CVE-2026-98686 PUBLISHED

smb: client: discard post-EOF pagecache when extending a file via zero range

Assigner: Linux
Reserved: 25.09.2026 Published: 18.10.2026 Updated: 18.10.2026

In the Linux kernel, the following vulnerability has been resolved:

smb: client: discard post-EOF pagecache when extending a file via zero range

smb3_zero_range() removed the pagecache only for the range being zeroed, so when it extends the file the folio straddling the old EOF - which may hold data dirtied past EOF through an mmap - was never dropped and became visible as file content once the file was extended.

Lower the discard boundary to the smaller of the zero-range offset and the old EOF.

Product Status

Vendor Linux
Product Linux
Versions Default: unaffected
  • affected from 72c419d9b073628d3b5b0b2fc787b724f1a8c726 to 94949b6b2f2bf0dba2e8786aed0b08cc6bc3a183 (excl.)
  • affected from 72c419d9b073628d3b5b0b2fc787b724f1a8c726 to b75dadb50a25eed525264bf6fea44fad94e7626f (excl.)
  • affected from 72c419d9b073628d3b5b0b2fc787b724f1a8c726 to 6a8279c98ad289b27c0bdb11adb3f0c0b7fd456d (excl.)
  • affected from 72c419d9b073628d3b5b0b2fc787b724f1a8c726 to da4fe97fb6c730d9c94a115c7bfa6f98e0d578d0 (excl.)
Vendor Linux
Product Linux
Versions Default: affected
  • Version 5.1 is affected
  • unaffected from 0 to 5.1 (excl.)
  • unaffected from 6.12.113 to 6.12.* (incl.)
  • unaffected from 6.18.56 to 6.18.* (incl.)
  • unaffected from 7.2.10 to 7.2.* (incl.)
  • unaffected from 7.3-rc6 to * (incl.)

References