Linux Kernel up to 6.15.9/6.16.0 IPv6 neigh_flush_dev iteration

Summaryinfo

A vulnerability categorized as critical has been discovered in Linux Kernel up to 6.15.9/6.16.0. Affected is the function neigh_flush_dev of the component IPv6 Module. Such manipulation leads to iteration. This vulnerability is traded as CVE-2025-38589. There is no exploit available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.15.9/6.16.0 and classified as critical. Affected by this issue is the function neigh_flush_dev of the component IPv6 Module. The manipulation with an unknown input leads to a iteration vulnerability. Using CWE to declare the problem leads to CWE-834. The product performs an iteration or loop without sufficiently limiting the number of times that the loop is executed. Impacted is availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: neighbour: Fix null-ptr-deref in neigh_flush_dev(). kernel test robot reported null-ptr-deref in neigh_flush_dev(). [0] The cited commit introduced per-netdev neighbour list and converted neigh_flush_dev() to use it instead of the global hash table. One thing we missed is that neigh_table_clear() calls neigh_ifdown() with NULL dev. Let's restore the hash table iteration. Note that IPv6 module is no longer unloadable, so neigh_table_clear() is called only when IPv6 fails to initialise, which is unlikely to happen. [0]: IPv6: Attempt to unregister permanent protocol 136 IPv6: Attempt to unregister permanent protocol 17 Oops: general protection fault, probably for non-canonical address 0xdffffc00000001a0: 0000 [#1] SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000d00-0x0000000000000d07] CPU: 1 UID: 0 PID: 1 Comm: systemd Tainted: G T 6.12.0-rc6-01246-gf7f52738637f #1 Tainted: [T]=RANDSTRUCT Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 RIP: 0010:neigh_flush_dev.llvm.6395807810224103582+0x52/0x570 Code: c1 e8 03 42 8a 04 38 84 c0 0f 85 15 05 00 00 31 c0 41 83 3e 0a 0f 94 c0 48 8d 1c c3 48 81 c3 f8 0c 00 00 48 89 d8 48 c1 e8 03 <42> 80 3c 38 00 74 08 48 89 df e8 f7 49 93 fe 4c 8b 3b 4d 85 ff 0f RSP: 0000:ffff88810026f408 EFLAGS: 00010206 RAX: 00000000000001a0 RBX: 0000000000000d00 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffffc0631640 RBP: ffff88810026f470 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: ffffffffc0625250 R14: ffffffffc0631640 R15: dffffc0000000000 FS: 00007f575cb83940(0000) GS:ffff8883aee00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f575db40008 CR3: 00000002bf936000 CR4: 00000000000406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> __neigh_ifdown.llvm.6395807810224103582+0x44/0x390 neigh_table_clear+0xb1/0x268 ndisc_cleanup+0x21/0x38 [ipv6] init_module+0x2f5/0x468 [ipv6] do_one_initcall+0x1ba/0x628 do_init_module+0x21a/0x530 load_module+0x2550/0x2ea0 __se_sys_finit_module+0x3d2/0x620 __x64_sys_finit_module+0x76/0x88 x64_sys_call+0x7ff/0xde8 do_syscall_64+0xfb/0x1e8 entry_SYSCALL_64_after_hwframe+0x67/0x6f RIP: 0033:0x7f575d6f2719 Code: 08 89 e8 5b 5d c3 66 2e 0f 1f 84 00 00 00 00 00 90 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 8b 0d b7 06 0d 00 f7 d8 64 89 01 48 RSP: 002b:00007fff82a2a268 EFLAGS: 00000246 ORIG_RAX: 0000000000000139 RAX: ffffffffffffffda RBX: 0000557827b45310 RCX: 00007f575d6f2719 RDX: 0000000000000000 RSI: 00007f575d584efd RDI: 0000000000000004 RBP: 00007f575d584efd R08: 0000000000000000 R09: 0000557827b47b00 R10: 0000000000000004 R11: 0000000000000246 R12: 0000000000020000 R13: 0000000000000000 R14: 0000557827b470e0 R15: 00007f575dbb4270 </TASK> Modules linked in: ipv6(+)

The advisory is available at git.kernel.org. This vulnerability is handled as CVE-2025-38589 since 04/16/2025. The exploitation is known to be difficult. Technical details are known, but there is no available exploit.

The vulnerability scanner Nessus provides a plugin with the ID 260176 (Linux Distros Unpatched Vulnerability : CVE-2025-38589), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.15.10, 6.16.1 or 6.17-rc1 eliminates this vulnerability. Applying the patch d9c4328795697ebc392a63fece3901999c09cddd/47fbd7f8df19bdfbe334ee83f35568c9a29221ae/1bbb76a899486827394530916f01214d049931b3 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the databases at Tenable (260176) and CERT Bund (WID-SEC-2025-1869). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Affected

• Debian Linux
• Amazon Linux 2
• Red Hat Enterprise Linux
• Ubuntu Linux
• SUSE Linux
• Oracle Linux
• SUSE openSUSE
• RESF Rocky Linux
• Dell Avamar
• Open Source Linux Kernel
• Dell NetWorker
• Dell Secure Connect Gateway
• IBM QRadar SIEM

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.0
• 6.1
• 6.2
• 6.3
• 6.4
• 6.5
• 6.6
• 6.7
• 6.8
• 6.9
• 6.10
• 6.11
• 6.12
• 6.13
• 6.14
• 6.15
• 6.15.0
• 6.15.1
• 6.15.2
• 6.15.3
• 6.15.4
• 6.15.5
• 6.15.6
• 6.15.7
• 6.15.8
• 6.15.9
• 6.16.0

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

If you want to get best quality of vulnerability data, you may have to visit VulDB.

Discussion