89 ea 48 89 ee 48 c7 c7 e0 c2 76 91 31 c0 e8 7f b1 f7 fc <0f> 0b 4d 89 e8 48 c7 c1 04 ff ff ff 48 89 ea 48 89 ee 48 c7 c7 60 RSP: 0018:fffffe8040b4fbd0 EFLAGS: 00010283 RAX: 00000000000000cc RBX: dffffc0000000000 RCX: ffffffff818c4054 RDX: ffffffff84947381 RSI: ffffffff818d1512 RDI: 0000000000000000 RBP: ffff8880aaa62c00 R08: 0000000000000001 R09: fffffbd008169f32 R10: fffffe8040b4f997 R11: 0000000000000001 R12: a1988d84f24943e4 R13: ffffffffffffff02 R14: ffffffffffffff04 R15: ffff8880aaa62c08 RBX: kasan shadow of 0x0 RCX: __wake_up_klogd.part.0+0x74/0xe0 kernel/printk/printk.c:4554 RDX: __list_del_entry_valid_or_report+0x141/0x200 lib/list_debug.c:58 RSI: vprintk+0x72/0x100 kernel/printk/printk_safe.c:71 RBP: autoslab_size_M_dev_P_net_core_dev_11127_8_1328_8_S_4096_A_64_n_139+0xc00/0x1000 [slab object] RSP: process kstack fffffe8040b4fbd0+0x7bd0/0x8000 [kworker/u8:7+netns 1804 ] R09: kasan shadow of process kstack fffffe8040b4f990+0x7990/0x8000 [kworker/u8:7+netns 1804 ] R10: process kstack fffffe8040b4f997+0x7997/0x8000 [kworker/u8:7+netns 1804 ] R15: autoslab_size_M_dev_P_net_core_dev_11127_8_1328_8_S_4096_A_64_n_139+0xc08/0x1000 [slab object] FS: 0000000000000000(0000) GS:ffff888116000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000748f5372c000 CR3: 0000000015408000 CR4: 00000000003406f0 shadow CR4: 00000000003406f0 Stack: 0000000000000000 ffffffff8a0c35e7 ffffffff8a0c3603 ffff8880aaa62c00 ffff8880aaa62c00 0000000000000004 ffff88811145311c 0000000000000005 0000000000000001 ffff8880aaa62000 fffffe8040b4fd40 ffffffff8a0c360d Call Trace: [] __list_del_entry_valid include/linux/list.h:131 [inline] fffffe8040b4fc28 [] __list_del_entry include/linux/list.h:248 [inline] fffffe8040b4fc28 [] list_del include/linux/list.h:262 [inl ---truncated--- ## Affected - `linux_kernel >= 6.1.127, < 6.1.130` - `linux_kernel >= 6.6.74, < 6.6.80` - `linux_kernel >= 6.12.11, < 6.12.17` - `linux_kernel >= 6.13, < 6.13.5` - `linux_kernel = 5.4.290` - `linux_kernel = 5.10.234` - `linux_kernel = 5.15.177` - `linux_kernel = 6.14` ## Remediation Upgrade past the affected range: - `linux_kernel 6.13.5`