CVE-2026-98850: Linux Vulnerability

Description

In the Linux kernel, the following vulnerability has been resolved: net/packet: prevent TX_RING byte count overflow tpacket_snd() drains every SEND_REQUEST frame in a TX ring and adds each valid packet length to the signed int len_sum. Userspace can recycle completed frames concurrently, so a single blocking send call is not bounded by the ring size. After enough successful transmissions len_sum wraps into the negative range. In particular, 65536 65535-byte frames followed by a 65007-byte frame produce 0xfffffdef, or -EIOCBQUEUED. sock_sendmsg_nosec() treats that as an impossible return and triggers a BUG. On systems configured to panic on oops, a CAP_NET_RAW holder can panic the host kernel. Stop before the next frame would make the byte count exceed INT_MAX. The positive short count leaves that frame pending for a later send call. A two-thread TPACKET_V2 reproducer triggered the BUG on an arm64 build of Linux 7.3-rc4. With this change, the same reproducer returned the expected positive short count without an oops.

Metrics

EPSS Probability

0.16%

4.8th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

Vendor	Product	Versions
Linux	Linux	>= 69e3c75f4d541a6eb151b3ef91f34033cb3ad6e1, < 1e6ee93cea4b77253b1b81eb5759899f959ebee3; >= 69e3c75f4d541a6eb151b3ef91f34033cb3ad6e1, < 70fefff0801d4c5405e515592d1e7ad1351530cd; >= 69e3c75f4d541a6eb151b3ef91f34033cb3ad6e1, < 4848c175b5984e6358bcca794ac1dee4d527efcc; >= 69e3c75f4d541a6eb151b3ef91f34033cb3ad6e1, < ae169d318d5d23bac76ece90a7e2b5cb760ed043; >= 69e3c75f4d541a6eb151b3ef91f34033cb3ad6e1, < be12b221c0301111eeb023be04add3c6ad7c21fe; >= 69e3c75f4d541a6eb151b3ef91f34033cb3ad6e1, < 69ca64bbb528898916f309552053c32a04a36ebc; >= 69e3c75f4d541a6eb151b3ef91f34033cb3ad6e1, < 9fd63d284e251332f4874ef9023cde472f315f86; >= 69e3c75f4d541a6eb151b3ef91f34033cb3ad6e1, < 2cf81fc9505b148b1b70068303ea6ea4b1212403
Linux	Linux	2.6.31

References

Timeline

Published: Oct 18, 2026
Last Modified: Oct 30, 2026
Status: Received

Frequently Asked Questions

What is CVE-2026-98850?

In the Linux kernel, the following vulnerability has been resolved: net/packet: prevent TX_RING byte count overflow tpacket_snd() drains every SEND_REQUEST frame in a TX ring and adds each valid packet length to the signed int len_sum. Userspace can recycle completed frames concurrently, so a single blocking send call is not bounded by the ring size. After enough successful transmissions len_sum wraps into the negative range. In particular, 65536 65535-byte frames followed by a 65007-byte frame produce 0xfffffdef, or -EIOCBQUEUED. sock_sendmsg_nosec() treats that as an impossible return and triggers a BUG. On systems configured to panic on oops, a CAP_NET_RAW holder can panic the host kernel. Stop before the next frame would make the byte count exceed INT_MAX. The positive short count leaves that frame pending for a later send call. A two-thread TPACKET_V2 reproducer triggered the BUG on an arm64 build of Linux 7.3-rc4. With this change, the same reproducer returned the expected positive short count without an oops.

How severe is CVE-2026-98850?

Severity scoring for CVE-2026-98850 is pending analysis. The EPSS model estimates a 0.16% probability of exploitation in the next 30 days.

How do I fix CVE-2026-98850?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

How Strix Helps

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