# CVE-2022-49904: linux: In the Linux kernel, the following vulnerability has been resolved:  net, neigh: Fix null-ptr-deref in neigh_table_cl...

CVE-2022-49904 is fixed in linux on 1 platform, first by DEBIAN-CVE-2022-49904, released May 1, 2025. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2022-49904
- Priority: Routine
- CVSS: 5.5 (medium)
- EPSS: 0.0020
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: May 1, 2025

## Description

In the Linux kernel, the following vulnerability has been resolved:  net, neigh: Fix null-ptr-deref in neigh_table_clear()  When IPv6 module gets initialized but hits an error in the middle, kenel panic with:  KASAN: null-ptr-deref in range [0x0000000000000598-0x000000000000059f] CPU: 1 PID: 361 Comm: insmod Hardware name: QEMU Standard PC (i440FX + PIIX, 1996) RIP: 0010:__neigh_ifdown.isra.0+0x24b/0x370 RSP: 0018:ffff888012677908 EFLAGS: 00000202 ... Call Trace:  <TASK>  neigh_table_clear+0x94/0x2d0  ndisc_cleanup+0x27/0x40 [ipv6]  inet6_init+0x21c/0x2cb [ipv6]  do_one_initcall+0xd3/0x4d0  do_init_module+0x1ae/0x670 ... Kernel panic - not syncing: Fatal exception  When ipv6 initialization fails, it will try to cleanup and calls:  neigh_table_clear()   neigh_ifdown(tbl, NULL)     pneigh_queue_purge(&tbl->proxy_queue, dev_net(dev == NULL))     # dev_net(NULL) triggers null-ptr-deref.  Fix it by passing NULL to pneigh_queue_purge() in neigh_ifdown() if dev is NULL, to make kernel not panic immediately.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | linux Debian 12.15 (bookworm) | 6.0.8-1 | [DEBIAN-CVE-2022-49904](https://patchblox.com/security/data/fix/linux/debian-cve-2022-49904.md) | May 1, 2025 |
| Linux | linux Debian 13.5 (trixie) | 6.0.8-1 | [DEBIAN-CVE-2022-49904](https://patchblox.com/security/data/fix/linux/debian-cve-2022-49904.md) | May 1, 2025 |
| Linux | linux Debian 14 | 6.0.8-1 | [DEBIAN-CVE-2022-49904](https://patchblox.com/security/data/fix/linux/debian-cve-2022-49904.md) | May 1, 2025 |

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