This is a note to let you know that I've just added the patch titled
ksmbd: fix deadlock in ksmbd_find_crypto_ctx()
to the 6.2-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:
ksmbd-fix-deadlock-in-ksmbd_find_crypto_ctx.patch
and it can be found in the queue-6.2 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 7b4323373d844954bb76e0e9f39c4e5fc785fa7b Mon Sep 17 00:00:00 2001
From: Namjae Jeon <linkinjeon@xxxxxxxxxx>
Date: Wed, 3 May 2023 08:44:14 +0900
Subject: ksmbd: fix deadlock in ksmbd_find_crypto_ctx()
From: Namjae Jeon <linkinjeon@xxxxxxxxxx>
commit 7b4323373d844954bb76e0e9f39c4e5fc785fa7b upstream.
Deadlock is triggered by sending multiple concurrent session setup
requests. It should be reused after releasing when getting ctx for crypto.
Multiple consecutive ctx uses cause deadlock while waiting for releasing
due to the limited number of ctx.
Cc: stable@xxxxxxxxxxxxxxx
Reported-by: zdi-disclosures@xxxxxxxxxxxxxx # ZDI-CAN-20591
Signed-off-by: Namjae Jeon <linkinjeon@xxxxxxxxxx>
Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/ksmbd/auth.c | 19 +++++++++++--------
1 file changed, 11 insertions(+), 8 deletions(-)
--- a/fs/ksmbd/auth.c
+++ b/fs/ksmbd/auth.c
@@ -221,22 +221,22 @@ int ksmbd_auth_ntlmv2(struct ksmbd_conn
{
char ntlmv2_hash[CIFS_ENCPWD_SIZE];
char ntlmv2_rsp[CIFS_HMAC_MD5_HASH_SIZE];
- struct ksmbd_crypto_ctx *ctx;
+ struct ksmbd_crypto_ctx *ctx = NULL;
char *construct = NULL;
int rc, len;
- ctx = ksmbd_crypto_ctx_find_hmacmd5();
- if (!ctx) {
- ksmbd_debug(AUTH, "could not crypto alloc hmacmd5\n");
- return -ENOMEM;
- }
-
rc = calc_ntlmv2_hash(conn, sess, ntlmv2_hash, domain_name);
if (rc) {
ksmbd_debug(AUTH, "could not get v2 hash rc %d\n", rc);
goto out;
}
+ ctx = ksmbd_crypto_ctx_find_hmacmd5();
+ if (!ctx) {
+ ksmbd_debug(AUTH, "could not crypto alloc hmacmd5\n");
+ return -ENOMEM;
+ }
+
rc = crypto_shash_setkey(CRYPTO_HMACMD5_TFM(ctx),
ntlmv2_hash,
CIFS_HMAC_MD5_HASH_SIZE);
@@ -272,6 +272,8 @@ int ksmbd_auth_ntlmv2(struct ksmbd_conn
ksmbd_debug(AUTH, "Could not generate md5 hash\n");
goto out;
}
+ ksmbd_release_crypto_ctx(ctx);
+ ctx = NULL;
rc = ksmbd_gen_sess_key(sess, ntlmv2_hash, ntlmv2_rsp);
if (rc) {
@@ -282,7 +284,8 @@ int ksmbd_auth_ntlmv2(struct ksmbd_conn
if (memcmp(ntlmv2->ntlmv2_hash, ntlmv2_rsp, CIFS_HMAC_MD5_HASH_SIZE) != 0)
rc = -EINVAL;
out:
- ksmbd_release_crypto_ctx(ctx);
+ if (ctx)
+ ksmbd_release_crypto_ctx(ctx);
kfree(construct);
return rc;
}
Patches currently in stable-queue which might be from linkinjeon@xxxxxxxxxx are
queue-6.2/ksmbd-not-allow-guest-user-on-multichannel.patch
queue-6.2/ksmbd-fix-memleak-in-session-setup.patch
queue-6.2/ksmbd-fix-null-pointer-dereference-in-smb2_get_info_filesystem.patch
queue-6.2/ksmbd-fix-racy-issue-under-cocurrent-smb2-tree-disconnect.patch
queue-6.2/ksmbd-fix-deadlock-in-ksmbd_find_crypto_ctx.patch
queue-6.2/ksmbd-call-rcu_barrier-in-ksmbd_server_exit.patch
