[PATCH v2] keys: prevent slab cache merging for key_jar
From: Mohammed EL Kadiri <hidden>
Date: 2026-06-10 06:50:58
Also in:
keyrings, linux-hardening, lkml
Subsystem:
keys/keyrings, security subsystem, the rest · Maintainers:
David Howells, Jarkko Sakkinen, Paul Moore, James Morris, "Serge E. Hallyn", Linus Torvalds
Add SLAB_NO_MERGE to key_jar to prevent the allocator from merging it with other similarly-sized caches. This hardens struct key isolation by ensuring dedicated slab pages. Acked-by: Vlastimil Babka (SUSE) <vbabka@kernel.org> Signed-off-by: Mohammed EL Kadiri <redacted> --- security/keys/key.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/security/keys/key.c b/security/keys/key.c
index 3bbdde778631..592b65cf8539 100644
--- a/security/keys/key.c
+++ b/security/keys/key.c@@ -1275,7 +1275,7 @@ void __init key_init(void) { /* allocate a slab in which we can store keys */ key_jar = kmem_cache_create("key_jar", sizeof(struct key), - 0, SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); + 0, SLAB_HWCACHE_ALIGN | SLAB_PANIC | SLAB_NO_MERGE, NULL); /* add the special key types */ list_add_tail(&key_type_keyring.link, &key_types_list);
--
2.43.0