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From: Thomas Huth <thuth@redhat.com>
To: Steve French <sfrench@samba.org>
Cc: Paulo Alcantara <pc@manguebit.org>,
	Ronnie Sahlberg <ronniesahlberg@gmail.com>,
	Shyam Prasad N <sprasad@microsoft.com>,
	Tom Talpey <tom@talpey.com>, Bharath SM <bharathsm@microsoft.com>,
	linux-cifs@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH 2/5] smb: client: Clear sensitive stack and heap data in smb2ops.c
Date: Wed, 12 Aug 2026 15:01:49 +0200	[thread overview]
Message-ID: <20260812130152.2861834-3-thuth@redhat.com> (raw)
In-Reply-To: <20260812130152.2861834-1-thuth@redhat.com>

From: Thomas Huth <thuth@redhat.com>

Make sure to not leak key-related data via the heap or the stack
by using kfree_sensitive() or memzero_explicit() here.

Signed-off-by: Thomas Huth <thuth@redhat.com>
---
 fs/smb/client/smb2ops.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/smb/client/smb2ops.c b/fs/smb/client/smb2ops.c
index 192649fec25d5..a3099a0e5c2be 100644
--- a/fs/smb/client/smb2ops.c
+++ b/fs/smb/client/smb2ops.c
@@ -1569,7 +1569,7 @@ SMB2_request_res_key(const unsigned int xid, struct cifs_tcon *tcon,
 	memcpy(pcchunk->SourceKey, res_key->ResumeKey, COPY_CHUNK_RES_KEY_SIZE);
 
 req_res_key_exit:
-	kfree(res_key);
+	kfree_sensitive(res_key);
 	return rc;
 }
 
@@ -4636,7 +4636,7 @@ crypt_message(struct TCP_Server_Info *server, int num_rqst,
 		rc = crypto_aead_setkey(tfm, key, SMB3_GCM256_CRYPTKEY_SIZE);
 	else
 		rc = crypto_aead_setkey(tfm, key, SMB3_GCM128_CRYPTKEY_SIZE);
-
+	memzero_explicit(key, sizeof(key));
 	if (rc) {
 		cifs_server_dbg(VFS, "%s: Failed to set aead key %d\n", __func__, rc);
 		return rc;
-- 
2.55.0


  parent reply	other threads:[~2026-08-12 13:02 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-08-12 13:01 [PATCH 0/5] smb: client: Avoid leaking of sensitive data to the stack or heap Thomas Huth
2026-08-12 13:01 ` [PATCH 1/5] smb: client: Clear sensitive stack data in smb2transport.c Thomas Huth
2026-08-12 13:01 ` Thomas Huth [this message]
2026-08-12 13:01 ` [PATCH 3/5] smb: client: Clear sensitive stack data in cifsencrypt.c Thomas Huth
2026-08-12 13:01 ` [PATCH 4/5] smb: client: Clear sensitive stack data in smb1encrypt.c Thomas Huth
2026-08-12 13:01 ` [PATCH 5/5] smb: client: Avoid leaking sensitive data to the heap in connect.c Thomas Huth

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