6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Bryam Vargas [ Upstream commit d14b5d0e97fccd27974fedc03b903408872907fd ] perm_read() bounds a permission value by SEL_VEC_MAX but never by the nprim of the owning class or common, which is taken verbatim from the policy image. security_get_permissions() then writes perms[value - 1] into an nprim-sized kcalloc() array, so a class declaring fewer permissions than its largest permission value drives an out-of-bounds heap write. The top-level symbol tables are validated this way; the nested per-class permission table is not. Reject a permission whose value exceeds nprim, which is already set when perm_read() runs. Well-formed policies are unaffected. Cc: stable@vger.kernel.org Fixes: 55fcf09b3fe4 ("selinux: add support for querying object classes and permissions from the running policy") Signed-off-by: Bryam Vargas Acked-by: Stephen Smalley [PM: tweak comment for line length] Signed-off-by: Paul Moore Signed-off-by: Sasha Levin --- security/selinux/ss/policydb.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/security/selinux/ss/policydb.c b/security/selinux/ss/policydb.c index 81e910aaf22a3..9e55c2c532435 100644 --- a/security/selinux/ss/policydb.c +++ b/security/selinux/ss/policydb.c @@ -1127,6 +1127,10 @@ static int perm_read(struct policydb *p, struct symtab *s, void *fp) len = le32_to_cpu(buf[0]); perdatum->value = le32_to_cpu(buf[1]); + rc = -EINVAL; + /* indexes an nprim-sized array in security_get_permissions() */ + if (perdatum->value > s->nprim) + goto bad; rc = str_read(&key, GFP_KERNEL, fp, len); if (rc) -- 2.53.0