CVE-2026-98850

/// Technical 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 p

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References