net/smc: stop killed, freed and out_of_sync sharing a byte
CVE-2026-80980 · published 11 Sept 2026
How serious is it
- Severity: critical, CVSS score 9.8 out of 10.
- No exploit prediction (EPSS) score yet.
- Not on the CISA list of exploited vulnerabilities.
- No public exploit in Exploit-DB.
Is your app affected by CVE-2026-80980?
Paste this prompt into Claude Code, Cursor or any AI coding tool: it runs a free Shippable scan of your project and fixes what it finds. Built with Lovable, Bolt or v0? Scan your live app. Or upload your package file.
Who is affected
- Linux Linux: b286a0651e4404ab96cdfdcdad8a839a26b3751e to < 297e96f38d3e4f1a3b84068950dd5c7a55bbdc7b, b286a0651e4404ab96cdfdcdad8a839a26b3751e to < 09a9cbadc05f452405de31012bd2c428b601291a, b286a0651e4404ab96cdfdcdad8a839a26b3751e to < 313f79149eb337411c64e2c247234b62ef9a3cb9, b286a0651e4404ab96cdfdcdad8a839a26b3751e to < 2cb7a8d64b7e8ccdc69bbe48fe9c4eaa79c33aec
- Linux Linux: 5.8
How to check
- Find out whether you run the affected product and which version, then compare it with the versions above.
How to fix
Copies a prompt for Claude Code, Cursor or Codex that asks it to check whether you run this product.
- Apply the vendor's update or mitigation from the references below. If there is none yet, limit exposure of the affected service until there is.
- If a vulnerable version was live, check your logs and rotate the secrets that server could read.
The advisory
In the Linux kernel, the following vulnerability has been resolved:
net/smc: stop killed, freed and out_of_sync sharing a byte
The three connection state flags are single-bit bitfields, so they occupy
one byte of struct smc_connection and every store to one is a
read-modify-write of the other two:
u8 killed : 1;
u8 freed : 1;
u8 out_of_sync : 1;
They are not written under a common lock. smc_cdc_msg_validate() sets
out_of_sync from the receive tasklet, while smc_conn_kill() sets killed
from process context under lock_sock(), and the receive path does not defer
to the backlog when the socket is owned -- smc_cdc_msg_recv() takes only
bh_lock_sock().
Give each flag its own byte so a store no longer touches its neighbours.
All readers test them as booleans and are unchanged. struct smc_connection
grows by two bytes.
Check your whole app
Dependencies are only half of it. Free and read-only: before you push, run npx shippable-dev scan localhost:3000 in your project folder, no account needed. For your live app, you prove it's yours with a one-line tag first.
References
- git.kernel.org/stable/c/297e96f38d3e4f1a3b84068950dd5c7a55bbdc7b
- git.kernel.org/stable/c/09a9cbadc05f452405de31012bd2c428b601291a
- git.kernel.org/stable/c/313f79149eb337411c64e2c247234b62ef9a3cb9
- git.kernel.org/stable/c/2cb7a8d64b7e8ccdc69bbe48fe9c4eaa79c33aec
- git.kernel.org/stable/c/db51a8658c11a82432b64999519a269c3aabb447
Merged from CVE List. Last updated 26 Oct 2026. All vulnerabilities · RSS · JSON