The patch below does not apply to the 4.9-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 6e1acfa387b9ff82cfc7db8cc3b6959221a95851 Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso pablo@netfilter.org Date: Thu, 17 Mar 2022 11:59:26 +0100 Subject: [PATCH] netfilter: nf_tables: validate registers coming from userspace.
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 pablo@netfilter.org
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index d71a33ae39b3..1f5a0eece0d1 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -9275,17 +9275,23 @@ int nft_parse_u32_check(const struct nlattr *attr, int max, u32 *dest) } EXPORT_SYMBOL_GPL(nft_parse_u32_check);
-static unsigned int nft_parse_register(const struct nlattr *attr) +static unsigned 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; }
/** @@ -9327,7 +9333,10 @@ 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; @@ -9382,7 +9391,10 @@ 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;