kernel/linux.git/include/linux, branch v4.20.10

cpu/hotplug: Fix "SMT disabled by BIOS" detection for KVM

2019-02-12T19:02:37+00:00

commit b284909abad48b07d3071a9fc9b5692b3e64914b upstream. With the following commit: 73d5e2b47264 ("cpu/hotplug: detect SMT disabled by BIOS") ... the hotplug code attempted to detect when SMT was disabled by BIOS, in which case it reported SMT as permanently disabled. However, that code broke a virt hotplug scenario, where the guest is booted with only primary CPU threads, and a sibling is brought online later. The problem is that there doesn't seem to be a way to reliably distinguish between the HW "SMT disabled by BIOS" case and the virt "sibling not yet brought online" case. So the above-mentioned commit was a bit misguided, as it permanently disabled SMT for both cases, preventing future virt sibling hotplugs. Going back and reviewing the original problems which were attempted to be solved by that commit, when SMT was disabled in BIOS: 1) /sys/devices/system/cpu/smt/control showed "on" instead of "notsupported"; and 2) vmx_vm_init() was incorrectly showing the L1TF_MSG_SMT warning. I'd propose that we instead consider #1 above to not actually be a problem. Because, at least in the virt case, it's possible that SMT wasn't disabled by BIOS and a sibling thread could be brought online later. So it makes sense to just always default the smt control to "on" to allow for that possibility (assuming cpuid indicates that the CPU supports SMT). The real problem is #2, which has a simple fix: change vmx_vm_init() to query the actual current SMT state -- i.e., whether any siblings are currently online -- instead of looking at the SMT "control" sysfs value. So fix it by: a) reverting the original "fix" and its followup fix: 73d5e2b47264 ("cpu/hotplug: detect SMT disabled by BIOS") bc2d8d262cba ("cpu/hotplug: Fix SMT supported evaluation") and b) changing vmx_vm_init() to query the actual current SMT state -- instead of the sysfs control value -- to determine whether the L1TF warning is needed. This also requires the 'sched_smt_present' variable to exported, instead of 'cpu_smt_control'. Fixes: 73d5e2b47264 ("cpu/hotplug: detect SMT disabled by BIOS") Reported-by: Igor Mammedov Signed-off-by: Josh Poimboeuf Signed-off-by: Thomas Gleixner Cc: Joe Mario Cc: Jiri Kosina Cc: Peter Zijlstra Cc: kvm@vger.kernel.org Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/e3a85d585da28cc333ecbc1e78ee9216e6da9396.1548794349.git.jpoimboe@redhat.com Signed-off-by: Greg Kroah-Hartman

HID: debug: fix the ring buffer implementation

2019-02-12T19:02:36+00:00

commit 13054abbaa4f1fd4e6f3b4b63439ec033b4c8035 upstream. Ring buffer implementation in hid_debug_event() and hid_debug_events_read() is strange allowing lost or corrupted data. After commit 717adfdaf147 ("HID: debug: check length before copy_to_user()") it is possible to enter an infinite loop in hid_debug_events_read() by providing 0 as count, this locks up a system. Fix this by rewriting the ring buffer implementation with kfifo and simplify the code. This fixes CVE-2019-3819. v2: fix an execution logic and add a comment v3: use __set_current_state() instead of set_current_state() Link: https://bugzilla.redhat.com/show_bug.cgi?id=1669187 Cc: stable@vger.kernel.org # v4.18+ Fixes: cd667ce24796 ("HID: use debugfs for events/reports dumping") Fixes: 717adfdaf147 ("HID: debug: check length before copy_to_user()") Signed-off-by: Vladis Dronov Reviewed-by: Oleg Nesterov Signed-off-by: Benjamin Tissoires Signed-off-by: Greg Kroah-Hartman

kvm: Change offset in kvm_write_guest_offset_cached to unsigned

2019-02-12T19:02:27+00:00

[ Upstream commit 7a86dab8cf2f0fdf508f3555dddfc236623bff60 ] Since the offset is added directly to the hva from the gfn_to_hva_cache, a negative offset could result in an out of bounds write. The existing BUG_ON only checks for addresses beyond the end of the gfn_to_hva_cache, not for addresses before the start of the gfn_to_hva_cache. Note that all current call sites have non-negative offsets. Fixes: 4ec6e8636256 ("kvm: Introduce kvm_write_guest_offset_cached()") Reported-by: Cfir Cohen Signed-off-by: Jim Mattson Reviewed-by: Cfir Cohen Reviewed-by: Peter Shier Reviewed-by: Krish Sadhukhan Reviewed-by: Sean Christopherson Signed-off-by: Radim Krčmář Signed-off-by: Sasha Levin

bpf: sk_msg, fix socket data_ready events

2019-02-12T19:02:26+00:00

[ Upstream commit 552de91068828daef50a227a665068cf8dde835e ] When a skb verdict program is in-use and either another BPF program redirects to that socket or the new SK_PASS support is used the data_ready callback does not wake up application. Instead because the stream parser/verdict is using the sk data_ready callback we wake up the stream parser/verdict block. Fix this by adding a helper to check if the stream parser block is enabled on the sk and if so call the saved pointer which is the upper layers wake up function. This fixes application stalls observed when an application is waiting for data in a blocking read(). Fixes: d829e9c4112b ("tls: convert to generic sk_msg interface") Signed-off-by: John Fastabend Signed-off-by: Daniel Borkmann Signed-off-by: Sasha Levin

drbd: Avoid Clang warning about pointless switch statment

2019-02-12T19:02:25+00:00

[ Upstream commit a52c5a16cf19d8a85831bb1b915a221dd4ffae3c ] There are several warnings from Clang about no case statement matching the constant 0: In file included from drivers/block/drbd/drbd_receiver.c:48: In file included from drivers/block/drbd/drbd_int.h:48: In file included from ./include/linux/drbd_genl_api.h:54: In file included from ./include/linux/genl_magic_struct.h:236: ./include/linux/drbd_genl.h:321:1: warning: no case matching constant switch condition '0' GENL_struct(DRBD_NLA_HELPER, 24, drbd_helper_info, ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ./include/linux/genl_magic_struct.h:220:10: note: expanded from macro 'GENL_struct' switch (0) { ^ Silence this warning by adding a 'case 0:' statement. Additionally, adjust the alignment of the statements in the ct_assert_unique macro to avoid a checkpatch warning. This solution was originally sent by Arnd Bergmann with a default case statement: https://lore.kernel.org/patchwork/patch/756723/ Link: https://github.com/ClangBuiltLinux/linux/issues/43 Suggested-by: Lars Ellenberg Signed-off-by: Nathan Chancellor Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

net/mlx5: EQ, Use the right place to store/read IRQ affinity hint

2019-02-12T19:02:09+00:00

[ Upstream commit 1e86ace4c140fd5a693e266c9b23409358f25381 ] Currently the cpu affinity hint mask for completion EQs is stored and read from the wrong place, since reading and storing is done from the same index, there is no actual issue with that, but internal irq_info for completion EQs stars at MLX5_EQ_VEC_COMP_BASE offset in irq_info array, this patch changes the code to use the correct offset to store and read the IRQ affinity hint. Signed-off-by: Saeed Mahameed Reviewed-by: Leon Romanovsky Reviewed-by: Tariq Toukan Signed-off-by: Leon Romanovsky Signed-off-by: Sasha Levin

gpiolib: Fix possible use after free on label

2019-02-12T19:02:04+00:00

[ Upstream commit 18534df419041e6c1f4b41af56ee7d41f757815c ] gpiod_request_commit() copies the pointer to the label passed as an argument only to be used later. But there's a chance the caller could immediately free the passed string(e.g., local variable). This could trigger a use after free when we use gpio label(e.g., gpiochip_unlock_as_irq(), gpiochip_is_requested()). To be on the safe side: duplicate the string with kstrdup_const() so that if an unaware user passes an address to a stack-allocated buffer, we won't get the arbitrary label. Also fix gpiod_set_consumer_name(). Signed-off-by: Muchun Song Signed-off-by: Linus Walleij Signed-off-by: Sasha Levin

of: overlay: add tests to validate kfrees from overlay removal

2019-02-06T16:27:44+00:00

commit 144552c786925314c1e7cb8f91a71dae1aca8798 upstream. Add checks: - attempted kfree due to refcount reaching zero before overlay is removed - properties linked to an overlay node when the node is removed - node refcount > one during node removal in a changeset destroy, if the node was created by the changeset After applying this patch, several validation warnings will be reported from the devicetree unittest during boot due to pre-existing devicetree bugs. The warnings will be similar to: OF: ERROR: of_node_release(), unexpected properties in /testcase-data/overlay-node/test-bus/test-unittest11 OF: ERROR: memory leak, expected refcount 1 instead of 2, of_node_get()/of_node_put() unbalanced - destroy cset entry: attach overlay node /testcase-data-2/substation@100/ hvac-medium-2 Tested-by: Alan Tull Signed-off-by: Frank Rowand Cc: Guenter Roeck Signed-off-by: Greg Kroah-Hartman

oom, oom_reaper: do not enqueue same task twice

2019-02-06T16:27:44+00:00

commit 9bcdeb51bd7d2ae9fe65ea4d60643d2aeef5bfe3 upstream. Arkadiusz reported that enabling memcg's group oom killing causes strange memcg statistics where there is no task in a memcg despite the number of tasks in that memcg is not 0. It turned out that there is a bug in wake_oom_reaper() which allows enqueuing same task twice which makes impossible to decrease the number of tasks in that memcg due to a refcount leak. This bug existed since the OOM reaper became invokable from task_will_free_mem(current) path in out_of_memory() in Linux 4.7, T1@P1 |T2@P1 |T3@P1 |OOM reaper ----------+----------+----------+------------ # Processing an OOM victim in a different memcg domain. try_charge() mem_cgroup_out_of_memory() mutex_lock(&oom_lock) try_charge() mem_cgroup_out_of_memory() mutex_lock(&oom_lock) try_charge() mem_cgroup_out_of_memory() mutex_lock(&oom_lock) out_of_memory() oom_kill_process(P1) do_send_sig_info(SIGKILL, @P1) mark_oom_victim(T1@P1) wake_oom_reaper(T1@P1) # T1@P1 is enqueued. mutex_unlock(&oom_lock) out_of_memory() mark_oom_victim(T2@P1) wake_oom_reaper(T2@P1) # T2@P1 is enqueued. mutex_unlock(&oom_lock) out_of_memory() mark_oom_victim(T1@P1) wake_oom_reaper(T1@P1) # T1@P1 is enqueued again due to oom_reaper_list == T2@P1 && T1@P1->oom_reaper_list == NULL. mutex_unlock(&oom_lock) # Completed processing an OOM victim in a different memcg domain. spin_lock(&oom_reaper_lock) # T1P1 is dequeued. spin_unlock(&oom_reaper_lock) but memcg's group oom killing made it easier to trigger this bug by calling wake_oom_reaper() on the same task from one out_of_memory() request. Fix this bug using an approach used by commit 855b018325737f76 ("oom, oom_reaper: disable oom_reaper for oom_kill_allocating_task"). As a side effect of this patch, this patch also avoids enqueuing multiple threads sharing memory via task_will_free_mem(current) path. Link: http://lkml.kernel.org/r/e865a044-2c10-9858-f4ef-254bc71d6cc2@i-love.sakura.ne.jp Link: http://lkml.kernel.org/r/5ee34fc6-1485-34f8-8790-903ddabaa809@i-love.sakura.ne.jp Fixes: af8e15cc85a25315 ("oom, oom_reaper: do not enqueue task if it is on the oom_reaper_list head") Signed-off-by: Tetsuo Handa Reported-by: Arkadiusz Miskiewicz Tested-by: Arkadiusz Miskiewicz Acked-by: Michal Hocko Acked-by: Roman Gushchin Cc: Tejun Heo Cc: Aleksa Sarai Cc: Jay Kamat Cc: Johannes Weiner Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

ipvlan, l3mdev: fix broken l3s mode wrt local routes

2019-02-06T16:27:35+00:00

[ Upstream commit d5256083f62e2720f75bb3c5a928a0afe47d6bc3 ] While implementing ipvlan l3 and l3s mode for kubernetes CNI plugin, I ran into the issue that while l3 mode is working fine, l3s mode does not have any connectivity to kube-apiserver and hence all pods end up in Error state as well. The ipvlan master device sits on top of a bond device and hostns traffic to kube-apiserver (also running in hostns) is DNATed from 10.152.183.1:443 to 139.178.29.207:37573 where the latter is the address of the bond0. While in l3 mode, a curl to https://10.152.183.1:443 or to https://139.178.29.207:37573 works fine from hostns, neither of them do in case of l3s. In the latter only a curl to https://127.0.0.1:37573 appeared to work where for local addresses of bond0 I saw kernel suddenly starting to emit ARP requests to query HW address of bond0 which remained unanswered and neighbor entries in INCOMPLETE state. These ARP requests only happen while in l3s. Debugging this further, I found the issue is that l3s mode is piggy- backing on l3 master device, and in this case local routes are using l3mdev_master_dev_rcu(dev) instead of net->loopback_dev as per commit f5a0aab84b74 ("net: ipv4: dst for local input routes should use l3mdev if relevant") and 5f02ce24c269 ("net: l3mdev: Allow the l3mdev to be a loopback"). I found that reverting them back into using the net->loopback_dev fixed ipvlan l3s connectivity and got everything working for the CNI. Now judging from 4fbae7d83c98 ("ipvlan: Introduce l3s mode") and the l3mdev paper in [0] the only sole reason why ipvlan l3s is relying on l3 master device is to get the l3mdev_ip_rcv() receive hook for setting the dst entry of the input route without adding its own ipvlan specific hacks into the receive path, however, any l3 domain semantics beyond just that are breaking l3s operation. Note that ipvlan also has the ability to dynamically switch its internal operation from l3 to l3s for all ports via ipvlan_set_port_mode() at runtime. In any case, l3 vs l3s soley distinguishes itself by 'de-confusing' netfilter through switching skb->dev to ipvlan slave device late in NF_INET_LOCAL_IN before handing the skb to L4. Minimal fix taken here is to add a IFF_L3MDEV_RX_HANDLER flag which, if set from ipvlan setup, gets us only the wanted l3mdev_l3_rcv() hook without any additional l3mdev semantics on top. This should also have minimal impact since dev->priv_flags is already hot in cache. With this set, l3s mode is working fine and I also get things like masquerading pod traffic on the ipvlan master properly working. [0] https://netdevconf.org/1.2/papers/ahern-what-is-l3mdev-paper.pdf Fixes: f5a0aab84b74 ("net: ipv4: dst for local input routes should use l3mdev if relevant") Fixes: 5f02ce24c269 ("net: l3mdev: Allow the l3mdev to be a loopback") Fixes: 4fbae7d83c98 ("ipvlan: Introduce l3s mode") Signed-off-by: Daniel Borkmann Cc: Mahesh Bandewar Cc: David Ahern Cc: Florian Westphal Cc: Martynas Pumputis Acked-by: David Ahern Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman