From a56e75fd71f8dfdc873ed6c14fecdfec563e3888 Mon Sep 17 00:00:00 2001 From: Alexander Chernavin Date: Tue, 14 Nov 2023 11:33:46 +0000 Subject: flowprobe: fix L3 header offset calculation for tx flows The recent TX flows generation fix introduced "l3_hdr_offset" which represents the offset of the IP header in the buffer's data. The problem is that it is erroneously defined as a 16-bit unsigned integer. If the calculated offset is negative, "l3_hdr_offset" will get a value close to UINT16_MAX. And the code will search the IP header somewhere beyond the buffer's data. For example, this will occur in the case when an ICMP error is being sent in response to a received packet. With this fix, make "l3_hdr_offset" a signed integer. Type: fix Change-Id: I6f1283c7ba02656d0f592519b5863e68348c5583 Signed-off-by: Alexander Chernavin (cherry picked from commit bae6b6d1f2a2e6623257afab21e05da2d795323a) --- src/plugins/flowprobe/node.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/src/plugins/flowprobe/node.c b/src/plugins/flowprobe/node.c index 22bb6cea80a..7645f5d71c5 100644 --- a/src/plugins/flowprobe/node.c +++ b/src/plugins/flowprobe/node.c @@ -388,7 +388,7 @@ add_to_flow_record_state (vlib_main_t *vm, vlib_node_runtime_t *node, vlib_buffer_get_current (b) : ethernet_buffer_get_header (b); u16 ethertype = clib_net_to_host_u16 (eth->type); - u16 l3_hdr_offset = (u8 *) eth - b->data + sizeof (ethernet_header_t); + i16 l3_hdr_offset = (u8 *) eth - b->data + sizeof (ethernet_header_t); /* *INDENT-OFF* */ flowprobe_key_t k = {}; /* *INDENT-ON* */ -- cgit 1.2.3-korg