Am 15.07.2010 12:16, schrieb Dan Carpenter: > On Thu, Jul 15, 2010 at 11:48:09AM +0200, Patrick McHardy wrote: >> Am 14.07.2010 23:04, schrieb Dan Carpenter: >>> Smatch complains that we copy too much data to the user in ebtables. >>> We copied EBT_FUNCTION_MAXNAMELEN (32) characters to the user here, but >>> "m->u.match->name" has XT_EXTENSION_MAXNAMELEN (29) characters. >>> >>> I'm not sure if this is a bug where someone got confused with m->u.name >>> which has 32 characters or if this is done for backwards compatability. >> >> Looking at ebtables.h, ebt_entry_match->name uses >> EBT_FUNCTION_MAXNAMELEN, which is 32 bytes. Where did you get >> XT_EXTENSION_MAXNAMELEN from? >> > > Exactly. ebt_entry_match->u.name uses EBT_FUNCTION_MAXNAMELEN but this is > from ebt_entry_match->u.match->name which is type struct xt_match. Right, I see. > But it looks like we're exporting struct ebt_match which also uses > EBT_FUNCTION_MAXNAMELEN. So maybe the fix is to copy ->u.name instead > of ->u.match->name. That name is not valid within the kernel, the union contains the xt_match pointer. So your patch seems correct, but we probably also need to adjust ebtables userspace. Jan? -- To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
