- 27 Aug, 2015 9 commits
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Julian Anastasov authored
[ Upstream commit 2c17d27c ] Incoming packet should be either in backlog queue or in RCU read-side section. Otherwise, the final sequence of flush_backlog() and synchronize_net() may miss packets that can run without device reference: CPU 1 CPU 2 skb->dev: no reference process_backlog:__skb_dequeue process_backlog:local_irq_enable on_each_cpu for flush_backlog => IPI(hardirq): flush_backlog - packet not found in backlog CPU delayed ... synchronize_net - no ongoing RCU read-side sections netdev_run_todo, rcu_barrier: no ongoing callbacks __netif_receive_skb_core:rcu_read_lock - too late free dev process packet for freed dev Fixes: 6e583ce5 ("net: eliminate refcounting in backlog queue") Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by:
Julian Anastasov <ja@ssi.bg> Signed-off-by:
David S. Miller <davem@davemloft.net> Signed-off-by:
Jiri Slaby <jslaby@suse.cz>
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Julian Anastasov authored
[ Upstream commit e9e4dd32 ] commit 381c759d ("ipv4: Avoid crashing in ip_error") fixes a problem where processed packet comes from device with destroyed inetdev (dev->ip_ptr). This is not expected because inetdev_destroy is called in NETDEV_UNREGISTER phase and packets should not be processed after dev_close_many() and synchronize_net(). Above fix is still required because inetdev_destroy can be called for other reasons. But it shows the real problem: backlog can keep packets for long time and they do not hold reference to device. Such packets are then delivered to upper levels at the same time when device is unregistered. Calling flush_backlog after NETDEV_UNREGISTER_FINAL still accounts all packets from backlog but before that some packets continue to be delivered to upper levels long after the synchronize_net call which is supposed to wait the last ones. Also, as Eric pointed out, processed packets, mostly from other devices, can continue to add new packets to backlog. Fix the problem by moving flush_backlog early, after the device driver is stopped and before the synchronize_net() call. Then use netif_running check to make sure we do not add more packets to backlog. We have to do it in enqueue_to_backlog context when the local IRQ is disabled. As result, after the flush_backlog and synchronize_net sequence all packets should be accounted. Thanks to Eric W. Biederman for the test script and his valuable feedback! Reported-by:
Vittorio Gambaletta <linuxbugs@vittgam.net> Fixes: 6e583ce5 ("net: eliminate refcounting in backlog queue") Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by:
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Oleg Nesterov authored
[ Upstream commit fecdf8be ] pktgen_thread_worker() is obviously racy, kthread_stop() can come between the kthread_should_stop() check and set_current_state(). Signed-off-by:
Oleg Nesterov <oleg@redhat.com> Reported-by:
Jan Stancek <jstancek@redhat.com> Reported-by:
Marcelo Leitner <mleitner@redhat.com> Signed-off-by:
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Nikolay Aleksandrov authored
[ Upstream commit f1158b74 ] Since commit b0e9a30d ("bridge: Add vlan id to multicast groups") there's a check in br_ip_equal() for a matching vlan id, but the mdb functions were not modified to use (or at least zero it) so when an entry was added it would have a garbage vlan id (from the local br_ip variable in __br_mdb_add/del) and this would prevent it from being matched and also deleted. So zero out the whole local ip var to protect ourselves from future changes and also to fix the current bug, since there's no vlan id support in the mdb uapi - use always vlan id 0. Example before patch: root@debian:~# bridge mdb add dev br0 port eth1 grp 239.0.0.1 permanent root@debian:~# bridge mdb dev br0 port eth1 grp 239.0.0.1 permanent root@debian:~# bridge mdb del dev br0 port eth1 grp 239.0.0.1 permanent RTNETLINK answers: Invalid argument After patch: root@debian:~# bridge mdb add dev br0 port eth1 grp 239.0.0.1 permanent root@debian:~# bridge mdb dev br0 port eth1 grp 239.0.0.1 permanent root@debian:~# bridge mdb del dev br0 port eth1 grp 239.0.0.1 permanent root@debian:~# bridge mdb Signed-off-by:
Nikolay Aleksandrov <razor@blackwall.org> Fixes: b0e9a30d ("bridge: Add vlan id to multicast groups") Signed-off-by:
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Stephen Smalley authored
[ Upstream commit fdd75ea8 ] Calling connect() with an AF_TIPC socket would trigger a series of error messages from SELinux along the lines of: SELinux: Invalid class 0 type=AVC msg=audit(1434126658.487:34500): avc: denied { <unprintable> } for pid=292 comm="kworker/u16:5" scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:object_r:unlabeled_t:s0 tclass=<unprintable> permissive=0 This was due to a failure to initialize the security state of the new connection sock by the tipc code, leaving it with junk in the security class field and an unlabeled secid. Add a call to security_sk_clone() to inherit the security state from the parent socket. Reported-by:
Tim Shearer <tim.shearer@overturenetworks.com> Signed-off-by:
Stephen Smalley <sds@tycho.nsa.gov> Acked-by:
Paul Moore <paul@paul-moore.com> Acked-by:
Ying Xue <ying.xue@windriver.com> Signed-off-by:
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Timo Teräs authored
[ Upstream commit fc24f2b2 ] Frag needed should be sent only if the inner header asked to not fragment. Currently fragmentation is broken if the tunnel has df set, but df was not asked in the original packet. The tunnel's df needs to be still checked to update internally the pmtu cache. Commit 23a3647b broke it, and this commit fixes the ipv4 df check back to the way it was. Fixes: 23a3647b ("ip_tunnels: Use skb-len to PMTU check.") Cc: Pravin B Shelar <pshelar@nicira.com> Signed-off-by:
Timo Teräs <timo.teras@iki.fi> Acked-by:
Pravin B Shelar <pshelar@nicira.com> Signed-off-by:
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Daniel Borkmann authored
[ Upstream commit 4f7d2cdf ] Jason Gunthorpe reported that since commit c02db8c6 ("rtnetlink: make SR-IOV VF interface symmetric"), we don't verify IFLA_VF_INFO attributes anymore with respect to their policy, that is, ifla_vfinfo_policy[]. Before, they were part of ifla_policy[], but they have been nested since placed under IFLA_VFINFO_LIST, that contains the attribute IFLA_VF_INFO, which is another nested attribute for the actual VF attributes such as IFLA_VF_MAC, IFLA_VF_VLAN, etc. Despite the policy being split out from ifla_policy[] in this commit, it's never applied anywhere. nla_for_each_nested() only does basic nla_ok() testing for struct nlattr, but it doesn't know about the data context and their requirements. Fix, on top of Jason's initial work, does 1) parsing of the attributes with the right policy, and 2) using the resulting parsed attribute table from 1) instead of the nla_for_each_nested() loop (just like we used to do when still part of ifla_policy[]). Reference: http://thread.gmane.org/gmane.linux.network/368913 Fixes: c02db8c6 ("rtnetlink: make SR-IOV VF interface symmetric") Reported-by:
Jason Gunthorpe <jgunthorpe@obsidianresearch.com> Cc: Chris Wright <chrisw@sous-sol.org> Cc: Sucheta Chakraborty <sucheta.chakraborty@qlogic.com> Cc: Greg Rose <gregory.v.rose@intel.com> Cc: Jeff Kirsher <jeffrey.t.kirsher@intel.com> Cc: Rony Efraim <ronye@mellanox.com> Cc: Vlad Zolotarov <vladz@cloudius-systems.com> Cc: Nicolas Dichtel <nicolas.dichtel@6wind.com> Cc: Thomas Graf <tgraf@suug.ch> Signed-off-by:
Daniel Borkmann <daniel@iogearbox.net> Acked-by:
Vlad Zolotarov <vladz@cloudius-systems.com> Signed-off-by:
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Eric Dumazet authored
[ Upstream commit d339727c ] User space can crash kernel with ip link add ifb10 numtxqueues 100000 type ifb We must replace a BUG_ON() by proper test and return -EINVAL for crazy values. Fixes: 60877a32 ("net: allow large number of tx queues") Signed-off-by:
Eric Dumazet <edumazet@google.com> Signed-off-by:
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Angga authored
[ Upstream commit 4c938d22 ] Before commit daad1512 ("ipv6: Make ipv6_is_mld() inline and use it from ip6_mc_input().") MLD packets were only processed locally. After the change, a copy of MLD packet goes through ip6_mr_input, causing MRT6MSG_NOCACHE message to be generated to user space. Make MLD packet only processed locally. Fixes: daad1512 ("ipv6: Make ipv6_is_mld() inline and use it from ip6_mc_input().") Signed-off-by:
Hermin Anggawijaya <hermin.anggawijaya@alliedtelesis.co.nz> Signed-off-by:
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- 25 Aug, 2015 31 commits
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Dave Airlie authored
commit 7f98ca45 upstream. We apparantly get a hotplug irq before we've initialised modesetting, [drm] Loading R100 Microcode BUG: unable to handle kernel NULL pointer dereference at (null) IP: [<c125f56f>] __mutex_lock_slowpath+0x23/0x91 *pde = 00000000 Oops: 0002 [#1] Modules linked in: radeon(+) drm_kms_helper ttm drm i2c_algo_bit backlight pcspkr psmouse evdev sr_mod input_leds led_class cdrom sg parport_pc parport floppy intel_agp intel_gtt lpc_ich acpi_cpufreq processor button mfd_core agpgart uhci_hcd ehci_hcd rng_core snd_intel8x0 snd_ac97_codec ac97_bus snd_pcm usbcore usb_common i2c_i801 i2c_core snd_timer snd soundcore thermal_sys CPU: 0 PID: 15 Comm: kworker/0:1 Not tainted 4.2.0-rc7-00015-gbf674028 #111 Hardware name: MicroLink /D850MV , BIOS MV85010A.86A.0067.P24.0304081124 04/08/2003 Workqueue: events radeon_hotplug_work_func [radeon] task: f6ca5900 ti: f6d3e000 task.ti: f6d3e000 EIP: 0060:[<c125f56f>] EFLAGS: 00010282 CPU: 0 EIP is at __mutex_lock_slowpath+0x23/0x91 EAX: 00000000 EBX: f5e900fc ECX: 00000000 EDX: fffffffe ESI: f6ca5900 EDI: f5e90100 EBP: f5e90000 ESP: f6d3ff0c DS: 007b ES: 007b FS: 0000 GS: 0000 SS: 0068 CR0: 8005003b CR2: 00000000 CR3: 36f61000 CR4: 000006d0 Stack: f5e90100 00000000 c103c4c1 f6d2a5a0 f5e900fc f6df394c c125f162 f8b0faca f6d2a5a0 c138ca00 f6df394c f7395600 c1034741 00d40000 00000000 f6d2a5a0 c138ca00 f6d2a5b8 c138ca10 c1034b58 00000001 f6d40000 f6ca5900 f6d0c940 Call Trace: [<c103c4c1>] ? dequeue_task_fair+0xa4/0xb7 [<c125f162>] ? mutex_lock+0x9/0xa [<f8b0faca>] ? radeon_hotplug_work_func+0x17/0x57 [radeon] [<c1034741>] ? process_one_work+0xfc/0x194 [<c1034b58>] ? worker_thread+0x18d/0x218 [<c10349cb>] ? rescuer_thread+0x1d5/0x1d5 [<c103742a>] ? kthread+0x7b/0x80 [<c12601c0>] ? ret_from_kernel_thread+0x20/0x30 [<c10373af>] ? init_completion+0x18/0x18 Code: 42 08 e8 8e a6 dd ff c3 57 56 53 83 ec 0c 8b 35 48 f7 37 c1 8b 10 4a 74 1a 89 c3 8d 78 04 8b 40 08 89 63 Reported-and-Tested-by:
Meelis Roos <mroos@linux.ee> Signed-off-by:
Dave Airlie <airlied@redhat.com> Signed-off-by:
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Mika Westerberg authored
commit 1abf25a2 upstream. Using -1 as platform device id means that the platform driver core will not assign any id to the device (the device name will not have id at all). This results problems on systems that have multiple PCHs (Platform Controller HUBs) because all of them also include their own copy of LPC device. All the subsequent device creations will fail because there already exists platform device with the same name. Fix this by passing PLATFORM_DEVID_AUTO as platform device id. This makes the platform device core to allocate new ids automatically. Signed-off-by:
Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by:
Lee Jones <lee.jones@linaro.org> Signed-off-by:
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Jiri Slaby authored
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Ilya Dryomov authored
commit 2761713d upstream. For write/discard obj_requests that involved a copyup method call, the opcode of the first op is CEPH_OSD_OP_CALL and the ->callback is rbd_img_obj_copyup_callback(). The latter frees copyup pages, sets ->xferred and delegates to rbd_img_obj_callback(), the "normal" image object callback, for reporting to block layer and putting refs. rbd_osd_req_callback() however treats CEPH_OSD_OP_CALL as a trivial op, which means obj_request is marked done in rbd_osd_trivial_callback(), *before* ->callback is invoked and rbd_img_obj_copyup_callback() has a chance to run. Marking obj_request done essentially means giving rbd_img_obj_callback() a license to end it at any moment, so if another obj_request from the same img_request is being completed concurrently, rbd_img_obj_end_request() may very well be called on such prematurally marked done request: <obj_request-1/2 reply> handle_reply() rbd_osd_req_callback() rbd_osd_trivial_callback() rbd_obj_request_complete() rbd_img_obj_copyup_callback() rbd_img_obj_callback() <obj_request-2/2 reply> handle_reply() rbd_osd_req_callback() rbd_osd_trivial_callback() for_each_obj_request(obj_request->img_request) { rbd_img_obj_end_request(obj_request-1/2) rbd_img_obj_end_request(obj_request-2/2) <-- } Calling rbd_img_obj_end_request() on such a request leads to trouble, in particular because its ->xfferred is 0. We report 0 to the block layer with blk_update_request(), get back 1 for "this request has more data in flight" and then trip on rbd_assert(more ^ (which == img_request->obj_request_count)); with rhs (which == ...) being 1 because rbd_img_obj_end_request() has been called for both requests and lhs (more) being 1 because we haven't got a chance to set ->xfferred in rbd_img_obj_copyup_callback() yet. To fix this, leverage that rbd wants to call class methods in only two cases: one is a generic method call wrapper (obj_request is standalone) and the other is a copyup (obj_request is part of an img_request). So make a dedicated handler for CEPH_OSD_OP_CALL and directly invoke rbd_img_obj_copyup_callback() from it if obj_request is part of an img_request, similar to how CEPH_OSD_OP_READ handler invokes rbd_img_obj_request_read_callback(). Since rbd_img_obj_copyup_callback() is now being called from the OSD request callback (only), it is renamed to rbd_osd_copyup_callback(). Cc: Alex Elder <elder@linaro.org> Signed-off-by:
Ilya Dryomov <idryomov@gmail.com> Reviewed-by:
Alex Elder <elder@linaro.org> [idryomov@gmail.com: backport to < 3.18: context] Signed-off-by:
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Alex Deucher authored
commit e037239e upstream. Signed-off-by:
Alex Deucher <alexander.deucher@amd.com> Signed-off-by:
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Michael Walle authored
commit 5c16179b upstream. The commit de3910eb ("edac: change the mem allocation scheme to make Documentation/kobject.txt happy") changed the memory allocation for the csrows member. But ppc4xx_edac was forgotten in the patch. Fix it. Signed-off-by:
Michael Walle <michael@walle.cc> Cc: linux-edac <linux-edac@vger.kernel.org> Cc: Mauro Carvalho Chehab <mchehab@osg.samsung.com> Link: http://lkml.kernel.org/r/1437469253-8611-1-git-send-email-michael@walle.ccSigned-off-by:
Borislav Petkov <bp@suse.de> Signed-off-by:
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Richard Weinberger authored
commit c0ddc8c7 upstream. In kbuild it is allowed to define objects in files named "Makefile" and "Kbuild". Currently localmodconfig reads objects only from "Makefile"s and misses modules like nouveau. Link: http://lkml.kernel.org/r/1437948415-16290-1-git-send-email-richard@nod.atReported-and-tested-by:
Leonidas Spyropoulos <artafinde@gmail.com> Signed-off-by:
Richard Weinberger <richard@nod.at> Signed-off-by:
Steven Rostedt <rostedt@goodmis.org> Signed-off-by:
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Joe Thornber authored
commit 7f518ad0 upstream. The device details and mapping trees were just being decremented before. Now btree_del() is called to do a deep delete. Signed-off-by:
Joe Thornber <ejt@redhat.com> Signed-off-by:
Mike Snitzer <snitzer@redhat.com> Signed-off-by:
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Peter Zijlstra authored
commit fed66e2c upstream. Vince reported that the fasync signal stuff doesn't work proper for inherited events. So fix that. Installing fasync allocates memory and sets filp->f_flags |= FASYNC, which upon the demise of the file descriptor ensures the allocation is freed and state is updated. Now for perf, we can have the events stick around for a while after the original FD is dead because of references from child events. So we cannot copy the fasync pointer around. We can however consistently use the parent's fasync, as that will be updated. Reported-and-Tested-by:
Vince Weaver <vincent.weaver@maine.edu> Signed-off-by:
Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Arnaldo Carvalho deMelo <acme@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: eranian@google.com Link: http://lkml.kernel.org/r/1434011521.1495.71.camel@twinsSigned-off-by:
Ingo Molnar <mingo@kernel.org> Signed-off-by:
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Bob Liu authored
commit 7b076750 upstream. We should consider info->feature_persistent when adding indirect page to list info->indirect_pages, else the BUG_ON() in blkif_free() would be triggered. When we are using persistent grants the indirect_pages list should always be empty because blkfront has pre-allocated enough persistent pages to fill all requests on the ring. Acked-by:
Roger Pau Monné <roger.pau@citrix.com> Signed-off-by:
Bob Liu <bob.liu@oracle.com> Signed-off-by:
Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by:
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Wanpeng Li authored
commit 4f32be67 upstream. After trying to drain pages from pagevec/pageset, we try to get reference count of the page again, however, the reference count of the page is not reduced if the page is still not on LRU list. Fix it by adding the put_page() to drop the page reference which is from __get_any_page(). Signed-off-by:
Wanpeng Li <wanpeng.li@hotmail.com> Acked-by:
Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> 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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Herton R. Krzesinski authored
commit 602b8593 upstream. The current semaphore code allows a potential use after free: in exit_sem we may free the task's sem_undo_list while there is still another task looping through the same semaphore set and cleaning the sem_undo list at freeary function (the task called IPC_RMID for the same semaphore set). For example, with a test program [1] running which keeps forking a lot of processes (which then do a semop call with SEM_UNDO flag), and with the parent right after removing the semaphore set with IPC_RMID, and a kernel built with CONFIG_SLAB, CONFIG_SLAB_DEBUG and CONFIG_DEBUG_SPINLOCK, you can easily see something like the following in the kernel log: Slab corruption (Not tainted): kmalloc-64 start=ffff88003b45c1c0, len=64 000: 6b 6b 6b 6b 6b 6b 6b 6b 00 6b 6b 6b 6b 6b 6b 6b kkkkkkkk.kkkkkkk 010: ff ff ff ff 6b 6b 6b 6b ff ff ff ff ff ff ff ff ....kkkk........ Prev obj: start=ffff88003b45c180, len=64 000: 00 00 00 00 ad 4e ad de ff ff ff ff 5a 5a 5a 5a .....N......ZZZZ 010: ff ff ff ff ff ff ff ff c0 fb 01 37 00 88 ff ff ...........7.... Next obj: start=ffff88003b45c200, len=64 000: 00 00 00 00 ad 4e ad de ff ff ff ff 5a 5a 5a 5a .....N......ZZZZ 010: ff ff ff ff ff ff ff ff 68 29 a7 3c 00 88 ff ff ........h).<.... BUG: spinlock wrong CPU on CPU#2, test/18028 general protection fault: 0000 [#1] SMP Modules linked in: 8021q mrp garp stp llc nf_conntrack_ipv4 nf_defrag_ipv4 ip6t_REJECT nf_reject_ipv6 nf_conntrack_ipv6 nf_defrag_ipv6 xt_state nf_conntrack ip6table_filter ip6_tables binfmt_misc ppdev input_leds joydev parport_pc parport floppy serio_raw virtio_balloon virtio_rng virtio_console virtio_net iosf_mbi crct10dif_pclmul crc32_pclmul ghash_clmulni_intel pcspkr qxl ttm drm_kms_helper drm snd_hda_codec_generic i2c_piix4 snd_hda_intel snd_hda_codec snd_hda_core snd_hwdep snd_seq snd_seq_device snd_pcm snd_timer snd soundcore crc32c_intel virtio_pci virtio_ring virtio pata_acpi ata_generic [last unloaded: speedstep_lib] CPU: 2 PID: 18028 Comm: test Not tainted 4.2.0-rc5+ #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.8.1-20150318_183358- 04/01/2014 RIP: spin_dump+0x53/0xc0 Call Trace: spin_bug+0x30/0x40 do_raw_spin_unlock+0x71/0xa0 _raw_spin_unlock+0xe/0x10 freeary+0x82/0x2a0 ? _raw_spin_lock+0xe/0x10 semctl_down.clone.0+0xce/0x160 ? __do_page_fault+0x19a/0x430 ? __audit_syscall_entry+0xa8/0x100 SyS_semctl+0x236/0x2c0 ? syscall_trace_leave+0xde/0x130 entry_SYSCALL_64_fastpath+0x12/0x71 Code: 8b 80 88 03 00 00 48 8d 88 60 05 00 00 48 c7 c7 a0 2c a4 81 31 c0 65 8b 15 eb 40 f3 7e e8 08 31 68 00 4d 85 e4 44 8b 4b 08 74 5e <45> 8b 84 24 88 03 00 00 49 8d 8c 24 60 05 00 00 8b 53 04 48 89 RIP [<ffffffff810d6053>] spin_dump+0x53/0xc0 RSP <ffff88003750fd68> ---[ end trace 783ebb76612867a0 ]--- NMI watchdog: BUG: soft lockup - CPU#3 stuck for 22s! [test:18053] Modules linked in: 8021q mrp garp stp llc nf_conntrack_ipv4 nf_defrag_ipv4 ip6t_REJECT nf_reject_ipv6 nf_conntrack_ipv6 nf_defrag_ipv6 xt_state nf_conntrack ip6table_filter ip6_tables binfmt_misc ppdev input_leds joydev parport_pc parport floppy serio_raw virtio_balloon virtio_rng virtio_console virtio_net iosf_mbi crct10dif_pclmul crc32_pclmul ghash_clmulni_intel pcspkr qxl ttm drm_kms_helper drm snd_hda_codec_generic i2c_piix4 snd_hda_intel snd_hda_codec snd_hda_core snd_hwdep snd_seq snd_seq_device snd_pcm snd_timer snd soundcore crc32c_intel virtio_pci virtio_ring virtio pata_acpi ata_generic [last unloaded: speedstep_lib] CPU: 3 PID: 18053 Comm: test Tainted: G D 4.2.0-rc5+ #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.8.1-20150318_183358- 04/01/2014 RIP: native_read_tsc+0x0/0x20 Call Trace: ? delay_tsc+0x40/0x70 __delay+0xf/0x20 do_raw_spin_lock+0x96/0x140 _raw_spin_lock+0xe/0x10 sem_lock_and_putref+0x11/0x70 SYSC_semtimedop+0x7bf/0x960 ? handle_mm_fault+0xbf6/0x1880 ? dequeue_task_fair+0x79/0x4a0 ? __do_page_fault+0x19a/0x430 ? kfree_debugcheck+0x16/0x40 ? __do_page_fault+0x19a/0x430 ? __audit_syscall_entry+0xa8/0x100 ? do_audit_syscall_entry+0x66/0x70 ? syscall_trace_enter_phase1+0x139/0x160 SyS_semtimedop+0xe/0x10 SyS_semop+0x10/0x20 entry_SYSCALL_64_fastpath+0x12/0x71 Code: 47 10 83 e8 01 85 c0 89 47 10 75 08 65 48 89 3d 1f 74 ff 7e c9 c3 0f 1f 44 00 00 55 48 89 e5 e8 87 17 04 00 66 90 c9 c3 0f 1f 00 <55> 48 89 e5 0f 31 89 c1 48 89 d0 48 c1 e0 20 89 c9 48 09 c8 c9 Kernel panic - not syncing: softlockup: hung tasks I wasn't able to trigger any badness on a recent kernel without the proper config debugs enabled, however I have softlockup reports on some kernel versions, in the semaphore code, which are similar as above (the scenario is seen on some servers running IBM DB2 which uses semaphore syscalls). The patch here fixes the race against freeary, by acquiring or waiting on the sem_undo_list lock as necessary (exit_sem can race with freeary, while freeary sets un->semid to -1 and removes the same sem_undo from list_proc or when it removes the last sem_undo). After the patch I'm unable to reproduce the problem using the test case [1]. [1] Test case used below: #include <stdio.h> #include <sys/types.h> #include <sys/ipc.h> #include <sys/sem.h> #include <sys/wait.h> #include <stdlib.h> #include <time.h> #include <unistd.h> #include <errno.h> #define NSEM 1 #define NSET 5 int sid[NSET]; void thread() { struct sembuf op; int s; uid_t pid = getuid(); s = rand() % NSET; op.sem_num = pid % NSEM; op.sem_op = 1; op.sem_flg = SEM_UNDO; semop(sid[s], &op, 1); exit(EXIT_SUCCESS); } void create_set() { int i, j; pid_t p; union { int val; struct semid_ds *buf; unsigned short int *array; struct seminfo *__buf; } un; /* Create and initialize semaphore set */ for (i = 0; i < NSET; i++) { sid[i] = semget(IPC_PRIVATE , NSEM, 0644 | IPC_CREAT); if (sid[i] < 0) { perror("semget"); exit(EXIT_FAILURE); } } un.val = 0; for (i = 0; i < NSET; i++) { for (j = 0; j < NSEM; j++) { if (semctl(sid[i], j, SETVAL, un) < 0) perror("semctl"); } } /* Launch threads that operate on semaphore set */ for (i = 0; i < NSEM * NSET * NSET; i++) { p = fork(); if (p < 0) perror("fork"); if (p == 0) thread(); } /* Free semaphore set */ for (i = 0; i < NSET; i++) { if (semctl(sid[i], NSEM, IPC_RMID)) perror("IPC_RMID"); } /* Wait for forked processes to exit */ while (wait(NULL)) { if (errno == ECHILD) break; }; } int main(int argc, char **argv) { pid_t p; srand(time(NULL)); while (1) { p = fork(); if (p < 0) { perror("fork"); exit(EXIT_FAILURE); } if (p == 0) { create_set(); goto end; } /* Wait for forked processes to exit */ while (wait(NULL)) { if (errno == ECHILD) break; }; } end: return 0; } [akpm@linux-foundation.org: use normal comment layout] Signed-off-by:
Herton R. Krzesinski <herton@redhat.com> Acked-by:
Manfred Spraul <manfred@colorfullife.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Rafael Aquini <aquini@redhat.com> CC: Aristeu Rozanski <aris@redhat.com> Cc: David Jeffery <djeffery@redhat.com> Signed-off-by:
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Manfred Spraul authored
commit 3ed1f8a9 upstream. sem_lock() did not properly pair memory barriers: !spin_is_locked() and spin_unlock_wait() are both only control barriers. The code needs an acquire barrier, otherwise the cpu might perform read operations before the lock test. As no primitive exists inside <include/spinlock.h> and since it seems noone wants another primitive, the code creates a local primitive within ipc/sem.c. With regards to -stable: The change of sem_wait_array() is a bugfix, the change to sem_lock() is a nop (just a preprocessor redefinition to improve the readability). The bugfix is necessary for all kernels that use sem_wait_array() (i.e.: starting from 3.10). Signed-off-by:
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Michal Hocko authored
commit ecf5fc6e upstream. Nikolay has reported a hang when a memcg reclaim got stuck with the following backtrace: PID: 18308 TASK: ffff883d7c9b0a30 CPU: 1 COMMAND: "rsync" #0 __schedule at ffffffff815ab152 #1 schedule at ffffffff815ab76e #2 schedule_timeout at ffffffff815ae5e5 #3 io_schedule_timeout at ffffffff815aad6a #4 bit_wait_io at ffffffff815abfc6 #5 __wait_on_bit at ffffffff815abda5 #6 wait_on_page_bit at ffffffff8111fd4f #7 shrink_page_list at ffffffff81135445 #8 shrink_inactive_list at ffffffff81135845 #9 shrink_lruvec at ffffffff81135ead #10 shrink_zone at ffffffff811360c3 #11 shrink_zones at ffffffff81136eff #12 do_try_to_free_pages at ffffffff8113712f #13 try_to_free_mem_cgroup_pages at ffffffff811372be #14 try_charge at ffffffff81189423 #15 mem_cgroup_try_charge at ffffffff8118c6f5 #16 __add_to_page_cache_locked at ffffffff8112137d #17 add_to_page_cache_lru at ffffffff81121618 #18 pagecache_get_page at ffffffff8112170b #19 grow_dev_page at ffffffff811c8297 #20 __getblk_slow at ffffffff811c91d6 #21 __getblk_gfp at ffffffff811c92c1 #22 ext4_ext_grow_indepth at ffffffff8124565c #23 ext4_ext_create_new_leaf at ffffffff81246ca8 #24 ext4_ext_insert_extent at ffffffff81246f09 #25 ext4_ext_map_blocks at ffffffff8124a848 #26 ext4_map_blocks at ffffffff8121a5b7 #27 mpage_map_one_extent at ffffffff8121b1fa #28 mpage_map_and_submit_extent at ffffffff8121f07b #29 ext4_writepages at ffffffff8121f6d5 #30 do_writepages at ffffffff8112c490 #31 __filemap_fdatawrite_range at ffffffff81120199 #32 filemap_flush at ffffffff8112041c #33 ext4_alloc_da_blocks at ffffffff81219da1 #34 ext4_rename at ffffffff81229b91 #35 ext4_rename2 at ffffffff81229e32 #36 vfs_rename at ffffffff811a08a5 #37 SYSC_renameat2 at ffffffff811a3ffc #38 sys_renameat2 at ffffffff811a408e #39 sys_rename at ffffffff8119e51e #40 system_call_fastpath at ffffffff815afa89 Dave Chinner has properly pointed out that this is a deadlock in the reclaim code because ext4 doesn't submit pages which are marked by PG_writeback right away. The heuristic was introduced by commit e62e384e ("memcg: prevent OOM with too many dirty pages") and it was applied only when may_enter_fs was specified. The code has been changed by c3b94f44 ("memcg: further prevent OOM with too many dirty pages") which has removed the __GFP_FS restriction with a reasoning that we do not get into the fs code. But this is not sufficient apparently because the fs doesn't necessarily submit pages marked PG_writeback for IO right away. ext4_bio_write_page calls io_submit_add_bh but that doesn't necessarily submit the bio. Instead it tries to map more pages into the bio and mpage_map_one_extent might trigger memcg charge which might end up waiting on a page which is marked PG_writeback but hasn't been submitted yet so we would end up waiting for something that never finishes. Fix this issue by replacing __GFP_IO by may_enter_fs check (for case 2) before we go to wait on the writeback. The page fault path, which is the only path that triggers memcg oom killer since 3.12, shouldn't require GFP_NOFS and so we shouldn't reintroduce the premature OOM killer issue which was originally addressed by the heuristic. As per David Chinner the xfs is doing similar thing since 2.6.15 already so ext4 is not the only affected filesystem. Moreover he notes: : For example: IO completion might require unwritten extent conversion : which executes filesystem transactions and GFP_NOFS allocations. The : writeback flag on the pages can not be cleared until unwritten : extent conversion completes. Hence memory reclaim cannot wait on : page writeback to complete in GFP_NOFS context because it is not : safe to do so, memcg reclaim or otherwise. [tytso@mit.edu: corrected the control flow] Fixes: c3b94f44 ("memcg: further prevent OOM with too many dirty pages") Reported-by:
Nikolay Borisov <kernel@kyup.com> Signed-off-by:
Michal Hocko <mhocko@suse.cz> Signed-off-by:
Hugh Dickins <hughd@google.com> Signed-off-by:
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NeilBrown authored
commit b97e9257 upstream Use separate bitmaps for each nodes in the cluster bitmap_read_sb() validates the bitmap superblock that it reads in. If it finds an inconsistency like a bad magic number or out-of-range version number, it prints an error and returns, but it incorrectly returns zero, so the array is still assembled with the (invalid) bitmap. This means it could try to use a bitmap with a new version number which it therefore does not understand. This bug was introduced in 3.5 and fix as part of a larger patch in 4.1. So the patch is suitable for any -stable kernel in that range. Fixes: 27581e5a ("md/bitmap: centralise allocation of bitmap file pages.") Signed-off-by:
NeilBrown <neilb@suse.com> Reported-by:
GuoQing Jiang <gqjiang@suse.com>
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Al Viro authored
commit f15133df upstream. path_openat() jumps to the wrong place after do_tmpfile() - it has already done path_cleanup() (as part of path_lookupat() called by do_tmpfile()), so doing that again can lead to double fput(). Signed-off-by:
Al Viro <viro@zeniv.linux.org.uk> Signed-off-by:
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Amanieu d'Antras authored
commit 3c00cb5e upstream. This function can leak kernel stack data when the user siginfo_t has a positive si_code value. The top 16 bits of si_code descibe which fields in the siginfo_t union are active, but they are treated inconsistently between copy_siginfo_from_user32, copy_siginfo_to_user32 and copy_siginfo_to_user. copy_siginfo_from_user32 is called from rt_sigqueueinfo and rt_tgsigqueueinfo in which the user has full control overthe top 16 bits of si_code. This fixes the following information leaks: x86: 8 bytes leaked when sending a signal from a 32-bit process to itself. This leak grows to 16 bytes if the process uses x32. (si_code = __SI_CHLD) x86: 100 bytes leaked when sending a signal from a 32-bit process to a 64-bit process. (si_code = -1) sparc: 4 bytes leaked when sending a signal from a 32-bit process to a 64-bit process. (si_code = any) parsic and s390 have similar bugs, but they are not vulnerable because rt_[tg]sigqueueinfo have checks that prevent sending a positive si_code to a different process. These bugs are also fixed for consistency. Signed-off-by:
Amanieu d'Antras <amanieu@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Chris Metcalf <cmetcalf@ezchip.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by:
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Amanieu d'Antras authored
commit 26135022 upstream. This function may copy the si_addr_lsb, si_lower and si_upper fields to user mode when they haven't been initialized, which can leak kernel stack data to user mode. Just checking the value of si_code is insufficient because the same si_code value is shared between multiple signals. This is solved by checking the value of si_signo in addition to si_code. Signed-off-by:
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Amanieu d'Antras authored
commit 3ead7c52 upstream. This function may copy the si_addr_lsb field to user mode when it hasn't been initialized, which can leak kernel stack data to user mode. Just checking the value of si_code is insufficient because the same si_code value is shared between multiple signals. This is solved by checking the value of si_signo in addition to si_code. Signed-off-by:
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Andy Lutomirski authored
commit 12e244f4 upstream. The previous fix confused a selector with a segment prefix. Fix it. Compile-tested only. Cc: stable@vger.kernel.org Cc: Juergen Gross <jgross@suse.com> Reported-by:
Andy Lutomirski <luto@kernel.org> Signed-off-by:
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Juergen Gross authored
commit 4809146b upstream. Commit 37868fe1 ("x86/ldt: Make modify_ldt synchronous") introduced a new struct ldt_struct anchored at mm->context.ldt. Adapt the x86 fpu emulation code to use that new structure. Signed-off-by:
Juergen Gross <jgross@suse.com> Reviewed-by:
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Juergen Gross authored
commit 136d9d83 upstream. Commit 37868fe1 ("x86/ldt: Make modify_ldt synchronous") introduced a new struct ldt_struct anchored at mm->context.ldt. convert_ip_to_linear() was changed to reflect this, but indexing into the ldt has to be changed as the pointer is no longer void *. Signed-off-by:
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Andy Lutomirski authored
commit 37868fe1 upstream. modify_ldt() has questionable locking and does not synchronize threads. Improve it: redesign the locking and synchronize all threads' LDTs using an IPI on all modifications. This will dramatically slow down modify_ldt in multithreaded programs, but there shouldn't be any multithreaded programs that care about modify_ldt's performance in the first place. This fixes some fallout from the CVE-2015-5157 fixes. Signed-off-by:
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Peter Zijlstra authored
commit 0a04b016 upstream. I want to use lockless_dereference() from seqlock.h, which would mean including rcupdate.h from it, however rcupdate.h already includes seqlock.h. Avoid this by moving lockless_dereference() into compiler.h. This is somewhat tricky since it uses smp_read_barrier_depends() which isn't available there, but its a CPP macro so we can get away with it. The alternative would be moving it into asm/barrier.h, but that would be updating each arch (I can do if people feel that is more appropriate). Cc: Paul McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by:
Rusty Russell <rusty@rustcorp.com.au> Signed-off-by:
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Paul E. McKenney authored
commit 54ef6df3 upstream. Although rcu_dereference() and friends can be used in situations where object lifetimes are being managed by something other than RCU, the resulting sparse and lockdep-RCU noise can be annoying. This commit therefore supplies a lockless_dereference(), which provides the protection for dereferences without the RCU-related debugging noise. Reported-by:
Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by:
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Peter Zijlstra authored
commit 47933ad4 upstream. A number of situations currently require the heavyweight smp_mb(), even though there is no need to order prior stores against later loads. Many architectures have much cheaper ways to handle these situations, but the Linux kernel currently has no portable way to make use of them. This commit therefore supplies smp_load_acquire() and smp_store_release() to remedy this situation. The new smp_load_acquire() primitive orders the specified load against any subsequent reads or writes, while the new smp_store_release() primitive orders the specifed store against any prior reads or writes. These primitives allow array-based circular FIFOs to be implemented without an smp_mb(), and also allow a theoretical hole in rcu_assign_pointer() to be closed at no additional expense on most architectures. In addition, the RCU experience transitioning from explicit smp_read_barrier_depends() and smp_wmb() to rcu_dereference() and rcu_assign_pointer(), respectively resulted in substantial improvements in readability. It therefore seems likely that replacing other explicit barriers with smp_load_acquire() and smp_store_release() will provide similar benefits. It appears that roughly half of the explicit barriers in core kernel code might be so replaced. [Changelog by PaulMck] Reviewed-by:
Will Deacon <will.deacon@arm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Cc: Michael Ellerman <michael@ellerman.id.au> Cc: Michael Neuling <mikey@neuling.org> Cc: Russell King <linux@arm.linux.org.uk> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Victor Kaplansky <VICTORK@il.ibm.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Oleg Nesterov <oleg@redhat.com> Link: http://lkml.kernel.org/r/20131213150640.908486364@infradead.orgSigned-off-by:
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Andy Lutomirski authored
commit 9b6e6a83 upstream. Returning to userspace is tricky: IRET can fail, and ESPFIX can rearrange the stack prior to IRET. The NMI nesting fixup relies on a precise stack layout and atomic IRET. Rather than trying to teach the NMI nesting fixup to handle ESPFIX and failed IRET, punt: run NMIs that came from user mode on the normal kernel stack. This will make some nested NMIs visible to C code, but the C code is okay with that. As a side effect, this should speed up perf: it eliminates an RDMSR when NMIs come from user mode. Signed-off-by:
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Andy Lutomirski authored
commit 0e181bb5 upstream. Now that do_nmi saves CR2, we don't need to save it in asm. Signed-off-by:
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Andy Lutomirski authored
commit 9d050416 upstream. 32-bit kernels handle nested NMIs in C. Enable the exact same handling on 64-bit kernels as well. This isn't currently necessary, but it will become necessary once the asm code starts allowing limited nesting. Signed-off-by:
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NeilBrown authored
commit 423f04d6 upstream. raid1_end_read_request() assumes that the In_sync bits are consistent with the ->degaded count. raid1_spare_active updates the In_sync bit before the ->degraded count and so exposes an inconsistency, as does error() So extend the spinlock in raid1_spare_active() and error() to hide those inconsistencies. This should probably be part of Commit: 34cab6f4 ("md/raid1: fix test for 'was read error from last working device'.") as it addresses the same issue. It fixes the same bug and should go to -stable for same reasons. Fixes: 76073054 ("md/raid1: clean up read_balance.") Signed-off-by:
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Joseph Qi authored
commit 209f7512 upstream. The "BUG_ON(list_empty(&osb->blocked_lock_list))" in ocfs2_downconvert_thread_do_work can be triggered in the following case: ocfs2dc has firstly saved osb->blocked_lock_count to local varibale processed, and then processes the dentry lockres. During the dentry put, it calls iput and then deletes rw, inode and open lockres from blocked list in ocfs2_mark_lockres_freeing. And this causes the variable `processed' to not reflect the number of blocked lockres to be processed, which triggers the BUG. Signed-off-by:
Joseph Qi <joseph.qi@huawei.com> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by:
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