Re: [PATCH 7/8] util: Check return value of lseek() while reading bound ports from procfs

[David Gibson <david@gibson.dropbear.id.au>]

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On Fri, Oct 07, 2022 at 02:47:41AM +0200, Stefano Brivio wrote:
> Coverity now noticed we're checking most lseek() return values, but
> not this. Not really relevant, but it doesn't hurt to check we can
> actually seek before reading lines.
> 
> Signed-off-by: Stefano Brivio <sbrivio(a)redhat.com>

Reviewed-by: David Gibson <david(a)gibson.dropbear.id.au>

> ---
>  util.c | 10 +++++++---
>  1 file changed, 7 insertions(+), 3 deletions(-)
> 
> diff --git a/util.c b/util.c
> index b366167..5b1e08a 100644
> --- a/util.c
> +++ b/util.c
> @@ -311,10 +311,14 @@ void procfs_scan_listen(struct ctx *c, uint8_t proto, int ip_version, int ns,
>  			path = "/proc/net/udp6";
>  	}
>  
> -	if (*fd != -1)
> -		lseek(*fd, 0, SEEK_SET);
> -	else if ((*fd = open(path, O_RDONLY | O_CLOEXEC)) < 0)
> +	if (*fd != -1) {
> +		if (lseek(*fd, 0, SEEK_SET)) {
> +			warn("lseek() failed on %s: %s", path, strerror(errno));
> +			return;
> +		}
> +	} else if ((*fd = open(path, O_RDONLY | O_CLOEXEC)) < 0) {
>  		return;
> +	}
>  
>  	lineread_init(&lr, *fd);
>  	lineread_get(&lr, &line); /* throw away header */

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson

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