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| author | David Windsor <dave@nullcore.net> | 2017-08-24 16:49:14 -0700 |
|---|---|---|
| committer | Kees Cook <keescook@chromium.org> | 2018-01-15 12:07:59 -0800 |
| commit | 8c2bc895a9347846b33c47124a75db624aa83677 (patch) | |
| tree | 1bad27c8f27e0212c8fec2c66954d177d28455d9 /net/ipv6/raw.c | |
| parent | 30c2c9f158f6c9cef41e916d1c7c11097df4befb (diff) | |
| download | lwn-8c2bc895a9347846b33c47124a75db624aa83677.tar.gz lwn-8c2bc895a9347846b33c47124a75db624aa83677.zip | |
ip: Define usercopy region in IP proto slab cache
The ICMP filters for IPv4 and IPv6 raw sockets need to be copied to/from
userspace. In support of usercopy hardening, this patch defines a region
in the struct proto slab cache in which userspace copy operations are
allowed.
example usage trace:
net/ipv4/raw.c:
raw_seticmpfilter(...):
...
copy_from_user(&raw_sk(sk)->filter, ..., optlen)
raw_geticmpfilter(...):
...
copy_to_user(..., &raw_sk(sk)->filter, len)
net/ipv6/raw.c:
rawv6_seticmpfilter(...):
...
copy_from_user(&raw6_sk(sk)->filter, ..., optlen)
rawv6_geticmpfilter(...):
...
copy_to_user(..., &raw6_sk(sk)->filter, len)
This region is known as the slab cache's usercopy region. Slab caches
can now check that each dynamically sized copy operation involving
cache-managed memory falls entirely within the slab's usercopy region.
This patch is modified from Brad Spengler/PaX Team's PAX_USERCOPY
whitelisting code in the last public patch of grsecurity/PaX based on my
understanding of the code. Changes or omissions from the original code are
mine and don't reflect the original grsecurity/PaX code.
Signed-off-by: David Windsor <dave@nullcore.net>
[kees: split from network patch, provide usage trace]
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Cc: netdev@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Diffstat (limited to 'net/ipv6/raw.c')
| -rw-r--r-- | net/ipv6/raw.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/net/ipv6/raw.c b/net/ipv6/raw.c index 761a473a07c5..08a85fabdfd1 100644 --- a/net/ipv6/raw.c +++ b/net/ipv6/raw.c @@ -1272,6 +1272,8 @@ struct proto rawv6_prot = { .hash = raw_hash_sk, .unhash = raw_unhash_sk, .obj_size = sizeof(struct raw6_sock), + .useroffset = offsetof(struct raw6_sock, filter), + .usersize = sizeof_field(struct raw6_sock, filter), .h.raw_hash = &raw_v6_hashinfo, #ifdef CONFIG_COMPAT .compat_setsockopt = compat_rawv6_setsockopt, |