Messages in this thread | | | Date | Tue, 23 Mar 2010 10:29:53 +0800 | Subject | Re: [PATCH] Netfilter: Fix integer overflow in net/ipv6/netfilter/ip6_tables.c | From | Xiaotian Feng <> |
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On Tue, Mar 23, 2010 at 9:34 AM, wzt wzt <wzt.wzt@gmail.com> wrote: >> I can see that the size might cause an overflow in the addition with >> sizeof(struct ipt_get_entries) > That's the integer overflow i pointed. > get.size is copy from the user space, it can be set as 0x7fffffff, > addition with sizeof(struct ipt_get_entries) can be overflow.
Patrick's point is that you're using "if (get.size >= INT_MAX / sizeof(struct ipt_get_entries))" So, did you find any chance that get.size * sizeof(struct ipt_get_entries) >= INT_MAX ?
And, for the addition overflow, can it be caught by
"if (*len != sizeof(struct ipt_get_entries) + get.size)" ???
> > if (*len != sizeof(struct ipt_get_entries) + get.size) { > duprintf("get_entries: %u != %zu\n", > *len, sizeof(get) + get.size); > return -EINVAL; > } > > so, check get.size max value before addition with sizeof(struct > ipt_get_entries) to prevent the integer overflow. > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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