From 270ae3d192cf1b13371175998c413ebf1c3deafb Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Thu, 17 Mar 2022 11:59:26 +0100 Subject: [PATCH] netfilter: nf_tables: validate registers coming from userspace. Origin: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git/commit?id=9e8d927cfa564e5a00cd287bd66fac6d45f0af39 commit 6e1acfa387b9ff82cfc7db8cc3b6959221a95851 upstream. Bail out in case userspace uses unsupported registers. Fixes: 49499c3e6e18 ("netfilter: nf_tables: switch registers to 32 bit addressing") Signed-off-by: Pablo Neira Ayuso Signed-off-by: Greg Kroah-Hartman Gbp-Pq: Topic bugfix/all Gbp-Pq: Name netfilter-nf_tables-validate-registers-coming-from-u.patch --- 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 f2c725b0c01..8958dda69a6 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -8486,26 +8486,23 @@ 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; } /** @@ -8556,7 +8553,10 @@ 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; @@ -8625,7 +8625,10 @@ 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; -- 2.30.2