In the Linux kernel, the following vulnerability has been resolved:
nfsd: initialize DRC hash table before registering shrinker
shrinker_register() precedes the INIT_LIST_HEAD loop and the
drc_hashsize store. On weakly-ordered architectures (arm64, ppc),
a shrinker scan can observe drc_hashsize before the bucket list
heads are initialized, causing a NULL deref in the DRC shrinker
callback.
Move bucket initialization and the drc_hashsize store before
shrinker_register() so the hash table is fully initialized before
it becomes visible to the shrinker.
References 4
https://git.kernel.org/stable/c/431c70ca5163c98c746f22f16cd58ca5aefec6dc
416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/b0c58934f5cc4f05b63ef6605dd10c1d0d489e88
416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/b57bd8cb739cb3cf88bdb1a5903a42a707a5c282
416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/f060f43a67635dbb393bf5dcbfc3e8b9a44942cb
416baaa9-dc9f-4396-8d5f-8c081fb06d67