Pull selinux fixes from Paul Moore:

 - Continue to improve the validation of SELinux policies during load

 - Fix a SELinux regression caused by bpffs changes in v7.2-rc1

 - Fix a SELinux preformance regression caused by SELinux changes in
   v7.2-rc1

* tag 'selinux-pr-20260805' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux:
  selinux: check level category sets once at load time
  selinux: require every boolean value to be defined
  selinux: reject an unclaimed class value in security_get_classes()
  selinux: require a class's permission values to cover its permission count
  selinux: do not cancel a policy conversion that never started
  selinux: bpf: check SBLABEL_MNT before isec init
  selinux: reject a class permission count below its inherited common
  selinux: reject a permission value exceeding the class permission count

Instantiate the file_truncate and path_truncate LSM hooks to reset the
action cache flags (IMA_DONE_MASK) as soon as truncation is requested,
so the file, based on policy, is re-collected, re-measured, re-audited,
and re-appraised on next access.

Tested-by: Frederick Lawler <fred@cloudflare.com>
Cc: stable@vger.kernel.org
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>

The digest-length check in xattr_verify() mixes int and size_t:

	if (xattr_len - sizeof(xattr_value->type) - hash_start >=
			iint->ima_hash->length)

sizeof() yields size_t, so the usual arithmetic conversions promote
the whole left-hand side to unsigned 64-bit before the subtraction
runs. For a truncated xattr this underflows instead of going negative:
a 1-byte IMA_XATTR_DIGEST_NG xattr (xattr_len == 1, hash_start == 1)
turns "1 - 1 - 1" into SIZE_MAX, which is trivially >= ima_hash->length.
The check then passes and the following memcmp() reads
iint->ima_hash->length bytes starting past the end of the buffer
vfs_getxattr_alloc() allocated for it.

Nothing upstream clamps xattr_len back into a safe range first:
ima_get_hash_algo() only special-cases xattr_len < 2 to pick a default
algorithm, and evm_verifyxattr() returns INTEGRITY_UNKNOWN rather than
failing when no HMAC key is loaded, so a truncated security.ima value
reaches the length check as-is.

Rewrite the comparison so every operand stays a signed int and no
implicit conversion to size_t can occur.

Fixes: 3ea7a56067e6 ("ima: provide hash algo info in the xattr")
Cc: stable@vger.kernel.org
Signed-off-by: Lincoln Wallace <locnnil0@gmail.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>

As reported by Jiri Vozar, commit 7edea6e8c8e8 ("selinux: beef up
isvalid checks") introduces a new loop in mls_level_isvalid() that
causes ~89-94% throughput regression in System V IPC message queue
operations (msgsnd/msgrcv).

Move the expensive part of the ebitmap checking to policy load time
instead as the reporter suggested.

Link: https://lore.kernel.org/selinux/CAMgFczCi2Z011dNf84Amc0Q-qnTt0+VUjWY+Y7zPyXdaH35Jvw@mail.gmail.com/
Fixes: 7edea6e8c8e8 ("selinux: beef up isvalid checks")
Reported-by: Jiri Vozar <jvozar@redhat.com>
Suggested-by: Jiri Vozar <jvozar@redhat.com>
Signed-off-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

p_bools.nprim comes from the policy image independently of how many
booleans follow it, and cond_index_bool() fills bool_val_to_struct[] at
value - 1, so a count larger than the values present leaves NULL entries.
Every user of that array then walks it by index and dereferences each
entry: cond_evaluate_expr() on the access-vector path,
security_get_bools() and security_get_bool_value() behind selinuxfs, and
security_set_bools(). A sparse class value is absorbed by
policydb_class_isvalid() and its siblings; booleans have no such
predicate, and no consumer that could use one.

Reject a boolean value that no boolean defines, once, where the array is
built. Conforming policies define every boolean they declare and are
unaffected.

Cc: stable@vger.kernel.org
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Bryam Vargas <hexlabsecurity@proton.me>
Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

security_get_classes() sizes an array by p_classes.nprim and fills it at
value - 1, so a class value the policy never defines leaves a NULL.
sel_make_classes() passes every entry to sel_make_dir(), reaching the same
d_alloc_name() dereference as the permission array. The class symbol table
is allowed to be sparse (policydb_class_isvalid() exists to absorb that),
but this getter builds its own array straight from the hash table and has
no such predicate.

Fail the lookup when a value went unclaimed instead of handing out the
NULL. Conforming policies define every class they declare and 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>
Signed-off-by: Paul Moore <paul@paul-moore.com>

security_get_permissions() sizes an array by the class's permissions.nprim
and fills it at value - 1, from the inherited common's permission table and
then the class's own. A value no permission defines leaves a NULL that
sel_make_perm_files() passes to d_alloc_name(), an oops inside
sel_write_load() that strands selinux_state.policy_mutex and leaves every
later load in uninterruptible sleep; two permissions sharing a value
overwrite the first kstrdup(). Bounding each value by nprim catches
neither, and neither would a count: the symbol table is keyed on the
permission name, so duplicates pass.

Track the values each permission table claims and require them to cover
exactly what its count declares, rejecting a count no value can reach.
Conforming 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>
Signed-off-by: Paul Moore <paul@paul-moore.com>

sel_write_load() calls selinux_policy_cancel() when sel_make_policy_nodes()
fails, and that helper dereferences the outgoing policy to cancel its
sidtab conversion. On the first policy load there is no outgoing policy:
security_load_policy() returns early for that case, before it converts
anything, and state->policy is still NULL. A first load that fails while
building the selinuxfs tree therefore takes a NULL dereference in
selinux_policy_cancel(), reached from a write(2) to /sys/fs/selinux/load.

Skip the cancel when there is no old policy, mirroring the check
security_load_policy() already makes before it converts.

Cc: stable@vger.kernel.org
Fixes: 02a52c5c8c3b ("selinux: move policy commit after updating selinuxfs")
Signed-off-by: Bryam Vargas <hexlabsecurity@proton.me>
Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

selinux_inode_init_security() marks the isec as initialized before
checking if mount labeling is supported (SBLABEL_MNT). This was fine
until commit 9722955b5430 ("bpf: Add simple xattr support to bpffs"),
where genfscon bpffs mounts fail the SBLABEL_MNT check as expected (no
xattrs) and yet leave the isec->initialized. This breaks subsequent
calls to inode_doinit_with_dentry().

Do the SBLABEL_MNT check before the inode security is initialized.

Cc: stable@vger.kernel.org
Closes: https://lore.kernel.org/all/akWdcp6P0FkNDzBk@google.com/
Fixes: 9722955b5430 ("bpf: Add simple xattr support to bpffs")
Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Carlos Llamas <cmllamas@google.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

security_get_permissions() maps an inherited common's permissions into
an array sized by the class's own permissions.nprim, but class_read()
takes that nprim verbatim from the policy image and never checks that it
covers the common.  A class that inherits a common of N permissions while
declaring a smaller nprim is accepted, and on load the common's
permissions are written past the class-sized array -- an out-of-bounds
heap write.

Reject a class whose permission count is below its inherited common's.
Well-formed policies, where the class count already includes the
inherited permissions, 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>
Signed-off-by: Paul Moore <paul@paul-moore.com>