[PATCH v2 1/2] ethdev: fix out-of-bounds write in GENEVE option conversion

[James Raphael Tiovalen <jamestiotio@gmail.com>]

rte_flow_conv_item_spec() is documented to truncate output to the
caller-supplied buffer size. For RTE_FLOW_ITEM_TYPE_GENEVE_OPT, the
deep-copy of the variable-length option data was gated on `size > 0`
instead of `size >= off + tmp`, the form used by the sibling RAW
branch. A caller passing a buffer just large enough for the header
struct had adjacent memory clobbered by up to `option_len * 4` bytes of
option payload.

Align the GENEVE_OPT guard with the RAW one.

Fixes: 841a0445442d ("ethdev: fix GENEVE option item conversion")
Cc: stable@dpdk.org

Signed-off-by: James Raphael Tiovalen <jamestiotio@gmail.com>
---
 lib/ethdev/rte_flow.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/ethdev/rte_flow.c b/lib/ethdev/rte_flow.c
index ec0fe08355..e534f2295b 100644
--- a/lib/ethdev/rte_flow.c
+++ b/lib/ethdev/rte_flow.c
@@ -701,7 +701,7 @@ rte_flow_conv_item_spec(void *buf, const size_t size,
 		src.geneve_opt = data;
 		dst.geneve_opt = buf;
 		tmp = spec.geneve_opt ? (spec.geneve_opt->option_len << 2) : 0;
-		if (size > 0 && tmp > 0 && src.geneve_opt->data) {
+		if (size >= off + tmp && tmp > 0 && src.geneve_opt->data) {
 			deep_src = (void *)((uintptr_t)(dst.geneve_opt + 1));
 			dst.geneve_opt->data = rte_memcpy(deep_src,
 							  src.geneve_opt->data,
-- 
2.43.0