Live › vulnerability › CVE-2026-98850
Go to dashboardA flaw in the Linux kernel's AF_PACKET TX ring code lets the signed byte counter wrap negative when a process keeps sending frames, which trips a kernel BUG. A local user holding CAP_NET_RAW can crash the host, and on systems set to panic on oops that takes the whole machine down.
Summary written from the sources below. Check the originals before acting.
First seen by InfraStack 2026-10-23 21:57 UTC. All times on this page are UTC.
Systems running a Linux kernel with AF_PACKET TX ring support that has not received the fix. Exposure needs a process with CAP_NET_RAW that uses TPACKET_V2 TX rings; the sources do not say which distributions or kernel versions are affected. Hosts without untrusted CAP_NET_RAW holders are less exposed.
No product ranges from the sources yet.
Each row is the first time that source carried this signal. The analyst’s rows are its own findings.
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.
This page as .md · .json · in your agent: get_signal("CVE-2026-98850")
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