[PATCH] gss_krb5: Fix memleak in krb5_make_rc4_seq_num

When kmalloc() fails, cipher should be freed
just like when krb5_rc4_setup_seq_key() fails.

Fixes: e7afe6c1d486b ("sunrpc: fix 4 more call sites that were using stack memory with a scatterlist")
Signed-off-by: Dinghao Liu <redacted>
---
 net/sunrpc/auth_gss/gss_krb5_seqnum.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/net/sunrpc/auth_gss/gss_krb5_seqnum.c b/net/sunrpc/auth_gss/gss_krb5_seqnum.c
index 507105127095..88ca58d11082 100644
--- a/net/sunrpc/auth_gss/gss_krb5_seqnum.c
+++ b/net/sunrpc/auth_gss/gss_krb5_seqnum.c

@@ -53,8 +53,10 @@ krb5_make_rc4_seq_num(struct krb5_ctx *kctx, int direction, s32 seqnum,
 		return PTR_ERR(cipher);
 
 	plain = kmalloc(8, GFP_NOFS);
-	if (!plain)
-		return -ENOMEM;
+	if (!plain) {
+		code = -ENOMEM;
+		goto out;
+	}
 
 	plain[0] = (unsigned char) ((seqnum >> 24) & 0xff);
 	plain[1] = (unsigned char) ((seqnum >> 16) & 0xff);

-- 
2.17.1

This code is rarely if ever used, and there are pending patches to
remove it completely, so I don't think it's worth trying to fix a rare
memory leak at this point.

--b.

On Thu, Aug 27, 2020 at 04:02:50PM +0800, Dinghao Liu wrote:

On Sat, 29 Aug 2020 at 18:43, J. Bruce Fields [off-list ref] wrote:

This code is rarely if ever used, and there are pending patches to
remove it completely, so I don't think it's worth trying to fix a rare
memory leak at this point.

--b.

FYI I just submitted v3 of my series removing this code to the
linux-crypto list, and so hopefully it will disappear in v5.10

On Thu, Aug 27, 2020 at 04:02:50PM +0800, Dinghao Liu wrote:

quoted

When kmalloc() fails, cipher should be freed
just like when krb5_rc4_setup_seq_key() fails.

Fixes: e7afe6c1d486b ("sunrpc: fix 4 more call sites that were using stack memory with a scatterlist")
Signed-off-by: Dinghao Liu <redacted>
---
 net/sunrpc/auth_gss/gss_krb5_seqnum.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/net/sunrpc/auth_gss/gss_krb5_seqnum.c b/net/sunrpc/auth_gss/gss_krb5_seqnum.c
index 507105127095..88ca58d11082 100644
--- a/net/sunrpc/auth_gss/gss_krb5_seqnum.c
+++ b/net/sunrpc/auth_gss/gss_krb5_seqnum.c

@@ -53,8 +53,10 @@ krb5_make_rc4_seq_num(struct krb5_ctx *kctx, int direction, s32 seqnum,
              return PTR_ERR(cipher);

      plain = kmalloc(8, GFP_NOFS);
-     if (!plain)
-             return -ENOMEM;
+     if (!plain) {
+             code = -ENOMEM;
+             goto out;
+     }

      plain[0] = (unsigned char) ((seqnum >> 24) & 0xff);
      plain[1] = (unsigned char) ((seqnum >> 16) & 0xff);
--

2.17.1