- 14 Mar, 2019 40 commits
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Taehee Yoo authored
BugLink: https://bugs.launchpad.net/bugs/1818806 commit 5d407b07 upstream. A kernel crash occurrs when defragmented packet is fragmented in ip_do_fragment(). In defragment routine, skb_orphan() is called and skb->ip_defrag_offset is set. but skb->sk and skb->ip_defrag_offset are same union member. so that frag->sk is not NULL. Hence crash occurrs in skb->sk check routine in ip_do_fragment() when defragmented packet is fragmented. test commands: %iptables -t nat -I POSTROUTING -j MASQUERADE %hping3 192.168.4.2 -s 1000 -p 2000 -d 60000 splat looks like: [ 261.069429] kernel BUG at net/ipv4/ip_output.c:636! [ 261.075753] invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN PTI [ 261.083854] CPU: 1 PID: 1349 Comm: hping3 Not tainted 4.19.0-rc2+ #3 [ 261.100977] RIP: 0010:ip_do_fragment+0x1613/0x2600 [ 261.106945] Code: e8 e2 38 e3 fe 4c 8b 44 24 18 48 8b 74 24 08 e9 92 f6 ff ff 80 3c 02 00 0f 85 da 07 00 00 48 8b b5 d0 00 00 00 e9 25 f6 ff ff <0f> 0b 0f 0b 44 8b 54 24 58 4c 8b 4c 24 18 4c 8b 5c 24 60 4c 8b 6c [ 261.127015] RSP: 0018:ffff8801031cf2c0 EFLAGS: 00010202 [ 261.134156] RAX: 1ffff1002297537b RBX: ffffed0020639e6e RCX: 0000000000000004 [ 261.142156] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff880114ba9bd8 [ 261.150157] RBP: ffff880114ba8a40 R08: ffffed0022975395 R09: ffffed0022975395 [ 261.158157] R10: 0000000000000001 R11: ffffed0022975394 R12: ffff880114ba9ca4 [ 261.166159] R13: 0000000000000010 R14: ffff880114ba9bc0 R15: dffffc0000000000 [ 261.174169] FS: 00007fbae2199700(0000) GS:ffff88011b400000(0000) knlGS:0000000000000000 [ 261.183012] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 261.189013] CR2: 00005579244fe000 CR3: 0000000119bf4000 CR4: 00000000001006e0 [ 261.198158] Call Trace: [ 261.199018] ? dst_output+0x180/0x180 [ 261.205011] ? save_trace+0x300/0x300 [ 261.209018] ? ip_copy_metadata+0xb00/0xb00 [ 261.213034] ? sched_clock_local+0xd4/0x140 [ 261.218158] ? kill_l4proto+0x120/0x120 [nf_conntrack] [ 261.223014] ? rt_cpu_seq_stop+0x10/0x10 [ 261.227014] ? find_held_lock+0x39/0x1c0 [ 261.233008] ip_finish_output+0x51d/0xb50 [ 261.237006] ? ip_fragment.constprop.56+0x220/0x220 [ 261.243011] ? nf_ct_l4proto_register_one+0x5b0/0x5b0 [nf_conntrack] [ 261.250152] ? rcu_is_watching+0x77/0x120 [ 261.255010] ? nf_nat_ipv4_out+0x1e/0x2b0 [nf_nat_ipv4] [ 261.261033] ? nf_hook_slow+0xb1/0x160 [ 261.265007] ip_output+0x1c7/0x710 [ 261.269005] ? ip_mc_output+0x13f0/0x13f0 [ 261.273002] ? __local_bh_enable_ip+0xe9/0x1b0 [ 261.278152] ? ip_fragment.constprop.56+0x220/0x220 [ 261.282996] ? nf_hook_slow+0xb1/0x160 [ 261.287007] raw_sendmsg+0x21f9/0x4420 [ 261.291008] ? dst_output+0x180/0x180 [ 261.297003] ? sched_clock_cpu+0x126/0x170 [ 261.301003] ? find_held_lock+0x39/0x1c0 [ 261.306155] ? stop_critical_timings+0x420/0x420 [ 261.311004] ? check_flags.part.36+0x450/0x450 [ 261.315005] ? _raw_spin_unlock_irq+0x29/0x40 [ 261.320995] ? _raw_spin_unlock_irq+0x29/0x40 [ 261.326142] ? cyc2ns_read_end+0x10/0x10 [ 261.330139] ? raw_bind+0x280/0x280 [ 261.334138] ? sched_clock_cpu+0x126/0x170 [ 261.338995] ? check_flags.part.36+0x450/0x450 [ 261.342991] ? __lock_acquire+0x4500/0x4500 [ 261.348994] ? inet_sendmsg+0x11c/0x500 [ 261.352989] ? dst_output+0x180/0x180 [ 261.357012] inet_sendmsg+0x11c/0x500 [ ... ] v2: - clear skb->sk at reassembly routine.(Eric Dumarzet) Fixes: fa0f5273 ("ip: use rb trees for IP frag queue.") Suggested-by:
Eric Dumazet <edumazet@google.com> Signed-off-by:
Taehee Yoo <ap420073@gmail.com> Reviewed-by:
David S. Miller <davem@davemloft.net> Signed-off-by:
Mao Wenan <maowenan@huawei.com> Signed-off-by:
Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by:
Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by:
Juerg Haefliger <juergh@canonical.com> Signed-off-by:
Khalid Elmously <khalid.elmously@canonical.com>
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Peter Oskolkov authored
BugLink: https://bugs.launchpad.net/bugs/1818806 commit a4fd284a upstream. This patch changes the runtime behavior of IP defrag queue: incoming in-order fragments are added to the end of the current list/"run" of in-order fragments at the tail. On some workloads, UDP stream performance is substantially improved: RX: ./udp_stream -F 10 -T 2 -l 60 TX: ./udp_stream -c -H <host> -F 10 -T 5 -l 60 with this patchset applied on a 10Gbps receiver: throughput=9524.18 throughput_units=Mbit/s upstream (net-next): throughput=4608.93 throughput_units=Mbit/s Reported-by:
Willem de Bruijn <willemb@google.com> Signed-off-by:
Peter Oskolkov <posk@google.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Florian Westphal <fw@strlen.de> Signed-off-by:
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Peter Oskolkov authored
BugLink: https://bugs.launchpad.net/bugs/1818806 commit 353c9cb3 upstream. This patch introduces several helper functions/macros that will be used in the follow-up patch. No runtime changes yet. The new logic (fully implemented in the second patch) is as follows: * Nodes in the rb-tree will now contain not single fragments, but lists of consecutive fragments ("runs"). * At each point in time, the current "active" run at the tail is maintained/tracked. Fragments that arrive in-order, adjacent to the previous tail fragment, are added to this tail run without triggering the re-balancing of the rb-tree. * If a fragment arrives out of order with the offset _before_ the tail run, it is inserted into the rb-tree as a single fragment. * If a fragment arrives after the current tail fragment (with a gap), it starts a new "tail" run, as is inserted into the rb-tree at the end as the head of the new run. skb->cb is used to store additional information needed here (suggested by Eric Dumazet). Reported-by:
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Peter Oskolkov authored
BugLink: https://bugs.launchpad.net/bugs/1818806 commit fa0f5273 upstream. Similar to TCP OOO RX queue, it makes sense to use rb trees to store IP fragments, so that OOO fragments are inserted faster. Tested: - a follow-up patch contains a rather comprehensive ip defrag self-test (functional) - ran neper `udp_stream -c -H <host> -F 100 -l 300 -T 20`: netstat --statistics Ip: 282078937 total packets received 0 forwarded 0 incoming packets discarded 946760 incoming packets delivered 18743456 requests sent out 101 fragments dropped after timeout 282077129 reassemblies required 944952 packets reassembled ok 262734239 packet reassembles failed (The numbers/stats above are somewhat better re: reassemblies vs a kernel without this patchset. More comprehensive performance testing TBD). Reported-by:
Jann Horn <jannh@google.com> Reported-by:
Juha-Matti Tilli <juha-matti.tilli@iki.fi> Suggested-by:
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Eric Dumazet authored
BugLink: https://bugs.launchpad.net/bugs/1818806 commit 88078d98 upstream. After working on IP defragmentation lately, I found that some large packets defeat CHECKSUM_COMPLETE optimization because of NIC adding zero paddings on the last (small) fragment. While removing the padding with pskb_trim_rcsum(), we set skb->ip_summed to CHECKSUM_NONE, forcing a full csum validation, even if all prior fragments had CHECKSUM_COMPLETE set. We can instead compute the checksum of the part we are trimming, usually smaller than the part we keep. Signed-off-by:
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Florian Westphal authored
BugLink: https://bugs.launchpad.net/bugs/1818806 commit 0ed4229b upstream. don't bother with pathological cases, they only waste cycles. IPv6 requires a minimum MTU of 1280 so we should never see fragments smaller than this (except last frag). v3: don't use awkward "-offset + len" v2: drop IPv4 part, which added same check w. IPV4_MIN_MTU (68). There were concerns that there could be even smaller frags generated by intermediate nodes, e.g. on radio networks. Cc: Peter Oskolkov <posk@google.com> Cc: Eric Dumazet <edumazet@google.com> Signed-off-by:
Florian Westphal <fw@strlen.de> Signed-off-by:
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Peter Oskolkov authored
BugLink: https://bugs.launchpad.net/bugs/1818806 commit 385114de upstream. Tested: see the next patch is the series. Suggested-by:
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Peter Oskolkov authored
BugLink: https://bugs.launchpad.net/bugs/1818806 commit 7969e5c4 upstream. This behavior is required in IPv6, and there is little need to tolerate overlapping fragments in IPv4. This change simplifies the code and eliminates potential DDoS attack vectors. Tested: ran ip_defrag selftest (not yet available uptream). Suggested-by:
Stephen Hemminger <stephen@networkplumber.org> Signed-off-by:
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Eric Dumazet authored
BugLink: https://bugs.launchpad.net/bugs/1818806 commit 3d234012 upstream. Giving an integer to proc_doulongvec_minmax() is dangerous on 64bit arches, since linker might place next to it a non zero value preventing a change to ip6frag_low_thresh. ip6frag_low_thresh is not used anymore in the kernel, but we do not want to prematuraly break user scripts wanting to change it. Since specifying a minimal value of 0 for proc_doulongvec_minmax() is moot, let's remove these zero values in all defrag units. Fixes: 6e00f7dd ("ipv6: frags: fix /proc/sys/net/ipv6/ip6frag_low_thresh") Signed-off-by:
Maciej Żenczykowski <maze@google.com> Signed-off-by:
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Eric Dumazet authored
BugLink: https://bugs.launchpad.net/bugs/1818806 commit bf663371 upstream. ip_defrag uses skb->cb[] to store the fragment offset, and unfortunately this integer is currently in a different cache line than skb->next, meaning that we use two cache lines per skb when finding the insertion point. By aliasing skb->ip_defrag_offset and skb->dev, we pack all the fields in a single cache line and save precious memory bandwidth. Note that after the fast path added by Changli Gao in commit d6bebca9 ("fragment: add fast path for in-order fragments") this change wont help the fast path, since we still need to access prev->len (2nd cache line), but will show great benefits when slow path is entered, since we perform a linear scan of a potentially long list. Also, note that this potential long list is an attack vector, we might consider also using an rb-tree there eventually. Signed-off-by:
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Eric Dumazet authored
BugLink: https://bugs.launchpad.net/bugs/1818806 commit c2615cf5 upstream. Put the read-mostly fields in a separate cache line at the beginning of struct netns_frags, to reduce false sharing noticed in inet_frag_kill() Signed-off-by:
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Eric Dumazet authored
BugLink: https://bugs.launchpad.net/bugs/1818806 commit e5d672a0 upstream. While under frags DDOS I noticed unfortunate false sharing between @nelems and @params.automatic_shrinking Move @nelems at the end of struct rhashtable so that first cache line is shared between all cpus, because almost never dirtied. Signed-off-by:
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Eric Dumazet authored
BugLink: https://bugs.launchpad.net/bugs/1818806 commit 05c0b86b upstream. Make it similar to IPv4 ip_expire(), and release the lock before calling icmp functions. Signed-off-by:
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Eric Dumazet authored
BugLink: https://bugs.launchpad.net/bugs/1818806 commit 1eec5d56 upstream. An skb_clone() was added in commit ec4fbd64 ("inet: frag: release spinlock before calling icmp_send()") While fixing the bug at that time, it also added a very high cost for DDOS frags, as the ICMP rate limit is applied after this expensive operation (skb_clone() + consume_skb(), implying memory allocations, copy, and freeing) We can use skb_get(head) here, all we want is to make sure skb wont be freed by another cpu. Signed-off-by:
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Eric Dumazet authored
BugLink: https://bugs.launchpad.net/bugs/1818806 commit 3e67f106 upstream. Some users are willing to provision huge amounts of memory to be able to perform reassembly reasonnably well under pressure. Current memory tracking is using one atomic_t and integers. Switch to atomic_long_t so that 64bit arches can use more than 2GB, without any cost for 32bit arches. Note that this patch avoids an overflow error, if high_thresh was set to ~2GB, since this test in inet_frag_alloc() was never true : if (... || frag_mem_limit(nf) > nf->high_thresh) Tested: $ echo 16000000000 >/proc/sys/net/ipv4/ipfrag_high_thresh <frag DDOS> $ grep FRAG /proc/net/sockstat FRAG: inuse 14705885 memory 16000002880 $ nstat -n ; sleep 1 ; nstat | grep Reas IpReasmReqds 3317150 0.0 IpReasmFails 3317112 0.0 Signed-off-by:
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Eric Dumazet authored
BugLink: https://bugs.launchpad.net/bugs/1818806 commit 2d44ed22 upstream. This function is obsolete, after rhashtable addition to inet defrag. Signed-off-by:
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Eric Dumazet authored
BugLink: https://bugs.launchpad.net/bugs/1818806 commit 399d1404 upstream. This refactors ip_expire() since one indentation level is removed. Note: in the future, we should try hard to avoid the skb_clone() since this is a serious performance cost. Under DDOS, the ICMP message wont be sent because of rate limits. Fact that ip6_expire_frag_queue() does not use skb_clone() is disturbing too. Presumably IPv6 should have the same issue than the one we fixed in commit ec4fbd64 ("inet: frag: release spinlock before calling icmp_send()") Signed-off-by:
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Eric Dumazet authored
BugLink: https://bugs.launchpad.net/bugs/1818806 commit 6befe4a7 upstream. Remove sum_frag_mem_limit(), ip_frag_mem() & ip6_frag_mem() Also since we use rhashtable we can bring back the number of fragments in "grep FRAG /proc/net/sockstat /proc/net/sockstat6" that was removed in commit 434d3054 ("inet: frag: don't account number of fragment queues") Signed-off-by:
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Paolo Abeni authored
BugLink: https://bugs.launchpad.net/bugs/1818806 commit f6f2a4a2 upstream. Setting the low threshold to 0 has no effect on frags allocation, we need to clear high_thresh instead. The code was pre-existent to commit 648700f7 ("inet: frags: use rhashtables for reassembly units"), but before the above, such assignment had a different role: prevent concurrent eviction from the worker and the netns cleanup helper. Fixes: 648700f7 ("inet: frags: use rhashtables for reassembly units") Signed-off-by:
Paolo Abeni <pabeni@redhat.com> Signed-off-by:
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Alexander Aring authored
BugLink: https://bugs.launchpad.net/bugs/1818806 commit f18fa5de upstream. This patch initialize stack variables which are used in frag_lowpan_compare_key to zero. In my case there are padding bytes in the structures ieee802154_addr as well in frag_lowpan_compare_key. Otherwise the key variable contains random bytes. The result is that a compare of two keys by memcmp works incorrect. Fixes: 648700f7 ("inet: frags: use rhashtables for reassembly units") Signed-off-by:
Alexander Aring <aring@mojatatu.com> Reported-by:
Stefan Schmidt <stefan@osg.samsung.com> Signed-off-by:
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Eric Dumazet authored
BugLink: https://bugs.launchpad.net/bugs/1818806 commit 648700f7 upstream. Some applications still rely on IP fragmentation, and to be fair linux reassembly unit is not working under any serious load. It uses static hash tables of 1024 buckets, and up to 128 items per bucket (!!!) A work queue is supposed to garbage collect items when host is under memory pressure, and doing a hash rebuild, changing seed used in hash computations. This work queue blocks softirqs for up to 25 ms when doing a hash rebuild, occurring every 5 seconds if host is under fire. Then there is the problem of sharing this hash table for all netns. It is time to switch to rhashtables, and allocate one of them per netns to speedup netns dismantle, since this is a critical metric these days. Lookup is now using RCU. A followup patch will even remove the refcount hold/release left from prior implementation and save a couple of atomic operations. Before this patch, 16 cpus (16 RX queue NIC) could not handle more than 1 Mpps frags DDOS. After the patch, I reach 9 Mpps without any tuning, and can use up to 2GB of storage for the fragments (exact number depends on frags being evicted after timeout) $ grep FRAG /proc/net/sockstat FRAG: inuse 1966916 memory 2140004608 A followup patch will change the limits for 64bit arches. Signed-off-by:
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Eric Dumazet authored
BugLink: https://bugs.launchpad.net/bugs/1818806 commit ae6da1f5 upstream. Rehashing and destroying large hash table takes a lot of time, and happens in process context. It is safe to add cond_resched() in rhashtable_rehash_table() and rhashtable_free_and_destroy() Signed-off-by:
Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by:
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Ben Hutchings authored
BugLink: https://bugs.launchpad.net/bugs/1818806 Extracted from commit ca26893f "rhashtable: Add rhlist interface". Cc: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by:
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Pablo Neira Ayuso authored
BugLink: https://bugs.launchpad.net/bugs/1818806 commit 5ca8cc5b upstream. This patch modifies __rhashtable_insert_fast() so it returns the existing object that clashes with the one that you want to insert. In case the object is successfully inserted, NULL is returned. Otherwise, you get an error via ERR_PTR(). This patch adapts the existing callers of __rhashtable_insert_fast() so they handle this new logic, and it adds a new rhashtable_lookup_get_insert_key() interface to fetch this existing object. nf_tables needs this change to improve handling of EEXIST cases via honoring the NLM_F_EXCL flag and by checking if the data part of the mapping matches what we have. Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Thomas Graf <tgraf@suug.ch> Signed-off-by:
Pablo Neira Ayuso <pablo@netfilter.org> Acked-by:
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Eric Dumazet authored
BugLink: https://bugs.launchpad.net/bugs/1818806 commit 807f1844 upstream. We want to call lowpan_net_frag_init() earlier. Similar to commit "inet: frags: refactor ipv6_frag_init()" This is a prereq to "inet: frags: use rhashtables for reassembly units" Signed-off-by:
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Eric Dumazet authored
BugLink: https://bugs.launchpad.net/bugs/1818806 commit 5b975bab upstream. We want to call inet_frags_init() earlier. This is a prereq to "inet: frags: use rhashtables for reassembly units" Signed-off-by:
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Eric Dumazet authored
BugLink: https://bugs.launchpad.net/bugs/1818806 commit 483a6e4f upstream. We need to call inet_frags_init() before register_pernet_subsys(), as a prereq for following patch ("inet: frags: use rhashtables for reassembly units") Signed-off-by:
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Eric Dumazet authored
BugLink: https://bugs.launchpad.net/bugs/1818806 commit 093ba729 upstream. In order to simplify the API, add a pointer to struct inet_frags. This will allow us to make things less complex. These functions no longer have a struct inet_frags parameter : inet_frag_destroy(struct inet_frag_queue *q /*, struct inet_frags *f */) inet_frag_put(struct inet_frag_queue *q /*, struct inet_frags *f */) inet_frag_kill(struct inet_frag_queue *q /*, struct inet_frags *f */) inet_frags_exit_net(struct netns_frags *nf /*, struct inet_frags *f */) ip6_expire_frag_queue(struct net *net, struct frag_queue *fq) Signed-off-by:
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Eric Dumazet authored
BugLink: https://bugs.launchpad.net/bugs/1818806 commit 787bea77 upstream. We will soon initialize one rhashtable per struct netns_frags in inet_frags_init_net(). This patch changes the return value to eventually propagate an error. Signed-off-by:
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Greg Kroah-Hartman authored
BugLink: https://bugs.launchpad.net/bugs/1818803Signed-off-by:
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Dave Chinner authored
BugLink: https://bugs.launchpad.net/bugs/1818803 commit 79f546a6 upstream. We recently had an oops reported on a 4.14 kernel in xfs_reclaim_inodes_count() where sb->s_fs_info pointed to garbage and so the m_perag_tree lookup walked into lala land. It produces an oops down this path during the failed mount: radix_tree_gang_lookup_tag+0xc4/0x130 xfs_perag_get_tag+0x37/0xf0 xfs_reclaim_inodes_count+0x32/0x40 xfs_fs_nr_cached_objects+0x11/0x20 super_cache_count+0x35/0xc0 shrink_slab.part.66+0xb1/0x370 shrink_node+0x7e/0x1a0 try_to_free_pages+0x199/0x470 __alloc_pages_slowpath+0x3a1/0xd20 __alloc_pages_nodemask+0x1c3/0x200 cache_grow_begin+0x20b/0x2e0 fallback_alloc+0x160/0x200 kmem_cache_alloc+0x111/0x4e0 The problem is that the superblock shrinker is running before the filesystem structures it depends on have been fully set up. i.e. the shrinker is registered in sget(), before ->fill_super() has been called, and the shrinker can call into the filesystem before fill_super() does it's setup work. Essentially we are exposed to both use-after-free and use-before-initialisation bugs here. To fix this, add a check for the SB_BORN flag in super_cache_count. In general, this flag is not set until ->fs_mount() completes successfully, so we know that it is set after the filesystem setup has completed. This matches the trylock_super() behaviour which will not let super_cache_scan() run if SB_BORN is not set, and hence will not allow the superblock shrinker from entering the filesystem while it is being set up or after it has failed setup and is being torn down. Cc: stable@kernel.org Signed-Off-By:
Dave Chinner <dchinner@redhat.com> Signed-off-by:
Al Viro <viro@zeniv.linux.org.uk> Signed-off-by:
Aaron Lu <aaron.lu@linux.alibaba.com> Signed-off-by:
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David Hildenbrand authored
BugLink: https://bugs.launchpad.net/bugs/1818803 commit e0a352fa upstream. We had a race in the old balloon compaction code before b1123ea6 ("mm: balloon: use general non-lru movable page feature") refactored it that became visible after backporting 195a8c43 ("virtio-balloon: deflate via a page list") without the refactoring. The bug existed from commit d6d86c0a ("mm/balloon_compaction: redesign ballooned pages management") till b1123ea6 ("mm: balloon: use general non-lru movable page feature"). d6d86c0a ("mm/balloon_compaction: redesign ballooned pages management") was backported to 3.12, so the broken kernels are stable kernels [3.12 - 4.7]. There was a subtle race between dropping the page lock of the newpage in __unmap_and_move() and checking for __is_movable_balloon_page(newpage). Just after dropping this page lock, virtio-balloon could go ahead and deflate the newpage, effectively dequeueing it and clearing PageBalloon, in turn making __is_movable_balloon_page(newpage) fail. This resulted in dropping the reference of the newpage via putback_lru_page(newpage) instead of put_page(newpage), leading to page->lru getting modified and a !LRU page ending up in the LRU lists. With 195a8c43 ("virtio-balloon: deflate via a page list") backported, one would suddenly get corrupted lists in release_pages_balloon(): - WARNING: CPU: 13 PID: 6586 at lib/list_debug.c:59 __list_del_entry+0xa1/0xd0 - list_del corruption. prev->next should be ffffe253961090a0, but was dead000000000100 Nowadays this race is no longer possible, but it is hidden behind very ugly handling of __ClearPageMovable() and __PageMovable(). __ClearPageMovable() will not make __PageMovable() fail, only PageMovable(). So the new check (__PageMovable(newpage)) will still hold even after newpage was dequeued by virtio-balloon. If anybody would ever change that special handling, the BUG would be introduced again. So instead, make it explicit and use the information of the original isolated page before migration. This patch can be backported fairly easy to stable kernels (in contrast to the refactoring). Link: http://lkml.kernel.org/r/20190129233217.10747-1-david@redhat.com Fixes: d6d86c0a ("mm/balloon_compaction: redesign ballooned pages management") Signed-off-by:
David Hildenbrand <david@redhat.com> Reported-by:
Vratislav Bendel <vbendel@redhat.com> Acked-by:
Michal Hocko <mhocko@suse.com> Acked-by:
Rafael Aquini <aquini@redhat.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Jan Kara <jack@suse.cz> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Dominik Brodowski <linux@dominikbrodowski.net> Cc: Matthew Wilcox <willy@infradead.org> Cc: Vratislav Bendel <vbendel@redhat.com> Cc: Rafael Aquini <aquini@redhat.com> Cc: Konstantin Khlebnikov <k.khlebnikov@samsung.com> Cc: Minchan Kim <minchan@kernel.org> Cc: <stable@vger.kernel.org> [3.12 - 4.7] Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by:
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Benjamin Herrenschmidt authored
BugLink: https://bugs.launchpad.net/bugs/1818803 commit 726e4109 upstream. For devices with a class, we create a "glue" directory between the parent device and the new device with the class name. This directory is never "explicitely" removed when empty however, this is left to the implicit sysfs removal done by kobject_release() when the object loses its last reference via kobject_put(). This is problematic because as long as it's not been removed from sysfs, it is still present in the class kset and in sysfs directory structure. The presence in the class kset exposes a use after free bug fixed by the previous patch, but the presence in sysfs means that until the kobject is released, which can take a while (especially with kobject debugging), any attempt at re-creating such as binding a new device for that class/parent pair, will result in a sysfs duplicate file name error. This fixes it by instead doing an explicit kobject_del() when the glue dir is empty, by keeping track of the number of child devices of the gluedir. This is made easy by the fact that all glue dir operations are done with a global mutex, and there's already a function (cleanup_glue_dir) called in all the right places taking that mutex that can be enhanced for this. It appears that this was in fact the intent of the function, but the implementation was wrong. Signed-off-by:
Benjamin Herrenschmidt <benh@kernel.crashing.org> Acked-by:
Zubin Mithra <zsm@chromium.org> Cc: Guenter Roeck <groeck@google.com> Signed-off-by:
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Paulo Alcantara authored
BugLink: https://bugs.launchpad.net/bugs/1818803 commit 28eb24ff upstream. In case a hostname resolves to a different IP address (e.g. long running mounts), make sure to resolve it every time prior to calling generic_ip_connect() in reconnect. Suggested-by:
Steve French <stfrench@microsoft.com> Signed-off-by:
Paulo Alcantara <palcantara@suse.de> Signed-off-by:
Pavel Shilovsky <pshilov@microsoft.com> Signed-off-by:
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Shakeel Butt authored
BugLink: https://bugs.launchpad.net/bugs/1818803 commit cefc7ef3 upstream. Syzbot instance running on upstream kernel found a use-after-free bug in oom_kill_process. On further inspection it seems like the process selected to be oom-killed has exited even before reaching read_lock(&tasklist_lock) in oom_kill_process(). More specifically the tsk->usage is 1 which is due to get_task_struct() in oom_evaluate_task() and the put_task_struct within for_each_thread() frees the tsk and for_each_thread() tries to access the tsk. The easiest fix is to do get/put across the for_each_thread() on the selected task. Now the next question is should we continue with the oom-kill as the previously selected task has exited? However before adding more complexity and heuristics, let's answer why we even look at the children of oom-kill selected task? The select_bad_process() has already selected the worst process in the system/memcg. Due to race, the selected process might not be the worst at the kill time but does that matter? The userspace can use the oom_score_adj interface to prefer children to be killed before the parent. I looked at the history but it seems like this is there before git history. Link: http://lkml.kernel.org/r/20190121215850.221745-1-shakeelb@google.com Reported-by: syzbot+7fbbfa368521945f0e3d@syzkaller.appspotmail.com Fixes: 6b0c81b3 ("mm, oom: reduce dependency on tasklist_lock") Signed-off-by:
Shakeel Butt <shakeelb@google.com> Reviewed-by:
Roman Gushchin <guro@fb.com> Acked-by:
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Andrei Vagin authored
BugLink: https://bugs.launchpad.net/bugs/1818803 commit 8fb335e0 upstream. Currently, exit_ptrace() adds all ptraced tasks in a dead list, then zap_pid_ns_processes() waits on all tasks in a current pidns, and only then are tasks from the dead list released. zap_pid_ns_processes() can get stuck on waiting tasks from the dead list. In this case, we will have one unkillable process with one or more dead children. Thanks to Oleg for the advice to release tasks in find_child_reaper(). Link: http://lkml.kernel.org/r/20190110175200.12442-1-avagin@gmail.com Fixes: 7c8bd232 ("exit: ptrace: shift "reap dead" code from exit_ptrace() to forget_original_parent()") Signed-off-by:
Andrei Vagin <avagin@gmail.com> Signed-off-by:
Oleg Nesterov <oleg@redhat.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: <stable@vger.kernel.org> Signed-off-by:
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Stefan Wahren authored
BugLink: https://bugs.launchpad.net/bugs/1818803 commit 2bd44dad upstream. We need to handle mmc_of_parse() errors during probe. This finally fixes the wifi regression on Raspberry Pi 3 series. In error case the wifi chip was permanently in reset because of the power sequence depending on the deferred probe of the GPIO expander. Fixes: b580c52d ("mmc: sdhci-iproc: add IPROC SDHCI driver") Cc: stable@vger.kernel.org Signed-off-by:
Stefan Wahren <stefan.wahren@i2se.com> Acked-by:
Adrian Hunter <adrian.hunter@intel.com> Signed-off-by:
Ulf Hansson <ulf.hansson@linaro.org> Signed-off-by:
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João Paulo Rechi Vita authored
BugLink: https://bugs.launchpad.net/bugs/1818803 [ Upstream commit 71b12bea ] According to Asus firmware engineers, the meaning of these codes is only to notify the OS that the screen brightness has been turned on/off by the EC. This does not match the meaning of KEY_DISPLAYTOGGLE / KEY_DISPLAY_OFF, where userspace is expected to change the display brightness. Signed-off-by:
João Paulo Rechi Vita <jprvita@endlessm.com> Signed-off-by:
Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by:
Sasha Levin <sashal@kernel.org> Signed-off-by:
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João Paulo Rechi Vita authored
BugLink: https://bugs.launchpad.net/bugs/1818803 [ Upstream commit b3f2f379 ] When the OS registers to handle events from the display off hotkey the EC will send a notification with 0x35 for every key press, independent of the backlight state. The behavior of this key on Windows, with the ATKACPI driver from Asus installed, is turning off the backlight of all connected displays with a fading effect, and any cursor input or key press turning the backlight back on. The key press or cursor input that wakes up the display is also passed through to the application under the cursor or under focus. The key that matches this behavior the closest is KEY_SCREENLOCK. Signed-off-by:
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Andreas Gruenbacher authored
BugLink: https://bugs.launchpad.net/bugs/1818803 commit e74c98ca upstream. This reverts commit 2d29f6b9. It turns out that the fix can lead to a ~20 percent performance regression in initial writes to the page cache according to iozone. Let's revert this for now to have more time for a proper fix. Cc: stable@vger.kernel.org # v3.13+ Signed-off-by:
Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by:
Bob Peterson <rpeterso@redhat.com> Signed-off-by:
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