user/sven/linux.git/include/linux/skbuff.h, branch v4.1.9

mm: make page pfmemalloc check more robust

2015-09-29T17:26:06Z

commit 2f064f3485cd29633ad1b3cfb00cc519509a3d72 upstream. Commit c48a11c7ad26 ("netvm: propagate page->pfmemalloc to skb") added checks for page->pfmemalloc to __skb_fill_page_desc(): if (page->pfmemalloc && !page->mapping) skb->pfmemalloc = true; It assumes page->mapping == NULL implies that page->pfmemalloc can be trusted. However, __delete_from_page_cache() can set set page->mapping to NULL and leave page->index value alone. Due to being in union, a non-zero page->index will be interpreted as true page->pfmemalloc. So the assumption is invalid if the networking code can see such a page. And it seems it can. We have encountered this with a NFS over loopback setup when such a page is attached to a new skbuf. There is no copying going on in this case so the page confuses __skb_fill_page_desc which interprets the index as pfmemalloc flag and the network stack drops packets that have been allocated using the reserves unless they are to be queued on sockets handling the swapping which is the case here and that leads to hangs when the nfs client waits for a response from the server which has been dropped and thus never arrive. The struct page is already heavily packed so rather than finding another hole to put it in, let's do a trick instead. We can reuse the index again but define it to an impossible value (-1UL). This is the page index so it should never see the value that large. Replace all direct users of page->pfmemalloc by page_is_pfmemalloc which will hide this nastiness from unspoiled eyes. The information will get lost if somebody wants to use page->index obviously but that was the case before and the original code expected that the information should be persisted somewhere else if that is really needed (e.g. what SLAB and SLUB do). [akpm@linux-foundation.org: fix blooper in slub] Fixes: c48a11c7ad26 ("netvm: propagate page->pfmemalloc to skb") Signed-off-by: Michal Hocko Debugged-by: Vlastimil Babka Debugged-by: Jiri Bohac Cc: Eric Dumazet Cc: David Miller Acked-by: Mel Gorman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

Revert "netfilter: bridge: query conntrack about skb dnat"

2015-05-20T11:51:25Z

This reverts commit c055d5b03bb4cb69d349d787c9787c0383abd8b2. There are two issues: 'dnat_took_place' made me think that this is related to -j DNAT/MASQUERADE. But thats only one part of the story. This is also relevant for SNAT when we undo snat translation in reverse/reply direction. Furthermore, I originally wanted to do this mainly to avoid storing ipv6 addresses once we make DNAT/REDIRECT work for ipv6 on bridges. However, I forgot about SNPT/DNPT which is stateless. So we can't escape storing address for ipv6 anyway. Might as well do it for ipv4 too. Reported-and-tested-by: Bernhard Thaler Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso

net: fix crash in build_skb()

2015-04-25T19:49:49Z

When I added pfmemalloc support in build_skb(), I forgot netlink was using build_skb() with a vmalloc() area. In this patch I introduce __build_skb() for netlink use, and build_skb() is a wrapper handling both skb->head_frag and skb->pfmemalloc This means netlink no longer has to hack skb->head_frag [ 1567.700067] kernel BUG at arch/x86/mm/physaddr.c:26! [ 1567.700067] invalid opcode: 0000 [#1] PREEMPT SMP KASAN [ 1567.700067] Dumping ftrace buffer: [ 1567.700067] (ftrace buffer empty) [ 1567.700067] Modules linked in: [ 1567.700067] CPU: 9 PID: 16186 Comm: trinity-c182 Not tainted 4.0.0-next-20150424-sasha-00037-g4796e21 #2167 [ 1567.700067] task: ffff880127efb000 ti: ffff880246770000 task.ti: ffff880246770000 [ 1567.700067] RIP: __phys_addr (arch/x86/mm/physaddr.c:26 (discriminator 3)) [ 1567.700067] RSP: 0018:ffff8802467779d8 EFLAGS: 00010202 [ 1567.700067] RAX: 000041000ed8e000 RBX: ffffc9008ed8e000 RCX: 000000000000002c [ 1567.700067] RDX: 0000000000000004 RSI: 0000000000000000 RDI: ffffffffb3fd6049 [ 1567.700067] RBP: ffff8802467779f8 R08: 0000000000000019 R09: ffff8801d0168000 [ 1567.700067] R10: ffff8801d01680c7 R11: ffffed003a02d019 R12: ffffc9000ed8e000 [ 1567.700067] R13: 0000000000000f40 R14: 0000000000001180 R15: ffffc9000ed8e000 [ 1567.700067] FS: 00007f2a7da3f700(0000) GS:ffff8801d1000000(0000) knlGS:0000000000000000 [ 1567.700067] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 1567.700067] CR2: 0000000000738308 CR3: 000000022e329000 CR4: 00000000000007e0 [ 1567.700067] Stack: [ 1567.700067] ffffc9000ed8e000 ffff8801d0168000 ffffc9000ed8e000 ffff8801d0168000 [ 1567.700067] ffff880246777a28 ffffffffad7c0a21 0000000000001080 ffff880246777c08 [ 1567.700067] ffff88060d302e68 ffff880246777b58 ffff880246777b88 ffffffffad9a6821 [ 1567.700067] Call Trace: [ 1567.700067] build_skb (include/linux/mm.h:508 net/core/skbuff.c:316) [ 1567.700067] netlink_sendmsg (net/netlink/af_netlink.c:1633 net/netlink/af_netlink.c:2329) [ 1567.774369] ? sched_clock_cpu (kernel/sched/clock.c:311) [ 1567.774369] ? netlink_unicast (net/netlink/af_netlink.c:2273) [ 1567.774369] ? netlink_unicast (net/netlink/af_netlink.c:2273) [ 1567.774369] sock_sendmsg (net/socket.c:614 net/socket.c:623) [ 1567.774369] sock_write_iter (net/socket.c:823) [ 1567.774369] ? sock_sendmsg (net/socket.c:806) [ 1567.774369] __vfs_write (fs/read_write.c:479 fs/read_write.c:491) [ 1567.774369] ? get_lock_stats (kernel/locking/lockdep.c:249) [ 1567.774369] ? default_llseek (fs/read_write.c:487) [ 1567.774369] ? vtime_account_user (kernel/sched/cputime.c:701) [ 1567.774369] ? rw_verify_area (fs/read_write.c:406 (discriminator 4)) [ 1567.774369] vfs_write (fs/read_write.c:539) [ 1567.774369] SyS_write (fs/read_write.c:586 fs/read_write.c:577) [ 1567.774369] ? SyS_read (fs/read_write.c:577) [ 1567.774369] ? __this_cpu_preempt_check (lib/smp_processor_id.c:63) [ 1567.774369] ? trace_hardirqs_on_caller (kernel/locking/lockdep.c:2594 kernel/locking/lockdep.c:2636) [ 1567.774369] ? trace_hardirqs_on_thunk (arch/x86/lib/thunk_64.S:42) [ 1567.774369] system_call_fastpath (arch/x86/kernel/entry_64.S:261) Fixes: 79930f5892e ("net: do not deplete pfmemalloc reserve") Signed-off-by: Eric Dumazet Reported-by: Sasha Levin Signed-off-by: David S. Miller

net: add skb_checksum_complete_unset

2015-04-21T01:57:26Z

This function changes ip_summed to CHECKSUM_NONE if CHECKSUM_COMPLETE is set. This is called to discard checksum-complete when packet is being modified and checksum is not pulled for headers in a layer. Signed-off-by: Tom Herbert Signed-off-by: David S. Miller

netfilter: bridge: make BRNF_PKT_TYPE flag a bool

2015-04-08T14:49:12Z

nf_bridge_info->mask is used for several things, for example to remember if skb->pkt_type was set to OTHER_HOST. For a bridge, OTHER_HOST is expected case. For ip forward its a non-starter though -- routing expects PACKET_HOST. Bridge netfilter thus changes OTHER_HOST to PACKET_HOST before hook invocation and then un-does it after hook traversal. This information is irrelevant outside of br_netfilter. After this change, ->mask now only contains flags that need to be known outside of br_netfilter in fast-path. Future patch changes mask into a 2bit state field in sk_buff, so that we can remove skb->nf_bridge pointer for good and consider all remaining places that access nf_bridge info content a not-so fastpath. Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso

netfilter: bridge: start splitting mask into public/private chunks

2015-04-08T14:49:11Z

->mask is a bit info field that mixes various use cases. In particular, we have flags that are mutually exlusive, and flags that are only used within br_netfilter while others need to be exposed to other parts of the kernel. Remove BRNF_8021Q/PPPoE flags. They're mutually exclusive and only needed within br_netfilter context. Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso

netfilter: bridge: don't use nf_bridge_info data to store mac header

2015-04-08T14:49:07Z

br_netfilter maintains an extra state, nf_bridge_info, which is attached to skb via skb->nf_bridge pointer. Amongst other things we use skb->nf_bridge->data to store the original mac header for every processed skb. This is required for ip refragmentation when using conntrack on top of bridge, because ip_fragment doesn't copy it from original skb. However there is no need anymore to do this unconditionally. Move this to the one place where its needed -- when br_netfilter calls ip_fragment(). Also switch to percpu storage for this so we can handle fragmenting without accessing nf_bridge meta data. Only user left is neigh resolution when DNAT is detected, to hold the original source mac address (neigh resolution builds new mac header using bridge mac), so rename ->data and reduce its size to whats needed. Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso

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

2015-03-20T22:51:09Z

Conflicts: drivers/net/ethernet/emulex/benet/be_main.c net/core/sysctl_net_core.c net/ipv4/inet_diag.c The be_main.c conflict resolution was really tricky. The conflict hunks generated by GIT were very unhelpful, to say the least. It split functions in half and moved them around, when the real actual conflict only existed solely inside of one function, that being be_map_pci_bars(). So instead, to resolve this, I checked out be_main.c from the top of net-next, then I applied the be_main.c changes from 'net' since the last time I merged. And this worked beautifully. The inet_diag.c and sysctl_net_core.c conflicts were simple overlapping changes, and were easily to resolve. Signed-off-by: David S. Miller

xps: must clear sender_cpu before forwarding

2015-03-12T03:51:18Z

John reported that my previous commit added a regression on his router. This is because sender_cpu & napi_id share a common location, so get_xps_queue() can see garbage and perform an out of bound access. We need to make sure sender_cpu is cleared before doing the transmit, otherwise any NIC busy poll enabled (skb_mark_napi_id()) can trigger this bug. Signed-off-by: Eric Dumazet Reported-by: John Bisected-by: John Fixes: 2bd82484bb4c ("xps: fix xps for stacked devices") Signed-off-by: David S. Miller

net: move skb->dropcount to skb->cb[]

2015-03-02T05:19:30Z

Commit 977750076d98 ("af_packet: add interframe drop cmsg (v6)") unionized skb->mark and skb->dropcount in order to allow recording of the socket drop count while maintaining struct sk_buff size. skb->dropcount was introduced since there was no available room in skb->cb[] in packet sockets. However, its introduction led to the inability to export skb->mark, or any other aliased field to userspace if so desired. Moving the dropcount metric to skb->cb[] eliminates this problem at the expense of 4 bytes less in skb->cb[] for protocol families using it. Signed-off-by: Eyal Birger Signed-off-by: David S. Miller