In the Linux kernel, the following vulnerability has been resolved:
netfilter: ip6t_rt: fix zero-address non-strict match out-of-bounds read
rt_mt6_check() permits rules to be configured with rtinfo->addrnr == 0
even when address matching (IP6T_RT_FST_MASK) is requested.
In the IP6T_RT_FST_NSTRICT path, rt_mt6() evaluates packet routing
addresses against rtinfo->addrs[i] and terminates backwards at the bottom
of the loop:
if (ipv6_addr_equal(ap, &rtinfo->addrs[i])) {
i++;
}
if (i == rtinfo->addrnr)
break;
When addrnr is 0, if the first packet address matches rtinfo->addrs[0],
i is incremented to 1. Because i is now strictly greater than addrnr (0),
the loop termination condition (i == rtinfo->addrnr) is bypassed and will
never be satisfied.
If a crafted IPv6 packet contains matching routing addresses, i will
advance past IP6T_RT_HOPS (16). The subsequent call to ipv6_addr_equal()
reads beyond struct ip6t_rt, triggering UBSAN/KASAN out-of-bounds warnings
or kernel panics.
Fix this by:
1. Rejecting rules in rt_mt6_check() where IP6T_RT_FST_MASK is set but
rtinfo->addrnr is zero.
2. In rt_mt6(), moving the termination condition (i < rtinfo->addrnr)
into the for-loop header condition and removing the backwards break
at the end of the loop body.
netfilter: ip6t_rt: fix zero-address non-strict match out-of-bounds read
rt_mt6_check() permits rules to be configured with rtinfo->addrnr == 0
even when address matching (IP6T_RT_FST_MASK) is requested.
In the IP6T_RT_FST_NSTRICT path, rt_mt6() evaluates packet routing
addresses against rtinfo->addrs[i] and terminates backwards at the bottom
of the loop:
if (ipv6_addr_equal(ap, &rtinfo->addrs[i])) {
i++;
}
if (i == rtinfo->addrnr)
break;
When addrnr is 0, if the first packet address matches rtinfo->addrs[0],
i is incremented to 1. Because i is now strictly greater than addrnr (0),
the loop termination condition (i == rtinfo->addrnr) is bypassed and will
never be satisfied.
If a crafted IPv6 packet contains matching routing addresses, i will
advance past IP6T_RT_HOPS (16). The subsequent call to ipv6_addr_equal()
reads beyond struct ip6t_rt, triggering UBSAN/KASAN out-of-bounds warnings
or kernel panics.
Fix this by:
1. Rejecting rules in rt_mt6_check() where IP6T_RT_FST_MASK is set but
rtinfo->addrnr is zero.
2. In rt_mt6(), moving the termination condition (i < rtinfo->addrnr)
into the for-loop header condition and removing the backwards break
at the end of the loop body.
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | |||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Linux | Linux | unaffected |
|
|||||||||||||||||||||||||||||||||
| Linux | Linux | affected |
|
No data.
No data.
OpenCVE Enrichment is a feature of OpenCVE that uses AI to automatically link vendors and products to CVEs. Learn more on GitHub.
No data.
Advisories
No advisories yet.
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Sun, 18 Oct 2026 17:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Weaknesses | CWE-125 |
Sun, 18 Oct 2026 15:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: netfilter: ip6t_rt: fix zero-address non-strict match out-of-bounds read rt_mt6_check() permits rules to be configured with rtinfo->addrnr == 0 even when address matching (IP6T_RT_FST_MASK) is requested. In the IP6T_RT_FST_NSTRICT path, rt_mt6() evaluates packet routing addresses against rtinfo->addrs[i] and terminates backwards at the bottom of the loop: if (ipv6_addr_equal(ap, &rtinfo->addrs[i])) { i++; } if (i == rtinfo->addrnr) break; When addrnr is 0, if the first packet address matches rtinfo->addrs[0], i is incremented to 1. Because i is now strictly greater than addrnr (0), the loop termination condition (i == rtinfo->addrnr) is bypassed and will never be satisfied. If a crafted IPv6 packet contains matching routing addresses, i will advance past IP6T_RT_HOPS (16). The subsequent call to ipv6_addr_equal() reads beyond struct ip6t_rt, triggering UBSAN/KASAN out-of-bounds warnings or kernel panics. Fix this by: 1. Rejecting rules in rt_mt6_check() where IP6T_RT_FST_MASK is set but rtinfo->addrnr is zero. 2. In rt_mt6(), moving the termination condition (i < rtinfo->addrnr) into the for-loop header condition and removing the backwards break at the end of the loop body. | |
| Title | netfilter: ip6t_rt: fix zero-address non-strict match out-of-bounds read | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
|
Projects
Sign in to view the affected projects.
MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-10-18T15:16:00.435Z
Reserved: 2026-09-25T10:25:14.352Z
Link: CVE-2026-98485
Vulnrichment
No data.
NVD
Status : Received
Published: 2026-10-18T16:16:59.187
Modified: 2026-10-18T16:16:59.187
Link: CVE-2026-98485
Redhat
No data.
OpenCVE Enrichment
Updated: 2026-10-18T17:15:14Z
Weaknesses