The max length of volume->vid value is 20 characters.
So increase idbuf[] size up to 20 to avoid overflow.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: d2ddc776a458 ("afs: Overhaul volume and server record caching and fileserver rotation")
Signed-off-by: Daniil Dulov <d.dulov@aladdin.ru>
---
 fs/afs/volume.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/afs/volume.c b/fs/afs/volume.c
index f84194b791d3..9d0da38bbcf6 100644
--- a/fs/afs/volume.c
+++ b/fs/afs/volume.c
@@ -302,7 +302,7 @@ static int afs_update_volume_status(struct afs_volume *volume, struct key *key)
 {
 	struct afs_server_list *new, *old, *discard;
 	struct afs_vldb_entry *vldb;
-	char idbuf[16];
+	char idbuf[19];
 	int ret, idsz;
 
 	_enter("");
-- 
2.25.1

On 2/11/2024 10:04 AM, Daniil Dulov wrote:
> The max length of volume->vid value is 20 characters.
> So increase idbuf[] size up to 20 to avoid overflow.
>
> Found by Linux Verification Center (linuxtesting.org) with SVACE.
>
> Fixes: d2ddc776a458 ("afs: Overhaul volume and server record caching and fileserver rotation")
> Signed-off-by: Daniil Dulov <d.dulov@aladdin.ru>
> ---
>   fs/afs/volume.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/fs/afs/volume.c b/fs/afs/volume.c
> index f84194b791d3..9d0da38bbcf6 100644
> --- a/fs/afs/volume.c
> +++ b/fs/afs/volume.c
> @@ -302,7 +302,7 @@ static int afs_update_volume_status(struct afs_volume *volume, struct key *key)
>   {
>   	struct afs_server_list *new, *old, *discard;
>   	struct afs_vldb_entry *vldb;
> -	char idbuf[16];
> +	char idbuf[19];
>   	int ret, idsz;
>   
>   	_enter("");

Thanks for the patch.

The commit message says idbuf[] is being increased to 20 chars but the 
patch only increases it to 19.

Should idbuf[] be 20 or should the commit message be altered?

Jeffrey Altman

Hello!

Thank you for the review. Yes, idbuf[] shoulf be 20 instead of 19. I'll send the correct patch in a minute.

Daniil Dulov


-----Original Message-----
From: Jeffrey E Altman [mailto:jaltman@auristor.com] 
Sent: Sunday, February 11, 2024 8:24 PM
To: Daniil Dulov <D.Dulov@aladdin.ru>; linux-afs@lists.infradead.org
Cc: Marc Dionne <marc.dionne@auristor.com>; David Howells <dhowells@redhat.com>; linux-kernel@vger.kernel.org; lvc-project@linuxtesting.org
Subject: Re: [PATCH] afs: Increase buffer size in afs_update_volume_status()

On 2/11/2024 10:04 AM, Daniil Dulov wrote:
> The max length of volume->vid value is 20 characters.
> So increase idbuf[] size up to 20 to avoid overflow.
>
> Found by Linux Verification Center (linuxtesting.org) with SVACE.
>
> Fixes: d2ddc776a458 ("afs: Overhaul volume and server record caching 
> and fileserver rotation")
> Signed-off-by: Daniil Dulov <d.dulov@aladdin.ru>
> ---
>   fs/afs/volume.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/fs/afs/volume.c b/fs/afs/volume.c index 
> f84194b791d3..9d0da38bbcf6 100644
> --- a/fs/afs/volume.c
> +++ b/fs/afs/volume.c
> @@ -302,7 +302,7 @@ static int afs_update_volume_status(struct afs_volume *volume, struct key *key)
>   {
>   	struct afs_server_list *new, *old, *discard;
>   	struct afs_vldb_entry *vldb;
> -	char idbuf[16];
> +	char idbuf[19];
>   	int ret, idsz;
>   
>   	_enter("");

Thanks for the patch.

The commit message says idbuf[] is being increased to 20 chars but the patch only increases it to 19.

Should idbuf[] be 20 or should the commit message be altered?

Jeffrey Altman