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Date: Mon, 25 Mar 2024 20:16:45 +0100
From: Jan Kara <jack@suse.cz>
To: Nikita Kiryushin <kiryushin@ancud.ru>
Cc: Jan Kara <jack@suse.cz>, Amir Goldstein <amir73il@gmail.com>,
	Matthew Bobrowski <repnop@google.com>,
	linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
	lvc-project@linuxtesting.org
Subject: Re: [PATCH] fanotify: remove unneeded sub-zero check for unsigned
 value
Message-ID: <20240325191645.viuo2f2zujx67ec6@quack3>
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 <d296ff1c-dcf7-4813-994b-3c4369debb7d@ancud.ru>
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On Thu 14-03-24 16:36:56, Nikita Kiryushin wrote:
> 
> Unsigned size_t len in copy_fid_info_to_user is checked
> for negative value. This check is redundant as it is
> always false.
> 
> Found by Linux Verification Center (linuxtesting.org) with SVACE.
> 
> Fixes: 5e469c830fdb ("fanotify: copy event fid info to user")
> Signed-off-by: Nikita Kiryushin <kiryushin@ancud.ru>

Looks good. Added to my tree. Thanks!

								Honza

> ---
>  fs/notify/fanotify/fanotify_user.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c
> index fbdc63cc10d9..4201723357cf 100644
> --- a/fs/notify/fanotify/fanotify_user.c
> +++ b/fs/notify/fanotify/fanotify_user.c
> @@ -502,7 +502,7 @@ static int copy_fid_info_to_user(__kernel_fsid_t *fsid, struct fanotify_fh *fh,
>  	}
>  	/* Pad with 0's */
> -	WARN_ON_ONCE(len < 0 || len >= FANOTIFY_EVENT_ALIGN);
> +	WARN_ON_ONCE(len >= FANOTIFY_EVENT_ALIGN);
>  	if (len > 0 && clear_user(buf, len))
>  		return -EFAULT;
> -- 
> 2.34.1
> 
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR