On Wed, 3 Jun 2026 12:28:05 +0300 Bing Zhao <[email protected]> wrote:
> In the asynchronous API definition and some drivers, the > rte_flow_item spec value may not be calculated by the driver due to the > reason of speed of light rule insertion rate and sometimes the input > parameters will be copied and changed internally. > > After copying, the spec and last will be protected by the keyword > const and cannot be changed in the code itself. And also the driver > needs some extra memory to do the calculation and extra conditions > to understand the length of each item spec. This is not efficient. > > To solve the issue and support usage of the following fix, a new OP > was introduced to calculate the spec and last values after applying > the mask inline. > > Signed-off-by: Bing Zhao <[email protected]> > --- More detailed AI review found some things that still need addressing. On Wed, 3 Jun 2026 12:28:05 +0300, Bing Zhao wrote: > Subject: [PATCH v4] ethdev: support inline calculating masked item value Error: byte-wise masking corrupts embedded pointers in deep-copy item types (RAW, FLEX, GENEVE_OPT). In rte_flow_conv_pattern(), the new mask application runs over the fixed item struct: size_t item_mask_size = mask ? rte_flow_conv_item_mask_size(src) : 0; ... size_t mask_size = RTE_MIN(ret, item_mask_size); for (j = 0; j < mask_size; j++) c_spec[j] &= mask[j]; item_mask_size is rte_flow_desc_item[type].size, the size of the fixed item struct. For RTE_FLOW_ITEM_TYPE_RAW, FLEX, and GENEVE_OPT, that fixed struct ends in an embedded pointer that rte_flow_conv_item_spec() has just populated to point at the deep-copied trailing data (rte_flow_item_raw.pattern, rte_flow_item_flex.pattern, rte_flow_item_geneve_opt.data). Because the masked range covers the whole fixed struct, the loop ANDs the bytes of that pointer with the mask's corresponding bytes (typically a NULL mask pointer), zeroing or garbling it. The converted item's pattern/data pointer is clobbered while the copied payload it should reference is left unreachable. A consumer that follows conv->pattern then dereferences NULL or a corrupt address. Plain value items (eth, ipv4, ...) are unaffected; only the deep-copy item types break, which is exactly what the test does not exercise. Suggested fix: do not blind-mask the entire fixed struct for items that carry an embedded pointer / desc_fn deep copy. Either skip masking when rte_flow_desc_item[type].desc_fn != NULL, or mask only the leading plain-data region and leave the pointer field (and trailing copied bytes) intact. Warning: the new test validates only an ETH pattern, so the RAW/FLEX/GENEVE_OPT path above is untested. A RAW item case would have surfaced the pointer corruption. Info: the Doxygen block for RTE_FLOW_CONV_OP_PATTERN_MASKED uses @p mask, @p spec, @p last, but those are item fields, not parameters of the op; the neighboring enum entries only document the @p src / @p dst types.
