CVE-2026-93794
In the Linux kernel, the following vulnerability has been resolved: smb/client: flush dirty data before punching a hole Punching a hole after a large buffered write may leave the range reported as data. Reproduce it with: xfs_io -f \ -c "pwrite -b 3m -S 0x61 0 3m" \ -c "fpunch 1m 1m" \ -c "seek -h 0" \ -c "seek -d 1m" \ /mnt/test/repro Punching 1 MiB at offset 1 MiB should produce: 0 1 MiB 2 MiB 3 MiB | DATA | HOLE | DATA | EOF Instead, the entire file is reported as data. SEEK_HOLE(0) returns EOF, and SEEK_DATA(1M) returns 1M. This happens because a dirty folio spanning the punched range can be written back after the punch and refill the hole. Fix this by flushing and waiting for dirty data in the punched range before invalidating the page cache and issuing FSCTL_SET_ZERO_DATA. The xfstests generic/539 pass against Samba/ksmbd with this change.
Affected versions
Linux kernel versions
3.17
and later are affected. Fixed in
6.6.158,
6.12.111,
6.18.53,
7.2
and their respective stable series.
References
4 totalFrequently asked questions
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What is CVE-2026-93794?
CVE-2026-93794 is a unscored severity Linux kernel vulnerability . It affects Linux kernel versions from 3.17 onward and has been patched in 6.6.158, 6.12.111, 6.18.53 and others. CVE-2026-93794 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
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Is there a patch available for CVE-2026-93794?
Yes. CVE-2026-93794 has been patched. Fixed versions include 6.6.158, 6.12.111, 6.18.53 and others. If you are running Linux kernel 3.17 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2026-93794 actively exploited?
No. CVE-2026-93794 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.