Re: [PATCH 4/5] tools/dm_depriv: Add first cut RLIMITs

[Ian Jackson <ian.jackson@citrix.com>]

George Dunlap writes ("[PATCH 4/5] tools/dm_depriv: Add first cut RLIMITs"):
> Limit the ability of a potentially compromised QEMU to consume system
> resources.  Key limits:
>  - RLIMIT_FSIZE (file size): 256KiB
>  - RLIMIT_NPROC (after uid changes to a unique uid)

Thanks.

> +static struct {
> +    int resource;
> +    rlim_t limit;
> +} rlimits[] = {
> +#define RLIMIT_ENTRY(r, l) \
> +    { .resource = r, .limit = l }
> +    /* Big enough for log files, not big enough for a DoS */
> +    RLIMIT_ENTRY(RLIMIT_FSIZE, 256*1024),
> +
> +    /* Shouldn't need any of these */
> +    RLIMIT_ENTRY(RLIMIT_NPROC, 0),
> +    RLIMIT_ENTRY(RLIMIT_CORE, 0),
> +    RLIMIT_ENTRY(RLIMIT_MSGQUEUE, 0),
> +    RLIMIT_ENTRY(RLIMIT_LOCKS, 0),
> +    RLIMIT_ENTRY(RLIMIT_MEMLOCK, 0),

I would have justified the values so this looked more tabular.

> +    /* Set various "easy" rlimits */
> +    for (i = 0; rlimits[i].resource != RLIMIT_NLIMITS; i++) {
> +        struct rlimit rlim;
> +
> +        rlim.rlim_cur = rlim.rlim_max = rlimits[i].limit;
> +        
> +        r = setrlimit(rlimits[i].resource, &rlim);
> +        if (r < 0) {
> +            LOGE(ERROR, "Setting rlimit %d to %lld failed\n",
> +                                  rlimits[i].resource,
> +                                  (unsigned long long)rlimits[i].limit);

I think you mean %llu not %lld.  With that last point changed,

Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>

Ian.

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