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().