When asn1_encode_sequence() fails, WARN is not the correct solution.
1. asn1_encode_sequence() is not an internal function (located in lib/asn1_encode.c). 2. Location is known, which makes the stack trace useless. 3. Results a crash if panic_on_warn is set.
It is also noteworthy that the use of WARN is undocumented, and it should be avoided unless there is a carefully considered rationale to use it.
Replace WARN with pr_err, and print the return value instead, which is only useful piece of information.
Cc: stable@vger.kernel.org # v5.13+ Fixes: f2219745250f ("security: keys: trusted: use ASN.1 TPM2 key format for the blobs") Signed-off-by: Jarkko Sakkinen jarkko@kernel.org --- security/keys/trusted-keys/trusted_tpm2.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/security/keys/trusted-keys/trusted_tpm2.c b/security/keys/trusted-keys/trusted_tpm2.c index dfeec06301ce..dbdd6a318b8b 100644 --- a/security/keys/trusted-keys/trusted_tpm2.c +++ b/security/keys/trusted-keys/trusted_tpm2.c @@ -38,6 +38,7 @@ static int tpm2_key_encode(struct trusted_key_payload *payload, u8 *end_work = scratch + SCRATCH_SIZE; u8 *priv, *pub; u16 priv_len, pub_len; + int ret;
priv_len = get_unaligned_be16(src) + 2; priv = src; @@ -79,8 +80,11 @@ static int tpm2_key_encode(struct trusted_key_payload *payload, work1 = payload->blob; work1 = asn1_encode_sequence(work1, work1 + sizeof(payload->blob), scratch, work - scratch); - if (WARN(IS_ERR(work1), "BUG: ASN.1 encoder failed")) - return PTR_ERR(work1); + if (IS_ERR(work1)) { + ret = PTR_ERR(work1); + pr_err("ASN.1 encode error %d\n", ret); + return ret; + }
return work1 - payload->blob; }