From: J. Bruce Fields Date: Wed, 21 Oct 2020 14:34:15 +0000 (-0400) Subject: NFSv4.2: fix failure to unregister shrinker X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=70438afbf17e5194dd607dd17759560a363b7bb4;p=linux.git NFSv4.2: fix failure to unregister shrinker We forgot to unregister the nfs4_xattr_large_entry_shrinker. That leaves the global list of shrinkers corrupted after unload of the nfs module, after which possibly unrelated code that calls register_shrinker() or unregister_shrinker() gets a BUG() with "supervisor write access in kernel mode". And similarly for the nfs4_xattr_large_entry_lru. Reported-by: Kris Karas Tested-By: Kris Karas Fixes: 95ad37f90c33 "NFSv4.2: add client side xattr caching." Signed-off-by: J. Bruce Fields CC: stable@vger.kernel.org Signed-off-by: Anna Schumaker --- diff --git a/fs/nfs/nfs42xattr.c b/fs/nfs/nfs42xattr.c index b51424ff8159e..6c2ce799150f4 100644 --- a/fs/nfs/nfs42xattr.c +++ b/fs/nfs/nfs42xattr.c @@ -1047,8 +1047,10 @@ out4: void nfs4_xattr_cache_exit(void) { + unregister_shrinker(&nfs4_xattr_large_entry_shrinker); unregister_shrinker(&nfs4_xattr_entry_shrinker); unregister_shrinker(&nfs4_xattr_cache_shrinker); + list_lru_destroy(&nfs4_xattr_large_entry_lru); list_lru_destroy(&nfs4_xattr_entry_lru); list_lru_destroy(&nfs4_xattr_cache_lru); kmem_cache_destroy(nfs4_xattr_cache_cachep);