linux-stable.git/security, branch v6.18.47

selinux: reject a permission value exceeding the class permission count

2026-08-23T12:26:54+00:00

commit d14b5d0e97fccd27974fedc03b903408872907fd upstream.

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: Greg Kroah-Hartman

selinux: reject an unclaimed class value in security_get_classes()

2026-08-23T12:26:54+00:00

commit 22b05fec62c0fe9864cfceb52f7d0f3a34d9b1dd upstream.

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 
Acked-by: Stephen Smalley 
Signed-off-by: Paul Moore 
Signed-off-by: Greg Kroah-Hartman

selinux: do not cancel a policy conversion that never started

2026-08-23T12:26:54+00:00

commit e5c0235a3c4e9eb047a16cd02323fe4ecf2f570e upstream.

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 
Acked-by: Stephen Smalley 
Signed-off-by: Paul Moore 
Signed-off-by: Greg Kroah-Hartman

selinux: reject a class permission count below its inherited common

2026-08-23T12:26:54+00:00

commit 9a82dcd98b6e6e11cfd162410967951f12152528 upstream.

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 
Acked-by: Stephen Smalley 
Signed-off-by: Paul Moore 
Signed-off-by: Greg Kroah-Hartman

selinux: require every boolean value to be defined

2026-08-23T12:26:54+00:00

commit a93d37a09b863810653f93d371fb197457d59deb upstream.

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 
Acked-by: Stephen Smalley 
Signed-off-by: Paul Moore 
Signed-off-by: Greg Kroah-Hartman

ima: Instantiate file_truncate and path_truncate hooks

2026-08-19T16:18:20+00:00

commit b80bed5c871a80151351342c065579405ce77145 upstream.

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 
Cc: stable@vger.kernel.org
Signed-off-by: Mimi Zohar 
Signed-off-by: Greg Kroah-Hartman

ima: fix out-of-bounds read in xattr_verify()

2026-08-19T16:17:57+00:00

commit 5ff232d31106f45ac87c3b64e1d35a0667777797 upstream.

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 
Signed-off-by: Mimi Zohar 
Signed-off-by: Greg Kroah-Hartman

keys: make keyring key-chunk byte order agree with keyring_diff_objects()

2026-08-09T18:25:01+00:00

[ Upstream commit 58565eef0f8d861aae92abfb7658458d661cee17 ]

keyring_get_key_chunk() loads description bytes into the index chunk low
address first, while keyring_diff_objects() numbers the first differing
bit from the low end and folds the absolute byte index into the level
without removing the inline-prefix offset the level already carries.
The two disagree on byte order and bit position, so the array can be
told two keys first differ at a bit that does not differ in the chunk
the walker uses, letting crafted descriptions collide into one node.

Load the chunk in the order keyring_diff_objects() assumes and drop the
inline-prefix length when folding the byte index into the level.  This
only changes the in-memory ordering used to place keys within a keyring;
add, search and read of non-colliding keys are unaffected.

Fixes: f771fde82051 ("keys: Simplify key description management")
Assisted-by: Claude:claude-opus-4-8
Signed-off-by: Michael Bommarito 
Reviewed-by: Jarkko Sakkinen 
Tested-by: Jarkko Sakkinen 
Link: https://lore.kernel.org/r/20260719161505.2423935-3-michael.bommarito@gmail.com
Signed-off-by: Jarkko Sakkinen 
Signed-off-by: Sasha Levin

keys: fix out-of-bounds read in keyring_get_key_chunk()

2026-08-09T18:25:01+00:00

[ Upstream commit 63918731f9ae25b5deb022f118e941e6dddfcef4 ]

For description-level chunks keyring_get_key_chunk() advances the read
pointer by level * sizeof(long) past the inline prefix but only
bounds-checks the prefix, so a long enough key description is read past
its kmemdup(desc, desc_len + 1) allocation.  Compute the full byte
offset and bounds-check the description against it before reading.

The walk only reaches a description-level chunk when two keys collide
through the hash, x, type and domain_tag chunks, so this is reached from
an unprivileged add_key(2) with a crafted pair of same-type keys whose
index hashes collide; KASAN reports a slab-out-of-bounds read.

Fixes: f771fde82051 ("keys: Simplify key description management")
Assisted-by: Claude:claude-opus-4-8
Signed-off-by: Michael Bommarito 
Reviewed-by: Jarkko Sakkinen 
Tested-by: Jarkko Sakkinen 
Link: https://lore.kernel.org/r/20260719161505.2423935-2-michael.bommarito@gmail.com
Signed-off-by: Jarkko Sakkinen 
Signed-off-by: Sasha Levin

KEYS: trusted: dcp: fix key_len validation and calc_blob_len() return type

2026-08-09T18:25:01+00:00

[ Upstream commit 35d661c98fe4733490f20b4311616a3c2c30abc0 ]

Two correctness and type-hygiene issues exist in the DCP trusted keys
implementation.

First, trusted_dcp_unseal() reads p->key_len from a user-supplied blob
without checking if it exceeds MAX_KEY_SIZE.  If a crafted blob provides a
payload_len larger than 128, the subsequent do_aead_crypto() call writes
past the end of the p->key array into the adjacent p->blob buffer within
the same struct trusted_key_payload -- the caller's own input, not
unrelated kernel memory.  While not exploitable, this violates strict array
bounds and triggers static analyzers.  Fix this by adding a validation
check against MIN_KEY_SIZE and MAX_KEY_SIZE immediately after reading the
length, matching the checks already done in trusted_core.c.

Second, calc_blob_len() calculates a sum in size_t that truncates to
unsigned int on 64-bit platforms.  Because the DCP hardware is only present
on 32-bit i.MX SoC platforms, size_t and unsigned int are functionally
equivalent in production, making this truncation harmless in practice.
Nevertheless, updating the return type to size_t (and subsequently updating
'blen' in the seal/unseal paths) resolves type-narrowing warnings and
improves overall code hygiene.

Fixes: 2e8a0f40a39c ("KEYS: trusted: Introduce NXP DCP-backed trusted keys")
Signed-off-by: Fabrice Derepas 
Reviewed-by: David Gstir 
Reviewed-by: Richard Weinberger 
Reviewed-by: Jarkko Sakkinen 
Tested-by: Jarkko Sakkinen 
Link: https://lore.kernel.org/r/20260719163939.3624767-1-fabrice.derepas@canonical.com
Signed-off-by: Jarkko Sakkinen 
Signed-off-by: Sasha Levin