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cifs: fix double free on failed kerberos auth

Message ID 20230110205520.4425-1-pc@cjr.nz (mailing list archive)
State New, archived
Headers show
Series cifs: fix double free on failed kerberos auth | expand

Commit Message

Paulo Alcantara Jan. 10, 2023, 8:55 p.m. UTC
If session setup failed with kerberos auth, we ended up freeing
cifs_ses::auth_key.response twice in SMB2_auth_kerberos() and
sesInfoFree().

Fix this by zeroing out cifs_ses::auth_key.response after freeing it
in SMB2_auth_kerberos().

Fixes: a4e430c8c8ba ("cifs: replace kfree() with kfree_sensitive() for sensitive data")
Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Acked-by: Ronnie Sahlberg <lsahlber@redhat.com>
---
 fs/cifs/smb2pdu.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

Comments

Steve French Jan. 10, 2023, 9:34 p.m. UTC | #1
merged into cifs-2.6.git for-next pending testing

Xioli,
Let me know if you want me to add your reported-by and/or tested-by

On Tue, Jan 10, 2023 at 2:55 PM Paulo Alcantara <pc@cjr.nz> wrote:
>
> If session setup failed with kerberos auth, we ended up freeing
> cifs_ses::auth_key.response twice in SMB2_auth_kerberos() and
> sesInfoFree().
>
> Fix this by zeroing out cifs_ses::auth_key.response after freeing it
> in SMB2_auth_kerberos().
>
> Fixes: a4e430c8c8ba ("cifs: replace kfree() with kfree_sensitive() for sensitive data")
> Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
> Acked-by: Ronnie Sahlberg <lsahlber@redhat.com>
> ---
>  fs/cifs/smb2pdu.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
> index 2c484d47c592..727f16b426be 100644
> --- a/fs/cifs/smb2pdu.c
> +++ b/fs/cifs/smb2pdu.c
> @@ -1482,8 +1482,11 @@ SMB2_auth_kerberos(struct SMB2_sess_data *sess_data)
>  out_put_spnego_key:
>         key_invalidate(spnego_key);
>         key_put(spnego_key);
> -       if (rc)
> +       if (rc) {
>                 kfree_sensitive(ses->auth_key.response);
> +               ses->auth_key.response = NULL;
> +               ses->auth_key.len = 0;
> +       }
>  out:
>         sess_data->result = rc;
>         sess_data->func = NULL;
> --
> 2.39.0
>
diff mbox series

Patch

diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index 2c484d47c592..727f16b426be 100644
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -1482,8 +1482,11 @@  SMB2_auth_kerberos(struct SMB2_sess_data *sess_data)
 out_put_spnego_key:
 	key_invalidate(spnego_key);
 	key_put(spnego_key);
-	if (rc)
+	if (rc) {
 		kfree_sensitive(ses->auth_key.response);
+		ses->auth_key.response = NULL;
+		ses->auth_key.len = 0;
+	}
 out:
 	sess_data->result = rc;
 	sess_data->func = NULL;