Missing Release of Resource after Effective Lifetime Affecting kernel-rt-debug-kvm package, versions *
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
Do your applications use this vulnerable package?
In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.
Test your applications- Snyk IDSNYK-RHEL10-KERNELRTDEBUGKVM-21266359
- published20 Oct 2026
- disclosed18 Oct 2026
Introduced: 18 Oct 2026
NewCVE-2026-98541 (opens in a new tab)How to fix?
There is no fixed version for RHEL:10 kernel-rt-debug-kvm.
NVD Description
Note: Versions mentioned in the description apply only to the upstream kernel-rt-debug-kvm package and not the kernel-rt-debug-kvm package as distributed by RHEL.
See How to fix? for RHEL:10 relevant fixed versions and status.
In the Linux kernel, the following vulnerability has been resolved:
fou: reject omitted FOU_ATTR_IPPROTO on FOU_ENCAP_DIRECT
Commit 7a9bc9e3f423 ("fou: Don't allow 0 for FOU_ATTR_IPPROTO.") added NLA_POLICY_MIN(NLA_U8, 1) to fou_nl_policy[FOU_ATTR_IPPROTO], which rejects an explicitly supplied FOU_ATTR_IPPROTO == 0 attribute with -ERANGE.
However, FOU_ATTR_IPPROTO is an optional netlink attribute. When a user sends FOU_CMD_ADD with FOU_ATTR_TYPE set to FOU_ENCAP_DIRECT and omits FOU_ATTR_IPPROTO entirely, nla_policy validation succeeds and parse_nl_config() leaves cfg->protocol as 0 (from memset(cfg, 0, sizeof(*cfg))). fou_create() then creates a FOU_ENCAP_DIRECT socket with fou->protocol == 0.
In fou_udp_recv(), returning -fou->protocol to udp_queue_rcv_one_skb() triggers IP protocol resubmission when fou->protocol > 0, whereas returning 0 tells the UDP tunnel layer that the skb was consumed without freeing it. When fou->protocol == 0, every packet received on the socket returns 0 from fou_udp_recv() and leaks the sk_buff.
Reject FOU_ENCAP_DIRECT when !cfg->protocol in fou_create() so that creating a direct encapsulation port without FOU_ATTR_IPPROTO fails with -EINVAL while leaving FOU_CMD_DEL and FOU_CMD_GET (which share parse_nl_config()) unaffected.
Tested in QEMU against Linux 7.3.0-rc3 by sending a FOU_CMD_ADD Generic Netlink request with FOU_ATTR_PORT = 5555 and FOU_ATTR_TYPE = FOU_ENCAP_DIRECT while omitting FOU_ATTR_IPPROTO. On the unfixed kernel, FOU_CMD_ADD succeeds (err = 0), FOU_CMD_GET reports fou->type = 1 and fou->protocol = 0, and sending 4000 UDP packets to 127.0.0.1:5555 leaks all 4000 sk_buffs (SUnreclaim in /proc/meminfo grows from 41456 kB to 59008 kB, +17552 kB); with this patch applied, FOU_CMD_ADD is rejected with -EINVAL (-22).
References
- https://bugzilla.redhat.com/show_bug.cgi?id=2554936
- https://access.redhat.com/security/cve/CVE-2026-98541
- https://git.kernel.org/stable/c/3bcc1624cc1cdcc05b566475d6e848093ab2a8f6
- https://git.kernel.org/stable/c/46b1ffb7e169c7e401dd890b29e55dbc261f8f01
- https://git.kernel.org/stable/c/520cf06b8ea0ba5bcc1b8b982ef07f02b5e56221
- https://git.kernel.org/stable/c/7f4ba56f5d310dd018972916167985010a5d66a1
- https://git.kernel.org/stable/c/8b43f40798bb2758489fbbcae7e841ad4443c213
- https://git.kernel.org/stable/c/b1229b210ef5a39c58be665e6798203751411842
- https://git.kernel.org/stable/c/d22609f3d13fc5baacd92c222731b03c593401db
- https://git.kernel.org/stable/c/fd20220f86947d66d4dba2d76f13a28dbd86ef30