- 28 Feb, 2013 21 commits
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Sagi Grimberg authored
commit 21a92735 upstream. With an RCU based mmu_notifier implementation, any callout to mmu_notifier_invalidate_range_{start,end}() or mmu_notifier_invalidate_page() would not be allowed to call schedule() as that could potentially allow a modification to the mmu_notifier structure while it is currently being used. Since srcu allocs 4 machine words per instance per cpu, we may end up with memory exhaustion if we use srcu per mm. So all mms share a global srcu. Note that during large mmu_notifier activity exit & unregister paths might hang for longer periods, but it is tolerable for current mmu_notifier clients. Signed-off-by:
Sagi Grimberg <sagig@mellanox.co.il> Signed-off-by:
Andrea Arcangeli <aarcange@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Haggai Eran <haggaie@mellanox.com> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by:
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Bjorn Helgaas authored
commit 4fa3e78b upstream. A bus_type has a list of devices (klist_devices), but the list and the subsys_private structure that contains it are not initialized until the bus_type is registered with bus_register(). The panic/reboot path has fixups that look up devices in pci_bus_type. If we panic before registering pci_bus_type, the bus_type exists but the list does not, so mach_reboot_fixups() trips over a null pointer and panics again: mach_reboot_fixups pci_get_device .. bus_find_device(&pci_bus_type, ...) bus->p is NULL Joonsoo reported a problem when panicking before PCI was initialized. I think this patch should be sufficient to replace the patch he posted here: https://lkml.org/lkml/2012/12/28/75 ("[PATCH] x86, reboot: skip reboot_fixups in early boot phase") Reported-by:
Joonsoo Kim <js1304@gmail.com> Signed-off-by:
Bjorn Helgaas <bhelgaas@google.com> Signed-off-by:
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Wei Liu authored
commit e7e44e44 upstream. Signed-off-by:
Wei Liu <wei.liu2@citrix.com> Signed-off-by:
Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by:
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Stefan Bader authored
commit 76eaca03 upstream. There is a loophole between Xen's current implementation of pv-spinlocks and the scheduler. This was triggerable through a testcase until v3.6 changed the TLB flushing code. The problem potentially is still there just not observable in the same way. What could happen was (is): 1. CPU n tries to schedule task x away and goes into a slow wait for the runq lock of CPU n-# (must be one with a lower number). 2. CPU n-#, while processing softirqs, tries to balance domains and goes into a slow wait for its own runq lock (for updating some records). Since this is a spin_lock_irqsave in softirq context, interrupts will be re-enabled for the duration of the poll_irq hypercall used by Xen. 3. Before the runq lock of CPU n-# is unlocked, CPU n-1 receives an interrupt (e.g. endio) and when processing the interrupt, tries to wake up task x. But that is in schedule and still on_cpu, so try_to_wake_up goes into a tight loop. 4. The runq lock of CPU n-# gets unlocked, but the message only gets sent to the first waiter, which is CPU n-# and that is busily stuck. 5. CPU n-# never returns from the nested interruption to take and release the lock because the scheduler uses a busy wait. And CPU n never finishes the task migration because the unlock notification only went to CPU n-#. To avoid this and since the unlocking code has no real sense of which waiter is best suited to grab the lock, just send the IPI to all of them. This causes the waiters to return from the hyper- call (those not interrupted at least) and do active spinlocking. BugLink: http://bugs.launchpad.net/bugs/1011792Acked-by:
Jan Beulich <JBeulich@suse.com> Signed-off-by:
Stefan Bader <stefan.bader@canonical.com> Signed-off-by:
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Jussi Kivilinna authored
commit bc6b8923 upstream. rtlwifi allocates both setup_packet and data buffer of control message urb, using shared kmalloc in _usbctrl_vendorreq_async_write. Structure used for allocating is: struct { u8 data[254]; struct usb_ctrlrequest dr; }; Because 'struct usb_ctrlrequest' is __packed, setup packet is unaligned and DMA mapping of both 'data' and 'dr' confuses ARM/sunxi, leading to memory corruptions and freezes. Patch changes setup packet to be allocated separately. [v2]: - Use WARN_ON_ONCE instead of WARN_ON Signed-off-by:
Jussi Kivilinna <jussi.kivilinna@mbnet.fi> Signed-off-by:
John W. Linville <linville@tuxdriver.com> Signed-off-by:
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Larry Finger authored
commit 8708aac7 upstream. A new model of the RTL8188CUS has appeared. Reported-and-tested-by:
Thomas Rosenkrantz <tom.rosary@googlemail.com> Signed-off-by:
Larry Finger <Larry.Finger@lwfinger.net> Signed-off-by:
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Larry Finger authored
commit ccae0e50 upstream. Bastian Bittorf reported that some of the silent freezes on a Linksys WRT54G were due to overflow of the RX DMA ring buffer, which was created with 64 slots. That finding reminded me that I was seeing similar crashed on a netbook, which also has a relatively slow processor. After increasing the number of slots to 128, runs on the netbook that previously failed now worked; however, I found that 109 slots had been used in one test. For that reason, the number of slots is being increased to 256. Signed-off-by:
David S. Miller <davem@davemloft.net> Signed-off-by:
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Johan Hovold authored
commit b2ca6990 upstream. Make sure serial-driver dtr_rts is called with disc_mutex held after checking the disconnected flag. Due to a bug in the tty layer, dtr_rts may get called after a device has been disconnected and the tty-device unregistered. Some drivers have had individual checks for disconnect to make sure the disconnected interface was not accessed, but this should really be handled in usb-serial core (at least until the long-standing tty-bug has been fixed). Note that the problem has been made more acute with commit 0998d063 ("device-core: Ensure drvdata = NULL when no driver is bound") as the port data is now also NULL when dtr_rts is called resulting in further oopses. Reported-by:
Chris Ruehl <chris.ruehl@gtsys.com.hk> Signed-off-by:
Johan Hovold <jhovold@gmail.com> Signed-off-by:
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Oleg Nesterov authored
commit 183d95cd upstream. See https://bugzilla.redhat.com/show_bug.cgi?id=904907 read command causes bash to abort with double free or corruption (out). A simple test-case from Roman: // Compile the reproducer and send sigchld ti that process. // EINTR occurs even if SA_RESTART flag is set. void handler(int sig) { } main() { struct sigaction act; act.sa_handler = handler; act.sa_flags = SA_RESTART; sigaction (SIGCHLD, &act, 0); struct termio ttp; ioctl(0, TCGETA, &ttp); while(1) { if (ioctl(0, TCSETAW, ttp) < 0) { if (errno == EINTR) { fprintf(stderr, "BUG!"); return(1); } } } } Change set_termios/set_termiox to return -ERESTARTSYS to fix this particular problem. I didn't dare to change other EINTR's in drivers/tty/, but they look equally wrong. Reported-by:
Roman Rakus <rrakus@redhat.com> Reported-by:
Lingzhu Xiang <lxiang@redhat.com> Signed-off-by:
Oleg Nesterov <oleg@redhat.com> Cc: Jiri Slaby <jslaby@suse.cz> Signed-off-by:
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Dirkjan Bussink authored
commit 4d9b1090 upstream. This change fixes a deadlock when the multiplexer is closed while there are still client side ports open. When the multiplexer is closed and there are active tty's it tries to close them with tty_vhangup. This has a problem though, because tty_vhangup needs the tty_lock. This patch changes it to unlock the tty_lock before attempting the hangup and relocks afterwards. The additional call to tty_port_tty_set is needed because otherwise the port stays active because of the reference counter. This change also exposed another problem that other code paths don't expect that the multiplexer could have been closed. This patch also adds checks for these cases in the gsmtty_ class of function that could be called. The documentation explicitly states that "first close all virtual ports before closing the physical port" but we've found this to not always reality in our field situations. The GPRS / UTMS modem sometimes crashes and needs a power cycle in that case which means cleanly shutting down everything is not always possible. This change makes it much more robust for our situation where at least the system is recoverable with this patch and doesn't hang in a deadlock situation inside the kernel. The patch is against the long term support kernel (3.4.27) and should apply cleanly to more recent branches. Tested with a Telit GE864-QUADV2 and Telit HE910 modem. Signed-off-by:
Dirkjan Bussink <dirkjan.bussink@nedap.com> Signed-off-by:
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Denis Efremov authored
commit f49a59c4 upstream. According to the other code in this driver and similar code in rme96 it seems, that spin_lock_irq in snd_rme32_capture_close function should be paired with spin_unlock_irq. Found by Linux Driver Verification project (linuxtesting.org). Signed-off-by:
Denis Efremov <yefremov.denis@gmail.com> Signed-off-by:
Takashi Iwai <tiwai@suse.de> Signed-off-by:
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Denis Efremov authored
commit dacae5a1 upstream. snd_ali_pointer function is called with local interrupts disabled. However it seems very strange to reenable them in such way. Found by Linux Driver Verification project (linuxtesting.org). Signed-off-by:
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Olaf Hering authored
commit 32068f65 upstream. Enable hyperv_clocksource only if its advertised as a feature. XenServer 6 returns the signature which is checked in ms_hyperv_platform(), but it does not offer all features. Currently the clocksource is enabled unconditionally in ms_hyperv_init_platform(), and the result is a hanging guest. Hyper-V spec Bit 1 indicates the availability of Partition Reference Counter. Register the clocksource only if this bit is set. The guest in question prints this in dmesg: [ 0.000000] Hypervisor detected: Microsoft HyperV [ 0.000000] HyperV: features 0x70, hints 0x0 This bug can be reproduced easily be setting 'viridian=1' in a HVM domU .cfg file. A workaround without this patch is to boot the HVM guest with 'clocksource=jiffies'. Signed-off-by:
Olaf Hering <olaf@aepfle.de> Link: http://lkml.kernel.org/r/1359940959-32168-1-git-send-email-kys@microsoft.comSigned-off-by:
K. Y. Srinivasan <kys@microsoft.com> Signed-off-by:
H. Peter Anvin <hpa@linux.intel.com> Signed-off-by:
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Leonid Shatz authored
commit b22affe0 upstream. hrtimer_enqueue_reprogram contains a race which could result in timer.base switch during unlock/lock sequence. hrtimer_enqueue_reprogram is releasing the lock protecting the timer base for calling raise_softirq_irqsoff() due to a lock ordering issue versus rq->lock. If during that time another CPU calls __hrtimer_start_range_ns() on the same hrtimer, the timer base might switch, before the current CPU can lock base->lock again and therefor the unlock_timer_base() call will unlock the wrong lock. [ tglx: Added comment and massaged changelog ] Signed-off-by:
Leonid Shatz <leonid.shatz@ravellosystems.com> Signed-off-by:
Izik Eidus <izik.eidus@ravellosystems.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Link: http://lkml.kernel.org/r/1359981217-389-1-git-send-email-izik.eidus@ravellosystems.comSigned-off-by:
Thomas Gleixner <tglx@linutronix.de> Signed-off-by:
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Stanislaw Gruszka authored
commit e6c42c29 upstream. The trinity fuzzer triggered a task_struct reference leak via clock_nanosleep with CPU_TIMERs. do_cpu_nanosleep() calls posic_cpu_timer_create(), but misses a corresponding posix_cpu_timer_del() which leads to the task_struct reference leak. Reported-and-tested-by:
Tommi Rantala <tt.rantala@gmail.com> Signed-off-by:
Stanislaw Gruszka <sgruszka@redhat.com> Cc: Dave Jones <davej@redhat.com> Cc: John Stultz <john.stultz@linaro.org> Cc: Oleg Nesterov <oleg@redhat.com> Link: http://lkml.kernel.org/r/20130215100810.GF4392@redhat.comSigned-off-by:
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Thomas Gleixner authored
commit e716efde upstream. commit 52553ddf(genirq: fix regression in irqfixup, irqpoll) introduced a potential deadlock by calling the action handler with the irq descriptor lock held. Remove the call and let the handling code run even for an interrupt where only a single action is registered. That matches the goal of the above commit and avoids the deadlock. Document the confusing action = desc->action reload in the handling loop while at it. Reported-and-tested-by:
"Wang, Warner" <warner.wang@hp.com> Tested-by:
Edward Donovan <edward.donovan@numble.net> Cc: "Wang, Song-Bo (Stoney)" <song-bo.wang@hp.com> Signed-off-by:
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H. Peter Anvin authored
commit 63a3f603 upstream. defined(@array) is deprecated in Perl and gives off a warning. Restructure the code to remove that warning. [ hpa: it would be interesting to revert to the timeconst.bc script. It appears that the failures reported by akpm during testing of that script was due to a known broken version of make, not a problem with bc. The Makefile rules could probably be restructured to avoid the make bug, or it is probably old enough that it doesn't matter. ] Reported-by:
Andi Kleen <ak@linux.intel.com> Signed-off-by:
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Linus Torvalds authored
commit 7c45512d upstream. Commit c060f943 ("mm: use aligned zone start for pfn_to_bitidx calculation") fixed out calculation of the index into the pageblock bitmap when a !SPARSEMEM zome was not aligned to pageblock_nr_pages. However, the _allocation_ of that bitmap had never taken this alignment requirement into accout, so depending on the exact size and alignment of the zone, the use of that index could then access past the allocation, resulting in some very subtle memory corruption. This was reported (and bisected) by Ingo Molnar: one of his random config builds would hang with certain very specific kernel command line options. In the meantime, commit c060f943 has been marked for stable, so this fix needs to be back-ported to the stable kernels that backported the commit to use the right alignment. Bisected-and-tested-by:
Ingo Molnar <mingo@kernel.org> Acked-by:
Mel Gorman <mgorman@suse.de> Signed-off-by:
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H. Peter Anvin authored
commit 07f4207a upstream. We have removed the remap allocator for x86-32, and x86-64 never had it (and doesn't need it). Remove residual reference to it. Reported-by:
Yinghai Lu <yinghai@kernel.org> Signed-off-by:
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H. Peter Anvin authored
commit bb112aec upstream. Remove reference to removed function resume_map_numa_kva(). Signed-off-by:
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Dave Hansen authored
commit f03574f2 upstream. This code was an optimization for 32-bit NUMA systems. It has probably been the cause of a number of subtle bugs over the years, although the conditions to excite them would have been hard to trigger. Essentially, we remap part of the kernel linear mapping area, and then sometimes part of that area gets freed back in to the bootmem allocator. If those pages get used by kernel data structures (say mem_map[] or a dentry), there's no big deal. But, if anyone ever tried to use the linear mapping for these pages _and_ cared about their physical address, bad things happen. For instance, say you passed __GFP_ZERO to the page allocator and then happened to get handed one of these pages, it zero the remapped page, but it would make a pte to the _old_ page. There are probably a hundred other ways that it could screw with things. We don't need to hang on to performance optimizations for these old boxes any more. All my 32-bit NUMA systems are long dead and buried, and I probably had access to more than most people. This code is causing real things to break today: https://lkml.org/lkml/2013/1/9/376 I looked in to actually fixing this, but it requires surgery to way too much brittle code, as well as stuff like per_cpu_ptr_to_phys(). [ hpa: Cc: this for -stable, since it is a memory corruption issue. However, an alternative is to simply mark NUMA as depends BROKEN rather than EXPERIMENTAL in the X86_32 subclause... ] Link: http://lkml.kernel.org/r/20130131005616.1C79F411@kernel.stglabs.ibm.comSigned-off-by:
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- 21 Feb, 2013 2 commits
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Greg Kroah-Hartman authored
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Alexandre SIMON authored
This patch corrects a buffer overflow in kernels from 3.0 to 3.4 when calling log_prefix() function from call_console_drivers(). This bug existed in previous releases but has been revealed with commit 162a7e75 (2.6.39 => 3.0) that made changes about how to allocate memory for early printk buffer (use of memblock_alloc). It disappears with commit 7ff9554b (3.4 => 3.5) that does a refactoring of printk buffer management. In log_prefix(), the access to "p[0]", "p[1]", "p[2]" or "simple_strtoul(&p[1], &endp, 10)" may cause a buffer overflow as this function is called from call_console_drivers by passing "&LOG_BUF(cur_index)" where the index must be masked to do not exceed the buffer's boundary. The trick is to prepare in call_console_drivers() a buffer with the necessary data (PRI field of syslog message) to be safely evaluated in log_prefix(). This patch can be applied to stable kernel branches 3.0.y, 3.2.y and 3.4.y. Without this patch, one can freeze a server running this loop from shell : $ export DUMMY=`cat /dev/urandom | tr -dc '12345AZERTYUIOPQSDFGHJKLMWXCVBNazertyuiopqsdfghjklmwxcvbn' | head -c255` $ while true do ; echo $DUMMY > /dev/kmsg ; done The "server freeze" depends on where memblock_alloc does allocate printk buffer : if the buffer overflow is inside another kernel allocation the problem may not be revealed, else the server may hangs up. Signed-off-by:
Alexandre SIMON <Alexandre.Simon@univ-lorraine.fr> Signed-off-by:
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- 17 Feb, 2013 9 commits
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Greg Kroah-Hartman authored
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Alexander Duyck authored
commit ae1c07a6 upstream. For some reason the reading of the RQDPC register was being artificially limited to 4K. Instead of limiting the value we should read the value and add the full amount. Otherwise this can lead to a misleading number of dropped packets when the actual value is in fact much higher. Signed-off-by:
Alexander Duyck <alexander.h.duyck@intel.com> Tested-by:
Jeff Pieper <jeffrey.e.pieper@intel.com> Signed-off-by:
Jeff Kirsher <jeffrey.t.kirsher@intel.com> Cc: Vinson Lee <vlee@twitter.com> Signed-off-by:
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Satoru Takeuchi authored
commit 1de63d60 upstream. There was a serious problem in samsung-laptop that its platform driver is designed to run under BIOS and running under EFI can cause the machine to become bricked or can cause Machine Check Exceptions. Discussion about this problem: https://bugs.launchpad.net/ubuntu-cdimage/+bug/1040557 https://bugzilla.kernel.org/show_bug.cgi?id=47121 The patches to fix this problem: efi: Make 'efi_enabled' a function to query EFI facilities 83e68189 samsung-laptop: Disable on EFI hardware e0094244 Unfortunately this problem comes back again if users specify "noefi" option. This parameter clears EFI_BOOT and that driver continues to run even if running under EFI. Refer to the document, this parameter should clear EFI_RUNTIME_SERVICES instead. Documentation/kernel-parameters.txt: =============================================================================== ... noefi [X86] Disable EFI runtime services support. ... =============================================================================== Documentation/x86/x86_64/uefi.txt: =============================================================================== ... - If some or all EFI runtime services don't work, you can try following kernel command line parameters to turn off some or all EFI runtime services. noefi turn off all EFI runtime services ... =============================================================================== Signed-off-by:
Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com> Link: http://lkml.kernel.org/r/511C2C04.2070108@jp.fujitsu.com Cc: Matt Fleming <matt.fleming@intel.com> Signed-off-by:
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Rafael J. Wysocki authored
commit 249bfb83 upstream. Devices are added to pci_pme_list when drivers use pci_enable_wake() or pci_wake_from_d3(), but they aren't removed from the list unless the driver explicitly disables wakeup. Many drivers never disable wakeup, so their devices remain on the list even after they are removed, e.g., via hotplug. A subsequent PME poll will oops when it tries to touch the device. This patch disables PME# on a device before removing it, which removes the device from pci_pme_list. This is safe even if the device never had PME# enabled. This oops can be triggered by unplugging a Thunderbolt ethernet adapter on a Macbook Pro, as reported by Daniel below. [bhelgaas: changelog] Reference: http://lkml.kernel.org/r/CAMVG2svG21yiM1wkH4_2pen2n+cr2-Zv7TbH3Gj+8MwevZjDbw@mail.gmail.comReported-and-tested-by:
Daniel J Blueman <daniel@quora.org> Signed-off-by:
Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by:
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Jan Beulich authored
commit 13d2b4d1 upstream. This fixes CVE-2013-0228 / XSA-42 Drew Jones while working on CVE-2013-0190 found that that unprivileged guest user in 32bit PV guest can use to crash the > guest with the panic like this: ------------- general protection fault: 0000 [#1] SMP last sysfs file: /sys/devices/vbd-51712/block/xvda/dev Modules linked in: sunrpc ipt_REJECT nf_conntrack_ipv4 nf_defrag_ipv4 iptable_filter ip_tables ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ipv6 xt_state nf_conntrack ip6table_filter ip6_tables ipv6 xen_netfront ext4 mbcache jbd2 xen_blkfront dm_mirror dm_region_hash dm_log dm_mod [last unloaded: scsi_wait_scan] Pid: 1250, comm: r Not tainted 2.6.32-356.el6.i686 #1 EIP: 0061:[<c0407462>] EFLAGS: 00010086 CPU: 0 EIP is at xen_iret+0x12/0x2b EAX: eb8d0000 EBX: 00000001 ECX: 08049860 EDX: 00000010 ESI: 00000000 EDI: 003d0f00 EBP: b77f8388 ESP: eb8d1fe0 DS: 0000 ES: 007b FS: 0000 GS: 00e0 SS: 0069 Process r (pid: 1250, ti=eb8d0000 task=c2953550 task.ti=eb8d0000) Stack: 00000000 0027f416 00000073 00000206 b77f8364 0000007b 00000000 00000000 Call Trace: Code: c3 8b 44 24 18 81 4c 24 38 00 02 00 00 8d 64 24 30 e9 03 00 00 00 8d 76 00 f7 44 24 08 00 00 02 80 75 33 50 b8 00 e0 ff ff 21 e0 <8b> 40 10 8b 04 85 a0 f6 ab c0 8b 80 0c b0 b3 c0 f6 44 24 0d 02 EIP: [<c0407462>] xen_iret+0x12/0x2b SS:ESP 0069:eb8d1fe0 general protection fault: 0000 [#2] ---[ end trace ab0d29a492dcd330 ]--- Kernel panic - not syncing: Fatal exception Pid: 1250, comm: r Tainted: G D --------------- 2.6.32-356.el6.i686 #1 Call Trace: [<c08476df>] ? panic+0x6e/0x122 [<c084b63c>] ? oops_end+0xbc/0xd0 [<c084b260>] ? do_general_protection+0x0/0x210 [<c084a9b7>] ? error_code+0x73/ ------------- Petr says: " I've analysed the bug and I think that xen_iret() cannot cope with mangled DS, in this case zeroed out (null selector/descriptor) by either xen_failsafe_callback() or RESTORE_REGS because the corresponding LDT entry was invalidated by the reproducer. " Jan took a look at the preliminary patch and came up a fix that solves this problem: "This code gets called after all registers other than those handled by IRET got already restored, hence a null selector in %ds or a non-null one that got loaded from a code or read-only data descriptor would cause a kernel mode fault (with the potential of crashing the kernel as a whole, if panic_on_oops is set)." The way to fix this is to realize that the we can only relay on the registers that IRET restores. The two that are guaranteed are the %cs and %ss as they are always fixed GDT selectors. Also they are inaccessible from user mode - so they cannot be altered. This is the approach taken in this patch. Another alternative option suggested by Jan would be to relay on the subtle realization that using the %ebp or %esp relative references uses the %ss segment. In which case we could switch from using %eax to %ebp and would not need the %ss over-rides. That would also require one extra instruction to compensate for the one place where the register is used as scaled index. However Andrew pointed out that is too subtle and if further work was to be done in this code-path it could escape folks attention and lead to accidents. Reviewed-by:
Petr Matousek <pmatouse@redhat.com> Reported-by:
Andrew Cooper <andrew.cooper3@citrix.com> Signed-off-by:
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Mel Gorman authored
commit 0ee364eb upstream. A user reported the following oops when a backup process reads /proc/kcore: BUG: unable to handle kernel paging request at ffffbb00ff33b000 IP: [<ffffffff8103157e>] kern_addr_valid+0xbe/0x110 [...] Call Trace: [<ffffffff811b8aaa>] read_kcore+0x17a/0x370 [<ffffffff811ad847>] proc_reg_read+0x77/0xc0 [<ffffffff81151687>] vfs_read+0xc7/0x130 [<ffffffff811517f3>] sys_read+0x53/0xa0 [<ffffffff81449692>] system_call_fastpath+0x16/0x1b Investigation determined that the bug triggered when reading system RAM at the 4G mark. On this system, that was the first address using 1G pages for the virt->phys direct mapping so the PUD is pointing to a physical address, not a PMD page. The problem is that the page table walker in kern_addr_valid() is not checking pud_large() and treats the physical address as if it was a PMD. If it happens to look like pmd_none then it'll silently fail, probably returning zeros instead of real data. If the data happens to look like a present PMD though, it will be walked resulting in the oops above. This patch adds the necessary pud_large() check. Unfortunately the problem was not readily reproducible and now they are running the backup program without accessing /proc/kcore so the patch has not been validated but I think it makes sense. Signed-off-by:
Rik van Riel <riel@redhat.coM> Reviewed-by:
Michal Hocko <mhocko@suse.cz> Acked-by:
Johannes Weiner <hannes@cmpxchg.org> Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/20130211145236.GX21389@suse.deSigned-off-by:
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Stoney Wang authored
commit cb214ede upstream. When a HP ProLiant DL980 G7 Server boots a regular kernel, there will be intermittent lost interrupts which could result in a hang or (in extreme cases) data loss. The reason is that this system only supports x2apic physical mode, while the kernel boots with a logical-cluster default setting. This bug can be worked around by specifying the "x2apic_phys" or "nox2apic" boot option, but we want to handle this system without requiring manual workarounds. The BIOS sets ACPI_FADT_APIC_PHYSICAL in FADT table. As all apicids are smaller than 255, BIOS need to pass the control to the OS with xapic mode, according to x2apic-spec, chapter 2.9. Current code handle x2apic when BIOS pass with xapic mode enabled: When user specifies x2apic_phys, or FADT indicates PHYSICAL: 1. During madt oem check, apic driver is set with xapic logical or xapic phys driver at first. 2. enable_IR_x2apic() will enable x2apic_mode. 3. if user specifies x2apic_phys on the boot line, x2apic_phys_probe() will install the correct x2apic phys driver and use x2apic phys mode. Otherwise it will skip the driver will let x2apic_cluster_probe to take over to install x2apic cluster driver (wrong one) even though FADT indicates PHYSICAL, because x2apic_phys_probe does not check FADT PHYSICAL. Add checking x2apic_fadt_phys in x2apic_phys_probe() to fix the problem. Signed-off-by:
Stoney Wang <song-bo.wang@hp.com> [ updated the changelog and simplified the code ] Signed-off-by:
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Kees Cook authored
commit e575a86f upstream. Without this patch, it is trivial to determine kernel page mappings by examining the error code reported to dmesg[1]. Instead, declare the entire kernel memory space as a violation of a present page. Additionally, since show_unhandled_signals is enabled by default, switch branch hinting to the more realistic expectation, and unobfuscate the setting of the PF_PROT bit to improve readability. [1] http://vulnfactory.org/blog/2013/02/06/a-linux-memory-trick/Reported-by:
Dan Rosenberg <dan.j.rosenberg@gmail.com> Suggested-by:
Brad Spengler <spender@grsecurity.net> Signed-off-by:
Kees Cook <keescook@chromium.org> Acked-by:
H. Peter Anvin <hpa@zytor.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20130207174413.GA12485@www.outflux.netSigned-off-by:
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Heiko Carstens authored
commit d911e03d upstream. Since ed4f2094 "s390/time: fix sched_clock() overflow" a new helper function is used to avoid overflows when converting TOD format values to nanosecond values. The kvm interrupt code formerly however only worked by accident because of an overflow. It tried to program a timer that would expire in more than ~29 years. Because of the old TOD-to-nanoseconds overflow bug the real expiry value however was much smaller, but now it isn't anymore. This however triggers yet another bug in the function that programs the clock comparator s390_next_ktime(): if the absolute "expires" value is after 2042 this will result in an overflow and the programmed value is lower than the current TOD value which immediatly triggers a clock comparator (= timer) interrupt. Since the timer isn't expired it will be programmed immediately again and so on... the result is a dead system. To fix this simply program the maximum possible value if an overflow is detected. Reported-by:
Christian Borntraeger <borntraeger@de.ibm.com> Tested-by:
Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by:
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- 14 Feb, 2013 8 commits
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Greg Kroah-Hartman authored
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Somnath Kotur authored
commit 93040ae5 upstream. Fixed spelling error in a comment as pointed out by DaveM. Also refactored existing code a bit to provide placeholders for another ASIC Bug workaround that will be checked-in soon after this. Signed-off-by:
Somnath Kotur <somnath.kotur@emulex.com> Signed-off-by:
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Nithin Nayak Sujir authored
[ Upstream commit daf3ec68 ] TG3_PHY_AUXCTL_SMDSP_ENABLE/DISABLE macros do a blind write to the phy auxiliary control register and overwrite the EXT_PKT_LEN (bit 14) resulting in intermittent crc errors on jumbo frames with some link partners. Change the code to do a read/modify/write. Signed-off-by:
Nithin Nayak Sujir <nsujir@broadcom.com> Signed-off-by:
Michael Chan <mchan@broadcom.com> Signed-off-by:
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Nithin Nayak Sujir authored
[ Upstream commit 9c13cb8b ] When netconsole is enabled, logging messages generated during tg3_open can result in a null pointer dereference for the uninitialized tg3 status block. Use the irq_sync flag to disable polling in the early stages. irq_sync is cleared when the driver is enabling interrupts after all initialization is completed. Signed-off-by:
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Sarveshwar Bandi authored
[ Upstream commit 6caab7b0 ] If lower layer driver leaves the ip header in the skb fragment, it needs to be first pulled into skb->data before inspecting ip header length or ip version number. Signed-off-by:
Sarveshwar Bandi <sarveshwar.bandi@emulex.com> Signed-off-by:
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Ilpo Järvinen authored
[ Upstream commit 6731d209 ] There are transients during normal FRTO procedure during which the packets_in_flight can go to zero between write_queue state updates and firing the resulting segments out. As FRTO processing occurs during that window the check must be more precise to not match "spuriously" :-). More specificly, e.g., when packets_in_flight is zero but FLAG_DATA_ACKED is true the problematic branch that set cwnd into zero would not be taken and new segments might be sent out later. Signed-off-by:
Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Tested-by:
Eric Dumazet <edumazet@google.com> Acked-by:
Neal Cardwell <ncardwell@google.com> Signed-off-by:
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Eric Dumazet authored
[ Upstream commit 2e5f4212 ] Commit 9dc27415 (tcp: fix ABC in tcp_slow_start()) uncovered a bug in FRTO code : tcp_process_frto() is setting snd_cwnd to 0 if the number of in flight packets is 0. As Neal pointed out, if no packet is in flight we lost our chance to disambiguate whether a loss timeout was spurious. We should assume it was a proper loss. Reported-by:
Pasi Kärkkäinen <pasik@iki.fi> Signed-off-by:
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Ian Campbell authored
[ Upstream commit b9149729 ] Signed-off-by:
Ian Campbell <ian.campbell@citrix.com> Acked-by:
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