diff options
| author | Bryam Vargas <hexlabsecurity@proton.me> | 2026-07-27 20:30:58 -0500 |
|---|---|---|
| committer | Paul Moore <paul@paul-moore.com> | 2026-07-30 16:14:50 -0400 |
| commit | d14b5d0e97fccd27974fedc03b903408872907fd (patch) | |
| tree | 0129f28106ed7000f2449052c16e2dca3a957b19 /security/selinux | |
| parent | f5098b6bae761e346ebcd9da7f95622c04733cff (diff) | |
selinux: reject a permission value exceeding the class permission count
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 <hexlabsecurity@proton.me>
Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com>
[PM: tweak comment for line length]
Signed-off-by: Paul Moore <paul@paul-moore.com>
Diffstat (limited to 'security/selinux')
| -rw-r--r-- | security/selinux/ss/policydb.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/security/selinux/ss/policydb.c b/security/selinux/ss/policydb.c index ead504a639e3..5ff4d095ec2e 100644 --- a/security/selinux/ss/policydb.c +++ b/security/selinux/ss/policydb.c @@ -1175,6 +1175,9 @@ static int perm_read(struct policydb *p, struct symtab *s, struct policy_file *f rc = -EINVAL; if (perdatum->value < 1 || perdatum->value > SEL_VEC_MAX) goto bad; + /* 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) |