From f667f577e6d29e62f55cdc4e1e39414913bf7c4c Mon Sep 17 00:00:00 2001 From: Phil Sutter Date: Tue, 28 Nov 2023 20:21:49 +0100 Subject: [PATCH] libxtables: xtoptions: Fix for non-CIDR-compatible hostmasks In order to parse the mask, xtopt_parse_hostmask() calls xtopt_parse_plenmask() thereby limiting netmask support to prefix lengths (alternatively specified in IP address notation). In order to lift this impractical restriction, make xtopt_parse_plenmask() aware of the fact that xtopt_parse_plen() may fall back to xtopt_parse_mask() which correctly initializes val.hmask itself and indicates non-CIDR-compatible masks by setting val.hlen to -1. So in order to support these odd masks, it is sufficient for xtopt_parse_plenmask() to skip its mask building from val.hlen value and take whatever val.hmask contains. Fixes: 66266abd17adc ("libxtables: XTTYPE_HOSTMASK support") Signed-off-by: Phil Sutter (cherry picked from commit 41139aee5e53304182a25f1e573f034b313f7232) --- libxtables/xtoptions.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/libxtables/xtoptions.c b/libxtables/xtoptions.c index b16bbfbe32311..d91a78f470eda 100644 --- a/libxtables/xtoptions.c +++ b/libxtables/xtoptions.c @@ -711,6 +711,10 @@ static void xtopt_parse_plenmask(struct xt_option_call *cb) xtopt_parse_plen(cb); + /* may not be convertible to CIDR notation */ + if (cb->val.hlen == (uint8_t)-1) + goto out_put; + memset(mask, 0xFF, sizeof(union nf_inet_addr)); /* This shifting is AF-independent. */ if (cb->val.hlen == 0) { @@ -731,6 +735,7 @@ static void xtopt_parse_plenmask(struct xt_option_call *cb) mask[1] = htonl(mask[1]); mask[2] = htonl(mask[2]); mask[3] = htonl(mask[3]); +out_put: if (entry->flags & XTOPT_PUT) memcpy(XTOPT_MKPTR(cb), mask, sizeof(union nf_inet_addr)); }