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2006-01-06[LSM-IPSec]: Corrections to LSM-IPSec NethooksTrent Jaeger
This patch contains two corrections to the LSM-IPsec Nethooks patches previously applied. (1) free a security context on a failed insert via xfrm_user interface in xfrm_add_policy. Memory leak. (2) change the authorization of the allocation of a security context in a xfrm_policy or xfrm_state from both relabelfrom and relabelto to setcontext. Signed-off-by: Trent Jaeger <tjaeger@cse.psu.edu> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-01-03[LSM-IPSec]: Security association restriction.Trent Jaeger
This patch series implements per packet access control via the extension of the Linux Security Modules (LSM) interface by hooks in the XFRM and pfkey subsystems that leverage IPSec security associations to label packets. Extensions to the SELinux LSM are included that leverage the patch for this purpose. This patch implements the changes necessary to the XFRM subsystem, pfkey interface, ipv4/ipv6, and xfrm_user interface to restrict a socket to use only authorized security associations (or no security association) to send/receive network packets. Patch purpose: The patch is designed to enable access control per packets based on the strongly authenticated IPSec security association. Such access controls augment the existing ones based on network interface and IP address. The former are very coarse-grained, and the latter can be spoofed. By using IPSec, the system can control access to remote hosts based on cryptographic keys generated using the IPSec mechanism. This enables access control on a per-machine basis or per-application if the remote machine is running the same mechanism and trusted to enforce the access control policy. Patch design approach: The overall approach is that policy (xfrm_policy) entries set by user-level programs (e.g., setkey for ipsec-tools) are extended with a security context that is used at policy selection time in the XFRM subsystem to restrict the sockets that can send/receive packets via security associations (xfrm_states) that are built from those policies. A presentation available at www.selinux-symposium.org/2005/presentations/session2/2-3-jaeger.pdf from the SELinux symposium describes the overall approach. Patch implementation details: On output, the policy retrieved (via xfrm_policy_lookup or xfrm_sk_policy_lookup) must be authorized for the security context of the socket and the same security context is required for resultant security association (retrieved or negotiated via racoon in ipsec-tools). This is enforced in xfrm_state_find. On input, the policy retrieved must also be authorized for the socket (at __xfrm_policy_check), and the security context of the policy must also match the security association being used. The patch has virtually no impact on packets that do not use IPSec. The existing Netfilter (outgoing) and LSM rcv_skb hooks are used as before. Also, if IPSec is used without security contexts, the impact is minimal. The LSM must allow such policies to be selected for the combination of socket and remote machine, but subsequent IPSec processing proceeds as in the original case. Testing: The pfkey interface is tested using the ipsec-tools. ipsec-tools have been modified (a separate ipsec-tools patch is available for version 0.5) that supports assignment of xfrm_policy entries and security associations with security contexts via setkey and the negotiation using the security contexts via racoon. The xfrm_user interface is tested via ad hoc programs that set security contexts. These programs are also available from me, and contain programs for setting, getting, and deleting policy for testing this interface. Testing of sa functions was done by tracing kernel behavior. Signed-off-by: Trent Jaeger <tjaeger@cse.psu.edu> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2005-11-10[XFRM]: Use generic netlink receive queue processorThomas Graf
Signed-off-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2005-11-10[NETLINK]: Make netlink_callback->done() optionalThomas Graf
Most netlink families make no use of the done() callback, making it optional gets rid of all unnecessary dummy implementations. Signed-off-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-29[NETLINK]: Add "groups" argument to netlink_kernel_createPatrick McHardy
Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-29[NETLINK]: Convert netlink users to use group numbers instead of bitmasksPatrick McHardy
Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-29[NETLINK]: Fix missing dst_groups initializations in netlink_broadcast usersPatrick McHardy
netlink_broadcast users must initialize NETLINK_CB(skb).dst_groups to the destination group mask for netlink_recvmsg. Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-29[NETLINK]: Add properly module refcounting for kernel netlink sockets.Harald Welte
- Remove bogus code for compiling netlink as module - Add module refcounting support for modules implementing a netlink protocol - Add support for autoloading modules that implement a netlink protocol as soon as someone opens a socket for that protocol Signed-off-by: Harald Welte <laforge@netfilter.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2005-07-26[XFRM]: Fix possible overflow of sock->sk_policyHerbert Xu
Spotted by, and original patch by, Balazs Scheidler. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2005-06-20[IPSEC]: Add xfrm_init_stateHerbert Xu
This patch adds xfrm_init_state which is simply a wrapper that calls xfrm_get_type and subsequently x->type->init_state. It also gets rid of the unused args argument. Abstracting it out allows us to add common initialisation code, e.g., to set family-specific flags. The add_time setting in xfrm_user.c was deleted because it's already set by xfrm_state_alloc. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Acked-by: James Morris <jmorris@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2005-06-18[IPSEC]: Add XFRMA_SA/XFRMA_POLICY for delete notificationHerbert Xu
This patch changes the format of the XFRM_MSG_DELSA and XFRM_MSG_DELPOLICY notification so that the main message sent is of the same format as that received by the kernel if the original message was via netlink. This also means that we won't lose the byid information carried in km_event. Since this user interface is introduced by Jamal's patch we can still afford to change it. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2005-06-18[IPSEC] Use NLMSG_LENGTH in xfrm_exp_state_notifyJamal Hadi Salim
Small fixup to use netlink macros instead of hardcoding. Signed-off-by: Jamal Hadi Salim <hadi@cyberus.ca> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2005-06-18[IPSEC] Fix xfrm_state leaks in error pathPatrick McHardy
Herbert Xu wrote: > @@ -1254,6 +1326,7 @@ static int pfkey_add(struct sock *sk, st > if (IS_ERR(x)) > return PTR_ERR(x); > > + xfrm_state_hold(x); This introduces a leak when xfrm_state_add()/xfrm_state_update() fail. We hold two references (one from xfrm_state_alloc(), one from xfrm_state_hold()), but only drop one. We need to take the reference because the reference from xfrm_state_alloc() can be dropped by __xfrm_state_delete(), so the fix is to drop both references on error. Same problem in xfrm_user.c. Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2005-06-18[IPSEC] Use XFRM_MSG_* instead of XFRM_SAP_*Herbert Xu
This patch removes XFRM_SAP_* and converts them over to XFRM_MSG_*. The netlink interface is meant to map directly onto the underlying xfrm subsystem. Therefore rather than using a new independent representation for the events we can simply use the existing ones from xfrm_user. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2005-06-18[IPSEC] Set byid for km_event in xfrm_get_policyHerbert Xu
This patch fixes policy deletion in xfrm_user so that it sets km_event.data.byid. This puts xfrm_user on par with what af_key does in this case. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2005-06-18[IPSEC] Turn km_event.data into a unionHerbert Xu
This patch turns km_event.data into a union. This makes code that uses it clearer. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2005-06-18[IPSEC] Add complete xfrm event notificationJamal Hadi Salim
Heres the final patch. What this patch provides - netlink xfrm events - ability to have events generated by netlink propagated to pfkey and vice versa. - fixes the acquire lets-be-happy-with-one-success issue Signed-off-by: Jamal Hadi Salim <hadi@cyberus.ca> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2005-05-19[IPSEC]: Verify key payload in verify_one_algoHerbert Xu
We need to verify that the payload contains enough data so that attach_one_algo can copy alg_key_len bits from the payload. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2005-05-19[IPSEC]: Fixed alg_key_len usage in attach_one_algoHerbert Xu
The variable alg_key_len is in bits and not bytes. The function attach_one_algo is currently using it as if it were in bytes. This causes it to read memory which may not be there. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2005-05-03[XFRM/RTNETLINK]: Decrement qlen properly in {xfrm_,rt}netlink_rcv().David S. Miller
If we free up a partially processed packet because it's skb->len dropped to zero, we need to decrement qlen because we are dropping out of the top-level loop so it will do the decrement for us. Spotted by Herbert Xu. Signed-off-by: David S. Miller <davem@davemloft.net>
2005-05-03[NETLINK]: Fix infinite loops in synchronous netlink changes.David S. Miller
The qlen should continue to decrement, even if we pop partially processed SKBs back onto the receive queue. Signed-off-by: David S. Miller <davem@davemloft.net>
2005-05-03[NETLINK]: Synchronous message processing.Herbert Xu
Let's recap the problem. The current asynchronous netlink kernel message processing is vulnerable to these attacks: 1) Hit and run: Attacker sends one or more messages and then exits before they're processed. This may confuse/disable the next netlink user that gets the netlink address of the attacker since it may receive the responses to the attacker's messages. Proposed solutions: a) Synchronous processing. b) Stream mode socket. c) Restrict/prohibit binding. 2) Starvation: Because various netlink rcv functions were written to not return until all messages have been processed on a socket, it is possible for these functions to execute for an arbitrarily long period of time. If this is successfully exploited it could also be used to hold rtnl forever. Proposed solutions: a) Synchronous processing. b) Stream mode socket. Firstly let's cross off solution c). It only solves the first problem and it has user-visible impacts. In particular, it'll break user space applications that expect to bind or communicate with specific netlink addresses (pid's). So we're left with a choice of synchronous processing versus SOCK_STREAM for netlink. For the moment I'm sticking with the synchronous approach as suggested by Alexey since it's simpler and I'd rather spend my time working on other things. However, it does have a number of deficiencies compared to the stream mode solution: 1) User-space to user-space netlink communication is still vulnerable. 2) Inefficient use of resources. This is especially true for rtnetlink since the lock is shared with other users such as networking drivers. The latter could hold the rtnl while communicating with hardware which causes the rtnetlink user to wait when it could be doing other things. 3) It is still possible to DoS all netlink users by flooding the kernel netlink receive queue. The attacker simply fills the receive socket with a single netlink message that fills up the entire queue. The attacker then continues to call sendmsg with the same message in a loop. Point 3) can be countered by retransmissions in user-space code, however it is pretty messy. In light of these problems (in particular, point 3), we should implement stream mode netlink at some point. In the mean time, here is a patch that implements synchronous processing. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2005-05-03[XFRM]: Cleanup xfrm_msg_min and xfrm_dispatchThomas Graf
Converts xfrm_msg_min and xfrm_dispatch to use c99 designated initializers to make greping a little bit easier. Also replaces two hardcoded message type with meaningful names. Signed-off-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2005-04-16Linux-2.6.12-rc2Linus Torvalds
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!