{"cve":"CVE-2025-21865","nvd":{"published":"2025-03-12T10:15:19.650","modified":"2026-10-15T02:17:40.350","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ngtp: Suppress list corruption splat in gtp_net_exit_batch_rtnl().\n\nBrad Spengler reported the list_del() corruption splat in\ngtp_net_exit_batch_rtnl(). [0]\n\nCommit eb28fd76c0a0 (\"gtp: Destroy device along with udp socket's netns\ndismantle.\") added the for_each_netdev() loop in gtp_net_exit_batch_rtnl()\nto destroy devices in each netns as done in geneve and ip tunnels.\n\nHowever, this could trigger ->dellink() twice for the same device during\n->exit_batch_rtnl().\n\nSay we have two netns A & B and gtp device B that resides in netns B but\nwhose UDP socket is in netns A.\n\n  1. cleanup_net() processes netns A and then B.\n\n  2. gtp_net_exit_batch_rtnl() finds the device B while iterating\n     netns A's gn->gtp_dev_list and calls ->dellink().\n\n  [ device B is not yet unlinked from netns B\n    as unregister_netdevice_many() has not been called. ]\n\n  3. gtp_net_exit_batch_rtnl() finds the device B while iterating\n     netns B's for_each_netdev() and calls ->dellink().\n\ngtp_dellink() cleans up the device's hash table, unlinks the dev from\ngn->gtp_dev_list, and calls unregister_netdevice_queue().\n\nBasically, calling gtp_dellink() multiple times is fine unless\nCONFIG_DEBUG_LIST is enabled.\n\nLet's remove for_each_netdev() in gtp_net_exit_batch_rtnl() and\ndelegate the destruction to default_device_exit_batch() as done\nin bareudp.\n\n[0]:\nlist_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)\nkernel BUG at lib/list_debug.c:58!\nOops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN\nCPU: 1 UID: 0 PID: 1804 Comm: kworker/u8:7 Tainted: G                T   6.12.13-grsec-full-20250211091339 #1\nTainted: [T]=RANDSTRUCT\nHardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014\nWorkqueue: netns cleanup_net\nRIP: 0010:[<ffffffff84947381>] __list_del_entry_valid_or_report+0x141/0x200 lib/list_debug.c:58\nCode: 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\nRSP: 0018:fffffe8040b4fbd0 EFLAGS: 00010283\nRAX: 00000000000000cc RBX: dffffc0000000000 RCX: ffffffff818c4054\nRDX: ffffffff84947381 RSI: ffffffff818d1512 RDI: 0000000000000000\nRBP: ffff8880aaa62c00 R08: 0000000000000001 R09: fffffbd008169f32\nR10: fffffe8040b4f997 R11: 0000000000000001 R12: a1988d84f24943e4\nR13: ffffffffffffff02 R14: ffffffffffffff04 R15: ffff8880aaa62c08\nRBX: kasan shadow of 0x0\nRCX: __wake_up_klogd.part.0+0x74/0xe0 kernel/printk/printk.c:4554\nRDX: __list_del_entry_valid_or_report+0x141/0x200 lib/list_debug.c:58\nRSI: vprintk+0x72/0x100 kernel/printk/printk_safe.c:71\nRBP: autoslab_size_M_dev_P_net_core_dev_11127_8_1328_8_S_4096_A_64_n_139+0xc00/0x1000 [slab object]\nRSP: process kstack fffffe8040b4fbd0+0x7bd0/0x8000 [kworker/u8:7+netns 1804 ]\nR09: kasan shadow of process kstack fffffe8040b4f990+0x7990/0x8000 [kworker/u8:7+netns 1804 ]\nR10: process kstack fffffe8040b4f997+0x7997/0x8000 [kworker/u8:7+netns 1804 ]\nR15: autoslab_size_M_dev_P_net_core_dev_11127_8_1328_8_S_4096_A_64_n_139+0xc08/0x1000 [slab object]\nFS:  0000000000000000(0000) GS:ffff888116000000(0000) knlGS:0000000000000000\nCS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\nCR2: 0000748f5372c000 CR3: 0000000015408000 CR4: 00000000003406f0 shadow CR4: 00000000003406f0\nStack:\n 0000000000000000 ffffffff8a0c35e7 ffffffff8a0c3603 ffff8880aaa62c00\n ffff8880aaa62c00 0000000000000004 ffff88811145311c 0000000000000005\n 0000000000000001 ffff8880aaa62000 fffffe8040b4fd40 ffffffff8a0c360d\nCall Trace:\n <TASK>\n [<ffffffff8a0c360d>] __list_del_entry_valid include/linux/list.h:131 [inline] fffffe8040b4fc28\n [<ffffffff8a0c360d>] __list_del_entry include/linux/list.h:248 [inline] fffffe8040b4fc28\n [<ffffffff8a0c360d>] list_del include/linux/list.h:262 [inl\n---truncated---","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":["CWE-787"],"references":["https://git.kernel.org/stable/c/33eb925c0c26e86ca540a08254806512bf911f22","https://git.kernel.org/stable/c/37e7644b961600ef0beb01d3970c3034a62913af","https://git.kernel.org/stable/c/4ccacf86491d33d2486b62d4d44864d7101b299d","https://git.kernel.org/stable/c/7f86fb07db65a470d0c11f79da551bd9466357dc","https://git.kernel.org/stable/c/9d03e7e37187ae140e716377599493987fb20c5b"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T22:00:17.429720821+00:00"},"epss":{"cve":"CVE-2025-21865","score":0.00252,"percentile":0.165,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}