linux.git/security/keys, branch v7.2-rc6

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

2026-07-23T15:23:39+00:00

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

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

2026-07-23T15:23:32+00:00

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

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

2026-07-23T15:23:23+00:00

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

keys: keyctl_pkey: replace BUG with return -EOPNOTSUPP

2026-06-15T12:19:13+00:00

Replace two BUG() calls in keyctl_pkey_params_get_2() and
keyctl_pkey_e_d_s() default cases with -EOPNOTSUPP, matching
the error style already used in these functions.

Signed-off-by: Mohammed EL Kadiri 
Signed-off-by: Jarkko Sakkinen

keys: request_key: replace BUG with return -EINVAL

2026-06-15T12:19:13+00:00

Replace BUG() in construct_get_dest_keyring() default case
with return -EINVAL to handle the unimplemented group keyring
destination gracefully.

Signed-off-by: Mohammed EL Kadiri 
Reviewed-by: Jarkko Sakkinen 
Link: https://lore.kernel.org/r/20260613130408.13709-2-med08elkadiri@gmail.com
Signed-off-by: Jarkko Sakkinen

keys: Pin request_key_auth payload in instantiate paths

2026-06-15T12:19:13+00:00

A: request_key()       B: KEYCTL_INSTANTIATE_IOV
================       =========================

create auth key
store rka in auth key
wait for helper
                       get auth key
                       load rka from auth key
                       copy user payload
                       sleep on #PF

helper completed
detach and free rka
destroy auth key
                       wake up
                       use rka->target_key
                       **USE-AFTER-FREE**

Give request_key_auth payloads a refcount.  Take a payload reference while
authkey->sem stabilizes the payload and revocation state.  Hold that
reference across the instantiate and reject paths.  Drop the auth key
owning reference from revoke and destroy.

[jarkko: Replaced the first two paragraphs of text with an actual
 concurrency scenario.]
Cc: stable@vger.kernel.org # v5.10+
Fixes: b5f545c880a2 ("[PATCH] keys: Permit running process to instantiate keys")
Reported-by: Shaomin Chen 
Closes: https://lore.kernel.org/r/20260519144403.436694-1-eeesssooo020@gmail.com
Signed-off-by: Shaomin Chen 
Signed-off-by: Jarkko Sakkinen

keys: prevent slab cache merging for key_jar

2026-06-15T12:19:13+00:00

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) 
Signed-off-by: Mohammed EL Kadiri 
Reviewed-by: Jarkko Sakkinen 
Link: https://lore.kernel.org/r/20260610065052.9120-1-med08elkadiri@gmail.com
Signed-off-by: Jarkko Sakkinen

keys: Replace strcpy(derived_buf, "AUTH_KEY") with strscpy(..., HASH_SIZE)

2026-06-15T12:19:13+00:00

derived_buf is guaranteed to be HASH_SIZE - and it is more than enough.
The strscpy() degenerates into an memcpy() (as did the strcpy()).
Do the same for the associated "ENC_KEY" copy.

Removes a possibly unbounded strcpy().

Signed-off-by: David Laight 
Reviewed-by: Jarkko Sakkinen 
Link: https://lore.kernel.org/r/20260606202633.5018-9-david.laight.linux@gmail.com
Signed-off-by: Jarkko Sakkinen

KEYS: Use acquire when reading state in keyring search

2026-06-15T12:19:12+00:00

The negative-key race fix added release/acquire ordering for key use.

Publish payload before state; read state before payload.

keyring_search_iterator() still uses READ_ONCE() before match callbacks.
An asymmetric match callback calls asymmetric_key_ids(), which reads
key->payload.data[asym_key_ids].

Use key_read_state() there to complete that ordering.

Fixes: 363b02dab09b ("KEYS: Fix race between updating and finding a negative key")
Signed-off-by: Gui-Dong Han 
Reviewed-by: Jarkko Sakkinen 
Link: https://lore.kernel.org/r/20260529033406.20673-1-hanguidong02@gmail.com
Signed-off-by: Jarkko Sakkinen

keys/trusted_keys: mark 'migratable' as __ro_after_init

2026-06-15T12:19:12+00:00

The 'migratable' variable is initialized only during the init phase
in the 'init_trusted' function and never changed. So, mark it as
__ro_after_init.

Signed-off-by: Len Bao 
Reviewed-by: Jarkko Sakkinen 
Link: https://lore.kernel.org/r/20260516152249.41851-1-len.bao@gmx.us
Signed-off-by: Jarkko Sakkinen