7.3-stable review patch. If anyone has any objections, please let me know. ------------------ From: Weiming Shi commit 9695df3b1db4ac4534274d38ee16e3b9b0bf910e upstream. The PKCS#8 parser deliberately leaves the asym_key_ids payload slot empty. key_or_keyring_common() unconditionally dereferences that slot when a PKCS#8 key is supplied to a key_or_keyring restriction. Both the plain and :chain forms reach this branch, allowing an unprivileged caller to trigger a NULL pointer dereference through KEYCTL_RESTRICT_KEYRING followed by add_key(). Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000 KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] RIP: 0010:key_or_keyring_common (crypto/asymmetric_keys/restrict.c:205 crypto/asymmetric_keys/restrict.c:279) Call Trace: __key_create_or_update (security/keys/key.c:884) key_create_or_update (security/keys/key.c:1021) __do_sys_add_key (security/keys/keyctl.c:134) do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) Kernel panic - not syncing: Fatal exception Reject an asymmetric restriction key without key IDs. A PKCS#8 private key cannot identify the signer of a candidate certificate and is not a valid trust anchor. Fixes: 3c58b2362ba8 ("KEYS: Implement PKCS#8 RSA Private Key parser [ver #2]") Cc: stable@vger.kernel.org Reported-by: Xiang Mei Link: https://lore.kernel.org/r/20260429181629.110802-2-bestswngs@gmail.com Assisted-by: Claude:claude-opus-4-8 Signed-off-by: Weiming Shi Signed-off-by: Herbert Xu Signed-off-by: Greg Kroah-Hartman --- crypto/asymmetric_keys/restrict.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) --- a/crypto/asymmetric_keys/restrict.c +++ b/crypto/asymmetric_keys/restrict.c @@ -243,10 +243,14 @@ static int key_or_keyring_common(struct if (IS_ERR(key)) key = NULL; } else if (trusted->type == &key_type_asymmetric) { + const struct asymmetric_key_ids *kids; const struct asymmetric_key_id **signer_ids; - signer_ids = (const struct asymmetric_key_id **) - asymmetric_key_ids(trusted)->id; + kids = asymmetric_key_ids(trusted); + if (!kids) + return -ENOKEY; + + signer_ids = (const struct asymmetric_key_id **)kids->id; /* * The auth_ids come from the candidate key (the