user/sven/linux.git/net/netlink, branch v3.0.45

netlink: fix possible spoofing from non-root processes

2012-10-02T16:47:22Z

[ Upstream commit 20e1db19db5d6b9e4e83021595eab0dc8f107bef ] Non-root user-space processes can send Netlink messages to other processes that are well-known for being subscribed to Netlink asynchronous notifications. This allows ilegitimate non-root process to send forged messages to Netlink subscribers. The userspace process usually verifies the legitimate origin in two ways: a) Socket credentials. If UID != 0, then the message comes from some ilegitimate process and the message needs to be dropped. b) Netlink portID. In general, portID == 0 means that the origin of the messages comes from the kernel. Thus, discarding any message not coming from the kernel. However, ctnetlink sets the portID in event messages that has been triggered by some user-space process, eg. conntrack utility. So other processes subscribed to ctnetlink events, eg. conntrackd, know that the event was triggered by some user-space action. Neither of the two ways to discard ilegitimate messages coming from non-root processes can help for ctnetlink. This patch adds capability validation in case that dst_pid is set in netlink_sendmsg(). This approach is aggressive since existing applications using any Netlink bus to deliver messages between two user-space processes will break. Note that the exception is NETLINK_USERSOCK, since it is reserved for netlink-to-netlink userspace communication. Still, if anyone wants that his Netlink bus allows netlink-to-netlink userspace, then they can set NL_NONROOT_SEND. However, by default, I don't think it makes sense to allow to use NETLINK_ROUTE to communicate two processes that are sending no matter what information that is not related to link/neighbouring/routing. They should be using NETLINK_USERSOCK instead for that. Signed-off-by: Pablo Neira Ayuso Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

netlink: fix races after skb queueing

2012-04-27T16:51:19Z

[ Upstream commit 4a7e7c2ad540e54c75489a70137bf0ec15d3a127 ] As soon as an skb is queued into socket receive_queue, another thread can consume it, so we are not allowed to reference skb anymore, or risk use after free. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net: convert %p usage to %pK

2011-05-24T05:13:12Z

The %pK format specifier is designed to hide exposed kernel pointers, specifically via /proc interfaces. Exposing these pointers provides an easy target for kernel write vulnerabilities, since they reveal the locations of writable structures containing easily triggerable function pointers. The behavior of %pK depends on the kptr_restrict sysctl. If kptr_restrict is set to 0, no deviation from the standard %p behavior occurs. If kptr_restrict is set to 1, the default, if the current user (intended to be a reader via seq_printf(), etc.) does not have CAP_SYSLOG (currently in the LSM tree), kernel pointers using %pK are printed as 0's. If kptr_restrict is set to 2, kernel pointers using %pK are printed as 0's regardless of privileges. Replacing with 0's was chosen over the default "(null)", which cannot be parsed by userland %p, which expects "(nil)". The supporting code for kptr_restrict and %pK are currently in the -mm tree. This patch converts users of %p in net/ to %pK. Cases of printing pointers to the syslog are not covered, since this would eliminate useful information for postmortem debugging and the reading of the syslog is already optionally protected by the dmesg_restrict sysctl. Signed-off-by: Dan Rosenberg Cc: James Morris Cc: Eric Dumazet Cc: Thomas Graf Cc: Eugene Teo Cc: Kees Cook Cc: Ingo Molnar Cc: David S. Miller Cc: Peter Zijlstra Cc: Eric Paris Signed-off-by: Andrew Morton Signed-off-by: David S. Miller

net,rcu: convert call_rcu(listeners_free_rcu) to kfree_rcu()

2011-05-08T05:50:51Z

The rcu callback listeners_free_rcu() just calls a kfree(), so we use kfree_rcu() instead of the call_rcu(listeners_free_rcu). Signed-off-by: Lai Jiangshan Acked-by: David S. Miller Signed-off-by: Paul E. McKenney Reviewed-by: Josh Triplett

Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6

2011-03-04T05:27:42Z

Conflicts: drivers/net/bnx2x/bnx2x.h

netlink: kill eff_cap from struct netlink_skb_parms

2011-03-03T21:32:07Z

Netlink message processing in the kernel is synchronous these days, capabilities can be checked directly in security_netlink_recv() from the current process. Signed-off-by: Patrick McHardy Reviewed-by: James Morris [chrisw: update to include pohmelfs and uvesafb] Signed-off-by: Chris Wright Signed-off-by: David S. Miller

netlink: kill loginuid/sessionid/sid members from struct netlink_skb_parms

2011-03-03T18:55:40Z

Netlink message processing in the kernel is synchronous these days, the session information can be collected when needed. Signed-off-by: Patrick McHardy Signed-off-by: David S. Miller

netlink: handle errors from netlink_dump()

2011-02-28T20:18:12Z

netlink_dump() may failed, but nobody handle its error. It generates output data, when a previous portion has been returned to user space. This mechanism works when all data isn't go in skb. If we enter in netlink_recvmsg() and skb is absent in the recv queue, the netlink_dump() will not been executed. So if netlink_dump() is failed one time, the new data never appear and the reader will sleep forever. netlink_dump() is called from two places: 1. from netlink_sendmsg->...->netlink_dump_start(). In this place we can report error directly and it will be returned by sendmsg(). 2. from netlink_recvmsg There we can't report error directly, because we have a portion of valid output data and call netlink_dump() for prepare the next portion. If netlink_dump() is failed, the socket will be mark as error and the next recvmsg will be failed. Signed-off-by: Andrey Vagin Signed-off-by: David S. Miller

Revert "netlink: test for all flags of the NLM_F_DUMP composite"

2011-01-19T21:34:20Z

This reverts commit 0ab03c2b1478f2438d2c80204f7fef65b1bca9cf. It breaks several things including the avahi daemon. Signed-off-by: David S. Miller

netlink: test for all flags of the NLM_F_DUMP composite

2011-01-10T00:25:03Z

Due to NLM_F_DUMP is composed of two bits, NLM_F_ROOT | NLM_F_MATCH, when doing "if (x & NLM_F_DUMP)", it tests for _either_ of the bits being set. Because NLM_F_MATCH's value overlaps with NLM_F_EXCL, non-dump requests with NLM_F_EXCL set are mistaken as dump requests. Substitute the condition to test for _all_ bits being set. Signed-off-by: Jan Engelhardt Acked-by: Pablo Neira Ayuso Signed-off-by: David S. Miller