Summary
In the Linux kernel, the following vulnerability has been resolved: neighbour: Fix null-ptr...
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:
__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
Modules linked in: ipv6(+)
Impact
The application dereferences a null pointer, causing a crash. Typical impact: denial of service via crash.
CVE-2025-38589 has a CVSS score of 5.5 (Medium). The vector is requires local access, low privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. No fixed version is listed yet, so configuration controls and monitoring matter more in the interim.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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Frequently Asked Questions
- What is CVE-2025-38589? CVE-2025-38589 is a medium-severity null pointer dereference vulnerability. No fixed version is listed yet. The application dereferences a null pointer, causing a crash.
- How severe is CVE-2025-38589? CVE-2025-38589 has a CVSS score of 5.5 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Is there a fix for CVE-2025-38589? No fixed version is listed for CVE-2025-38589 yet. Monitor the advisory for updates and apply mitigations in the interim.
- Is CVE-2025-38589 exploitable, and should I be worried? Whether CVE-2025-38589 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2025-38589 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.