linux-kernel - Re: [PATCH] xfs: donot need to check return value of xlog

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <0ba12a13-6cc4-5f44-fa06-ead350f819d5@sandeen.net>
Date:   Mon, 29 Aug 2022 11:06:48 -0500
From:   Eric Sandeen <sandeen@...deen.net>
To:     Zhiqiang Liu <liuzhiqiang26@...wei.com>,
        "Darrick J. Wong" <djwong@...nel.org>, linux-xfs@...r.kernel.org,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Cc:     linfeilong <linfeilong@...wei.com>,
        wuguanghao <wuguanghao3@...wei.com>
Subject: Re: [PATCH] xfs: donot need to check return value of xlog_kvmalloc()

On 8/22/22 6:46 AM, Zhiqiang Liu wrote:
> 
> In xfs_attri_log_nameval_alloc(), xlog_kvmalloc() is called
> to alloc memory, which will always return
> successfully, so we donot need to check return value.
> 
> Signed-off-by: Zhiqiang Liu <liuzhiqiang26@...wei.com>

I think this is fine. xlog_kvmalloc loops until success, and its other
caller does not check the return value.

This isn't really strictly a fix (it's harmless) but it "fixes"

Fixes: commit 4183e4f27f402 ("xfs: share xattr name and value buffers when logging xattr updates")

Reviewed-by: Eric Sandeen <sandeen@...hat.com>

That said, I think that xfs_attri_log_nameval_alloc() also cannot fail, so
perhaps its callers don't need checks either?

> ---
>  fs/xfs/xfs_attr_item.c | 2 --
>  1 file changed, 2 deletions(-)
> 
> diff --git a/fs/xfs/xfs_attr_item.c b/fs/xfs/xfs_attr_item.c
> index 5077a7ad5646..667e151a2bca 100644
> --- a/fs/xfs/xfs_attr_item.c
> +++ b/fs/xfs/xfs_attr_item.c
> @@ -86,8 +86,6 @@ xfs_attri_log_nameval_alloc(
>  	 */
>  	nv = xlog_kvmalloc(sizeof(struct xfs_attri_log_nameval) +
>  					name_len + value_len);
> -	if (!nv)
> -		return nv;
> 
>  	nv->name.i_addr = nv + 1;
>  	nv->name.i_len = name_len;