Bug 2513383 (CVE-2026-68322)

Summary: CVE-2026-68322 kernel: rds: Fix inet6_addr_lst NULL dereference when IPv6 is disabled
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
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Doc Text:
A flaw was found in the Linux kernel's Reliable Datagram Sockets (RDS) component. A local user can trigger a null pointer dereference by attempting to bind an RDS socket to an IPv6 address when IPv6 is explicitly disabled. This can lead to a system crash, resulting in a Denial of Service (DoS).
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description OSIDB Bzimport 2026-08-10 12:34:20 UTC 
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.