Patchwork [net-next] rds: debug: fix null check on static array

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Submitter Prashant Bhole
Date Dec. 6, 2017, 1:47 a.m.
Message ID <20171206014704.3796-1-bhole_prashant_q7@lab.ntt.co.jp>
Download mbox | patch
Permalink /patch/396511/
State New
Headers show

Comments

Prashant Bhole - Dec. 6, 2017, 1:47 a.m.
t_name cannot be NULL since it is an array field of a struct.
Replacing null check on static array with string length check using
strnlen()

Signed-off-by: Prashant Bhole <bhole_prashant_q7@lab.ntt.co.jp>
---
 net/rds/connection.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
Sowmini Varadhan - Dec. 6, 2017, 11:32 a.m.
On (12/06/17 10:47), Prashant Bhole wrote:
> 
> t_name cannot be NULL since it is an array field of a struct.
> Replacing null check on static array with string length check using
> strnlen()

t_name is always initialized for all rds transports today,  and would
be all zeros unless someone stomped over that memory (in which case
there could be more serious issues than a busted debug string) but
it's good  to be safe and check I suppose.

Acked-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>

--Sowmini
santosh shilimkar - Dec. 6, 2017, 4:36 p.m.
On 12/6/2017 3:32 AM, Sowmini Varadhan wrote:
> On (12/06/17 10:47), Prashant Bhole wrote:
>>
>> t_name cannot be NULL since it is an array field of a struct.
>> Replacing null check on static array with string length check using
>> strnlen()
> 
> t_name is always initialized for all rds transports today,  and would
> be all zeros unless someone stomped over that memory (in which case
> there could be more serious issues than a busted debug string) but
> it's good  to be safe and check I suppose.

Thanks Sowmini !!

Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
David Miller - Dec. 6, 2017, 8:03 p.m.
From: Prashant Bhole <bhole_prashant_q7@lab.ntt.co.jp>
Date: Wed,  6 Dec 2017 10:47:04 +0900

> t_name cannot be NULL since it is an array field of a struct.
> Replacing null check on static array with string length check using
> strnlen()
> 
> Signed-off-by: Prashant Bhole <bhole_prashant_q7@lab.ntt.co.jp>

Applied, thank you.

Patch

diff --git a/net/rds/connection.c b/net/rds/connection.c
index 9efc82c665b5..6492c0b608a4 100644
--- a/net/rds/connection.c
+++ b/net/rds/connection.c
@@ -230,8 +230,8 @@  static struct rds_connection *__rds_conn_create(struct net *net,
 
 	rdsdebug("allocated conn %p for %pI4 -> %pI4 over %s %s\n",
 	  conn, &laddr, &faddr,
-	  trans->t_name ? trans->t_name : "[unknown]",
-	  is_outgoing ? "(outgoing)" : "");
+	  strnlen(trans->t_name, sizeof(trans->t_name)) ? trans->t_name :
+	  "[unknown]", is_outgoing ? "(outgoing)" : "");
 
 	/*
 	 * Since we ran without holding the conn lock, someone could