CVE-2026-89717

About vulnerability

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

zram: set default primary compressor in zram_destroy_comps()

Patch series “zram: fix zram issues reported by sashiko”.

Sashiko drove by and reported [1] a couple of zram issues: a possible BUG_ON() in zlib code due to missing winbits range validation and one possible NULL-ptr dereference in zcomp. Both are low risk yet still worth fixing.

This patch (of 2):

zram_destroy_comps() resets all compressors and leaves them set to NULL, including the primary one, which is invalid device state, as now comp_algorithm_show()->strcmp() can be called on a NULL compressor. Set default primary compressor in zram_destroy_comps().

Affected product:

AlmaLinux 9.2 ESU , Debian 10 ELS , Debian 11 ELS , TuxCare 9.6 ESU , TuxCare 9.8 ESU

Affected packages:

linux @ 5.10.259 (+4 more)

Live-patch status from KernelCare for each operating system.