From: Daniel Borkmann <dan...@iogearbox.net> Date: Tue, 08 Aug 2017 02:46:16 +0200
> On 08/07/2017 04:21 PM, Edward Cree wrote: >> This series simplifies alignment tracking, generalises bounds tracking >> and >> fixes some bounds-tracking bugs in the BPF verifier. Pointer >> arithmetic on >> packet pointers, stack pointers, map value pointers and context >> pointers has >> been unified, and bounds on these pointers are only checked when the >> pointer >> is dereferenced. >> Operations on pointers which destroy all relation to the original >> pointer >> (such as multiplies and shifts) are disallowed if >> !env->allow_ptr_leaks, >> otherwise they convert the pointer to an unknown scalar and feed it to >> the >> normal scalar arithmetic handling. >> Pointer types have been unified with the corresponding >> adjusted-pointer types >> where those existed (e.g. PTR_TO_MAP_VALUE[_ADJ] or FRAME_PTR vs >> PTR_TO_STACK); similarly, CONST_IMM and UNKNOWN_VALUE have been >> unified into >> SCALAR_VALUE. >> Pointer types (except CONST_PTR_TO_MAP, PTR_TO_MAP_VALUE_OR_NULL and >> PTR_TO_PACKET_END, which do not allow arithmetic) have a 'fixed >> offset' and >> a 'variable offset'; the former is used when e.g. adding an immediate >> or a >> known-constant register, as long as it does not overflow. Otherwise >> the >> latter is used, and any operation creating a new variable offset >> creates a >> new 'id' (and, for PTR_TO_PACKET, clears the 'range'). >> SCALAR_VALUEs use the 'variable offset' fields to track the range of >> possible >> values; the 'fixed offset' should never be set on a scalar. > > Been testing and reviewing the series over the last several days, > looks > reasonable to me as far as I can tell. Thanks for all the hard work on > unifying this, Edward! > > Acked-by: Daniel Borkmann <dan...@iogearbox.net> Series applied, thanks everyone!
