| From bippy-5f407fcff5a0 Mon Sep 17 00:00:00 2001 |
| From: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| To: <linux-cve-announce@vger.kernel.org> |
| Reply-to: <cve@kernel.org>, <linux-kernel@vger.kernel.org> |
| Subject: CVE-2025-21678: gtp: Destroy device along with udp socket's netns dismantle. |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| gtp: Destroy device along with udp socket's netns dismantle. |
| |
| gtp_newlink() links the device to a list in dev_net(dev) instead of |
| src_net, where a udp tunnel socket is created. |
| |
| Even when src_net is removed, the device stays alive on dev_net(dev). |
| Then, removing src_net triggers the splat below. [0] |
| |
| In this example, gtp0 is created in ns2, and the udp socket is created |
| in ns1. |
| |
| ip netns add ns1 |
| ip netns add ns2 |
| ip -n ns1 link add netns ns2 name gtp0 type gtp role sgsn |
| ip netns del ns1 |
| |
| Let's link the device to the socket's netns instead. |
| |
| Now, gtp_net_exit_batch_rtnl() needs another netdev iteration to remove |
| all gtp devices in the netns. |
| |
| [0]: |
| ref_tracker: net notrefcnt@000000003d6e7d05 has 1/2 users at |
| sk_alloc (./include/net/net_namespace.h:345 net/core/sock.c:2236) |
| inet_create (net/ipv4/af_inet.c:326 net/ipv4/af_inet.c:252) |
| __sock_create (net/socket.c:1558) |
| udp_sock_create4 (net/ipv4/udp_tunnel_core.c:18) |
| gtp_create_sock (./include/net/udp_tunnel.h:59 drivers/net/gtp.c:1423) |
| gtp_create_sockets (drivers/net/gtp.c:1447) |
| gtp_newlink (drivers/net/gtp.c:1507) |
| rtnl_newlink (net/core/rtnetlink.c:3786 net/core/rtnetlink.c:3897 net/core/rtnetlink.c:4012) |
| rtnetlink_rcv_msg (net/core/rtnetlink.c:6922) |
| netlink_rcv_skb (net/netlink/af_netlink.c:2542) |
| netlink_unicast (net/netlink/af_netlink.c:1321 net/netlink/af_netlink.c:1347) |
| netlink_sendmsg (net/netlink/af_netlink.c:1891) |
| ____sys_sendmsg (net/socket.c:711 net/socket.c:726 net/socket.c:2583) |
| ___sys_sendmsg (net/socket.c:2639) |
| __sys_sendmsg (net/socket.c:2669) |
| do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83) |
| |
| WARNING: CPU: 1 PID: 60 at lib/ref_tracker.c:179 ref_tracker_dir_exit (lib/ref_tracker.c:179) |
| Modules linked in: |
| CPU: 1 UID: 0 PID: 60 Comm: kworker/u16:2 Not tainted 6.13.0-rc5-00147-g4c1224501e9d #5 |
| Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 |
| Workqueue: netns cleanup_net |
| RIP: 0010:ref_tracker_dir_exit (lib/ref_tracker.c:179) |
| Code: 00 00 00 fc ff df 4d 8b 26 49 bd 00 01 00 00 00 00 ad de 4c 39 f5 0f 85 df 00 00 00 48 8b 74 24 08 48 89 df e8 a5 cc 12 02 90 <0f> 0b 90 48 8d 6b 44 be 04 00 00 00 48 89 ef e8 80 de 67 ff 48 89 |
| RSP: 0018:ff11000009a07b60 EFLAGS: 00010286 |
| RAX: 0000000000002bd3 RBX: ff1100000f4e1aa0 RCX: 1ffffffff0e40ac6 |
| RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8423ee3c |
| RBP: ff1100000f4e1af0 R08: 0000000000000001 R09: fffffbfff0e395ae |
| R10: 0000000000000001 R11: 0000000000036001 R12: ff1100000f4e1af0 |
| R13: dead000000000100 R14: ff1100000f4e1af0 R15: dffffc0000000000 |
| FS: 0000000000000000(0000) GS:ff1100006ce80000(0000) knlGS:0000000000000000 |
| CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 |
| CR2: 00007f9b2464bd98 CR3: 0000000005286005 CR4: 0000000000771ef0 |
| DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 |
| DR3: 0000000000000000 DR6: 00000000fffe07f0 DR7: 0000000000000400 |
| PKRU: 55555554 |
| Call Trace: |
| <TASK> |
| ? __warn (kernel/panic.c:748) |
| ? ref_tracker_dir_exit (lib/ref_tracker.c:179) |
| ? report_bug (lib/bug.c:201 lib/bug.c:219) |
| ? handle_bug (arch/x86/kernel/traps.c:285) |
| ? exc_invalid_op (arch/x86/kernel/traps.c:309 (discriminator 1)) |
| ? asm_exc_invalid_op (./arch/x86/include/asm/idtentry.h:621) |
| ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/irqflags.h:42 ./arch/x86/include/asm/irqflags.h:97 ./arch/x86/include/asm/irqflags.h:155 ./include/linux/spinlock_api_smp.h:151 kernel/locking/spinlock.c:194) |
| ? ref_tracker_dir_exit (lib/ref_tracker.c:179) |
| ? __pfx_ref_tracker_dir_exit (lib/ref_tracker.c:158) |
| ? kfree (mm/slub.c:4613 mm/slub.c:4761) |
| net_free (net/core/net_namespace.c:476 net/core/net_namespace.c:467) |
| cleanup_net (net/core/net_namespace.c:664 (discriminator 3)) |
| process_one_work (kernel/workqueue.c:3229) |
| worker_thread (kernel/workqueue.c:3304 kernel/workqueue.c:3391) |
| kthread (kernel/kthread.c:389) |
| ret_from_fork (arch/x86/kernel/process.c:147) |
| ret_from_fork_asm (arch/x86/entry/entry_64.S:257) |
| </TASK> |
| |
| The Linux kernel CVE team has assigned CVE-2025-21678 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 4.7 with commit 459aa660eb1d8ce67080da1983bb81d716aa5a69 and fixed in 5.4.290 with commit c986380c1d5274c4d5e935addc807d6791cc23eb |
| Issue introduced in 4.7 with commit 459aa660eb1d8ce67080da1983bb81d716aa5a69 and fixed in 5.10.234 with commit 5f1678346109ff3a6d229d33437fcba3cce9209d |
| Issue introduced in 4.7 with commit 459aa660eb1d8ce67080da1983bb81d716aa5a69 and fixed in 5.15.177 with commit 036f8d814a2cd11ee8ef62b8f3e7ce5dec0ee4f3 |
| Issue introduced in 4.7 with commit 459aa660eb1d8ce67080da1983bb81d716aa5a69 and fixed in 6.1.127 with commit efec287cbac92ac6ee8312a89221854760e13b34 |
| Issue introduced in 4.7 with commit 459aa660eb1d8ce67080da1983bb81d716aa5a69 and fixed in 6.6.74 with commit bb11f992f5a475bc68ef959f17a55306f0328495 |
| Issue introduced in 4.7 with commit 459aa660eb1d8ce67080da1983bb81d716aa5a69 and fixed in 6.12.11 with commit 86f73d4ab2f27deeff22ba9336ad103d94f12ac7 |
| Issue introduced in 4.7 with commit 459aa660eb1d8ce67080da1983bb81d716aa5a69 and fixed in 6.13 with commit eb28fd76c0a08a47b470677c6cef9dd1c60e92d1 |
| |
| Please see https://www.kernel.org for a full list of currently supported |
| kernel versions by the kernel community. |
| |
| Unaffected versions might change over time as fixes are backported to |
| older supported kernel versions. The official CVE entry at |
| https://cve.org/CVERecord/?id=CVE-2025-21678 |
| will be updated if fixes are backported, please check that for the most |
| up to date information about this issue. |
| |
| |
| Affected files |
| ============== |
| |
| The file(s) affected by this issue are: |
| drivers/net/gtp.c |
| |
| |
| Mitigation |
| ========== |
| |
| The Linux kernel CVE team recommends that you update to the latest |
| stable kernel version for this, and many other bugfixes. Individual |
| changes are never tested alone, but rather are part of a larger kernel |
| release. Cherry-picking individual commits is not recommended or |
| supported by the Linux kernel community at all. If however, updating to |
| the latest release is impossible, the individual changes to resolve this |
| issue can be found at these commits: |
| https://git.kernel.org/stable/c/c986380c1d5274c4d5e935addc807d6791cc23eb |
| https://git.kernel.org/stable/c/5f1678346109ff3a6d229d33437fcba3cce9209d |
| https://git.kernel.org/stable/c/036f8d814a2cd11ee8ef62b8f3e7ce5dec0ee4f3 |
| https://git.kernel.org/stable/c/efec287cbac92ac6ee8312a89221854760e13b34 |
| https://git.kernel.org/stable/c/bb11f992f5a475bc68ef959f17a55306f0328495 |
| https://git.kernel.org/stable/c/86f73d4ab2f27deeff22ba9336ad103d94f12ac7 |
| https://git.kernel.org/stable/c/eb28fd76c0a08a47b470677c6cef9dd1c60e92d1 |
