- 05 Sep, 2018 40 commits
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Gustavo A. R. Silva authored
commit d49dbfad upstream. val can be indirectly controlled by user-space, hence leading to a potential exploitation of the Spectre variant 1 vulnerability. This issue was detected with the help of Smatch: vers/hwmon/nct6775.c:2698 store_pwm_weight_temp_sel() warn: potential spectre issue 'data->temp_src' [r] Fix this by sanitizing val before using it to index data->temp_src Notice that given that speculation windows are large, the policy is to kill the speculation on the first load and not worry if it can be completed with a dependent load/store [1]. [1] https://marc.info/?l=linux-kernel&m=152449131114778&w=2 Cc: stable@vger.kernel.org Signed-off-by:
Gustavo A. R. Silva <gustavo@embeddedor.com> Signed-off-by:
Guenter Roeck <linux@roeck-us.net> Signed-off-by:
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Andi Kleen authored
commit cc51e542 upstream. On Nehalem and newer core CPUs the CPU cache internally uses 44 bits physical address space. The L1TF workaround is limited by this internal cache address width, and needs to have one bit free there for the mitigation to work. Older client systems report only 36bit physical address space so the range check decides that L1TF is not mitigated for a 36bit phys/32GB system with some memory holes. But since these actually have the larger internal cache width this warning is bogus because it would only really be needed if the system had more than 43bits of memory. Add a new internal x86_cache_bits field. Normally it is the same as the physical bits field reported by CPUID, but for Nehalem and newerforce it to be at least 44bits. Change the L1TF memory size warning to use the new cache_bits field to avoid bogus warnings and remove the bogus comment about memory size. Fixes: 17dbca11 ("x86/speculation/l1tf: Add sysfs reporting for l1tf") Reported-by:
George Anchev <studio@anchev.net> Reported-by:
Christopher Snowhill <kode54@gmail.com> Signed-off-by:
Andi Kleen <ak@linux.intel.com> Signed-off-by:
Thomas Gleixner <tglx@linutronix.de> Cc: x86@kernel.org Cc: linux-kernel@vger.kernel.org Cc: Michael Hocko <mhocko@suse.com> Cc: vbabka@suse.cz Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20180824170351.34874-1-andi@firstfloor.orgSigned-off-by:
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Andi Kleen authored
commit 1ab534e8 upstream. The check for Spectre microcodes does not check for family 6, only the model numbers. Add a family 6 check to avoid ambiguity with other families. Fixes: a5b29663 ("x86/cpufeature: Blacklist SPEC_CTRL/PRED_CMD on early Spectre v2 microcodes") Signed-off-by:
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Nick Desaulniers authored
commit 1f59a458 upstream. This should have been marked extern inline in order to pick up the out of line definition in arch/x86/kernel/irqflags.S. Fixes: 208cbb32 ("x86/irqflags: Provide a declaration for native_save_fl") Reported-by:
Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by:
Nick Desaulniers <ndesaulniers@google.com> Signed-off-by:
Juergen Gross <jgross@suse.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20180827214011.55428-1-ndesaulniers@google.comSigned-off-by:
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Andy Lutomirski authored
commit 4012e77a upstream. A NMI can hit in the middle of context switching or in the middle of switch_mm_irqs_off(). In either case, CR3 might not match current->mm, which could cause copy_from_user_nmi() and friends to read the wrong memory. Fix it by adding a new nmi_uaccess_okay() helper and checking it in copy_from_user_nmi() and in __copy_from_user_nmi()'s callers. Signed-off-by:
Andy Lutomirski <luto@kernel.org> Signed-off-by:
Rik van Riel <riel@surriel.com> Cc: Nadav Amit <nadav.amit@gmail.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Jann Horn <jannh@google.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/dd956eba16646fd0b15c3c0741269dfd84452dac.1535557289.git.luto@kernel.orgSigned-off-by:
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Samuel Neves authored
commit e78e5a91 upstream. In the __getcpu function, lsl is using the wrong target and destination registers. Luckily, the compiler tends to choose %eax for both variables, so it has been working so far. Fixes: a582c540 ("x86/vdso: Use RDPID in preference to LSL when available") Signed-off-by:
Samuel Neves <sneves@dei.uc.pt> Signed-off-by:
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Dan Carpenter authored
commit 19da44cd upstream. The info->groups[] array is allocated in imx1_pinctrl_parse_dt(). It has info->ngroups elements. Thus the > here should be >= to prevent reading one element beyond the end of the array. Cc: stable@vger.kernel.org Fixes: 30612cd9 ("pinctrl: imx1 core driver") Signed-off-by:
Dan Carpenter <dan.carpenter@oracle.com> Reviewed-by:
Uwe Kleine-König <u.kleine-könig@pengutronix.de> Acked-by:
Dong Aisheng <Aisheng.dong@nxp.com> Signed-off-by:
Linus Walleij <linus.walleij@linaro.org> Signed-off-by:
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Gustavo A. R. Silva authored
commit ae1c696a upstream. There is a potential execution path in which function platform_get_resource() returns NULL. If this happens, we will end up having a NULL pointer dereference. Fix this by replacing devm_ioremap with devm_ioremap_resource, which has the NULL check and the memory region request. This code was detected with the help of Coccinelle. Cc: stable@vger.kernel.org Fixes: 2bd8d1d5 ("ASoC: sirf: Add audio usp interface driver") Signed-off-by:
Mark Brown <broonie@kernel.org> Signed-off-by:
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Takashi Iwai authored
commit c889a45d upstream. zx-tdm driver sets the DAI driver definitions with the format bits wrongly set with SNDRV_PCM_FORMAT_*, instead of SNDRV_PCM_FMTBIT_*. This patch corrects the definitions. Spotted by a sparse warning: sound/soc/zte/zx-tdm.c:363:35: warning: restricted snd_pcm_format_t degrades to integer Fixes: 870e0ddc ("ASoC: zx-tdm: add zte's tdm controller driver") Cc: <stable@vger.kernel.org> Signed-off-by:
Takashi Iwai <tiwai@suse.de> Signed-off-by:
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Jerome Brunet authored
commit 4febced1 upstream. When merging codec formats, dpcm_runtime_base_format() should skip the codecs which are not supporting the current stream direction. At the moment, if a BE link has more than one codec, and only one of these codecs has no capture DAI, it becomes impossible to start a capture stream because the merged format would be 0. Skipping invalid codec DAI solves the problem. Fixes: b073ed4e ("ASoC: soc-pcm: DPCM cares BE format") Signed-off-by:
Jerome Brunet <jbrunet@baylibre.com> Signed-off-by:
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Michael Buesch authored
commit 2aa650d1 upstream. strncpy might not NUL-terminate the string, if the name equals the buffer size. Use strlcpy instead. Signed-off-by:
Michael Buesch <m@bues.ch> Cc: stable@vger.kernel.org Signed-off-by:
Kalle Valo <kvalo@codeaurora.org> Signed-off-by:
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Michael Buesch authored
commit 4d77a89e upstream. strncpy might not NUL-terminate the string, if the name equals the buffer size. Use strlcpy instead. Signed-off-by:
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Mikulas Patocka authored
commit 91ba11fb upstream. Division is slow, so it shouldn't be done by the pixel generating code. The driver supports only 2 or 4 bytes per pixel, so we can replace division with a shift. Signed-off-by:
Mikulas Patocka <mpatocka@redhat.com> Cc: stable@vger.kernel.org Signed-off-by:
Dave Airlie <airlied@redhat.com> Signed-off-by:
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Mikulas Patocka authored
commit 09a00abe upstream. We must use kzalloc when allocating the fb_deferred_io structure. Otherwise, the field first_io is undefined and it causes a crash. Signed-off-by:
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Mikulas Patocka authored
commit 542bb978 upstream. Allocations larger than PAGE_ALLOC_COSTLY_ORDER are unreliable and they may fail anytime. This patch fixes the udl kms driver so that when a large alloactions fails, it tries to do multiple smaller allocations. Signed-off-by:
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Mikulas Patocka authored
commit 8456b99c upstream. If we leave urbs around, it causes not only leak, but also memory corruption. This patch fixes the function udl_free_urb_list, so that it always waits for all urbs that are in progress. Signed-off-by:
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Kirill Tkhai authored
commit 109728cc upstream. The above error path returns with page unlocked, so this place seems also to behave the same. Fixes: f8dbdf81 ("fuse: rework fuse_readpages()") Signed-off-by:
Kirill Tkhai <ktkhai@virtuozzo.com> Signed-off-by:
Miklos Szeredi <mszeredi@redhat.com> Signed-off-by:
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Miklos Szeredi authored
commit e8f3bd77 upstream. syzbot is hitting NULL pointer dereference at process_init_reply(). This is because deactivate_locked_super() is called before response for initial request is processed. Fix this by aborting and waiting for all requests (including FUSE_INIT) before resetting fc->sb. Original patch by Tetsuo Handa <penguin-kernel@I-love.SKAURA.ne.jp>. Reported-by:
syzbot <syzbot+b62f08f4d5857755e3bc@syzkaller.appspotmail.com> Fixes: e27c9d38 ("fuse: fuse: add time_gran to INIT_OUT") Cc: <stable@vger.kernel.org> # v3.19 Signed-off-by:
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Miklos Szeredi authored
commit b8f95e5d upstream. fuse_abort_conn() does not guarantee that all async requests have actually finished aborting (i.e. their ->end() function is called). This could actually result in still used inodes after umount. Add a helper to wait until all requests are fully done. This is done by looking at the "num_waiting" counter. When this counter drops to zero, we can be sure that no more requests are outstanding. Fixes: 0d8e84b0 ("fuse: simplify request abort") Cc: <stable@vger.kernel.org> # v4.2 Signed-off-by:
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Miklos Szeredi authored
commit 45ff350b upstream. fuse_dev_release() assumes that it's the only one referencing the fpq->processing list, but that's not true, since fuse_abort_conn() can be doing the same without any serialization between the two. Fixes: c3696046 ("fuse: separate pqueue for clones") Cc: <stable@vger.kernel.org> # v4.2 Signed-off-by:
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Miklos Szeredi authored
commit 87114373 upstream. Refcounting of request is broken when fuse_abort_conn() is called and request is on the fpq->io list: - ref is taken too late - then it is not dropped Fixes: 0d8e84b0 ("fuse: simplify request abort") Cc: <stable@vger.kernel.org> # v4.2 Signed-off-by:
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Miklos Szeredi authored
commit 63576c13 upstream. If parallel dirops are enabled in FUSE_INIT reply, then first operation may leave fi->mutex held. Reported-by:
syzbot <syzbot+3f7b29af1baa9d0a55be@syzkaller.appspotmail.com> Fixes: 5c672ab3 ("fuse: serialize dirops by default") Cc: <stable@vger.kernel.org> # v4.7 Signed-off-by:
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Andrey Ryabinin authored
commit a2477b0e upstream. fuse_dev_splice_write() reads pipe->buffers to determine the size of 'bufs' array before taking the pipe_lock(). This is not safe as another thread might change the 'pipe->buffers' between the allocation and taking the pipe_lock(). So we end up with too small 'bufs' array. Move the bufs allocations inside pipe_lock()/pipe_unlock() to fix this. Fixes: dd3bb14f ("fuse: support splice() writing to fuse device") Signed-off-by:
Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: <stable@vger.kernel.org> # v2.6.35 Signed-off-by:
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Josh Poimboeuf authored
commit 94d7a86c upstream. These are already defined higher up in the file. Fixes: 7db92e16 ("x86/kvm: Move l1tf setup function") Signed-off-by:
Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by:
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Thomas Gleixner authored
commit 024d83ca upstream. Mikhail reported the following lockdep splat: WARNING: possible irq lock inversion dependency detected CPU 0/KVM/10284 just changed the state of lock: 000000000d538a88 (&st->lock){+...}, at: speculative_store_bypass_update+0x10b/0x170 but this lock was taken by another, HARDIRQ-safe lock in the past: (&(&sighand->siglock)->rlock){-.-.} and interrupts could create inverse lock ordering between them. Possible interrupt unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&st->lock); local_irq_disable(); lock(&(&sighand->siglock)->rlock); lock(&st->lock); <Interrupt> lock(&(&sighand->siglock)->rlock); *** DEADLOCK *** The code path which connects those locks is: speculative_store_bypass_update() ssb_prctl_set() do_seccomp() do_syscall_64() In svm_vcpu_run() speculative_store_bypass_update() is called with interupts enabled via x86_virt_spec_ctrl_set_guest/host(). This is actually a false positive, because GIF=0 so interrupts are disabled even if IF=1; however, we can easily move the invocations of x86_virt_spec_ctrl_set_guest/host() into the interrupt disabled region to cure it, and it's a good idea to keep the GIF=0/IF=1 area as small and self-contained as possible. Fixes: 1f50ddb4 ("x86/speculation: Handle HT correctly on AMD") Reported-by:
Mikhail Gavrilov <mikhail.v.gavrilov@gmail.com> Signed-off-by:
Paolo Bonzini <pbonzini@redhat.com> Signed-off-by:
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Rian Hunter authored
commit dc76803e upstream. The consolidation of the start_thread() functions removed the export unintentionally. This breaks binfmt handlers built as a module. Add it back. Fixes: e634d8fc ("x86-64: merge the standard and compat start_thread() functions") Signed-off-by:
Rian Hunter <rian@alum.mit.edu> Signed-off-by:
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Andy Lutomirski authored
commit 2e549b2e upstream. Currently, if the vDSO ends up containing an indirect branch or call, GCC will emit the "external thunk" style of retpoline, and it will fail to link. Fix it by building the vDSO with inline retpoline thunks. I haven't seen any reports of this triggering on an unpatched kernel. Fixes: commit 76b04384 ("x86/retpoline: Add initial retpoline support") Signed-off-by:
Matt Rickard <matt@softrans.com.au> Cc: Borislav Petkov <bp@alien8.de> Cc: Jason Vas Dias <jason.vas.dias@gmail.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Andi Kleen <ak@linux.intel.com> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/c76538cd3afbe19c6246c2d1715bc6a60bd63985.1534448381.git.luto@kernel.orgSigned-off-by:
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Vlastimil Babka authored
commit 6a012288 upstream. Two users have reported [1] that they have an "extremely unlikely" system with more than MAX_PA/2 memory and L1TF mitigation is not effective. Make the warning more helpful by suggesting the proper mem=X kernel boot parameter to make it effective and a link to the L1TF document to help decide if the mitigation is worth the unusable RAM. [1] https://bugzilla.suse.com/show_bug.cgi?id=1105536Suggested-by:
Michal Hocko <mhocko@suse.com> Signed-off-by:
Vlastimil Babka <vbabka@suse.cz> Acked-by:
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Vlastimil Babka authored
commit b0a182f8 upstream. Two users have reported [1] that they have an "extremely unlikely" system with more than MAX_PA/2 memory and L1TF mitigation is not effective. In fact it's a CPU with 36bits phys limit (64GB) and 32GB memory, but due to holes in the e820 map, the main region is almost 500MB over the 32GB limit: [ 0.000000] BIOS-e820: [mem 0x0000000100000000-0x000000081effffff] usable Suggestions to use 'mem=32G' to enable the L1TF mitigation while losing the 500MB revealed, that there's an off-by-one error in the check in l1tf_select_mitigation(). l1tf_pfn_limit() returns the last usable pfn (inclusive) and the range check in the mitigation path does not take this into account. Instead of amending the range check, make l1tf_pfn_limit() return the first PFN which is over the limit which is less error prone. Adjust the other users accordingly. [1] https://bugzilla.suse.com/show_bug.cgi?id=1105536 Fixes: 17dbca11 ("x86/speculation/l1tf: Add sysfs reporting for l1tf") Reported-by:
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Vlastimil Babka authored
commit 9df95169 upstream. On 32bit PAE kernels on 64bit hardware with enough physical bits, l1tf_pfn_limit() will overflow unsigned long. This in turn affects max_swapfile_size() and can lead to swapon returning -EINVAL. This has been observed in a 32bit guest with 42 bits physical address size, where max_swapfile_size() overflows exactly to 1 << 32, thus zero, and produces the following warning to dmesg: [ 6.396845] Truncating oversized swap area, only using 0k out of 2047996k Fix this by using unsigned long long instead. Fixes: 17dbca11 ("x86/speculation/l1tf: Add sysfs reporting for l1tf") Fixes: 377eeaa8 ("x86/speculation/l1tf: Limit swap file size to MAX_PA/2") Reported-by:
Dominique Leuenberger <dimstar@suse.de> Reported-by:
Adrian Schroeter <adrian@suse.de> Signed-off-by:
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Peter Zijlstra authored
commit d86564a2 upstream. Jann reported that x86 was missing required TLB invalidates when he hit the !*batch slow path in tlb_remove_table(). This is indeed the case; RCU_TABLE_FREE does not provide TLB (cache) invalidates, the PowerPC-hash where this code originated and the Sparc-hash where this was subsequently used did not need that. ARM which later used this put an explicit TLB invalidate in their __p*_free_tlb() functions, and PowerPC-radix followed that example. But when we hooked up x86 we failed to consider this. Fix this by (optionally) hooking tlb_remove_table() into the TLB invalidate code. NOTE: s390 was also needing something like this and might now be able to use the generic code again. [ Modified to be on top of Nick's cleanups, which simplified this patch now that tlb_flush_mmu_tlbonly() really only flushes the TLB - Linus ] Fixes: 9e52fc2b ("x86/mm: Enable RCU based page table freeing (CONFIG_HAVE_RCU_TABLE_FREE=y)") Reported-by:
Jann Horn <jannh@google.com> Signed-off-by:
Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by:
Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by:
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Nicholas Piggin authored
commit db7ddef3 upstream. There is no need to call this from tlb_flush_mmu_tlbonly, it logically belongs with tlb_flush_mmu_free. This makes future fixes simpler. [ This was originally done to allow code consolidation for the mmu_notifier fix, but it also ends up helping simplify the HAVE_RCU_TABLE_INVALIDATE fix. - Linus ] Signed-off-by:
Nicholas Piggin <npiggin@gmail.com> Acked-by:
Will Deacon <will.deacon@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: stable@kernel.org Signed-off-by:
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Takashi Iwai authored
commit 58e73aa1 upstream. The commit 5d9f40b5 ("platform/x86: ideapad-laptop: Add Y520-15IKBN to no_hw_rfkill") added the entry for Y20-15IKBN, and it turned out that another variant, Y20-15IKBM, also requires the no_hw_rfkill. Trim the last letter from the string so that it matches to both Y20-15IKBN and Y20-15IKBM models. Bugzilla: https://bugzilla.opensuse.org/show_bug.cgi?id=1098626 Cc: <stable@vger.kernel.org> Signed-off-by:
Darren Hart (VMware) <dvhart@infradead.org> Signed-off-by:
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Michal Wnukowski authored
commit f1ed3df2 upstream. In many architectures loads may be reordered with older stores to different locations. In the nvme driver the following two operations could be reordered: - Write shadow doorbell (dbbuf_db) into memory. - Read EventIdx (dbbuf_ei) from memory. This can result in a potential race condition between driver and VM host processing requests (if given virtual NVMe controller has a support for shadow doorbell). If that occurs, then the NVMe controller may decide to wait for MMIO doorbell from guest operating system, and guest driver may decide not to issue MMIO doorbell on any of subsequent commands. This issue is purely timing-dependent one, so there is no easy way to reproduce it. Currently the easiest known approach is to run "Oracle IO Numbers" (orion) that is shipped with Oracle DB: orion -run advanced -num_large 0 -size_small 8 -type rand -simulate \ concat -write 40 -duration 120 -matrix row -testname nvme_test Where nvme_test is a .lun file that contains a list of NVMe block devices to run test against. Limiting number of vCPUs assigned to given VM instance seems to increase chances for this bug to occur. On test environment with VM that got 4 NVMe drives and 1 vCPU assigned the virtual NVMe controller hang could be observed within 10-20 minutes. That correspond to about 400-500k IO operations processed (or about 100GB of IO read/writes). Orion tool was used as a validation and set to run in a loop for 36 hours (equivalent of pushing 550M IO operations). No issues were observed. That suggest that the patch fixes the issue. Fixes: f9f38e33 ("nvme: improve performance for virtual NVMe devices") Signed-off-by:
Michal Wnukowski <wnukowski@google.com> Reviewed-by:
Keith Busch <keith.busch@intel.com> Reviewed-by:
Sagi Grimberg <sagi@grimberg.me> [hch: updated changelog and comment a bit] Signed-off-by:
Christoph Hellwig <hch@lst.de> Signed-off-by:
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Eric Sandeen authored
commit f39b3f45 upstream. When ext4_find_entry() falls back to "searching the old fashioned way" due to a corrupt dx dir, it needs to reset the error code to NULL so that the nonstandard ERR_BAD_DX_DIR code isn't returned to userspace. https://bugzilla.kernel.org/show_bug.cgi?id=199947Reported-by:
Anatoly Trosinenko <anatoly.trosinenko@yandex.com> Reviewed-by:
Andreas Dilger <adilger@dilger.ca> Signed-off-by:
Eric Sandeen <sandeen@redhat.com> Signed-off-by:
Theodore Ts'o <tytso@mit.edu> Cc: stable@vger.kernel.org Signed-off-by:
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Arnd Bergmann authored
commit a4d2aadc upstream. While working on extended rand for last_error/first_error timestamps, I noticed that the endianess is wrong; we access the little-endian fields in struct ext4_super_block as native-endian when we print them. This adds a special case in ext4_attr_show() and ext4_attr_store() to byteswap the superblock fields if needed. In older kernels, this code was part of super.c, it got moved to sysfs.c in linux-4.4. Cc: stable@vger.kernel.org Fixes: 52c198c6 ("ext4: add sysfs entry showing whether the fs contains errors") Reviewed-by:
Arnd Bergmann <arnd@arndb.de> Signed-off-by:
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Theodore Ts'o authored
commit 7d95178c upstream. Extended attribute names are defined to be NUL-terminated, so the name must not contain a NUL character. This is important because there are places when remove extended attribute, the code uses strlen to determine the length of the entry. That should probably be fixed at some point, but code is currently really messy, so the simplest fix for now is to simply validate that the extended attributes are sane. https://bugzilla.kernel.org/show_bug.cgi?id=200401Reported-by:
Wen Xu <wen.xu@gatech.edu> Signed-off-by:
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Prasad Sodagudi authored
commit cfd35514 upstream. When cpu_stop_queue_work() releases the lock for the stopper thread that was queued into its wake queue, preemption is enabled, which leads to the following deadlock: CPU0 CPU1 sched_setaffinity(0, ...) __set_cpus_allowed_ptr() stop_one_cpu(0, ...) stop_two_cpus(0, 1, ...) cpu_stop_queue_work(0, ...) cpu_stop_queue_two_works(0, ..., 1, ...) -grabs lock for migration/0- -spins with preemption disabled, waiting for migration/0's lock to be released- -adds work items for migration/0 and queues migration/0 to its wake_q- -releases lock for migration/0 and preemption is enabled- -current thread is preempted, and __set_cpus_allowed_ptr has changed the thread's cpu allowed mask to CPU1 only- -acquires migration/0 and migration/1's locks- -adds work for migration/0 but does not add migration/0 to wake_q, since it is already in a wake_q- -adds work for migration/1 and adds migration/1 to its wake_q- -releases migration/0 and migration/1's locks, wakes migration/1, and enables preemption- -since migration/1 is requested to run, migration/1 begins to run and waits on migration/0, but migration/0 will never be able to run, since the thread that can wake it is affine to CPU1- Disable preemption in cpu_stop_queue_work() before queueing works for stopper threads, and queueing the stopper thread in the wake queue, to ensure that the operation of queueing the works and waking the stopper threads is atomic. Fixes: 0b26351b ("stop_machine, sched: Fix migrate_swap() vs. active_balance() deadlock") Signed-off-by:
Prasad Sodagudi <psodagud@codeaurora.org> Signed-off-by:
Isaac J. Manjarres <isaacm@codeaurora.org> Signed-off-by:
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Peter Zijlstra authored
commit b80a2bfc upstream. The code flow in cpu_stop_queue_two_works() is a little arcane; fix this by lifting the preempt_disable() to the top to create more natural nesting wrt the spinlocks and make the wake_up_q() and preempt_enable() unconditional at the end. Furthermore, enable preemption in the -EDEADLK case, such that we spin-wait with preemption enabled. Suggested-by:
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Claudio Imbrenda authored
commit 306d6c49 upstream. When the oom killer kills a userspace process in the page fault handler while in guest context, the fault handler fails to release the mm_sem if the FAULT_FLAG_RETRY_NOWAIT option is set. This leads to a deadlock when tearing down the mm when the process terminates. This bug can only happen when pfault is enabled, so only KVM clients are affected. The problem arises in the rare cases in which handle_mm_fault does not release the mm_sem. This patch fixes the issue by manually releasing the mm_sem when needed. Fixes: 24eb3a82 ("KVM: s390: Add FAULT_FLAG_RETRY_NOWAIT for guest fault") Cc: <stable@vger.kernel.org> # 3.15+ Signed-off-by:
Claudio Imbrenda <imbrenda@linux.vnet.ibm.com> Signed-off-by:
Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by:
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