user/sven/linux.git/include, branch v4.19.58

bpf: fix bpf_jit_limit knob for PAGE_SIZE >= 64K

2019-07-10T07:53:47Z

[ Upstream commit fdadd04931c2d7cd294dc5b2b342863f94be53a3 ] Michael and Sandipan report: Commit ede95a63b5 introduced a bpf_jit_limit tuneable to limit BPF JIT allocations. At compile time it defaults to PAGE_SIZE * 40000, and is adjusted again at init time if MODULES_VADDR is defined. For ppc64 kernels, MODULES_VADDR isn't defined, so we're stuck with the compile-time default at boot-time, which is 0x9c400000 when using 64K page size. This overflows the signed 32-bit bpf_jit_limit value: root@ubuntu:/tmp# cat /proc/sys/net/core/bpf_jit_limit -1673527296 and can cause various unexpected failures throughout the network stack. In one case `strace dhclient eth0` reported: setsockopt(5, SOL_SOCKET, SO_ATTACH_FILTER, {len=11, filter=0x105dd27f8}, 16) = -1 ENOTSUPP (Unknown error 524) and similar failures can be seen with tools like tcpdump. This doesn't always reproduce however, and I'm not sure why. The more consistent failure I've seen is an Ubuntu 18.04 KVM guest booted on a POWER9 host would time out on systemd/netplan configuring a virtio-net NIC with no noticeable errors in the logs. Given this and also given that in near future some architectures like arm64 will have a custom area for BPF JIT image allocations we should get rid of the BPF_JIT_LIMIT_DEFAULT fallback / default entirely. For 4.21, we have an overridable bpf_jit_alloc_exec(), bpf_jit_free_exec() so therefore add another overridable bpf_jit_alloc_exec_limit() helper function which returns the possible size of the memory area for deriving the default heuristic in bpf_jit_charge_init(). Like bpf_jit_alloc_exec() and bpf_jit_free_exec(), the new bpf_jit_alloc_exec_limit() assumes that module_alloc() is the default JIT memory provider, and therefore in case archs implement their custom module_alloc() we use MODULES_{END,_VADDR} for limits and otherwise for vmalloc_exec() cases like on ppc64 we use VMALLOC_{END,_START}. Additionally, for archs supporting large page sizes, we should change the sysctl to be handled as long to not run into sysctl restrictions in future. Fixes: ede95a63b5e8 ("bpf: add bpf_jit_limit knob to restrict unpriv allocations") Reported-by: Sandipan Das Reported-by: Michael Roth Signed-off-by: Daniel Borkmann Tested-by: Michael Roth Signed-off-by: Alexei Starovoitov Signed-off-by: Sasha Levin

ip6: fix skb leak in ip6frag_expire_frag_queue()

2019-07-10T07:53:46Z

[ Upstream commit 47d3d7fdb10a21c223036b58bd70ffdc24a472c4 ] Since ip6frag_expire_frag_queue() now pulls the head skb from frag queue, we should no longer use skb_get(), since this leads to an skb leak. Stefan Bader initially reported a problem in 4.4.stable [1] caused by the skb_get(), so this patch should also fix this issue. 296583.091021] kernel BUG at /build/linux-6VmqmP/linux-4.4.0/net/core/skbuff.c:1207! [296583.091734] Call Trace: [296583.091749] [] __pskb_pull_tail+0x50/0x350 [296583.091764] [] _decode_session6+0x26a/0x400 [296583.091779] [] __xfrm_decode_session+0x39/0x50 [296583.091795] [] icmpv6_route_lookup+0xf0/0x1c0 [296583.091809] [] icmp6_send+0x5e1/0x940 [296583.091823] [] ? __netif_receive_skb+0x18/0x60 [296583.091838] [] ? netif_receive_skb_internal+0x32/0xa0 [296583.091858] [] ? ixgbe_clean_rx_irq+0x594/0xac0 [ixgbe] [296583.091876] [] ? nf_ct_net_exit+0x50/0x50 [nf_defrag_ipv6] [296583.091893] [] icmpv6_send+0x21/0x30 [296583.091906] [] ip6_expire_frag_queue+0xe0/0x120 [296583.091921] [] nf_ct_frag6_expire+0x1f/0x30 [nf_defrag_ipv6] [296583.091938] [] call_timer_fn+0x37/0x140 [296583.091951] [] ? nf_ct_net_exit+0x50/0x50 [nf_defrag_ipv6] [296583.091968] [] run_timer_softirq+0x234/0x330 [296583.091982] [] __do_softirq+0x109/0x2b0 Fixes: d4289fcc9b16 ("net: IP6 defrag: use rbtrees for IPv6 defrag") Signed-off-by: Eric Dumazet Reported-by: Stefan Bader Cc: Peter Oskolkov Cc: Florian Westphal Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

futex: Update comments and docs about return values of arch futex code

2019-07-03T11:14:49Z

commit 427503519739e779c0db8afe876c1b33f3ac60ae upstream. The architecture implementations of 'arch_futex_atomic_op_inuser()' and 'futex_atomic_cmpxchg_inatomic()' are permitted to return only -EFAULT, -EAGAIN or -ENOSYS in the case of failure. Update the comments in the asm-generic/ implementation and also a stray reference in the robust futex documentation. Signed-off-by: Will Deacon Signed-off-by: Greg Kroah-Hartman

bpf: fix unconnected udp hooks

2019-07-03T11:14:48Z

commit 983695fa676568fc0fe5ddd995c7267aabc24632 upstream. Intention of cgroup bind/connect/sendmsg BPF hooks is to act transparently to applications as also stated in original motivation in 7828f20e3779 ("Merge branch 'bpf-cgroup-bind-connect'"). When recently integrating the latter two hooks into Cilium to enable host based load-balancing with Kubernetes, I ran into the issue that pods couldn't start up as DNS got broken. Kubernetes typically sets up DNS as a service and is thus subject to load-balancing. Upon further debugging, it turns out that the cgroupv2 sendmsg BPF hooks API is currently insufficient and thus not usable as-is for standard applications shipped with most distros. To break down the issue we ran into with a simple example: # cat /etc/resolv.conf nameserver 147.75.207.207 nameserver 147.75.207.208 For the purpose of a simple test, we set up above IPs as service IPs and transparently redirect traffic to a different DNS backend server for that node: # cilium service list ID Frontend Backend 1 147.75.207.207:53 1 => 8.8.8.8:53 2 147.75.207.208:53 1 => 8.8.8.8:53 The attached BPF program is basically selecting one of the backends if the service IP/port matches on the cgroup hook. DNS breaks here, because the hooks are not transparent enough to applications which have built-in msg_name address checks: # nslookup 1.1.1.1 ;; reply from unexpected source: 8.8.8.8#53, expected 147.75.207.207#53 ;; reply from unexpected source: 8.8.8.8#53, expected 147.75.207.208#53 ;; reply from unexpected source: 8.8.8.8#53, expected 147.75.207.207#53 [...] ;; connection timed out; no servers could be reached # dig 1.1.1.1 ;; reply from unexpected source: 8.8.8.8#53, expected 147.75.207.207#53 ;; reply from unexpected source: 8.8.8.8#53, expected 147.75.207.208#53 ;; reply from unexpected source: 8.8.8.8#53, expected 147.75.207.207#53 [...] ; <<>> DiG 9.11.3-1ubuntu1.7-Ubuntu <<>> 1.1.1.1 ;; global options: +cmd ;; connection timed out; no servers could be reached For comparison, if none of the service IPs is used, and we tell nslookup to use 8.8.8.8 directly it works just fine, of course: # nslookup 1.1.1.1 8.8.8.8 1.1.1.1.in-addr.arpa name = one.one.one.one. In order to fix this and thus act more transparent to the application, this needs reverse translation on recvmsg() side. A minimal fix for this API is to add similar recvmsg() hooks behind the BPF cgroups static key such that the program can track state and replace the current sockaddr_in{,6} with the original service IP. From BPF side, this basically tracks the service tuple plus socket cookie in an LRU map where the reverse NAT can then be retrieved via map value as one example. Side-note: the BPF cgroups static key should be converted to a per-hook static key in future. Same example after this fix: # cilium service list ID Frontend Backend 1 147.75.207.207:53 1 => 8.8.8.8:53 2 147.75.207.208:53 1 => 8.8.8.8:53 Lookups work fine now: # nslookup 1.1.1.1 1.1.1.1.in-addr.arpa name = one.one.one.one. Authoritative answers can be found from: # dig 1.1.1.1 ; <<>> DiG 9.11.3-1ubuntu1.7-Ubuntu <<>> 1.1.1.1 ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 51550 ;; flags: qr rd ra ad; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 1 ;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags:; udp: 512 ;; QUESTION SECTION: ;1.1.1.1. IN A ;; AUTHORITY SECTION: . 23426 IN SOA a.root-servers.net. nstld.verisign-grs.com. 2019052001 1800 900 604800 86400 ;; Query time: 17 msec ;; SERVER: 147.75.207.207#53(147.75.207.207) ;; WHEN: Tue May 21 12:59:38 UTC 2019 ;; MSG SIZE rcvd: 111 And from an actual packet level it shows that we're using the back end server when talking via 147.75.207.20{7,8} front end: # tcpdump -i any udp [...] 12:59:52.698732 IP foo.42011 > google-public-dns-a.google.com.domain: 18803+ PTR? 1.1.1.1.in-addr.arpa. (38) 12:59:52.698735 IP foo.42011 > google-public-dns-a.google.com.domain: 18803+ PTR? 1.1.1.1.in-addr.arpa. (38) 12:59:52.701208 IP google-public-dns-a.google.com.domain > foo.42011: 18803 1/0/0 PTR one.one.one.one. (67) 12:59:52.701208 IP google-public-dns-a.google.com.domain > foo.42011: 18803 1/0/0 PTR one.one.one.one. (67) [...] In order to be flexible and to have same semantics as in sendmsg BPF programs, we only allow return codes in [1,1] range. In the sendmsg case the program is called if msg->msg_name is present which can be the case in both, connected and unconnected UDP. The former only relies on the sockaddr_in{,6} passed via connect(2) if passed msg->msg_name was NULL. Therefore, on recvmsg side, we act in similar way to call into the BPF program whenever a non-NULL msg->msg_name was passed independent of sk->sk_state being TCP_ESTABLISHED or not. Note that for TCP case, the msg->msg_name is ignored in the regular recvmsg path and therefore not relevant. For the case of ip{,v6}_recv_error() paths, picked up via MSG_ERRQUEUE, the hook is not called. This is intentional as it aligns with the same semantics as in case of TCP cgroup BPF hooks right now. This might be better addressed in future through a different bpf_attach_type such that this case can be distinguished from the regular recvmsg paths, for example. Fixes: 1cedee13d25a ("bpf: Hooks for sys_sendmsg") Signed-off-by: Daniel Borkmann Acked-by: Andrey Ignatov Acked-by: Martin KaFai Lau Acked-by: Martynas Pumputis Signed-off-by: Alexei Starovoitov Signed-off-by: Daniel Borkmann Signed-off-by: Greg Kroah-Hartman

bpf: simplify definition of BPF_FIB_LOOKUP related flags

2019-07-03T11:14:48Z

commit b1d6c15b9d824a58c5415673f374fac19e8eccdf upstream. Previously, the BPF_FIB_LOOKUP_{DIRECT,OUTPUT} flags in the BPF UAPI were defined with the help of BIT macro. This had the following issues: - In order to use any of the flags, a user was required to depend on . - No other flag in bpf.h uses the macro, so it seems that an unwritten convention is to use (1 << (nr)) to define BPF-related flags. Fixes: 87f5fc7e48dd ("bpf: Provide helper to do forwarding lookups in kernel FIB table") Signed-off-by: Martynas Pumputis Acked-by: Andrii Nakryiko Signed-off-by: Daniel Borkmann Signed-off-by: Greg Kroah-Hartman

SUNRPC: Clean up initialisation of the struct rpc_rqst

2019-07-03T11:14:46Z

commit 9dc6edcf676fe188430e8b119f91280bbf285163 upstream. Move the initialisation back into xprt.c. Signed-off-by: Trond Myklebust Cc: Yihao Wu Cc: Caspar Zhang Signed-off-by: Greg Kroah-Hartman

9p: Add refcount to p9_req_t

2019-07-03T11:14:42Z

[ Upstream commit 728356dedeff8ef999cb436c71333ef4ac51a81c ] To avoid use-after-free(s), use a refcount to keep track of the usable references to any instantiated struct p9_req_t. This commit adds p9_req_put(), p9_req_get() and p9_req_try_get() as wrappers to kref_put(), kref_get() and kref_get_unless_zero(). These are used by the client and the transports to keep track of valid requests' references. p9_free_req() is added back and used as callback by kref_put(). Add SLAB_TYPESAFE_BY_RCU as it ensures that the memory freed by kmem_cache_free() will not be reused for another type until the rcu synchronisation period is over, so an address gotten under rcu read lock is safe to inc_ref() without corrupting random memory while the lock is held. Link: http://lkml.kernel.org/r/1535626341-20693-1-git-send-email-asmadeus@codewreck.org Co-developed-by: Dominique Martinet Signed-off-by: Tomas Bortoli Reported-by: syzbot+467050c1ce275af2a5b8@syzkaller.appspotmail.com Signed-off-by: Dominique Martinet Signed-off-by: Sasha Levin

9p: add a per-client fcall kmem_cache

2019-07-03T11:14:42Z

[ Upstream commit 91a76be37ff89795526c452a6799576b03bec501 ] Having a specific cache for the fcall allocations helps speed up end-to-end latency. The caches will automatically be merged if there are multiple caches of items with the same size so we do not need to try to share a cache between different clients of the same size. Since the msize is negotiated with the server, only allocate the cache after that negotiation has happened - previous allocations or allocations of different sizes (e.g. zero-copy fcall) are made with kmalloc directly. Some figures on two beefy VMs with Connect-IB (sriov) / trans=rdma, with ior running 32 processes in parallel doing small 32 bytes IOs: - no alloc (4.18-rc7 request cache): 65.4k req/s - non-power of two alloc, no patch: 61.6k req/s - power of two alloc, no patch: 62.2k req/s - non-power of two alloc, with patch: 64.7k req/s - power of two alloc, with patch: 65.1k req/s Link: http://lkml.kernel.org/r/1532943263-24378-2-git-send-email-asmadeus@codewreck.org Signed-off-by: Dominique Martinet Acked-by: Jun Piao Cc: Matthew Wilcox Cc: Greg Kurz Signed-off-by: Sasha Levin

9p: embed fcall in req to round down buffer allocs

2019-07-03T11:14:42Z

[ Upstream commit 523adb6cc10b48655c0abe556505240741425b49 ] 'msize' is often a power of two, or at least page-aligned, so avoiding an overhead of two dozen bytes for each allocation will help the allocator do its work and reduce memory fragmentation. Link: http://lkml.kernel.org/r/1533825236-22896-1-git-send-email-asmadeus@codewreck.org Suggested-by: Matthew Wilcox Signed-off-by: Dominique Martinet Reviewed-by: Greg Kurz Acked-by: Jun Piao Cc: Matthew Wilcox Signed-off-by: Sasha Levin

9p: Use a slab for allocating requests

2019-07-03T11:14:41Z

[ Upstream commit 996d5b4db4b191f2676cf8775565cab8a5e2753b ] Replace the custom batch allocation with a slab. Use an IDR to store pointers to the active requests instead of an array. We don't try to handle P9_NOTAG specially; the IDR will happily shrink all the way back once the TVERSION call has completed. Link: http://lkml.kernel.org/r/20180711210225.19730-6-willy@infradead.org Signed-off-by: Matthew Wilcox Cc: Eric Van Hensbergen Cc: Ron Minnich Cc: Latchesar Ionkov Signed-off-by: Dominique Martinet Signed-off-by: Sasha Levin