kernel.git/net/netlink, branch linux-3.15.y

netlink: Fix handling of error from netlink_dump().

2014-07-28T15:08:24Z

[ Upstream commit ac30ef832e6af0505b6f0251a6659adcfa74975e ] netlink_dump() returns a negative errno value on error. Until now, netlink_recvmsg() directly recorded that negative value in sk->sk_err, but that's wrong since sk_err takes positive errno values. (This manifests as userspace receiving a positive return value from the recv() system call, falsely indicating success.) This bug was introduced in the commit that started checking the netlink_dump() return value, commit b44d211 (netlink: handle errors from netlink_dump()). Multithreaded Netlink dumps are one way to trigger this behavior in practice, as described in the commit message for the userspace workaround posted here: http://openvswitch.org/pipermail/dev/2014-June/042339.html This commit also fixes the same bug in netlink_poll(), introduced in commit cd1df525d (netlink: add flow control for memory mapped I/O). Signed-off-by: Ben Pfaff Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

netlink: Only check file credentials for implicit destinations

2014-06-02T23:34:09Z

It was possible to get a setuid root or setcap executable to write to it's stdout or stderr (which has been set made a netlink socket) and inadvertently reconfigure the networking stack. To prevent this we check that both the creator of the socket and the currentl applications has permission to reconfigure the network stack. Unfortunately this breaks Zebra which always uses sendto/sendmsg and creates it's socket without any privileges. To keep Zebra working don't bother checking if the creator of the socket has privilege when a destination address is specified. Instead rely exclusively on the privileges of the sender of the socket. Note from Andy: This is exactly Eric's code except for some comment clarifications and formatting fixes. Neither I nor, I think, anyone else is thrilled with this approach, but I'm hesitant to wait on a better fix since 3.15 is almost here. Note to stable maintainers: This is a mess. An earlier series of patches in 3.15 fix a rather serious security issue (CVE-2014-0181), but they did so in a way that breaks Zebra. The offending series includes: commit aa4cf9452f469f16cea8c96283b641b4576d4a7b Author: Eric W. Biederman Date: Wed Apr 23 14:28:03 2014 -0700 net: Add variants of capable for use on netlink messages If a given kernel version is missing that series of fixes, it's probably worth backporting it and this patch. if that series is present, then this fix is critical if you care about Zebra. Cc: stable@vger.kernel.org Signed-off-by: "Eric W. Biederman" Signed-off-by: Andy Lutomirski Signed-off-by: David S. Miller

net: Use netlink_ns_capable to verify the permisions of netlink messages

2014-04-24T17:44:54Z

It is possible by passing a netlink socket to a more privileged executable and then to fool that executable into writing to the socket data that happens to be valid netlink message to do something that privileged executable did not intend to do. To keep this from happening replace bare capable and ns_capable calls with netlink_capable, netlink_net_calls and netlink_ns_capable calls. Which act the same as the previous calls except they verify that the opener of the socket had the desired permissions as well. Reported-by: Andy Lutomirski Signed-off-by: "Eric W. Biederman" Signed-off-by: David S. Miller

net: Add variants of capable for use on netlink messages

2014-04-24T17:44:54Z

netlink_net_capable - The common case use, for operations that are safe on a network namespace netlink_capable - For operations that are only known to be safe for the global root netlink_ns_capable - The general case of capable used to handle special cases __netlink_ns_capable - Same as netlink_ns_capable except taking a netlink_skb_parms instead of the skbuff of a netlink message. Signed-off-by: "Eric W. Biederman" Signed-off-by: David S. Miller

netlink: Rename netlink_capable netlink_allowed

2014-04-24T17:44:53Z

netlink_capable is a static internal function in af_netlink.c and we have better uses for the name netlink_capable. Signed-off-by: "Eric W. Biederman" Signed-off-by: David S. Miller

net: Fix use after free by removing length arg from sk_data_ready callbacks.

2014-04-11T20:15:36Z

Several spots in the kernel perform a sequence like: skb_queue_tail(&sk->s_receive_queue, skb); sk->sk_data_ready(sk, skb->len); But at the moment we place the SKB onto the socket receive queue it can be consumed and freed up. So this skb->len access is potentially to freed up memory. Furthermore, the skb->len can be modified by the consumer so it is possible that the value isn't accurate. And finally, no actual implementation of this callback actually uses the length argument. And since nobody actually cared about it's value, lots of call sites pass arbitrary values in such as '0' and even '1'. So just remove the length argument from the callback, that way there is no confusion whatsoever and all of these use-after-free cases get fixed as a side effect. Based upon a patch by Eric Dumazet and his suggestion to audit this issue tree-wide. Signed-off-by: David S. Miller

netlink: autosize skb lengthes

2014-03-10T17:56:26Z

One known problem with netlink is the fact that NLMSG_GOODSIZE is really small on PAGE_SIZE==4096 architectures, and it is difficult to know in advance what buffer size is used by the application. This patch adds an automatic learning of the size. First netlink message will still be limited to ~4K, but if user used bigger buffers, then following messages will be able to use up to 16KB. This speedups dump() operations by a large factor and should be safe for legacy applications. Signed-off-by: Eric Dumazet Cc: Thomas Graf Acked-by: Thomas Graf Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2014-03-06T01:32:02Z

Conflicts: drivers/net/wireless/ath/ath9k/recv.c drivers/net/wireless/mwifiex/pcie.c net/ipv6/sit.c The SIT driver conflict consists of a bug fix being done by hand in 'net' (missing u64_stats_init()) whilst in 'net-next' a helper was created (netdev_alloc_pcpu_stats()) which takes care of this. The two wireless conflicts were overlapping changes. Signed-off-by: David S. Miller

net: Fix permission check in netlink_connect()

2014-02-25T23:35:14Z

netlink_sendmsg() was changed to prevent non-root processes from sending messages with dst_pid != 0. netlink_connect() however still only checks if nladdr->nl_groups is set. This patch modifies netlink_connect() to check for the same condition. Signed-off-by: Mike Pecovnik Signed-off-by: David S. Miller

netlink: fix checkpatch errors space and "foo *bar"

2014-02-17T21:57:28Z

ERROR: spaces required and "(foo*)" should be "(foo *)" Signed-off-by: Wang Yufen Signed-off-by: David S. Miller