* Re: [bug report] rhashtable: Add nested tables
[not found] <20170216121703.GA26276@mwanda>
@ 2017-02-25 14:38 ` Herbert Xu
2017-02-27 2:34 ` David Miller
0 siblings, 1 reply; 2+ messages in thread
From: Herbert Xu @ 2017-02-25 14:38 UTC (permalink / raw)
To: Dan Carpenter; +Cc: kernel-janitors, netdev, Thomas Graf
On Thu, Feb 16, 2017 at 03:17:03PM +0300, Dan Carpenter wrote:
> Hello Herbert Xu,
>
> This is a semi-automatic email about new static checker warnings.
>
> The patch 40137906c5f5: "rhashtable: Add nested tables" from Feb 11,
> 2017, leads to the following Smatch complaint:
>
> lib/rhashtable.c:149 bucket_table_free()
> warn: variable dereferenced before check 'tbl' (see line 146)
>
> lib/rhashtable.c
> 145 {
> 146 if (tbl->nest)
> ^^^^^^^^^
> New unchecked dereference.
>
> 147 nested_bucket_table_free(tbl);
> 148
> 149 if (tbl)
> ^^^
> Old code checked for NULL.
>
> 150 kvfree(tbl->locks);
> 151
Thanks for catching this. I checked all the callers and none
of them can provide a NULL pointer so let's just kill the check.
---8<---
Subject: rhashtable: Fix use before NULL check in bucket_table_free
Dan Carpenter reported a use before NULL check bug in the function
bucket_table_free. In fact we don't need the NULL check at all as
no caller can provide a NULL argument. So this patch fixes this by
simply removing it.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
---
lib/rhashtable.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)
diff --git a/lib/rhashtable.c b/lib/rhashtable.c
index 172454e..fac1a78 100644
--- a/lib/rhashtable.c
+++ b/lib/rhashtable.c
@@ -146,9 +146,7 @@ static void bucket_table_free(const struct bucket_table *tbl)
if (tbl->nest)
nested_bucket_table_free(tbl);
- if (tbl)
- kvfree(tbl->locks);
-
+ kvfree(tbl->locks);
kvfree(tbl);
}
--
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
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