Cloudanix VulnDB

CVE-2026-68322

None

CVSS

—

EPSS

0.2%

Published

Aug 10, 2026

CISA due date

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Cloudanix analysis

Schedule a fix SSVC: Track

A bug in the Linux kernel can make the whole computer crash if IPv6 is turned off and certain network programs try to start.

Exploitation
Requires User Interaction
Attacker needs
Local User
Complexity
Moderate
Impact
Denial Of Service
Component
OS kernel
Class
Memory Corruption
Remediation
Upgrade
Effort
Medium
Patch risk
Low

What it actually does

NULL pointer dereference in __ipv6_chk_addr_and_flags triggered during RDS socket bind to IPv6 address when the kernel boots with ipv6.disable=1, because inet6_addr_lst remains uninitialized.

Why it matters to the business

Unprivileged local processes can trigger immediate kernel crashes on affected Linux systems, causing denial of service, unplanned reboots, and potential loss of in-flight work or sessions.

How an attack unfolds

An attacker with local access creates an RDS socket and issues a bind call using an IPv6 address; because IPv6 initialization was skipped, the kernel dereferences a null pointer in the address check routine and panics.

How to fix it

Apply the upstream kernel patch that ensures inet6_addr_lst is initialized even when ipv6.disable=1, or upgrade to a distribution kernel containing the fix for this RDS NULL dereference.

How to confirm the fix worked

Confirm the patch is present by checking that inet6_init() no longer early-returns before addrconf_init() when the ipv6.disable parameter is set; re-run the provided Syzkaller reproducer and verify it no longer causes a null-ptr-deref oops.

Typical attack path

  1. Obtain local shell or execute code on target Linux host
  2. Create PF_RDS/SOCK_SEQPACKET socket
  3. Prepare sockaddr_in6 structure with AF_INET6 and target address
  4. Call bind() on the socket
  5. Kernel panics in __ipv6_chk_addr_and_flags

How to detect it

Search kernel logs and crash dumps for the call trace containing rds_tcp_laddr_check, rds_trans_get_preferred, rds_bind and the KASAN null-ptr-deref report in __ipv6_chk_addr_and_flags; correlate with boots that have ipv6.disable=1 on the kernel command line.

  • rds_tcp_laddr_check+0x155
  • __ipv6_chk_addr_and_flags+0x1df
  • KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]
  • RIP: 0010:__ipv6_chk_addr_and_flags

What your security team should do

  • Prioritize patching kernel packages on all systems that may boot with ipv6.disable=1
  • Restrict unprivileged users from creating RDS sockets via seccomp or LSM policy until patches are applied
  • Monitor kernel logs for oops entries containing rds_tcp_laddr_check and __ipv6_chk_addr_and_flags

The record

In the Linux kernel, the following vulnerability has been resolved: rds: Fix inet6_addr_lst NULL dereference when IPv6 is disabled When booting with the 'ipv6.disable=1' parameter, inet6_addr_lst is never initialized because inet6_init() exits before addrconf_init() is called to initialize it. An attempt to bind an RDS socket to an ipv6 address results in a crash in __ipv6_chk_addr_and_flags() KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f] RIP: 0010:__ipv6_chk_addr_and_flags+0x1df/0x7e0 Call Trace: <TASK> ipv6_chk_addr+0x3b/0x50 rds_tcp_laddr_check+0x155/0x3b0 [rds_tcp] rds_trans_get_preferred+0x15d/0x2d0 [rds] ? trace_hardirqs_on+0x2d/0x110 rds_bind+0x1433/0x1d60 [rds] ? rds_remove_bound+0xd50/0xd50 [rds] ? aa_af_perm+0x250/0x250 ? __might_fault+0xde/0x190 ? __sys_bind+0x1dc/0x210 __sys_bind+0x1dc/0x210 ? __ia32_sys_socketpair+0x100/0x100 ? restore_fpregs_from_fpstate+0x53/0x100 __x64_sys_bind+0x73/0xb0 ? syscall_enter_from_user_mode+0x1c/0x50 do_syscall_64+0x34/0x80 entry_SYSCALL_64_after_hwframe+0x6e/0xd8 RIP: 0033:0x7f47f8269ea9 </TASK> The following code reproduces the issue: struct sockaddr_in6 addr; s = socket(PF_RDS, SOCK_SEQPACKET, 0); memset(&addr, 0, sizeof(addr)); inet_pton(AF_INET6, ADDRESS, &addr.sin6_addr); addr.sin6_family = AF_INET6; addr.sin6_port = htons(PORT); bind(s, &addr, sizeof(addr)); Found by InfoTeCS on behalf of Linux Verification Center (linuxtesting.org) with Syzkaller.

Affected packages

Ecosystem Package Introduced Fixed