Re: Security Anti Symlink Attack Patch for 2.1.71

[Pavel Machek]

Hi!

> It is very common for tools to use temporary files in /tmp. Sadly anyone
> can create a symlink in /tmp and thus potentially redirect the creation of
> said temporary files.
> 
> The following patch was originaly for 2.0.32 by [e-mail]. I ported
> it to 2.1.71 and separated it from another patch that came with it.
> 
> The patch is also available from
> ftp://ftp.fuller.edu/Linux/symlink-attack-patch-2.1.71

I quite like this patch, but I do not like security_alert code... Aha,
ok! It is long enough, and pretty ugly, but pretty generic. 

If you made something like antiflood_printk and let every user print
what _they_ think is neccessary, it might be better. Somethink like
net_ratelimit() functionality...

								Pavel

> +#define security_alert(msg) { \
> +	static unsigned long warning_time = 0, no_flood_yet = 0; \
> +\
> +/* Make sure at least one minute passed since the last warning logged */ \
> +	if (!warning_time || jiffies - warning_time > 60 * HZ) { \
> +		warning_time = jiffies; no_flood_yet = 1; \
> +		printk( \
> +			KERN_ALERT \
> +			"Possible " msg " exploit attempt:\n" \
> +			KERN_ALERT \
> +			"Process %s (pid %d, uid %d, euid %d).\n", \
> +			current->comm, current->pid, \
> +			current->uid, current->euid); \
> +	} else if (no_flood_yet) { \
> +		warning_time = jiffies; no_flood_yet = 0; \
> +		printk( \
> +			KERN_ALERT \
> +			"More possible " msg " exploit attempts follow.\n"); \
> +	} \
> +}
> +

									Pavel

-- 
I'm really [e-mail]. 	   Pavel
Look at http://atrey.karlin.mff.cuni.cz/~pavel/ ;-).