[PATCH 6.1 266/473] SUNRPC: Fix gss_free_in_token_pages()

Greg Kroah-Hartman
2024-06-06T14:16:23Z

From: Chuck Lever <chuck.lever@oracle.com>

[ Upstream commit bafa6b4d95d97877baa61883ff90f7e374427fae ]

Dan Carpenter says:
> Commit 5866efa8cbfb ("SUNRPC: Fix svcauth_gss_proxy_init()") from Oct
> 24, 2019 (linux-next), leads to the following Smatch static checker
> warning:
>
> net/sunrpc/auth_gss/svcauth_gss.c:1039 gss_free_in_token_pages()
> warn: iterator 'i' not incremented
>
> net/sunrpc/auth_gss/svcauth_gss.c
> 1034 static void gss_free_in_token_pages(struct gssp_in_token *in_token)
> 1035 {
> 1036 u32 inlen;
> 1037 int i;
> 1038
> --> 1039 i = 0;
> 1040 inlen = in_token->page_len;
> 1041 while (inlen) {
> 1042 if (in_token->pages[i])
> 1043 put_page(in_token->pages[i]);
> ^
> This puts page zero over and over.
>
> 1044 inlen -= inlen > PAGE_SIZE ? PAGE_SIZE : inlen;
> 1045 }
> 1046
> 1047 kfree(in_token->pages);
> 1048 in_token->pages = NULL;
> 1049 }

Based on the way that the ->pages[] array is constructed in
gss_read_proxy_verf(), we know that once the loop encounters a NULL
page pointer, the remaining array elements must also be NULL.

Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Suggested-by: Trond Myklebust <trondmy@hammerspace.com>
Fixes: 5866efa8cbfb ("SUNRPC: Fix svcauth_gss_proxy_init()")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/sunrpc/auth_gss/svcauth_gss.c | 10 ++--------
1 file changed, 2 insertions(+), 8 deletions(-)

diff --git a/net/sunrpc/auth_gss/svcauth_gss.c b/net/sunrpc/auth_gss/svcauth_gss.c
index bdc34ea0d939d..9d045aa6805d7 100644
--- a/net/sunrpc/auth_gss/svcauth_gss.c
+++ b/net/sunrpc/auth_gss/svcauth_gss.c
@@ -1132,17 +1132,11 @@ gss_read_verf(struct rpc_gss_wire_cred *gc,

static void gss_free_in_token_pages(struct gssp_in_token *in_token)
{
- u32 inlen;
int i;

i = 0;
- inlen = in_token->page_len;
- while (inlen) {
- if (in_token->pages[i])
- put_page(in_token->pages[i]);
- inlen -= inlen > PAGE_SIZE ? PAGE_SIZE : inlen;
- }
-
+ while (in_token->pages[i])
+ put_page(in_token->pages[i++]);
kfree(in_token->pages);
in_token->pages = NULL;
}
--
2.43.0