net, neigh: Fix null-ptr-deref in neigh_table_clear() (CVE-2022-49904)

Summary

net, neigh: Fix null-ptr-deref in neigh_table_clear()

Original description

The description as published by the source.

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:

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.

Source: OSV.dev (Open Source Vulnerabilities) NVD OSV

Affected packages

Linux Kernel

[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.14.299"}]},{"type":"ECOSYSTEM","events":[{"introduced":"4.15.0"},{"fixed":"4.19.265"}]},{"type":"ECOSYSTEM","events":[{"introduced":"4.20.0"},{"fixed":"5.4.224"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.5.0"},{"fixed":"5.10.154"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.11.0"},{"fixed":"5.15.78"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.0.8"}]}]

Fix status by distribution

Fixed packages published by each distribution for this CVE

Debian DEBIAN-CVE-2022-49904 linux Fixed in: 5.10.158-1
Ubuntu UBUNTU-CVE-2022-49904 linux-azure Fixed in: 4.15.0-1162.177~14.04.1

Summary

Original description

Affected packages

Fix status by distribution

References