- 07 Oct, 2015 7 commits
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Mathias Nyman authored
commit 365038d8 upstream. When we manually need to move the TR dequeue pointer we need to set the correct cycle bit as well. Previously we used the trb pointer from the last event received as a base, but this was changed in commit 1f81b6d2 ("usb: xhci: Prefer endpoint context dequeue pointer") to use the dequeue pointer from the endpoint context instead It turns out some Asmedia controllers advance the dequeue pointer stored in the endpoint context past the event triggering TRB, and this messed up the way the cycle bit was calculated. Instead of adding a quirk or complicating the already hard to follow cycle bit code, the whole cycle bit calculation is now simplified and adapted to handle event and endpoint context dequeue pointer differences. [js] do not touch find_trb_seg, it is still in use in other portions of the code Fixes: 1f81b6d2 ("usb: xhci: Prefer endpoint context dequeue pointer") Reported-by:
Maciej Puzio <mx34567@gmail.com> Reported-by:
Evan Langlois <uudruid74@gmail.com> Reviewed-by:
Julius Werner <jwerner@chromium.org> Tested-by:
Mathias Nyman <mathias.nyman@linux.intel.com> Signed-off-by:
Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by:
Jiri Slaby <jslaby@suse.cz>
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Mathias Nyman authored
commit b8cb91e0 upstream. The xhci in Intel Sunrisepoint and Cherryview platforms need a driver workaround for a Stuck PME that might either block PME events in suspend, or create spurious PME events preventing runtime suspend. Workaround is to clear a internal PME flag, BIT(28) in a vendor specific PMCTRL register at offset 0x80a4, in both suspend resume callbacks Without this, xhci connected usb devices might never be able to wake up the system from suspend, or prevent device from going to suspend (xhci d3) Signed-off-by:
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Jan H. Schönherr authored
commit dd9d3843 upstream. There is a race condition in SMP bootup code, which may result in WARNING: CPU: 0 PID: 1 at kernel/workqueue.c:4418 workqueue_cpu_up_callback() or kernel BUG at kernel/smpboot.c:135! It can be triggered with a bit of luck in Linux guests running on busy hosts. CPU0 CPUn ==== ==== _cpu_up() __cpu_up() start_secondary() set_cpu_online() cpumask_set_cpu(cpu, to_cpumask(cpu_online_bits)); cpu_notify(CPU_ONLINE) <do stuff, see below> cpumask_set_cpu(cpu, to_cpumask(cpu_active_bits)); During the various CPU_ONLINE callbacks CPUn is online but not active. Several things can go wrong at that point, depending on the scheduling of tasks on CPU0. Variant 1: cpu_notify(CPU_ONLINE) workqueue_cpu_up_callback() rebind_workers() set_cpus_allowed_ptr() This call fails because it requires an active CPU; rebind_workers() ends with a warning: WARNING: CPU: 0 PID: 1 at kernel/workqueue.c:4418 workqueue_cpu_up_callback() Variant 2: cpu_notify(CPU_ONLINE) smpboot_thread_call() smpboot_unpark_threads() .. __kthread_unpark() __kthread_bind() wake_up_state() .. select_task_rq() select_fallback_rq() The ->wake_cpu of the unparked thread is not allowed, making a call to select_fallback_rq() necessary. Then, select_fallback_rq() cannot find an allowed, active CPU and promptly resets the allowed CPUs, so that the task in question ends up on CPU0. When those unparked tasks are eventually executed, they run immediately into a BUG: kernel BUG at kernel/smpboot.c:135! Just changing the order in which the online/active bits are set (and adding some memory barriers), would solve the two issues above. However, it would change the order of operations back to the one before commit 6acbfb96 ("sched: Fix hotplug vs. set_cpus_allowed_ptr()"), thus, reintroducing that particular problem. Going further back into history, we have at least the following commits touching this topic: - commit 2baab4e9 ("sched: Fix select_fallback_rq() vs cpu_active/cpu_online") - commit 5fbd036b ("sched: Cleanup cpu_active madness") Together, these give us the following non-working solutions: - secondary CPU sets active before online, because active is assumed to be a subset of online; - secondary CPU sets online before active, because the primary CPU assumes that an online CPU is also active; - secondary CPU sets online and waits for primary CPU to set active, because it might deadlock. Commit 875ebe94 ("powerpc/smp: Wait until secondaries are active & online") introduces an arch-specific solution to this arch-independent problem. Now, go for a more general solution without explicit waiting and simply set active twice: once on the secondary CPU after online was set and once on the primary CPU after online was seen. set_cpus_allowed_ptr()") Signed-off-by:
Jan H. Schönherr <jschoenh@amazon.de> Acked-by:
Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Anton Blanchard <anton@samba.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Joerg Roedel <jroedel@suse.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matt Wilson <msw@amazon.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: 6acbfb96 ("sched: Fix hotplug vs. set_cpus_allowed_ptr()") Link: http://lkml.kernel.org/r/1439408156-18840-1-git-send-email-jschoenh@amazon.deSigned-off-by:
Ingo Molnar <mingo@kernel.org> Signed-off-by:
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Paul E. McKenney authored
commit 26cdfedf upstream. If a system is idle from an RCU perspective for longer than specified by CONFIG_RCU_CPU_STALL_TIMEOUT, and if one CPU starts a grace period just as a second checks for CPU stalls, and if this second CPU happens to see the old value of rsp->jiffies_stall, it will incorrectly report a CPU stall. This is quite rare, but apparently occurs deterministically on systems with about 6TB of memory. This commit therefore orders accesses to the data used to determine whether or not a CPU stall is in progress. Grace-period initialization and cleanup first increments rsp->completed to mark the end of the previous grace period, then records the current jiffies in rsp->gp_start, then records the jiffies at which a stall can be expected to occur in rsp->jiffies_stall, and finally increments rsp->gpnum to mark the start of the new grace period. Now, this ordering by itself does not prevent false positives. For example, if grace-period initialization was delayed between recording rsp->gp_start and rsp->jiffies_stall, the CPU stall warning code might still see an old value of rsp->jiffies_stall. Therefore, this commit also orders the CPU stall warning accesses as well, loading rsp->gpnum and jiffies, then rsp->jiffies_stall, then rsp->gp_start, and finally rsp->completed. This ordering means that the false-positive scenario in the previous paragraph would result in rsp->completed being greater than or equal to rsp->gpnum, which is never valid for a CPU stall, allowing the false positive to be rejected. Furthermore, any fetch that gets an old value of rsp->jiffies_stall must also get an old value of rsp->gpnum, which will again be rejected by the comparison of rsp->gpnum and rsp->completed. Situations where rsp->gp_start is later than rsp->jiffies_stall are also rejected, as are situations where jiffies is less than rsp->jiffies_stall. Although use of unsynchronized accesses means that there are likely still some false-positive scenarios (synchronization has proven to be a very bad idea on large systems), this should get rid of a large class of these scenarios. Reported-by:
Fabian Herschel <fabian.herschel@suse.com> Reported-by:
Michal Hocko <mhocko@suse.com> Signed-off-by:
Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by:
Michal Hocko <mhocko@suse.cz> Tested-by:
Jochen Striepe <jochen@tolot.escape.de> Signed-off-by:
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Jan Kara authored
commit 841df7df upstream. Commit 6f6a6fda "jbd2: fix ocfs2 corrupt when updating journal superblock fails" changed jbd2_cleanup_journal_tail() to return EIO when the journal is aborted. That makes logic in jbd2_log_do_checkpoint() bail out which is fine, except that jbd2_journal_destroy() expects jbd2_log_do_checkpoint() to always make a progress in cleaning the journal. Without it jbd2_journal_destroy() just loops in an infinite loop. Fix jbd2_journal_destroy() to cleanup journal checkpoint lists of jbd2_log_do_checkpoint() fails with error. Reported-by:
Eryu Guan <guaneryu@gmail.com> Tested-by:
Jan Kara <jack@suse.com> Signed-off-by:
Theodore Ts'o <tytso@mit.edu> Signed-off-by:
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Andy Lutomirski authored
commit fc57a7c6 upstream. PARAVIRT_ADJUST_EXCEPTION_FRAME generates this code (using nmi as an example, trimmed for readability): ff 15 00 00 00 00 callq *0x0(%rip) # 2796 <nmi+0x6> 2792: R_X86_64_PC32 pv_irq_ops+0x2c That's a call through a function pointer to regular C function that does nothing on native boots, but that function isn't protected against kprobes, isn't marked notrace, and is certainly not guaranteed to preserve any registers if the compiler is feeling perverse. This is bad news for a CLBR_NONE operation. Of course, if everything works correctly, once paravirt ops are patched, it gets nopped out, but what if we hit this code before paravirt ops are patched in? This can potentially cause breakage that is very difficult to debug. A more subtle failure is possible here, too: if _paravirt_nop uses the stack at all (even just to push RBP), it will overwrite the "NMI executing" variable if it's called in the NMI prologue. The Xen case, perhaps surprisingly, is fine, because it's already written in asm. Fix all of the cases that default to paravirt_nop (including adjust_exception_frame) with a big hammer: replace paravirt_nop with an asm function that is just a ret instruction. The Xen case may have other problems, so document them. This is part of a fix for some random crashes that Sasha saw. Reported-and-tested-by:
Sasha Levin <sasha.levin@oracle.com> Signed-off-by:
Andy Lutomirski <luto@kernel.org> Link: http://lkml.kernel.org/r/8f5d2ba295f9d73751c33d97fda03e0495d9ade0.1442791737.git.luto@kernel.orgSigned-off-by:
Thomas Gleixner <tglx@linutronix.de> Signed-off-by:
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Andy Lutomirski authored
commit 83c133cf upstream. The NMI entry code that switches to the normal kernel stack needs to be very careful not to clobber any extra stack slots on the NMI stack. The code is fine under the assumption that SWAPGS is just a normal instruction, but that assumption isn't really true. Use SWAPGS_UNSAFE_STACK instead. This is part of a fix for some random crashes that Sasha saw. Fixes: 9b6e6a83 ("x86/nmi/64: Switch stacks on userspace NMI entry") Reported-and-tested-by:
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- 05 Oct, 2015 9 commits
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Jiri Slaby authored
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Paul Mackerras authored
commit e297c939 upstream. This fixes a race which can result in the same virtual IRQ number being assigned to two different MSI interrupts. The most visible consequence of that is usually a warning and stack trace from the sysfs code about an attempt to create a duplicate entry in sysfs. The race happens when one CPU (say CPU 0) is disposing of an MSI while another CPU (say CPU 1) is setting up an MSI. CPU 0 calls (for example) pnv_teardown_msi_irqs(), which calls msi_bitmap_free_hwirqs() to indicate that the MSI (i.e. its hardware IRQ number) is no longer in use. Then, before CPU 0 gets to calling irq_dispose_mapping() to free up the virtal IRQ number, CPU 1 comes in and calls msi_bitmap_alloc_hwirqs() to allocate an MSI, and gets the same hardware IRQ number that CPU 0 just freed. CPU 1 then calls irq_create_mapping() to get a virtual IRQ number, which sees that there is currently a mapping for that hardware IRQ number and returns the corresponding virtual IRQ number (which is the same virtual IRQ number that CPU 0 was using). CPU 0 then calls irq_dispose_mapping() and frees that virtual IRQ number. Now, if another CPU comes along and calls irq_create_mapping(), it is likely to get the virtual IRQ number that was just freed, resulting in the same virtual IRQ number apparently being used for two different hardware interrupts. To fix this race, we just move the call to msi_bitmap_free_hwirqs() to after the call to irq_dispose_mapping(). Since virq_to_hw() doesn't work for the virtual IRQ number after irq_dispose_mapping() has been called, we need to call it before irq_dispose_mapping() and remember the result for the msi_bitmap_free_hwirqs() call. The pattern of calling msi_bitmap_free_hwirqs() before irq_dispose_mapping() appears in 5 places under arch/powerpc, and appears to have originated in commit 05af7bd2 ("[POWERPC] MPIC U3/U4 MSI backend") from 2007. Fixes: 05af7bd2 ("[POWERPC] MPIC U3/U4 MSI backend") Reported-by:
Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by:
Paul Mackerras <paulus@samba.org> Signed-off-by:
Michael Ellerman <mpe@ellerman.id.au> Signed-off-by:
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Neil Brown authored
commit ee5d004f upstream. The 'event_work' worker used by dm-raid may still be running when the array is stopped. This can result in an oops. So flush the workqueue on which it is run after detaching and before destroying the device. Reported-by:
Heinz Mauelshagen <heinzm@redhat.com> Signed-off-by:
NeilBrown <neilb@suse.com> Fixes: 9d09e663 ("dm: raid456 basic support") Signed-off-by:
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Eric W. Biederman authored
commit 397d425d upstream. In rare cases a directory can be renamed out from under a bind mount. In those cases without special handling it becomes possible to walk up the directory tree to the root dentry of the filesystem and down from the root dentry to every other file or directory on the filesystem. Like division by zero .. from an unconnected path can not be given a useful semantic as there is no predicting at which path component the code will realize it is unconnected. We certainly can not match the current behavior as the current behavior is a security hole. Therefore when encounting .. when following an unconnected path return -ENOENT. - Add a function path_connected to verify path->dentry is reachable from path->mnt.mnt_root. AKA to validate that rename did not do something nasty to the bind mount. To avoid races path_connected must be called after following a path component to it's next path component. Signed-off-by:
"Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by:
Al Viro <viro@zeniv.linux.org.uk> Signed-off-by:
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Eric W. Biederman authored
commit cde93be4 upstream. A rename can result in a dentry that by walking up d_parent will never reach it's mnt_root. For lack of a better term I call this an escaped path. prepend_path is called by four different functions __d_path, d_absolute_path, d_path, and getcwd. __d_path only wants to see paths are connected to the root it passes in. So __d_path needs prepend_path to return an error. d_absolute_path similarly wants to see paths that are connected to some root. Escaped paths are not connected to any mnt_root so d_absolute_path needs prepend_path to return an error greater than 1. So escaped paths will be treated like paths on lazily unmounted mounts. getcwd needs to prepend "(unreachable)" so getcwd also needs prepend_path to return an error. d_path is the interesting hold out. d_path just wants to print something, and does not care about the weird cases. Which raises the question what should be printed? Given that <escaped_path>/<anything> should result in -ENOENT I believe it is desirable for escaped paths to be printed as empty paths. As there are not really any meaninful path components when considered from the perspective of a mount tree. So tweak prepend_path to return an empty path with an new error code of 3 when it encounters an escaped path. Signed-off-by:
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Andy Lutomirski authored
commit 810bc075 upstream. We have a tricky bug in the nested NMI code: if we see RSP pointing to the NMI stack on NMI entry from kernel mode, we assume that we are executing a nested NMI. This isn't quite true. A malicious userspace program can point RSP at the NMI stack, issue SYSCALL, and arrange for an NMI to happen while RSP is still pointing at the NMI stack. Fix it with a sneaky trick. Set DF in the region of code that the RSP check is intended to detect. IRET will clear DF atomically. ( Note: other than paravirt, there's little need for all this complexity. We could check RIP instead of RSP. ) Signed-off-by:
Steven Rostedt <rostedt@goodmis.org> Cc: Borislav Petkov <bp@suse.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by:
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Andy Lutomirski authored
commit a27507ca upstream. Check the repeat_nmi .. end_repeat_nmi special case first. The next patch will rework the RSP check and, as a side effect, the RSP check will no longer detect repeat_nmi .. end_repeat_nmi, so we'll need this ordering of the checks. Note: this is more subtle than it appears. The check for repeat_nmi .. end_repeat_nmi jumps straight out of the NMI code instead of adjusting the "iret" frame to force a repeat. This is necessary, because the code between repeat_nmi and end_repeat_nmi sets "NMI executing" and then writes to the "iret" frame itself. If a nested NMI comes in and modifies the "iret" frame while repeat_nmi is also modifying it, we'll end up with garbage. The old code got this right, as does the new code, but the new code is a bit more explicit. If we were to move the check right after the "NMI executing" check, then we'd get it wrong and have random crashes. ( Because the "NMI executing" check would jump to the code that would modify the "iret" frame without checking if the interrupted NMI was currently modifying it. ) Signed-off-by:
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Andy Lutomirski authored
commit 0b22930e upstream. I found the nested NMI documentation to be difficult to follow. Improve the comments. Signed-off-by:
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Wilson Kok authored
[ Upstream commit 41fc0143 ] dump_rules returns skb length and not error. But when family == AF_UNSPEC, the caller of dump_rules assumes that it returns an error. Hence, when family == AF_UNSPEC, we continue trying to dump on -EMSGSIZE errors resulting in incorrect dump idx carried between skbs belonging to the same dump. This results in fib rule dump always only dumping rules that fit into the first skb. This patch fixes dump_rules to return error so that we exit correctly and idx is correctly maintained between skbs that are part of the same dump. [rd] fix for <= 3.19: fib_nl_fill_rule() returns skb->len, make the check 'err < 0' Signed-off-by:
Wilson Kok <wkok@cumulusnetworks.com> Signed-off-by:
Roopa Prabhu <roopa@cumulusnetworks.com> Signed-off-by:
David S. Miller <davem@davemloft.net> Signed-off-by:
Roland Dreier <roland@purestorage.com> Signed-off-by:
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- 30 Sep, 2015 24 commits
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Jesse Gross authored
[ Upstream commit ae5f2fb1 ] When support for megaflows was introduced, OVS needed to start installing flows with a mask applied to them. Since masking is an expensive operation, OVS also had an optimization that would only take the parts of the flow keys that were covered by a non-zero mask. The values stored in the remaining pieces should not matter because they are masked out. While this works fine for the purposes of matching (which must always look at the mask), serialization to netlink can be problematic. Since the flow and the mask are serialized separately, the uninitialized portions of the flow can be encoded with whatever values happen to be present. In terms of functionality, this has little effect since these fields will be masked out by definition. However, it leaks kernel memory to userspace, which is a potential security vulnerability. It is also possible that other code paths could look at the masked key and get uninitialized data, although this does not currently appear to be an issue in practice. This removes the mask optimization for flows that are being installed. This was always intended to be the case as the mask optimizations were really targetting per-packet flow operations. Fixes: 03f0d916 ("openvswitch: Mega flow implementation") Signed-off-by:
Jesse Gross <jesse@nicira.com> Acked-by:
Pravin B Shelar <pshelar@nicira.com> Signed-off-by:
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Marcelo Ricardo Leitner authored
[ Upstream commit 8e2d61e0 ] Consider sctp module is unloaded and is being requested because an user is creating a sctp socket. During initialization, sctp will add the new protocol type and then initialize pernet subsys: status = sctp_v4_protosw_init(); if (status) goto err_protosw_init; status = sctp_v6_protosw_init(); if (status) goto err_v6_protosw_init; status = register_pernet_subsys(&sctp_net_ops); The problem is that after those calls to sctp_v{4,6}_protosw_init(), it is possible for userspace to create SCTP sockets like if the module is already fully loaded. If that happens, one of the possible effects is that we will have readers for net->sctp.local_addr_list list earlier than expected and sctp_net_init() does not take precautions while dealing with that list, leading to a potential panic but not limited to that, as sctp_sock_init() will copy a bunch of blank/partially initialized values from net->sctp. The race happens like this: CPU 0 | CPU 1 socket() | __sock_create | socket() inet_create | __sock_create list_for_each_entry_rcu( | answer, &inetsw[sock->type], | list) { | inet_create /* no hits */ | if (unlikely(err)) { | ... | request_module() | /* socket creation is blocked | * the module is fully loaded | */ | sctp_init | sctp_v4_protosw_init | inet_register_protosw | list_add_rcu(&p->list, | last_perm); | | list_for_each_entry_rcu( | answer, &inetsw[sock->type], sctp_v6_protosw_init | list) { | /* hit, so assumes protocol | * is already loaded | */ | /* socket creation continues | * before netns is initialized | */ register_pernet_subsys | Simply inverting the initialization order between register_pernet_subsys() and sctp_v4_protosw_init() is not possible because register_pernet_subsys() will create a control sctp socket, so the protocol must be already visible by then. Deferring the socket creation to a work-queue is not good specially because we loose the ability to handle its errors. So, as suggested by Vlad, the fix is to split netns initialization in two moments: defaults and control socket, so that the defaults are already loaded by when we register the protocol, while control socket initialization is kept at the same moment it is today. Fixes: 4db67e80 ("sctp: Make the address lists per network namespace") Signed-off-by:
Vlad Yasevich <vyasevich@gmail.com> Signed-off-by:
Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by:
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Daniel Borkmann authored
[ Upstream commit 1853c949 ] Ken-ichirou reported that running netlink in mmap mode for receive in combination with nlmon will throw a NULL pointer dereference in __kfree_skb() on nlmon_xmit(), in my case I can also trigger an "unable to handle kernel paging request". The problem is the skb_clone() in __netlink_deliver_tap_skb() for skbs that are mmaped. I.e. the cloned skb doesn't have a destructor, whereas the mmap netlink skb has it pointed to netlink_skb_destructor(), set in the handler netlink_ring_setup_skb(). There, skb->head is being set to NULL, so that in such cases, __kfree_skb() doesn't perform a skb_release_data() via skb_release_all(), where skb->head is possibly being freed through kfree(head) into slab allocator, although netlink mmap skb->head points to the mmap buffer. Similarly, the same has to be done also for large netlink skbs where the data area is vmalloced. Therefore, as discussed, make a copy for these rather rare cases for now. This fixes the issue on my and Ken-ichirou's test-cases. Reference: http://thread.gmane.org/gmane.linux.network/371129 Fixes: bcbde0d4 ("net: netlink: virtual tap device management") Reported-by:
Ken-ichirou MATSUZAWA <chamaken@gmail.com> Signed-off-by:
Daniel Borkmann <daniel@iogearbox.net> Tested-by:
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Richard Laing authored
[ Upstream commit 25b4a44c ] In the IPv6 multicast routing code the mrt_lock was not being released correctly in the MFC iterator, as a result adding or deleting a MIF would cause a hang because the mrt_lock could not be acquired. This fix is a copy of the code for the IPv4 case and ensures that the lock is released correctly. Signed-off-by:
Richard Laing <richard.laing@alliedtelesis.co.nz> Acked-by:
Cong Wang <cwang@twopensource.com> Signed-off-by:
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Daniel Borkmann authored
[ Upstream commit e41b0bed ] We previously register IPPROTO_ROUTING offload under inet6_add_offload(), but in error path, we try to unregister it with inet_del_offload(). This doesn't seem correct, it should actually be inet6_del_offload(), also ipv6_exthdrs_offload_exit() from that commit seems rather incorrect (it also uses rthdr_offload twice), but it got removed entirely later on. Fixes: 3336288a ("ipv6: Switch to using new offload infrastructure.") Signed-off-by:
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Eugene Shatokhin authored
[ Upstream commit f50791ac ] It is needed to check EVENT_NO_RUNTIME_PM bit of dev->flags in usbnet_stop(), but its value should be read before it is cleared when dev->flags is set to 0. The problem was spotted and the fix was provided by Oliver Neukum <oneukum@suse.de>. Signed-off-by:
Eugene Shatokhin <eugene.shatokhin@rosalab.ru> Acked-by:
Oliver Neukum <oneukum@suse.com> Signed-off-by:
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huaibin Wang authored
[ Upstream commit d4257295 ] When a tunnel is deleted, the cached dst entry should be released. This problem may prevent the removal of a netns (seen with a x-netns IPv6 gre tunnel): unregister_netdevice: waiting for lo to become free. Usage count = 3 CC: Dmitry Kozlov <xeb@mail.ru> Fixes: c12b395a ("gre: Support GRE over IPv6") Signed-off-by:
huaibin Wang <huaibin.wang@6wind.com> Signed-off-by:
Nicolas Dichtel <nicolas.dichtel@6wind.com> Signed-off-by:
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Hin-Tak Leung authored
commit 7cb74be6 upstream. Pages looked up by __hfs_bnode_create() (called by hfs_bnode_create() and hfs_bnode_find() for finding or creating pages corresponding to an inode) are immediately kmap()'ed and used (both read and write) and kunmap()'ed, and should not be page_cache_release()'ed until hfs_bnode_free(). This patch fixes a problem I first saw in July 2012: merely running "du" on a large hfsplus-mounted directory a few times on a reasonably loaded system would get the hfsplus driver all confused and complaining about B-tree inconsistencies, and generates a "BUG: Bad page state". Most recently, I can generate this problem on up-to-date Fedora 22 with shipped kernel 4.0.5, by running "du /" (="/" + "/home" + "/mnt" + other smaller mounts) and "du /mnt" simultaneously on two windows, where /mnt is a lightly-used QEMU VM image of the full Mac OS X 10.9: $ df -i / /home /mnt Filesystem Inodes IUsed IFree IUse% Mounted on /dev/mapper/fedora-root 3276800 551665 2725135 17% / /dev/mapper/fedora-home 52879360 716221 52163139 2% /home /dev/nbd0p2 4294967295 1387818 4293579477 1% /mnt After applying the patch, I was able to run "du /" (60+ times) and "du /mnt" (150+ times) continuously and simultaneously for 6+ hours. There are many reports of the hfsplus driver getting confused under load and generating "BUG: Bad page state" or other similar issues over the years. [1] The unpatched code [2] has always been wrong since it entered the kernel tree. The only reason why it gets away with it is that the kmap/memcpy/kunmap follow very quickly after the page_cache_release() so the kernel has not had a chance to reuse the memory for something else, most of the time. The current RW driver appears to have followed the design and development of the earlier read-only hfsplus driver [3], where-by version 0.1 (Dec 2001) had a B-tree node-centric approach to read_cache_page()/page_cache_release() per bnode_get()/bnode_put(), migrating towards version 0.2 (June 2002) of caching and releasing pages per inode extents. When the current RW code first entered the kernel [2] in 2005, there was an REF_PAGES conditional (and "//" commented out code) to switch between B-node centric paging to inode-centric paging. There was a mistake with the direction of one of the REF_PAGES conditionals in __hfs_bnode_create(). In a subsequent "remove debug code" commit [4], the read_cache_page()/page_cache_release() per bnode_get()/bnode_put() were removed, but a page_cache_release() was mistakenly left in (propagating the "REF_PAGES <-> !REF_PAGE" mistake), and the commented-out page_cache_release() in bnode_release() (which should be spanned by !REF_PAGES) was never enabled. References: [1]: Michael Fox, Apr 2013 http://www.spinics.net/lists/linux-fsdevel/msg63807.html ("hfsplus volume suddenly inaccessable after 'hfs: recoff %d too large'") Sasha Levin, Feb 2015 http://lkml.org/lkml/2015/2/20/85 ("use after free") https://bugs.launchpad.net/ubuntu/+source/linux/+bug/740814 https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1027887 https://bugzilla.kernel.org/show_bug.cgi?id=42342 https://bugzilla.kernel.org/show_bug.cgi?id=63841 https://bugzilla.kernel.org/show_bug.cgi?id=78761 [2]: http://git.kernel.org/cgit/linux/kernel/git/tglx/history.git/commit/\ fs/hfs/bnode.c?id=d1081202 commit d1081202 Author: Andrew Morton <akpm@osdl.org> Date: Wed Feb 25 16:17:36 2004 -0800 [PATCH] HFS rewrite http://git.kernel.org/cgit/linux/kernel/git/tglx/history.git/commit/\ fs/hfsplus/bnode.c?id=91556682 commit 91556682 Author: Andrew Morton <akpm@osdl.org> Date: Wed Feb 25 16:17:48 2004 -0800 [PATCH] HFS+ support [3]: http://sourceforge.net/projects/linux-hfsplus/ http://sourceforge.net/projects/linux-hfsplus/files/Linux%202.4.x%20patch/hfsplus%200.1/ http://sourceforge.net/projects/linux-hfsplus/files/Linux%202.4.x%20patch/hfsplus%200.2/ http://linux-hfsplus.cvs.sourceforge.net/viewvc/linux-hfsplus/linux/\ fs/hfsplus/bnode.c?r1=1.4&r2=1.5 Date: Thu Jun 6 09:45:14 2002 +0000 Use buffer cache instead of page cache in bnode.c. Cache inode extents. [4]: http://git.kernel.org/cgit/linux/kernel/git/\ stable/linux-stable.git/commit/?id=a5e3985f commit a5e3985f Author: Roman Zippel <zippel@linux-m68k.org> Date: Tue Sep 6 15:18:47 2005 -0700 [PATCH] hfs: remove debug code Signed-off-by:
Hin-Tak Leung <htl10@users.sourceforge.net> Signed-off-by:
Sergei Antonov <saproj@gmail.com> Reviewed-by:
Anton Altaparmakov <anton@tuxera.com> Reported-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by:
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Alexey Brodkin authored
commit f1590670 upstream. Current implementation of descriptor init procedure only takes care about setting/clearing ownership flag in "des0"/"des1" fields while it is perfectly possible to get unexpected bits set because of the following factors: [1] On driver probe underlying memory allocated with dma_alloc_coherent() might not be zeroed and so it will be filled with garbage. [2] During driver operation some bits could be set by SD/MMC controller (for example error flags etc). And unexpected and/or randomly set flags in "des0"/"des1" fields may lead to unpredictable behavior of GMAC DMA block. This change addresses both items above with: [1] Use of dma_zalloc_coherent() instead of simple dma_alloc_coherent() to make sure allocated memory is zeroed. That shouldn't affect performance because this allocation only happens once on driver probe. [2] Do explicit zeroing of both "des0" and "des1" fields of all buffer descriptors during initialization of DMA transfer. And while at it fixed identation of dma_free_coherent() counterpart as well. Signed-off-by:
Alexey Brodkin <abrodkin@synopsys.com> Cc: Giuseppe Cavallaro <peppe.cavallaro@st.com> Cc: arc-linux-dev@synopsys.com Cc: linux-kernel@vger.kernel.org Cc: stable@vger.kernel.org Cc: David Miller <davem@davemloft.net> Signed-off-by:
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Noa Osherovich authored
commit 5e99b139 upstream. The mlx4 IB driver implementation for ib_query_ah used a wrong offset (28 instead of 29) when link type is Ethernet. Fixed to use the correct one. Fixes: fa417f7b ('IB/mlx4: Add support for IBoE') Signed-off-by:
Shani Michaeli <shanim@mellanox.com> Signed-off-by:
Noa Osherovich <noaos@mellanox.com> Signed-off-by:
Or Gerlitz <ogerlitz@mellanox.com> Signed-off-by:
Doug Ledford <dledford@redhat.com> Signed-off-by:
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Jack Morgenstein authored
commit 2b135db3 upstream. The pkey mapping for RoCE must remain the default mapping: VFs: virtual index 0 = mapped to real index 0 (0xFFFF) All others indices: mapped to a real pkey index containing an invalid pkey. PF: virtual index i = real index i. Don't allow users to change these mappings using files found in sysfs. Fixes: c1e7e466 ('IB/mlx4: Add iov directory in sysfs under the ib device') Signed-off-by:
Jack Morgenstein <jackm@dev.mellanox.co.il> Signed-off-by:
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Yishai Hadas authored
commit 35d4a0b6 upstream. Fixes: 2a72f212 ("IB/uverbs: Remove dev_table") Before this commit there was a device look-up table that was protected by a spin_lock used by ib_uverbs_open and by ib_uverbs_remove_one. When it was dropped and container_of was used instead, it enabled the race with remove_one as dev might be freed just after: dev = container_of(inode->i_cdev, struct ib_uverbs_device, cdev) but before the kref_get. In addition, this buggy patch added some dead code as container_of(x,y,z) can never be NULL and so dev can never be NULL. As a result the comment above ib_uverbs_open saying "the open method will either immediately run -ENXIO" is wrong as it can never happen. The solution follows Jason Gunthorpe suggestion from below URL: https://www.mail-archive.com/linux-rdma@vger.kernel.org/msg25692.html cdev will hold a kref on the parent (the containing structure, ib_uverbs_device) and only when that kref is released it is guaranteed that open will never be called again. In addition, fixes the active count scheme to use an atomic not a kref to prevent WARN_ON as pointed by above comment from Jason. Signed-off-by:
Yishai Hadas <yishaih@mellanox.com> Signed-off-by:
Shachar Raindel <raindel@mellanox.com> Reviewed-by:
Jason Gunthorpe <jgunthorpe@obsidianresearch.com> Signed-off-by:
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Christoph Hellwig authored
commit b632ffa7 upstream. We have many WR opcodes that are only supported in kernel space and/or require optional information to be copied into the WR structure. Reject all those not explicitly handled so that we can't pass invalid information to drivers. Signed-off-by:
Christoph Hellwig <hch@lst.de> Reviewed-by:
Sagi Grimberg <sagig@mellanox.com> Signed-off-by:
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Mike Marciniszyn authored
commit d6f1c17e upstream. The lkey table is allocated with with a get_user_pages() with an order based on a number of index bits from a module parameter. The underlying kernel code cannot allocate that many contiguous pages. There is no reason the underlying memory needs to be physically contiguous. This patch: - switches the allocation/deallocation to vmalloc/vfree - caps the number of bits to 23 to insure at least 1 generation bit o this matches the module parameter description Reviewed-by:
Vinit Agnihotri <vinit.abhay.agnihotri@intel.com> Signed-off-by:
Mike Marciniszyn <mike.marciniszyn@intel.com> Signed-off-by:
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Hin-Tak Leung authored
commit b4cc0efe upstream. Fix B-tree corruption when a new record is inserted at position 0 in the node in hfs_brec_insert(). This is an identical change to the corresponding hfs b-tree code to Sergei Antonov's "hfsplus: fix B-tree corruption after insertion at position 0", to keep similar code paths in the hfs and hfsplus drivers in sync, where appropriate. Signed-off-by:
Vyacheslav Dubeyko <slava@dubeyko.com> Cc: Anton Altaparmakov <anton@tuxera.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Christoph Hellwig <hch@infradead.org> Cc: <stable@vger.kernel.org> Signed-off-by:
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David Vrabel authored
commit 1401c00e upstream. Unmapping may require sleeping and we unmap while holding priv->lock, so convert it to a mutex. Signed-off-by:
David Vrabel <david.vrabel@citrix.com> Reviewed-by:
Stefano Stabellini <stefano.stabellini@eu.citrix.com> Cc: Ian Campbell <ian.campbell@citrix.com> Signed-off-by:
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NeilBrown authored
commit 299b0685 upstream. 'reshape_position' tracks where in the reshape we have reached. 'reshape_safe' tracks where in the reshape we have safely recorded in the metadata. These are compared to determine when to update the metadata. So it is important that reshape_safe is initialised properly. Currently it isn't. When starting a reshape from the beginning it usually has the correct value by luck. But when reducing the number of devices in a RAID10, it has the wrong value and this leads to the metadata not being updated correctly. This can lead to corruption if the reshape is not allowed to complete. This patch is suitable for any -stable kernel which supports RAID10 reshape, which is 3.5 and later. Fixes: 3ea7daa5 ("md/raid10: add reshape support") Signed-off-by:
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Jialing Fu authored
commit 71f8a4b8 upstream. The following panic is captured in ker3.14, but the issue still exists in latest kernel. --------------------------------------------------------------------- [ 20.738217] c0 3136 (Compiler) Unable to handle kernel NULL pointer dereference at virtual address 00000578 ...... [ 20.738499] c0 3136 (Compiler) PC is at _raw_spin_lock_irqsave+0x24/0x60 [ 20.738527] c0 3136 (Compiler) LR is at _raw_spin_lock_irqsave+0x20/0x60 [ 20.740134] c0 3136 (Compiler) Call trace: [ 20.740165] c0 3136 (Compiler) [<ffffffc0008ee900>] _raw_spin_lock_irqsave+0x24/0x60 [ 20.740200] c0 3136 (Compiler) [<ffffffc0000dd024>] __wake_up+0x1c/0x54 [ 20.740230] c0 3136 (Compiler) [<ffffffc000639414>] mmc_wait_data_done+0x28/0x34 [ 20.740262] c0 3136 (Compiler) [<ffffffc0006391a0>] mmc_request_done+0xa4/0x220 [ 20.740314] c0 3136 (Compiler) [<ffffffc000656894>] sdhci_tasklet_finish+0xac/0x264 [ 20.740352] c0 3136 (Compiler) [<ffffffc0000a2b58>] tasklet_action+0xa0/0x158 [ 20.740382] c0 3136 (Compiler) [<ffffffc0000a2078>] __do_softirq+0x10c/0x2e4 [ 20.740411] c0 3136 (Compiler) [<ffffffc0000a24bc>] irq_exit+0x8c/0xc0 [ 20.740439] c0 3136 (Compiler) [<ffffffc00008489c>] handle_IRQ+0x48/0xac [ 20.740469] c0 3136 (Compiler) [<ffffffc000081428>] gic_handle_irq+0x38/0x7c ---------------------------------------------------------------------- Because in SMP, "mrq" has race condition between below two paths: path1: CPU0: <tasklet context> static void mmc_wait_data_done(struct mmc_request *mrq) { mrq->host->context_info.is_done_rcv = true; // // If CPU0 has just finished "is_done_rcv = true" in path1, and at // this moment, IRQ or ICache line missing happens in CPU0. // What happens in CPU1 (path2)? // // If the mmcqd thread in CPU1(path2) hasn't entered to sleep mode: // path2 would have chance to break from wait_event_interruptible // in mmc_wait_for_data_req_done and continue to run for next // mmc_request (mmc_blk_rw_rq_prep). // // Within mmc_blk_rq_prep, mrq is cleared to 0. // If below line still gets host from "mrq" as the result of // compiler, the panic happens as we traced. wake_up_interruptible(&mrq->host->context_info.wait); } path2: CPU1: <The mmcqd thread runs mmc_queue_thread> static int mmc_wait_for_data_req_done(... { ... while (1) { wait_event_interruptible(context_info->wait, (context_info->is_done_rcv || context_info->is_new_req)); static void mmc_blk_rw_rq_prep(... { ... memset(brq, 0, sizeof(struct mmc_blk_request)); This issue happens very coincidentally; however adding mdelay(1) in mmc_wait_data_done as below could duplicate it easily. static void mmc_wait_data_done(struct mmc_request *mrq) { mrq->host->context_info.is_done_rcv = true; + mdelay(1); wake_up_interruptible(&mrq->host->context_info.wait); } At runtime, IRQ or ICache line missing may just happen at the same place of the mdelay(1). This patch gets the mmc_context_info at the beginning of function, it can avoid this race condition. Signed-off-by:
Jialing Fu <jlfu@marvell.com> Tested-by:
Shawn Lin <shawn.lin@rock-chips.com> Fixes: 2220eedf ("mmc: fix async request mechanism ....") Signed-off-by:
Ulf Hansson <ulf.hansson@linaro.org> Signed-off-by:
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Jann Horn authored
commit fbb18169 upstream. It was possible for an attacking user to trick root (or another user) into writing his coredumps into an attacker-readable, pre-existing file using rename() or link(), causing the disclosure of secret data from the victim process' virtual memory. Depending on the configuration, it was also possible to trick root into overwriting system files with coredumps. Fix that issue by never writing coredumps into existing files. Requirements for the attack: - The attack only applies if the victim's process has a nonzero RLIMIT_CORE and is dumpable. - The attacker can trick the victim into coredumping into an attacker-writable directory D, either because the core_pattern is relative and the victim's cwd is attacker-writable or because an absolute core_pattern pointing to a world-writable directory is used. - The attacker has one of these: A: on a system with protected_hardlinks=0: execute access to a folder containing a victim-owned, attacker-readable file on the same partition as D, and the victim-owned file will be deleted before the main part of the attack takes place. (In practice, there are lots of files that fulfill this condition, e.g. entries in Debian's /var/lib/dpkg/info/.) This does not apply to most Linux systems because most distros set protected_hardlinks=1. B: on a system with protected_hardlinks=1: execute access to a folder containing a victim-owned, attacker-readable and attacker-writable file on the same partition as D, and the victim-owned file will be deleted before the main part of the attack takes place. (This seems to be uncommon.) C: on any system, independent of protected_hardlinks: write access to a non-sticky folder containing a victim-owned, attacker-readable file on the same partition as D (This seems to be uncommon.) The basic idea is that the attacker moves the victim-owned file to where he expects the victim process to dump its core. The victim process dumps its core into the existing file, and the attacker reads the coredump from it. If the attacker can't move the file because he does not have write access to the containing directory, he can instead link the file to a directory he controls, then wait for the original link to the file to be deleted (because the kernel checks that the link count of the corefile is 1). A less reliable variant that requires D to be non-sticky works with link() and does not require deletion of the original link: link() the file into D, but then unlink() it directly before the kernel performs the link count check. On systems with protected_hardlinks=0, this variant allows an attacker to not only gain information from coredumps, but also clobber existing, victim-writable files with coredumps. (This could theoretically lead to a privilege escalation.) Signed-off-by:
Jann Horn <jann@thejh.net> Cc: Kees Cook <keescook@chromium.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by:
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Jaewon Kim authored
commit c54839a7 upstream. reclaim_clean_pages_from_list() assumes that shrink_page_list() returns number of pages removed from the candidate list. But shrink_page_list() puts back mlocked pages without passing it to caller and without counting as nr_reclaimed. This increases nr_isolated. To fix this, this patch changes shrink_page_list() to pass unevictable pages back to caller. Caller will take care those pages. Minchan said: It fixes two issues. 1. With unevictable page, cma_alloc will be successful. Exactly speaking, cma_alloc of current kernel will fail due to unevictable pages. 2. fix leaking of NR_ISOLATED counter of vmstat With it, too_many_isolated works. Otherwise, it could make hang until the process get SIGKILL. Signed-off-by:
Jaewon Kim <jaewon31.kim@samsung.com> Acked-by:
Minchan Kim <minchan@kernel.org> Cc: Mel Gorman <mgorman@techsingularity.net> Acked-by:
Vlastimil Babka <vbabka@suse.cz> Signed-off-by:
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Helge Deller authored
commit b1b4e435 upstream. When detecting a serial port on newer PA-RISC machines (with iosapic) we have a long way to go to find the right IRQ line, registering it, then registering the serial port and the irq handler for the serial port. During this phase spurious interrupts for the serial port may happen which then crashes the kernel because the action handler might not have been set up yet. So, basically it's a race condition between the serial port hardware and the CPU which sets up the necessary fields in the irq sructs. The main reason for this race is, that we unmask the serial port irqs too early without having set up everything properly before (which isn't easily possible because we need the IRQ number to register the serial ports). This patch is a work-around for this problem. It adds checks to the CPU irq handler to verify if the IRQ action field has been initialized already. If not, we just skip this interrupt (which isn't critical for a serial port at bootup). The real fix would probably involve rewriting all PA-RISC specific IRQ code (for CPU, IOSAPIC, GSC and EISA) to use IRQ domains with proper parenting of the irq chips and proper irq enabling along this line. This bug has been in the PA-RISC port since the beginning, but the crashes happened very rarely with currently used hardware. But on the latest machine which I bought (a C8000 workstation), which uses the fastest CPUs (4 x PA8900, 1GHz) and which has the largest possible L1 cache size (64MB each), the kernel crashed at every boot because of this race. So, without this patch the machine would currently be unuseable. For the record, here is the flow logic: 1. serial_init_chip() in 8250_gsc.c calls iosapic_serial_irq(). 2. iosapic_serial_irq() calls txn_alloc_irq() to find the irq. 3. iosapic_serial_irq() calls cpu_claim_irq() to register the CPU irq 4. cpu_claim_irq() unmasks the CPU irq (which it shouldn't!) 5. serial_init_chip() then registers the 8250 port. Problems: - In step 4 the CPU irq shouldn't have been registered yet, but after step 5 - If serial irq happens between 4 and 5 have finished, the kernel will crash Signed-off-by:
Helge Deller <deller@gmx.de> Signed-off-by:
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Trond Myklebust authored
commit e9ae58ae upstream. We should ensure that we always set the pgio_header's error field if a READ or WRITE RPC call returns an error. The current code depends on 'hdr->good_bytes' always being initialised to a large value, which is not always done correctly by callers. When this happens, applications may end up missing important errors. Signed-off-by:
Trond Myklebust <trond.myklebust@primarydata.com> Signed-off-by:
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NeilBrown authored
commit efcbc04e upstream. It is unusual to combine the open flags O_RDONLY and O_EXCL, but it appears that libre-office does just that. [pid 3250] stat("/home/USER/.config", {st_mode=S_IFDIR|0700, st_size=8192, ...}) = 0 [pid 3250] open("/home/USER/.config/libreoffice/4-suse/user/extensions/buildid", O_RDONLY|O_EXCL <unfinished ...> NFSv4 takes O_EXCL as a sign that a setattr command should be sent, probably to reset the timestamps. When it was an O_RDONLY open, the SETATTR command does not identify any actual attributes to change. If no delegation was provided to the open, the SETATTR uses the all-zeros stateid and the request is accepted (at least by the Linux NFS server - no harm, no foul). If a read-delegation was provided, this is used in the SETATTR request, and a Netapp filer will justifiably claim NFS4ERR_BAD_STATEID, which the Linux client takes as a sign to retry - indefinitely. So only treat O_EXCL specially if O_CREAT was also given. Signed-off-by:
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Filipe Manana authored
commit 1f9b8c8f upstream. While we are committing a transaction, it's possible the previous one is still finishing its commit and therefore we wait for it to finish first. However we were not checking if that previous transaction ended up getting aborted after we waited for it to commit, so we ended up committing the current transaction which can lead to fs corruption because the new superblock can point to trees that have had one or more nodes/leafs that were never durably persisted. The following sequence diagram exemplifies how this is possible: CPU 0 CPU 1 transaction N starts (...) btrfs_commit_transaction(N) cur_trans->state = TRANS_STATE_COMMIT_START; (...) cur_trans->state = TRANS_STATE_COMMIT_DOING; (...) cur_trans->state = TRANS_STATE_UNBLOCKED; root->fs_info->running_transaction = NULL; btrfs_start_transaction() --> starts transaction N + 1 btrfs_write_and_wait_transaction(trans, root); --> starts writing all new or COWed ebs created at transaction N creates some new ebs, COWs some existing ebs but doesn't COW or deletes eb X btrfs_commit_transaction(N + 1) (...) cur_trans->state = TRANS_STATE_COMMIT_START; (...) wait_for_commit(root, prev_trans); --> prev_trans == transaction N btrfs_write_and_wait_transaction() continues writing ebs --> fails writing eb X, we abort transaction N and set bit BTRFS_FS_STATE_ERROR on fs_info->fs_state, so no new transactions can start after setting that bit cleanup_transaction() btrfs_cleanup_one_transaction() wakes up task at CPU 1 continues, doesn't abort because cur_trans->aborted (transaction N + 1) is zero, and no checks for bit BTRFS_FS_STATE_ERROR in fs_info->fs_state are made btrfs_write_and_wait_transaction(trans, root); --> succeeds, no errors during writeback write_ctree_super(trans, root, 0); --> succeeds --> we have now a superblock that points us to some root that uses eb X, which was never written to disk In this scenario future attempts to read eb X from disk results in an error message like "parent transid verify failed on X wanted Y found Z". So fix this by aborting the current transaction if after waiting for the previous transaction we verify that it was aborted. Signed-off-by:
Filipe Manana <fdmanana@suse.com> Reviewed-by:
Josef Bacik <jbacik@fb.com> Reviewed-by:
Liu Bo <bo.li.liu@oracle.com> Signed-off-by:
Chris Mason <clm@fb.com> Signed-off-by:
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