CVE-2022-49904: net, neigh: Fix null-ptr-deref in neigh_table_clear()
In the Linux kernel, the following vulnerability has been resolved:
net, neigh: Fix null-ptr-deref in neightableclear()
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:neighifdown.isra.0+0x24b/0x370 RSP: 0018:ffff888012677908 EFLAGS: 00000202 ... Call Trace: <TASK> neightableclear+0x94/0x2d0 ndisccleanup+0x27/0x40 [ipv6] inet6init+0x21c/0x2cb [ipv6] dooneinitcall+0xd3/0x4d0 doinitmodule+0x1ae/0x670 ... Kernel panic - not syncing: Fatal exception
When ipv6 initialization fails, it will try to cleanup and calls:
neightableclear() neighifdown(tbl, NULL) pneighqueuepurge(&tbl->proxyqueue, devnet(dev == NULL)) # devnet(NULL) triggers null-ptr-deref.
Fix it by passing NULL to pneighqueuepurge() in neighifdown() if dev is NULL, to make kernel not panic immediately.
Affected Software
Remediation
Event History
Frequently Asked Questions
What is the severity of CVE-2022-49904?
CVE-2022-49904 is classified as having a high severity due to the potential for kernel panic when the IPv6 module encounters an error.
How do I fix CVE-2022-49904?
To mitigate CVE-2022-49904, update your Linux kernel to the latest stable version that includes the patch for this vulnerability.
What components are impacted by CVE-2022-49904?
CVE-2022-49904 affects the IPv6 module within the Linux kernel, specifically during its initialization process.
What are the consequences of CVE-2022-49904?
The primary consequence of CVE-2022-49904 is a kernel panic that can disrupt system reliability and availability.
What versions of Linux kernel are affected by CVE-2022-49904?
CVE-2022-49904 impacts specific versions of the Linux kernel; users should review their current version and apply the necessary updates.