From fa52bc22580632b4b78c263e338ddfbe235a8218 Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Mon, 19 Jun 2023 22:43:04 +0200 Subject: parser: reject zero-length interface names device "" results in an assertion during evaluation. Before: nft: expression.c:426: constant_expr_alloc: Assertion `(((len) + (8) - 1) / (8)) > 0' failed. After: zero_length_devicename_assert:3:42-49: Error: you cannot set an empty interface name type filter hook ingress device""lo" priority -1 ^^^^^^^^ Signed-off-by: Florian Westphal --- src/parser_bison.y | 36 +++++++++++++++++++++++++++++++----- 1 file changed, 31 insertions(+), 5 deletions(-) (limited to 'src/parser_bison.y') diff --git a/src/parser_bison.y b/src/parser_bison.y index f5f6bf04..9a4204c0 100644 --- a/src/parser_bison.y +++ b/src/parser_bison.y @@ -144,6 +144,33 @@ static bool already_set(const void *attr, const struct location *loc, return true; } +static struct expr *ifname_expr_alloc(const struct location *location, + struct list_head *queue, + const char *name) +{ + unsigned int length = strlen(name); + struct expr *expr; + + if (length == 0) { + xfree(name); + erec_queue(error(location, "empty interface name"), queue); + return NULL; + } + + if (length > 16) { + xfree(name); + erec_queue(error(location, "interface name too long"), queue); + return NULL; + } + + expr = constant_expr_alloc(location, &ifname_type, BYTEORDER_HOST_ENDIAN, + length * BITS_PER_BYTE, name); + + xfree(name); + + return expr; +} + #define YYLLOC_DEFAULT(Current, Rhs, N) location_update(&Current, Rhs, N) #define symbol_value(loc, str) \ @@ -2664,12 +2691,11 @@ int_num : NUM { $$ = $1; } dev_spec : DEVICE string { - struct expr *expr; + struct expr *expr = ifname_expr_alloc(&@$, state->msgs, $2); + + if (!expr) + YYERROR; - expr = constant_expr_alloc(&@$, &string_type, - BYTEORDER_HOST_ENDIAN, - strlen($2) * BITS_PER_BYTE, $2); - xfree($2); $$ = compound_expr_alloc(&@$, EXPR_LIST); compound_expr_add($$, expr); -- cgit v1.2.3