linux/net/netlink, branch v3.10.44

net: rework recvmsg handler msg_name and msg_namelen logic

2013-12-08T15:29:25Z

[ Upstream commit f3d3342602f8bcbf37d7c46641cb9bca7618eb1c ] This patch now always passes msg->msg_namelen as 0. recvmsg handlers must set msg_namelen to the proper size <= sizeof(struct sockaddr_storage) to return msg_name to the user. This prevents numerous uninitialized memory leaks we had in the recvmsg handlers and makes it harder for new code to accidentally leak uninitialized memory. Optimize for the case recvfrom is called with NULL as address. We don't need to copy the address at all, so set it to NULL before invoking the recvmsg handler. We can do so, because all the recvmsg handlers must cope with the case a plain read() is called on them. read() also sets msg_name to NULL. Also document these changes in include/linux/net.h as suggested by David Miller. Changes since RFC: Set msg->msg_name = NULL if user specified a NULL in msg_name but had a non-null msg_namelen in verify_iovec/verify_compat_iovec. This doesn't affect sendto as it would bail out earlier while trying to copy-in the address. It also more naturally reflects the logic by the callers of verify_iovec. With this change in place I could remove " if (!uaddr || msg_sys->msg_namelen == 0) msg->msg_name = NULL ". This change does not alter the user visible error logic as we ignore msg_namelen as long as msg_name is NULL. Also remove two unnecessary curly brackets in ___sys_recvmsg and change comments to netdev style. Cc: David Miller Suggested-by: Eric Dumazet Signed-off-by: Hannes Frederic Sowa Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

genl: Hold reference on correct module while netlink-dump.

2013-09-14T13:54:55Z

[ Upstream commit 33c6b1f6b154894321f5734e50c66621e9134e7e ] netlink dump operations take module as parameter to hold reference for entire netlink dump duration. Currently it holds ref only on genl module which is not correct when we use ops registered to genl from another module. Following patch adds module pointer to genl_ops so that netlink can hold ref count on it. Signed-off-by: Pravin B Shelar CC: Jesse Gross CC: Johannes Berg Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

genl: Fix genl dumpit() locking.

2013-09-14T13:54:55Z

[ Upstream commit 9b96309c5b0b9e466773c07a5bc8b7b68fcf010a ] In case of genl-family with parallel ops off, dumpif() callback is expected to run under genl_lock, But commit def3117493eafd9df (genl: Allow concurrent genl callbacks.) changed this behaviour where only first dumpit() op was called under genl-lock. For subsequent dump, only nlk->cb_lock was taken. Following patch fixes it by defining locked dumpit() and done() callback which takes care of genl-locking. Signed-off-by: Pravin B Shelar CC: Jesse Gross CC: Johannes Berg Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

Revert "genetlink: fix family dump race"

2013-08-20T22:32:57Z

This reverts commit aab4f8d490ef8c184d854d5f630438c10406765c, commit 58ad436fcf49810aa006016107f494c9ac9013db upstream, as it causes problems. Cc: Johannes Berg Cc: Andrei Otcheretianski Cc: David S. Miller Signed-off-by: Greg Kroah-Hartman

genetlink: fix family dump race

2013-08-20T15:43:03Z

commit 58ad436fcf49810aa006016107f494c9ac9013db upstream. When dumping generic netlink families, only the first dump call is locked with genl_lock(), which protects the list of families, and thus subsequent calls can access the data without locking, racing against family addition/removal. This can cause a crash. Fix it - the locking needs to be conditional because the first time around it's already locked. A similar bug was reported to me on an old kernel (3.4.47) but the exact scenario that happened there is no longer possible, on those kernels the first round wasn't locked either. Looking at the current code I found the race described above, which had also existed on the old kernel. Reported-by: Andrei Otcheretianski Signed-off-by: Johannes Berg Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

genetlink: release cb_lock before requesting additional module

2013-08-12T01:35:25Z

[ Upstream commit c74f2b2678f40b80265dd53556f1f778c8e1823f ] Requesting external module with cb_lock taken can result in the deadlock like showed below: [ 2458.111347] Showing all locks held in the system: [ 2458.111347] 1 lock held by NetworkManager/582: [ 2458.111347] #0: (cb_lock){++++++}, at: [] genl_rcv+0x19/0x40 [ 2458.111347] 1 lock held by modprobe/603: [ 2458.111347] #0: (cb_lock){++++++}, at: [] genl_lock_all+0x15/0x30 [ 2461.579457] SysRq : Show Blocked State [ 2461.580103] task PC stack pid father [ 2461.580103] NetworkManager D ffff880034b84500 4040 582 1 0x00000080 [ 2461.580103] ffff8800197ff720 0000000000000046 00000000001d5340 ffff8800197fffd8 [ 2461.580103] ffff8800197fffd8 00000000001d5340 ffff880019631700 7fffffffffffffff [ 2461.580103] ffff8800197ff880 ffff8800197ff878 ffff880019631700 ffff880019631700 [ 2461.580103] Call Trace: [ 2461.580103] [] schedule+0x29/0x70 [ 2461.580103] [] schedule_timeout+0x1c1/0x360 [ 2461.580103] [] ? mark_held_locks+0xbb/0x140 [ 2461.580103] [] ? _raw_spin_unlock_irq+0x2c/0x50 [ 2461.580103] [] ? trace_hardirqs_on_caller+0xfd/0x1c0 [ 2461.580103] [] wait_for_completion_killable+0xe8/0x170 [ 2461.580103] [] ? wake_up_state+0x20/0x20 [ 2461.580103] [] call_usermodehelper_exec+0x1a5/0x210 [ 2461.580103] [] ? wait_for_completion_killable+0x3d/0x170 [ 2461.580103] [] __request_module+0x1b3/0x370 [ 2461.580103] [] ? trace_hardirqs_on_caller+0xfd/0x1c0 [ 2461.580103] [] ctrl_getfamily+0x159/0x190 [ 2461.580103] [] genl_family_rcv_msg+0x1f4/0x2e0 [ 2461.580103] [] ? genl_family_rcv_msg+0x2e0/0x2e0 [ 2461.580103] [] genl_rcv_msg+0x8e/0xd0 [ 2461.580103] [] netlink_rcv_skb+0xa9/0xc0 [ 2461.580103] [] genl_rcv+0x28/0x40 [ 2461.580103] [] netlink_unicast+0xdd/0x190 [ 2461.580103] [] netlink_sendmsg+0x329/0x750 [ 2461.580103] [] sock_sendmsg+0x99/0xd0 [ 2461.580103] [] ? local_clock+0x5f/0x70 [ 2461.580103] [] ? lock_release_non_nested+0x308/0x350 [ 2461.580103] [] ___sys_sendmsg+0x39e/0x3b0 [ 2461.580103] [] ? kvm_clock_read+0x2f/0x50 [ 2461.580103] [] ? sched_clock+0x9/0x10 [ 2461.580103] [] ? sched_clock_local+0x1d/0x80 [ 2461.580103] [] ? sched_clock_cpu+0xa8/0x100 [ 2461.580103] [] ? trace_hardirqs_off+0xd/0x10 [ 2461.580103] [] ? local_clock+0x5f/0x70 [ 2461.580103] [] ? lock_release_holdtime.part.28+0xf/0x1a0 [ 2461.580103] [] ? fget_light+0xf9/0x510 [ 2461.580103] [] ? fget_light+0x3c/0x510 [ 2461.580103] [] __sys_sendmsg+0x42/0x80 [ 2461.580103] [] SyS_sendmsg+0x12/0x20 [ 2461.580103] [] system_call_fastpath+0x16/0x1b [ 2461.580103] modprobe D ffff88000f2c8000 4632 603 602 0x00000080 [ 2461.580103] ffff88000f04fba8 0000000000000046 00000000001d5340 ffff88000f04ffd8 [ 2461.580103] ffff88000f04ffd8 00000000001d5340 ffff8800377d4500 ffff8800377d4500 [ 2461.580103] ffffffff81d0b260 ffffffff81d0b268 ffffffff00000000 ffffffff81d0b2b0 [ 2461.580103] Call Trace: [ 2461.580103] [] schedule+0x29/0x70 [ 2461.580103] [] rwsem_down_write_failed+0xed/0x1a0 [ 2461.580103] [] ? update_cpu_load_active+0x10/0xb0 [ 2461.580103] [] call_rwsem_down_write_failed+0x13/0x20 [ 2461.580103] [] ? down_write+0x9d/0xb2 [ 2461.580103] [] ? genl_lock_all+0x15/0x30 [ 2461.580103] [] genl_lock_all+0x15/0x30 [ 2461.580103] [] genl_register_family+0x53/0x1f0 [ 2461.580103] [] ? 0xffffffffa01dbfff [ 2461.580103] [] genl_register_family_with_ops+0x20/0x80 [ 2461.580103] [] ? 0xffffffffa01dbfff [ 2461.580103] [] nl80211_init+0x24/0xf0 [cfg80211] [ 2461.580103] [] ? 0xffffffffa01dbfff [ 2461.580103] [] cfg80211_init+0x43/0xdb [cfg80211] [ 2461.580103] [] do_one_initcall+0xfa/0x1b0 [ 2461.580103] [] ? set_memory_nx+0x43/0x50 [ 2461.580103] [] load_module+0x1c6f/0x27f0 [ 2461.580103] [] ? store_uevent+0x40/0x40 [ 2461.580103] [] SyS_finit_module+0x86/0xb0 [ 2461.580103] [] system_call_fastpath+0x16/0x1b [ 2461.580103] Sched Debug Version: v0.10, 3.11.0-0.rc1.git4.1.fc20.x86_64 #1 Problem start to happen after adding net-pf-16-proto-16-family-nl80211 alias name to cfg80211 module by below commit (though that commit itself is perfectly fine): commit fb4e156886ce6e8309e912d8b370d192330d19d3 Author: Marcel Holtmann Date: Sun Apr 28 16:22:06 2013 -0700 nl80211: Add generic netlink module alias for cfg80211/nl80211 Reported-and-tested-by: Jeff Layton Reported-by: Richard W.M. Jones Signed-off-by: Stanislaw Gruszka Reviewed-by: Pravin B Shelar Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

netlink: fix error propagation in netlink_mmap()

2013-06-11T09:52:47Z

Return the error if something went wrong instead of unconditionally returning 0. Signed-off-by: Patrick McHardy Signed-off-by: David S. Miller

net: fix sk_buff head without data area

2013-06-05T00:26:49Z

Eric Dumazet spotted that we have to check skb->head instead of skb->data as skb->head points to the beginning of the data area of the skbuff. Similarly, we have to initialize the skb->head pointer, not skb->data in __alloc_skb_head. After this fix, netlink crashes in the release path of the sk_buff, so let's fix that as well. This bug was introduced in (0ebd0ac net: add function to allocate sk_buff head without data area). Reported-by: Eric Dumazet Signed-off-by: Pablo Neira Ayuso Signed-off-by: David S. Miller

netlink: kconfig: move mmap i/o into netlink kconfig

2013-05-01T19:02:42Z

Currently, in menuconfig, Netlink's new mmaped IO is the very first entry under the ``Networking support'' item and comes even before ``Networking options'': [ ] Netlink: mmaped IO Networking options ---> ... Lets move this into ``Networking options'' under netlink's Kconfig, since this might be more appropriate. Introduced by commit ccdfcc398 (``netlink: mmaped netlink: ring setup''). Signed-off-by: Daniel Borkmann Signed-off-by: David S. Miller

netlink: Fix skb ref counting.

2013-05-01T18:57:03Z

Commit f9c2288837ba072b21dba955f04a4c97eaa77b1e (netlink: implement memory mapped recvmsg) increamented skb->users ref count twice for a dump op which does not look right. Following patch fixes that. CC: Patrick McHardy Signed-off-by: Pravin B Shelar Signed-off-by: David S. Miller