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| author | THOBY Simon <Simon.THOBY@viveris.fr> | 2021-08-22 08:55:26 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-11-17 11:04:52 +0100 |
| commit | 45a47382941d9702ec50608b6e4edd27c2bdd15a (patch) | |
| tree | d11accc90a7bf1e135afa6ab450524cfb9c5094c | |
| parent | a3c6e358fbe42247c347c6b777167e5c4351248d (diff) | |
| download | linux-45a47382941d9702ec50608b6e4edd27c2bdd15a.tar.gz linux-45a47382941d9702ec50608b6e4edd27c2bdd15a.tar.bz2 linux-45a47382941d9702ec50608b6e4edd27c2bdd15a.zip | |
IMA: reject unknown hash algorithms in ima_get_hash_algo
commit cb181da161963eddc9de0000de6ab2c7942be219 upstream.
The new function validate_hash_algo() assumed that ima_get_hash_algo()
always return a valid 'enum hash_algo', but it returned the
user-supplied value present in the digital signature without
any bounds checks.
Update ima_get_hash_algo() to always return a valid hash algorithm,
defaulting on 'ima_hash_algo' when the user-supplied value inside
the xattr is invalid.
Signed-off-by: THOBY Simon <Simon.THOBY@viveris.fr>
Reported-by: syzbot+e8bafe7b82c739eaf153@syzkaller.appspotmail.com
Fixes: 50f742dd9147 ("IMA: block writes of the security.ima xattr with unsupported algorithms")
Reviewed-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | security/integrity/ima/ima_appraise.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c index 530514df1c9a..0f868df0f30e 100644 --- a/security/integrity/ima/ima_appraise.c +++ b/security/integrity/ima/ima_appraise.c @@ -184,7 +184,8 @@ enum hash_algo ima_get_hash_algo(const struct evm_ima_xattr_data *xattr_value, switch (xattr_value->type) { case EVM_IMA_XATTR_DIGSIG: sig = (typeof(sig))xattr_value; - if (sig->version != 2 || xattr_len <= sizeof(*sig)) + if (sig->version != 2 || xattr_len <= sizeof(*sig) + || sig->hash_algo >= HASH_ALGO__LAST) return ima_hash_algo; return sig->hash_algo; break; |