At present the ipv6_renew_options_kern() function ends up calling into
access_ok() which is problematic if done from inside an interrupt as
access_ok() calls WARN_ON_IN_IRQ() on some (all?) architectures
(x86-64 is affected). Example warning/backtrace is shown below:
WARNING: CPU: 1 PID: 3144 at lib/usercopy.c:11 _copy_from_user+0x85/0x90
...
Call Trace:
<IRQ>
ipv6_renew_option+0xb2/0xf0
ipv6_renew_options+0x26a/0x340
ipv6_renew_options_kern+0x2c/0x40
calipso_req_setattr+0x72/0xe0
netlbl_req_setattr+0x126/0x1b0
selinux_netlbl_inet_conn_request+0x80/0x100
selinux_inet_conn_request+0x6d/0xb0
security_inet_conn_request+0x32/0x50
tcp_conn_request+0x35f/0xe00
? __lock_acquire+0x250/0x16c0
? selinux_socket_sock_rcv_skb+0x1ae/0x210
? tcp_rcv_state_process+0x289/0x106b
tcp_rcv_state_process+0x289/0x106b
? tcp_v6_do_rcv+0x1a7/0x3c0
tcp_v6_do_rcv+0x1a7/0x3c0
tcp_v6_rcv+0xc82/0xcf0
ip6_input_finish+0x10d/0x690
ip6_input+0x45/0x1e0
? ip6_rcv_finish+0x1d0/0x1d0
ipv6_rcv+0x32b/0x880
? ip6_make_skb+0x1e0/0x1e0
__netif_receive_skb_core+0x6f2/0xdf0
? process_backlog+0x85/0x250
? process_backlog+0x85/0x250
? process_backlog+0xec/0x250
process_backlog+0xec/0x250
net_rx_action+0x153/0x480
__do_softirq+0xd9/0x4f7
do_softirq_own_stack+0x2a/0x40
</IRQ>
...
While not present in the backtrace, ipv6_renew_option() ends up calling
access_ok() via the following chain:
access_ok()
_copy_from_user()
copy_from_user()
ipv6_renew_option()
The fix presented in this patch is to perform the userspace copy
earlier in the call chain such that it is only called when the option
data is actually coming from userspace; that place is
do_ipv6_setsockopt(). Not only does this solve the problem seen in
the backtrace above, it also allows us to simplify the code quite a
bit by removing ipv6_renew_options_kern() completely. We also take
this opportunity to cleanup ipv6_renew_options()/ipv6_renew_option()
a small amount as well.
This patch is heavily based on a rough patch by Al Viro. I've taken
his original patch, converted a kmemdup() call in do_ipv6_setsockopt()
to a memdup_user() call, made better use of the e_inval jump target in
the same function, and cleaned up the use ipv6_renew_option() by
ipv6_renew_options().
CC: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.
Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David Windsor <dwindsor@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.
Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David Windsor <dwindsor@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When using CALIPSO with IPPROTO_UDP it is possible to trigger a GPF as the
IP header may have moved.
Also update the payload length after adding the CALIPSO option.
Signed-off-by: Richard Haines <richard_c_haines@btinternet.com>
Acked-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Huw Davies <huw@codeweavers.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently, if calipso_genopt fails then the error exit path
does not free the ipv6_opt_hdr new causing a memory leak. Fix
this by kfree'ing new on the error exit path.
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This works in exactly the same way as the CIPSO label cache.
The idea is to allow the lsm to cache the result of a secattr
lookup so that it doesn't need to perform the lookup for
every skbuff.
It introduces two sysctl controls:
calipso_cache_enable - enables/disables the cache.
calipso_cache_bucket_size - sets the size of a cache bucket.
Signed-off-by: Huw Davies <huw@codeweavers.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Lengths, checksum and the DOI are checked. Checking of the
level and categories are left for the socket layer.
CRC validation is performed in the calipso module to avoid
unconditionally linking crc_ccitt() into ipv6.
Signed-off-by: Huw Davies <huw@codeweavers.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
In some cases, the lsm needs to add the label to the skbuff directly.
A NF_INET_LOCAL_OUT IPv6 hook is added to selinux to match the IPv4
behaviour. This allows selinux to label the skbuffs that it requires.
Signed-off-by: Huw Davies <huw@codeweavers.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Request sockets need to have a label that takes into account the
incoming connection as well as their parent's label. This is used
for the outgoing SYN-ACK and for their child full-socket.
Signed-off-by: Huw Davies <huw@codeweavers.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
CALIPSO is a hop-by-hop IPv6 option. A lot of this patch is based on
the equivalent CISPO code. The main difference is due to manipulating
the options in the hop-by-hop header.
Signed-off-by: Huw Davies <huw@codeweavers.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Remove a specified DOI through the NLBL_CALIPSO_C_REMOVE command.
It requires the attribute:
NLBL_CALIPSO_A_DOI.
Signed-off-by: Huw Davies <huw@codeweavers.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Enumerate the DOI list through the NLBL_CALIPSO_C_LISTALL command.
It takes no attributes.
Signed-off-by: Huw Davies <huw@codeweavers.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Query a specified DOI through the NLBL_CALIPSO_C_LIST command.
It requires the attribute:
NLBL_CALIPSO_A_DOI.
The reply will contain:
NLBL_CALIPSO_A_MTYPE
Signed-off-by: Huw Davies <huw@codeweavers.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
CALIPSO is a packet labelling protocol for IPv6 which is very similar
to CIPSO. It is specified in RFC 5570. Much of the code is based on
the current CIPSO code.
This adds support for adding passthrough-type CALIPSO DOIs through the
NLBL_CALIPSO_C_ADD command. It requires attributes:
NLBL_CALIPSO_A_TYPE which must be CALIPSO_MAP_PASS.
NLBL_CALIPSO_A_DOI.
In passthrough mode the CALIPSO engine will map MLS secattr levels
and categories directly to the packet label.
At this stage, the major difference between this and the CIPSO
code is that IPv6 may be compiled as a module. To allow for
this the CALIPSO functions are registered at module init time.
Signed-off-by: Huw Davies <huw@codeweavers.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Paul Moore