Patch "ksmbd: avoid out of bounds access in decode_preauth_ctxt()" has been added to the 6.2-stable tree

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



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

    ksmbd: avoid out of bounds access in decode_preauth_ctxt()

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-avoid-out-of-bounds-access-in-decode_preauth_ctxt.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 e7067a446264a7514fa1cfaa4052cdb6803bc6a2 Mon Sep 17 00:00:00 2001
From: David Disseldorp <ddiss@xxxxxxx>
Date: Thu, 13 Apr 2023 23:49:57 +0900
Subject: ksmbd: avoid out of bounds access in decode_preauth_ctxt()

From: David Disseldorp <ddiss@xxxxxxx>

commit e7067a446264a7514fa1cfaa4052cdb6803bc6a2 upstream.

Confirm that the accessed pneg_ctxt->HashAlgorithms address sits within
the SMB request boundary; deassemble_neg_contexts() only checks that the
eight byte smb2_neg_context header + (client controlled) DataLength are
within the packet boundary, which is insufficient.

Checking for sizeof(struct smb2_preauth_neg_context) is overkill given
that the type currently assumes SMB311_SALT_SIZE bytes of trailing Salt.

Signed-off-by: David Disseldorp <ddiss@xxxxxxx>
Acked-by: Namjae Jeon <linkinjeon@xxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 fs/ksmbd/smb2pdu.c |   23 ++++++++++++++---------
 1 file changed, 14 insertions(+), 9 deletions(-)

--- a/fs/ksmbd/smb2pdu.c
+++ b/fs/ksmbd/smb2pdu.c
@@ -872,17 +872,21 @@ static void assemble_neg_contexts(struct
 }
 
 static __le32 decode_preauth_ctxt(struct ksmbd_conn *conn,
-				  struct smb2_preauth_neg_context *pneg_ctxt)
+				  struct smb2_preauth_neg_context *pneg_ctxt,
+				  int len_of_ctxts)
 {
-	__le32 err = STATUS_NO_PREAUTH_INTEGRITY_HASH_OVERLAP;
+	/*
+	 * sizeof(smb2_preauth_neg_context) assumes SMB311_SALT_SIZE Salt,
+	 * which may not be present. Only check for used HashAlgorithms[1].
+	 */
+	if (len_of_ctxts < MIN_PREAUTH_CTXT_DATA_LEN)
+		return STATUS_INVALID_PARAMETER;
 
-	if (pneg_ctxt->HashAlgorithms == SMB2_PREAUTH_INTEGRITY_SHA512) {
-		conn->preauth_info->Preauth_HashId =
-			SMB2_PREAUTH_INTEGRITY_SHA512;
-		err = STATUS_SUCCESS;
-	}
+	if (pneg_ctxt->HashAlgorithms != SMB2_PREAUTH_INTEGRITY_SHA512)
+		return STATUS_NO_PREAUTH_INTEGRITY_HASH_OVERLAP;
 
-	return err;
+	conn->preauth_info->Preauth_HashId = SMB2_PREAUTH_INTEGRITY_SHA512;
+	return STATUS_SUCCESS;
 }
 
 static void decode_encrypt_ctxt(struct ksmbd_conn *conn,
@@ -1010,7 +1014,8 @@ static __le32 deassemble_neg_contexts(st
 				break;
 
 			status = decode_preauth_ctxt(conn,
-						     (struct smb2_preauth_neg_context *)pctx);
+						     (struct smb2_preauth_neg_context *)pctx,
+						     len_of_ctxts);
 			if (status != STATUS_SUCCESS)
 				break;
 		} else if (pctx->ContextType == SMB2_ENCRYPTION_CAPABILITIES) {


Patches currently in stable-queue which might be from ddiss@xxxxxxx are

queue-6.2/ksmbd-avoid-out-of-bounds-access-in-decode_preauth_ctxt.patch



[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Index of Archives]     [Linux USB Devel]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]

  Powered by Linux