CVE-2026-80710: Linux kernel · s390/dasd: Fix undersized format-check buffer
Affects Linux kernelSource CVE Database V5
Not known to be exploited · CVSS 7.8 High · fixed in e16e0fc54120cee3c6f0362de95aab6792865857 : patch Linux kernel soon.
Data as of 30 Oct 2026, 12:49 UTC
Thin evidence
One scorer or none| CNA (Linux) | CVSS 3.1 | 7.8 |
|---|
- CISA SSVC
- Exploitation
- No evidence of active exploitation and no public proof of concept
- Automatable
- Attackers cannot reliably automate steps 1–4 of the kill chain
- Technical impact
- Total control over the software or total information disclosure
CISA SSVC assessment, 2026-10-16.
- Patch
- Available – fixed in e16e0fc54120cee3c6f0362de95aab6792865857, aca18289c86f22d3fc2f3f6ff615286e7b1702f6, 87f3389cd3920714c53e704778f7ca7f1cf0c39c +3
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 28 Aug 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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Description
In the Linux kernel, the following vulnerability has been resolved: s390/dasd: Fix undersized format-check buffer fmt_buffer_size in dasd_eckd_check_device_format() is declared as int, even though one of the multiplicands, sizeof(struct eckd_count), is a size_t. The expression trkcount * rpt_max * sizeof(struct eckd_count) is therefore correctly evaluated at 64-bit width, but the result is silently truncated when it is stored back into the 32-bit fmt_buffer_size variable. For a sufficiently large track range (start_unit/stop_unit are caller-controlled) this truncation yields a buffer size far smaller than the number of tracks actually requested. kzalloc() then succeeds with an undersized allocation, while the subsequent channel program build still operates on the untruncated track count and writes past the end of that buffer. Compute the buffer size with check_mul_overflow() and keep it in a size_t, so that a value that no longer fits results in -EINVAL instead of a silently truncated allocation size.
References
- git.kernel.org/stable/c/3d6be353ba0515247f527c6522348ac730b86ff0 (opens in a new tab)
- git.kernel.org/stable/c/aca18289c86f22d3fc2f3f6ff615286e7b1702f6 (opens in a new tab)
- git.kernel.org/stable/c/9f88dda2f22927d22498801a92cab6a9424eaf86 (opens in a new tab)
- git.kernel.org/stable/c/e16e0fc54120cee3c6f0362de95aab6792865857 (opens in a new tab)
- git.kernel.org/stable/c/87f3389cd3920714c53e704778f7ca7f1cf0c39c (opens in a new tab)
- git.kernel.org/stable/c/7f40b346462f563a0d6e841a77b5163d2a882a04 (opens in a new tab)