7.3-stable review patch. If anyone has any objections, please let me know. ------------------ From: Stefano Garzarella commit 11077cbcc2695f71c944a84a5f08c6672ab759f1 upstream. tpm2_key_decode() allocates 4 bytes more than needed. The ASN.1 callbacks tpm2_key_priv() and tpm2_key_pub() provide the lengths of TPM2B_PRIVATE and TPM2B_PUBLIC, so ctx.priv_len and ctx.pub_len already account for the 2-byte `size` field each of those structures starts with. I noticed this while reviewing commit 114f00d738f1 ("KEYS: trusted: Fix tpm2_load_cmd() boundary check"), which correctly reports ctx.priv_len + ctx.pub_len as the decoded blob size [1]. Let's allocate exactly that amount, matching the data copied into the blob. [1] https://lore.kernel.org/linux-integrity/apfoKo-BdwaLXtkT@sgarzare-redhat/ Cc: stable@vger.kernel.org # v5.13+ Fixes: f2219745250f ("security: keys: trusted: use ASN.1 TPM2 key format for the blobs") Signed-off-by: Stefano Garzarella Link: https://lore.kernel.org/r/20260923173506.41519-1-sgarzare@redhat.com Reviewed-by: Jarkko Sakkinen Signed-off-by: Jarkko Sakkinen Signed-off-by: Greg Kroah-Hartman --- security/keys/trusted-keys/trusted_tpm2.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/security/keys/trusted-keys/trusted_tpm2.c +++ b/security/keys/trusted-keys/trusted_tpm2.c @@ -115,7 +115,7 @@ static int tpm2_key_decode(struct truste if (ctx.priv_len + ctx.pub_len > MAX_BLOB_SIZE) return -EINVAL; - blob = kmalloc(ctx.priv_len + ctx.pub_len + 4, GFP_KERNEL); + blob = kmalloc(ctx.priv_len + ctx.pub_len, GFP_KERNEL); if (!blob) return -ENOMEM;