4.15-stable review patch. If anyone has any objections, please let me know.
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From: David Disseldorp ddiss@suse.de
commit ce512d79d0466a604793addb6b769d12ee326822 upstream.
If chap_server_compute_md5() fails early, e.g. via CHAP_N mismatch, then crypto_free_shash() is called with a NULL pointer which gets dereferenced in crypto_shash_tfm().
Fixes: 69110e3cedbb ("iscsi-target: Use shash and ahash") Suggested-by: Markus Elfring elfring@users.sourceforge.net Signed-off-by: David Disseldorp ddiss@suse.de Cc: stable@vger.kernel.org # 4.6+ Signed-off-by: Nicholas Bellinger nab@linux-iscsi.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/target/iscsi/iscsi_target_auth.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/drivers/target/iscsi/iscsi_target_auth.c +++ b/drivers/target/iscsi/iscsi_target_auth.c @@ -421,7 +421,8 @@ static int chap_server_compute_md5( auth_ret = 0; out: kzfree(desc); - crypto_free_shash(tfm); + if (tfm) + crypto_free_shash(tfm); kfree(challenge); kfree(challenge_binhex); return auth_ret;