From a60661352d5a05ade59567d1562b12d6a0121853 Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Tue, 16 May 2023 16:44:30 +0200 Subject: [PATCH] netfilter: nf_tables: validate registers coming from userspace. [ bfcfe6b3cdd49aec05edc762572828e0e1d9c7e3 ] Bail out in case userspace uses unsupported registers. Fixes: 73590c994412 ("netfilter: nf_tables: switch registers to 32 bit addressing") Signed-off-by: Pablo Neira Ayuso Signed-off-by: Sasha Levin --- net/netfilter/nf_tables_api.c | 31 +++++++++++++++++-------------- 1 file changed, 17 insertions(+), 14 deletions(-) diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 8a0095664e619..a90bf82ea1435 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -7384,26 +7384,23 @@ int nft_parse_u32_check(const struct nlattr *attr, int max, u32 *dest) } EXPORT_SYMBOL_GPL(nft_parse_u32_check); -/** - * nft_parse_register - parse a register value from a netlink attribute - * - * @attr: netlink attribute - * - * Parse and translate a register value from a netlink attribute. - * Registers used to be 128 bit wide, these register numbers will be - * mapped to the corresponding 32 bit register numbers. - */ -static unsigned int nft_parse_register(const struct nlattr *attr) +static int nft_parse_register(const struct nlattr *attr, u32 *preg) { unsigned int reg; reg = ntohl(nla_get_be32(attr)); switch (reg) { case NFT_REG_VERDICT...NFT_REG_4: - return reg * NFT_REG_SIZE / NFT_REG32_SIZE; + *preg = reg * NFT_REG_SIZE / NFT_REG32_SIZE; + break; + case NFT_REG32_00...NFT_REG32_15: + *preg = reg + NFT_REG_SIZE / NFT_REG32_SIZE - NFT_REG32_00; + break; default: - return reg + NFT_REG_SIZE / NFT_REG32_SIZE - NFT_REG32_00; + return -ERANGE; } + + return 0; } /** @@ -7454,7 +7451,10 @@ int nft_parse_register_load(const struct nlattr *attr, u8 *sreg, u32 len) u32 reg; int err; - reg = nft_parse_register(attr); + err = nft_parse_register(attr, ®); + if (err < 0) + return err; + err = nft_validate_register_load(reg, len); if (err < 0) return err; @@ -7523,7 +7523,10 @@ int nft_parse_register_store(const struct nft_ctx *ctx, int err; u32 reg; - reg = nft_parse_register(attr); + err = nft_parse_register(attr, ®); + if (err < 0) + return err; + err = nft_validate_register_store(ctx, reg, data, type, len); if (err < 0) return err; -- 2.39.5