Out-of-bounds heap access in Linux kernel CAN gateway cgw_csum_crc8_rel()
CVE-2026-31570 is a Linux kernel vulnerability in the CAN gateway subsystem, specifically in cgw_csum_crc8_rel(). The function correctly computes bounds-safe indices for from_idx, to_idx, and result_idx via calc_idx(), but then mistakenly uses the raw signed s8 fields crc8->from_idx and crc8->result_idx in the checksum loop and result write instead of the validated local variables from, to, and res. As a result, negative indices can bypass the guard logic: for example, with from_idx = to_idx = result_idx = -64 on a 64-byte CAN FD frame, calc_idx(-64, 64) resolves to 0 so validation succeeds, but the loop still starts at i = -64 and reads cf->data[-64], and the result write targets cf->data[-64]. This causes slab out-of-bounds heap access before the start of the canfd_frame object. The issue was confirmed with KASAN on linux-7.0-rc2. The fix updates cgw_csum_crc8_rel() to consistently use the validated indices, matching the safe behavior already present in the companion function cgw_csum_xor_rel().
Are you exposed to this one?
Mallory correlates every CVE against your assets, your vendors, and active adversary campaigns. Know which vulnerabilities matter for you, not just which ones are loud.
Impact, mitigation & remediation
What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.
Impact
What an attacker gets, and what they’ve been doing with it.
Mitigation
If you can’t patch tonight, do this now.
Remediation
Patch, then assume compromise.
Exploits
No public exploits tracked yet. Mallory keeps watching.
No public exploit code observed for this vulnerability.
Affected products & vendors
Products and vendors Mallory has correlated with this vulnerability. Open in Mallory to drill down to specific CPE configurations and version ranges.
Vendor-confirmed product mapping. Mallory continuously reconciles this list against your asset inventory.
Recent activity
4 sources tracked across advisories and community write-ups. News coverage will land here when it surfaces.
No news coverage yet. Advisories and community discussion only.
The version that knows your environment.
Query your assets running an affected version, and investigate the blast radius.
Every observed campaign linking this CVE to a named adversary.
Malware families riding this exploit, with evidence and IOCs.
YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.
Cross-references every affected SKU, including bundled OEM variants.
Community discussion across Reddit, Mastodon, and other social sources.