Patch "target/iscsi: avoid NULL dereference in CHAP auth error path" has been added to the 4.15-stable tree

This is a note to let you know that I've just added the patch titled

target/iscsi: avoid NULL dereference in CHAP auth error path

to the 4.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
target-iscsi-avoid-null-dereference-in-chap-auth-error-path.patch
and it can be found in the queue-4.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: David Disseldorp <[email protected]>
Date: Wed, 13 Dec 2017 18:22:30 +0100
Subject: target/iscsi: avoid NULL dereference in CHAP auth error path

From: David Disseldorp <[email protected]>

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().

---
 drivers/target/iscsi/iscsi_target_auth.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

@@ -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;

Patches currently in stable-queue which might be from [email protected] are

queue-4.15/target-iscsi-avoid-null-dereference-in-chap-auth-error-path.patch