[PATCH 5/6] staging: ozwpan: Increase farewell report size.
rupesh.gujare at atmel.com
Fri Aug 2 11:00:44 UTC 2013
On 02/08/13 11:27, Dan Carpenter wrote:
> On Thu, Aug 01, 2013 at 06:45:01PM +0100, Rupesh Gujare wrote:
>> Farewell report size can be bigger than one byte, increase array
>> size to accomodate maximum 32 bytes of farewell report.
> Gar... No. This is not right.
> 1) There is no check limiting the size to 32 and it could be up to
> 253 bytes.
> 2) Use defines instead of magic numbers.
> 3) The oz_farewell struct is supposed to be a variable length struct
> but the variable part is put in the middle. It doesn't make any
> sense to put the length of the variable size array after then end
> of the array because we can never find it again! Put the
> variable size array at the end. Make it a zero length array.
> u8 len;
> u8 report;
> 4) In oz_add_farewell() we do this:
> f = kmalloc(sizeof(struct oz_farewell) + len - 1, GFP_ATOMIC);
> The "- 1" refers to sizeof(f->report) but because it was a magic
> number then it was missed when the sizeof(f->report) changed.
> 5) In [patch 6/6] we set the ->len member. But because it is at the
> end of a variable length array with no limit check the remote
> attacker can just rewrite it using the memcpy() on the next line.
A patch follows to fix above issues.
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