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| author | Lukas Wunner <lukas@wunner.de> | 2019-10-31 11:06:24 +0100 |
|---|---|---|
| committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2019-11-04 20:58:32 +0100 |
| commit | 250367c59e6ba0d79d702a059712d66edacd4a1a (patch) | |
| tree | c316c40d5d3f8182058c04674af060a2c514ea61 /include | |
| parent | netfilter: nf_tables_offload: check for register data length mismatches (diff) | |
| download | linux-250367c59e6ba0d79d702a059712d66edacd4a1a.tar.xz linux-250367c59e6ba0d79d702a059712d66edacd4a1a.zip | |
netfilter: nf_tables: Align nft_expr private data to 64-bit
Invoking the following commands on a 32-bit architecture with strict
alignment requirements (such as an ARMv7-based Raspberry Pi) results
in an alignment exception:
# nft add table ip test-ip4
# nft add chain ip test-ip4 output { type filter hook output priority 0; }
# nft add rule ip test-ip4 output quota 1025 bytes
Alignment trap: not handling instruction e1b26f9f at [<7f4473f8>]
Unhandled fault: alignment exception (0x001) at 0xb832e824
Internal error: : 1 [#1] PREEMPT SMP ARM
Hardware name: BCM2835
[<7f4473fc>] (nft_quota_do_init [nft_quota])
[<7f447448>] (nft_quota_init [nft_quota])
[<7f4260d0>] (nf_tables_newrule [nf_tables])
[<7f4168dc>] (nfnetlink_rcv_batch [nfnetlink])
[<7f416bd0>] (nfnetlink_rcv [nfnetlink])
[<8078b334>] (netlink_unicast)
[<8078b664>] (netlink_sendmsg)
[<8071b47c>] (sock_sendmsg)
[<8071bd18>] (___sys_sendmsg)
[<8071ce3c>] (__sys_sendmsg)
[<8071ce94>] (sys_sendmsg)
The reason is that nft_quota_do_init() calls atomic64_set() on an
atomic64_t which is only aligned to 32-bit, not 64-bit, because it
succeeds struct nft_expr in memory which only contains a 32-bit pointer.
Fix by aligning the nft_expr private data to 64-bit.
Fixes: 96518518cc41 ("netfilter: add nftables")
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Cc: stable@vger.kernel.org # v3.13+
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/net/netfilter/nf_tables.h | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/include/net/netfilter/nf_tables.h b/include/net/netfilter/nf_tables.h index 001d294edf57..2d0275f13bbf 100644 --- a/include/net/netfilter/nf_tables.h +++ b/include/net/netfilter/nf_tables.h @@ -820,7 +820,8 @@ struct nft_expr_ops { */ struct nft_expr { const struct nft_expr_ops *ops; - unsigned char data[]; + unsigned char data[] + __attribute__((aligned(__alignof__(u64)))); }; static inline void *nft_expr_priv(const struct nft_expr *expr) |