From: Pablo Neira Ayuso pablo@netfilter.org
[ 6e1acfa387b9ff82cfc7db8cc3b6959221a95851 ]
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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/netfilter/nf_tables_api.c | 31 +++++++++++++++++-------------- 1 file changed, 17 insertions(+), 14 deletions(-)
--- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -5615,26 +5615,23 @@ int nft_parse_u32_check(const struct nla } 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; }
/** @@ -5685,7 +5682,10 @@ int nft_parse_register_load(const struct 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; @@ -5761,7 +5761,10 @@ int nft_parse_register_store(const struc 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;