- 06 Feb, 2017 40 commits
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Al Viro authored
commit 3b8767a8 upstream. It should check access_ok(). Otherwise a bunch of places turn into trivially exploitable rootholes. Signed-off-by:
Al Viro <viro@zeniv.linux.org.uk> Signed-off-by:
Willy Tarreau <w@1wt.eu>
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Al Viro authored
commit 9ad18b75 upstream. both for access_ok() failures and for faults halfway through Signed-off-by:
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Vineet Gupta authored
commit 05d9d0b9 upstream. Al reported potential issue with ARC get_user() as it wasn't clearing out destination pointer in case of fault due to bad address etc. Verified using following | { | u32 bogus1 = 0xdeadbeef; | u64 bogus2 = 0xdead; | int rc1, rc2; | | pr_info("Orig values %x %llx\n", bogus1, bogus2); | rc1 = get_user(bogus1, (u32 __user *)0x40000000); | rc2 = get_user(bogus2, (u64 __user *)0x50000000); | pr_info("access %d %d, new values %x %llx\n", | rc1, rc2, bogus1, bogus2); | } | [ARCLinux]# insmod /mnt/kernel-module/qtn.ko | Orig values deadbeef dead | access -14 -14, new values 0 0 Reported-by:
Vineet Gupta <vgupta@synopsys.com> Signed-off-by:
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Al Viro authored
commit fd2d2b19 upstream. Signed-off-by:
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Al Viro authored
commit c2f18fa4 upstream. * should zero on any failure * __get_user() should use __copy_from_user(), not copy_from_user() Signed-off-by:
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Al Viro authored
commit c6852389 upstream. It could be done in exception-handling bits in __get_user_b() et.al., but the surgery involved would take more knowledge of sh64 details than I have or _want_ to have. Signed-off-by:
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Al Viro authored
commit c90a3bc5 upstream. Signed-off-by:
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Al Viro authored
commit 43403eab upstream. Signed-off-by:
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Al Viro authored
commit d0cf3851 upstream. Signed-off-by:
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Al Viro authored
commit e98b9e37 upstream. Signed-off-by:
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John David Anglin authored
commit 6ed51832 upstream. We have one critical section in the syscall entry path in which we switch from the userspace stack to kernel stack. In the event of an external interrupt, the interrupt code distinguishes between those two states by analyzing the value of sr7. If sr7 is zero, it uses the kernel stack. Therefore it's important, that the value of sr7 is in sync with the currently enabled stack. This patch now disables interrupts while executing the critical section. This prevents the interrupt handler to possibly see an inconsistent state which in the worst case can lead to crashes. Interestingly, in the syscall exit path interrupts were already disabled in the critical section which switches back to the userspace stack. Signed-off-by:
John David Anglin <dave.anglin@bell.net> Signed-off-by:
Helge Deller <deller@gmx.de> Signed-off-by:
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Stefan Haberland authored
commit 9ba333dc upstream. When a device is in a status where CIO has killed all I/O by itself the interrupt for a clear request may not contain an irb to determine the clear function. Instead it contains an error pointer -EIO. This was ignored by the DASD int_handler leading to a hanging device waiting for a clear interrupt. Handle -EIO error pointer correctly for requests that are clear pending and treat the clear as successful. Signed-off-by:
Stefan Haberland <sth@linux.vnet.ibm.com> Reviewed-by:
Sebastian Ott <sebott@linux.vnet.ibm.com> Signed-off-by:
Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by:
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Dan Carpenter authored
commit 55f1cf83 upstream. The pio_dev[] array has MAX_NR_PIO_DEVICES elements so the > should be >=. Fixes: 5f97f7f9 ('[PATCH] avr32 architecture') Signed-off-by:
Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by:
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Guenter Roeck authored
commit 65c0044c upstream. avr32 builds fail with: arch/avr32/kernel/built-in.o: In function `arch_ptrace': (.text+0x650): undefined reference to `___copy_from_user' arch/avr32/kernel/built-in.o:(___ksymtab+___copy_from_user+0x0): undefined reference to `___copy_from_user' kernel/built-in.o: In function `proc_doulongvec_ms_jiffies_minmax': (.text+0x5dd8): undefined reference to `___copy_from_user' kernel/built-in.o: In function `proc_dointvec_minmax_sysadmin': sysctl.c:(.text+0x6174): undefined reference to `___copy_from_user' kernel/built-in.o: In function `ptrace_has_cap': ptrace.c:(.text+0x69c0): undefined reference to `___copy_from_user' kernel/built-in.o:ptrace.c:(.text+0x6b90): more undefined references to `___copy_from_user' follow Fixes: 8630c322 ("avr32: fix copy_from_user()") Cc: Al Viro <viro@zeniv.linux.org.uk> Acked-by:
Havard Skinnemoen <hskinnemoen@gmail.com> Acked-by:
Hans-Christian Noren Egtvedt <egtvedt@samfundet.no> Signed-off-by:
Guenter Roeck <linux@roeck-us.net> Signed-off-by:
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Al Viro authored
commit 8630c322 upstream. really ugly, but apparently avr32 compilers turns access_ok() into something so bad that they want it in assembler. Left that way, zeroing added in inline wrapper. Signed-off-by:
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Pan Xinhui authored
commit 11b7e154 upstream. When we merge two contiguous partitions whose signatures are marked NVRAM_SIG_FREE, We need update prev's length and checksum, then write it to nvram, not cur's. So lets fix this mistake now. Also use memset instead of strncpy to set the partition's name. It's more readable if we want to fill up with duplicate chars . Fixes: fa2b4e54 ("powerpc/nvram: Improve partition removal") Signed-off-by:
Pan Xinhui <xinhui.pan@linux.vnet.ibm.com> Signed-off-by:
Michael Ellerman <mpe@ellerman.id.au> Signed-off-by:
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Paul Mackerras authored
commit 1a34439e upstream. Debugging a data corruption issue with virtio-net/vhost-net led to the observation that __copy_tofrom_user was occasionally returning a value 16 larger than it should. Since the return value from __copy_tofrom_user is the number of bytes not copied, this means that __copy_tofrom_user can occasionally return a value larger than the number of bytes it was asked to copy. In turn this can cause higher-level copy functions such as copy_page_to_iter_iovec to corrupt memory by copying data into the wrong memory locations. It turns out that the failing case involves a fault on the store at label 79, and at that point the first unmodified byte of the destination is at R3 + 16. Consequently the exception handler for that store needs to add 16 to R3 before using it to work out how many bytes were not copied, but in this one case it was not adding the offset to R3. To fix it, this moves the label 179 to the point where we add 16 to R3. I have checked manually all the exception handlers for the loads and stores in this code and the rest of them are correct (it would be excellent to have an automated test of all the exception cases). This bug has been present since this code was initially committed in May 2002 to Linux version 2.5.20. Signed-off-by:
Paul Mackerras <paulus@ozlabs.org> Signed-off-by:
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Gavin Shan authored
commit 5adaf862 upstream. This fixes the warnings reported from sparse: pci.c:312:33: warning: restricted __be64 degrades to integer pci.c:313:33: warning: restricted __be64 degrades to integer Fixes: cee72d5b ("powerpc/powernv: Display diag data on p7ioc EEH errors") Signed-off-by:
Gavin Shan <gwshan@linux.vnet.ibm.com> Signed-off-by:
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Anton Blanchard authored
commit 5045ea37 upstream. __kernel_get_syscall_map() and __kernel_clock_getres() use cmpli to check if the passed in pointer is non zero. cmpli maps to a 32 bit compare on binutils, so we ignore the top 32 bits. A simple test case can be created by passing in a bogus pointer with the bottom 32 bits clear. Using a clk_id that is handled by the VDSO, then one that is handled by the kernel shows the problem: printf("%d\n", clock_getres(CLOCK_REALTIME, (void *)0x100000000)); printf("%d\n", clock_getres(CLOCK_BOOTTIME, (void *)0x100000000)); And we get: 0 -1 The bigger issue is if we pass a valid pointer with the bottom 32 bits clear, in this case we will return success but won't write any data to the pointer. I stumbled across this issue because the LLVM integrated assembler doesn't accept cmpli with 3 arguments. Fix this by converting them to cmpldi. Fixes: a7f290da ("[PATCH] powerpc: Merge vdso's and add vdso support to 32 bits kernel") Signed-off-by:
Anton Blanchard <anton@samba.org> Signed-off-by:
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Paul Mackerras authored
commit f077aaf0 upstream. In commit c60ac569 ("powerpc: Update kernel VSID range", 2013-03-13) we lost a check on the region number (the top four bits of the effective address) for addresses below PAGE_OFFSET. That commit replaced a check that the top 18 bits were all zero with a check that bits 46 - 59 were zero (performed for all addresses, not just user addresses). This means that userspace can access an address like 0x1000_0xxx_xxxx_xxxx and we will insert a valid SLB entry for it. The VSID used will be the same as if the top 4 bits were 0, but the page size will be some random value obtained by indexing beyond the end of the mm_ctx_high_slices_psize array in the paca. If that page size is the same as would be used for region 0, then userspace just has an alias of the region 0 space. If the page size is different, then no HPTE will be found for the access, and the process will get a SIGSEGV (since hash_page_mm() will refuse to create a HPTE for the bogus address). The access beyond the end of the mm_ctx_high_slices_psize can be at most 5.5MB past the array, and so will be in RAM somewhere. Since the access is a load performed in real mode, it won't fault or crash the kernel. At most this bug could perhaps leak a little bit of information about blocks of 32 bytes of memory located at offsets of i * 512kB past the paca->mm_ctx_high_slices_psize array, for 1 <= i <= 11. Fixes: c60ac569 ("powerpc: Update kernel VSID range") Signed-off-by:
Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by:
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Marcin Nowakowski authored
commit 74f1077b upstream. Currently regs_return_value always negates reg[2] if it determines the syscall has failed, but when called in kernel context this check is invalid and may result in returning a wrong value. This fixes errors reported by CONFIG_KPROBES_SANITY_TEST Fixes: d7e7528b ("Audit: push audit success and retcode into arch ptrace.h") Signed-off-by:
Marcin Nowakowski <marcin.nowakowski@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/14381/Signed-off-by:
Ralf Baechle <ralf@linux-mips.org> Signed-off-by:
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Paul Burton authored
commit 305723ab upstream. Malta boards used with CPU emulators feature a switch to disable use of an IOCU. Software has to check this switch & ignore any present IOCU if the switch is closed. The read used to do this was unsafe for 64 bit kernels, as it simply casted the address 0xbf403000 to a pointer & dereferenced it. Whilst in a 32 bit kernel this would access kseg1, in a 64 bit kernel this attempts to access xuseg & results in an address error exception. Fix by accessing a correctly formed ckseg1 address generated using the CKSEG1ADDR macro. Whilst modifying this code, define the name of the register and the bit we care about within it, which indicates whether PCI DMA is routed to the IOCU or straight to DRAM. The code previously checked that bit 0 was also set, but the least significant 7 bits of the CONFIG_GEN0 register contain the value of the MReqInfo signal provided to the IOCU OCP bus, so singling out bit 0 makes little sense & that part of the check is dropped. Signed-off-by:
Paul Burton <paul.burton@imgtec.com> Fixes: b6d92b4a ("MIPS: Add option to disable software I/O coherency.") Cc: Matt Redfearn <matt.redfearn@imgtec.com> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Kees Cook <keescook@chromium.org> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/14187/Signed-off-by:
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Will Deacon authored
commit 3a402a70 upstream. When TIF_SINGLESTEP is set for a task, the single-step state machine is enabled and we must take care not to reset it to the active-not-pending state if it is already in the active-pending state. Unfortunately, that's exactly what user_enable_single_step does, by unconditionally setting the SS bit in the SPSR for the current task. This causes failures in the GDB testsuite, where GDB ends up missing expected step traps if the instruction being stepped generates another trap, e.g. PTRACE_EVENT_FORK from an SVC instruction. This patch fixes the problem by preserving the current state of the stepping state machine when TIF_SINGLESTEP is set on the current thread. Cc: <stable@vger.kernel.org> Reported-by:
Yao Qi <yao.qi@arm.com> Signed-off-by:
Will Deacon <will.deacon@arm.com> Signed-off-by:
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Will Deacon authored
commit 872c63fb upstream. smp_mb__before_spinlock() is intended to upgrade a spin_lock() operation to a full barrier, such that prior stores are ordered with respect to loads and stores occuring inside the critical section. Unfortunately, the core code defines the barrier as smp_wmb(), which is insufficient to provide the required ordering guarantees when used in conjunction with our load-acquire-based spinlock implementation. This patch overrides the arm64 definition of smp_mb__before_spinlock() to map to a full smp_mb(). Cc: Peter Zijlstra <peterz@infradead.org> Reported-by:
Alan Stern <stern@rowland.harvard.edu> Signed-off-by:
Catalin Marinas <catalin.marinas@arm.com> Signed-off-by:
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James Hogan authored
commit 3146bc64 upstream. AT_VECTOR_SIZE_ARCH should be defined with the maximum number of NEW_AUX_ENT entries that ARCH_DLINFO can contain, but it wasn't defined for arm64 at all even though ARCH_DLINFO will contain one NEW_AUX_ENT for the VDSO address. This shouldn't be a problem as AT_VECTOR_SIZE_BASE includes space for AT_BASE_PLATFORM which arm64 doesn't use, but lets define it now and add the comment above ARCH_DLINFO as found in several other architectures to remind future modifiers of ARCH_DLINFO to keep AT_VECTOR_SIZE_ARCH up to date. Fixes: f668cd16 ("arm64: ELF definitions") Signed-off-by:
James Hogan <james.hogan@imgtec.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: linux-arm-kernel@lists.infradead.org Signed-off-by:
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Mark Rutland authored
commit 7d9e8f71 upstream. Generally, taking an unexpected exception should be a fatal event, and bad_mode is intended to cater for this. However, it should be possible to contain unexpected synchronous exceptions from EL0 without bringing the kernel down, by sending a SIGILL to the task. We tried to apply this approach in commit 9955ac47 ("arm64: don't kill the kernel on a bad esr from el0"), by sending a signal for any bad_mode call resulting from an EL0 exception. However, this also applies to other unexpected exceptions, such as SError and FIQ. The entry paths for these exceptions branch to bad_mode without configuring the link register, and have no kernel_exit. Thus, if we take one of these exceptions from EL0, bad_mode will eventually return to the original user link register value. This patch fixes this by introducing a new bad_el0_sync handler to cater for the recoverable case, and restoring bad_mode to its original state, whereby it calls panic() and never returns. The recoverable case branches to bad_el0_sync with a bl, and returns to userspace via the usual ret_to_user mechanism. Signed-off-by:
Mark Rutland <mark.rutland@arm.com> Fixes: 9955ac47 ("arm64: don't kill the kernel on a bad esr from el0") Reported-by:
Mark Salter <msalter@redhat.com> Cc: Will Deacon <will.deacon@arm.com> Cc: stable@vger.kernel.org Signed-off-by:
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Russell King authored
commit 06dfe5cc upstream. SA1111 PCMCIA was broken when PCMCIA switched to using dev_pm_ops for the PCMCIA socket class. PCMCIA used to handle suspend/resume via the socket hosting device, which happened at normal device suspend/resume time. However, the referenced commit changed this: much of the resume now happens much earlier, in the noirq resume handler of dev_pm_ops. However, on SA1111, the PCMCIA device is not accessible as the SA1111 has not been resumed at _noirq time. It's slightly worse than that, because the SA1111 has already been put to sleep at _noirq time, so suspend doesn't work properly. Fix this by converting the core SA1111 code to use dev_pm_ops as well, and performing its own suspend/resume at noirq time. This fixes these errors in the kernel log: pcmcia_socket pcmcia_socket0: time out after reset pcmcia_socket pcmcia_socket1: time out after reset and the resulting lack of PCMCIA cards after a S2RAM cycle. Fixes: d7646f76 ("pcmcia: use dev_pm_ops for class pcmcia_socket_class") Signed-off-by:
Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by:
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Russell King authored
commit da60626e upstream. Clear the current reset status prior to rebooting the platform. This adds the bit missing from 04fef228 ("[ARM] pxa: introduce reset_status and clear_reset_status for driver's usage"). Fixes: 04fef228 ("[ARM] pxa: introduce reset_status and clear_reset_status for driver's usage") Signed-off-by:
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Srinivas Ramana authored
commit 117e5e9c upstream. If the bootloader uses the long descriptor format and jumps to kernel decompressor code, TTBCR may not be in a right state. Before enabling the MMU, it is required to clear the TTBCR.PD0 field to use TTBR0 for translation table walks. The commit dbece458 ("ARM: 7501/1: decompressor: reset ttbcr for VMSA ARMv7 cores") does the reset of TTBCR.N, but doesn't consider all the bits for the size of TTBCR.N. Clear TTBCR.PD0 field and reset all the three bits of TTBCR.N to indicate the use of TTBR0 and the correct base address width. Fixes: dbece458 ("ARM: 7501/1: decompressor: reset ttbcr for VMSA ARMv7 cores") Acked-by:
Robin Murphy <robin.murphy@arm.com> Signed-off-by:
Srinivas Ramana <sramana@codeaurora.org> Signed-off-by:
Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by:
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Robin Murphy authored
commit ba6dea4f upstream. Whilst MPIDR values themselves are less than 32 bits, it is still perfectly valid for a DT to have #address-cells > 1 in the CPUs node, resulting in the "reg" property having leading zero cell(s). In that situation, the big-endian nature of the data conspires with the current behaviour of only reading the first cell to cause the kernel to think all CPUs have ID 0, and become resoundingly unhappy as a consequence. Take the full property length into account when parsing CPUs so as to be correct under any circumstances. Cc: Russell King <linux@armlinux.org.uk> Signed-off-by:
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Baoquan He authored
commit c3db901c upstream. The current code missed freeing domain id when free a domain of struct dma_ops_domain. Signed-off-by:
Baoquan He <bhe@redhat.com> Fixes: ec487d1a ('x86, AMD IOMMU: add domain allocation and deallocation functions') Signed-off-by:
Joerg Roedel <jroedel@suse.de> Signed-off-by:
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Joerg Roedel authored
commit 3254de6b upstream. Not doing so might cause IO-Page-Faults when a device uses an alias request-id and the alias-dte is left in a lower page-mode which does not cover the address allocated from the iova-allocator. Fixes: 492667da ('x86/amd-iommu: Remove amd_iommu_pd_table') Signed-off-by:
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Michael S. Tsirkin authored
commit 577f183a upstream. On x86/um CONFIG_SMP is never defined. As a result, several macros match the asm-generic variant exactly. Drop the local definitions and pull in asm-generic/barrier.h instead. This is in preparation to refactoring this code area. Signed-off-by:
Michael S. Tsirkin <mst@redhat.com> Acked-by:
Arnd Bergmann <arnd@arndb.de> Acked-by:
Richard Weinberger <richard@nod.at> Acked-by:
Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by:
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H.J. Lu authored
commit 6d92bc9d upstream. The 32-bit x86 assembler in binutils 2.26 will generate R_386_GOT32X relocation to get the symbol address in PIC. When the compressed x86 kernel isn't built as PIC, the linker optimizes R_386_GOT32X relocations to their fixed symbol addresses. However, when the compressed x86 kernel is loaded at a different address, it leads to the following load failure: Failed to allocate space for phdrs during the decompression stage. If the compressed x86 kernel is relocatable at run-time, it should be compiled with -fPIE, instead of -fPIC, if possible and should be built as Position Independent Executable (PIE) so that linker won't optimize R_386_GOT32X relocation to its fixed symbol address. Older linkers generate R_386_32 relocations against locally defined symbols, _bss, _ebss, _got and _egot, in PIE. It isn't wrong, just less optimal than R_386_RELATIVE. But the x86 kernel fails to properly handle R_386_32 relocations when relocating the kernel. To generate R_386_RELATIVE relocations, we mark _bss, _ebss, _got and _egot as hidden in both 32-bit and 64-bit x86 kernels. To build a 64-bit compressed x86 kernel as PIE, we need to disable the relocation overflow check to avoid relocation overflow errors. We do this with a new linker command-line option, -z noreloc-overflow, which got added recently: commit 4c10bbaa0912742322f10d9d5bb630ba4e15dfa7 Author: H.J. Lu <hjl.tools@gmail.com> Date: Tue Mar 15 11:07:06 2016 -0700 Add -z noreloc-overflow option to x86-64 ld Add -z noreloc-overflow command-line option to the x86-64 ELF linker to disable relocation overflow check. This can be used to avoid relocation overflow check if there will be no dynamic relocation overflow at run-time. The 64-bit compressed x86 kernel is built as PIE only if the linker supports -z noreloc-overflow. So far 64-bit relocatable compressed x86 kernel boots fine even when it is built as a normal executable. Signed-off-by:
H.J. Lu <hjl.tools@gmail.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org [ Edited the changelog and comments. ] Signed-off-by:
Ingo Molnar <mingo@kernel.org> Signed-off-by:
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Steven Rostedt authored
commit 15301a57 upstream. Åukasz Daniluk reported that on a RHEL kernel that his machine would lock up after enabling function tracer. I asked him to bisect the functions within available_filter_functions, which he did and it came down to three: _paravirt_nop(), _paravirt_ident_32() and _paravirt_ident_64() It was found that this is only an issue when noreplace-paravirt is added to the kernel command line. This means that those functions are most likely called within critical sections of the funtion tracer, and must not be traced. In newer kenels _paravirt_nop() is defined within gcc asm(), and is no longer an issue. But both _paravirt_ident_{32,64}() causes the following splat when they are traced: mm/pgtable-generic.c:33: bad pmd ffff8800d2435150(0000000001d00054) mm/pgtable-generic.c:33: bad pmd ffff8800d3624190(0000000001d00070) mm/pgtable-generic.c:33: bad pmd ffff8800d36a5110(0000000001d00054) mm/pgtable-generic.c:33: bad pmd ffff880118eb1450(0000000001d00054) NMI watchdog: BUG: soft lockup - CPU#2 stuck for 22s! [systemd-journal:469] Modules linked in: e1000e CPU: 2 PID: 469 Comm: systemd-journal Not tainted 4.6.0-rc4-test+ #513 Hardware name: Hewlett-Packard HP Compaq Pro 6300 SFF/339A, BIOS K01 v02.05 05/07/2012 task: ffff880118f740c0 ti: ffff8800d4aec000 task.ti: ffff8800d4aec000 RIP: 0010:[<ffffffff81134148>] [<ffffffff81134148>] queued_spin_lock_slowpath+0x118/0x1a0 RSP: 0018:ffff8800d4aefb90 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff88011eb16d40 RDX: ffffffff82485760 RSI: 000000001f288820 RDI: ffffea0000008030 RBP: ffff8800d4aefb90 R08: 00000000000c0000 R09: 0000000000000000 R10: ffffffff821c8e0e R11: 0000000000000000 R12: ffff880000200fb8 R13: 00007f7a4e3f7000 R14: ffffea000303f600 R15: ffff8800d4b562e0 FS: 00007f7a4e3d7840(0000) GS:ffff88011eb00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f7a4e3f7000 CR3: 00000000d3e71000 CR4: 00000000001406e0 Call Trace: _raw_spin_lock+0x27/0x30 handle_pte_fault+0x13db/0x16b0 handle_mm_fault+0x312/0x670 __do_page_fault+0x1b1/0x4e0 do_page_fault+0x22/0x30 page_fault+0x28/0x30 __vfs_read+0x28/0xe0 vfs_read+0x86/0x130 SyS_read+0x46/0xa0 entry_SYSCALL_64_fastpath+0x1e/0xa8 Code: 12 48 c1 ea 0c 83 e8 01 83 e2 30 48 98 48 81 c2 40 6d 01 00 48 03 14 c5 80 6a 5d 82 48 89 0a 8b 41 08 85 c0 75 09 f3 90 8b 41 08 <85> c0 74 f7 4c 8b 09 4d 85 c9 74 08 41 0f 18 09 eb 02 f3 90 8b Reported-by:
Åukasz Daniluk <lukasz.daniluk@intel.com> Signed-off-by:
Steven Rostedt <rostedt@goodmis.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by:
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Jiri Kosina authored
commit 39380b80 upstream. Currently it's possible for broken (or malicious) userspace to flood a kernel log indefinitely with messages a-la Program dmidecode tried to access /dev/mem between f0000->100000 because range_is_allowed() is case of CONFIG_STRICT_DEVMEM being turned on dumps this information each and every time devmem_is_allowed() fails. Reportedly userspace that is able to trigger contignuous flow of these messages exists. It would be possible to rate limit this message, but that'd have a questionable value; the administrator wouldn't get information about all the failing accessess, so then the information would be both superfluous and incomplete at the same time :) Returning EPERM (which is what is actually happening) is enough indication for userspace what has happened; no need to log this particular error as some sort of special condition. Signed-off-by:
Jiri Kosina <jkosina@suse.cz> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luis R. Rodriguez <mcgrof@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Toshi Kani <toshi.kani@hp.com> Link: http://lkml.kernel.org/r/alpine.LNX.2.00.1607081137020.24757@cbobk.fhfr.pmSigned-off-by:
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Wanpeng Li authored
commit 2e63ad4b upstream. native_smp_prepare_cpus -> default_setup_apic_routing -> enable_IR_x2apic -> irq_remapping_prepare -> intel_prepare_irq_remapping -> intel_setup_irq_remapping So IR table is setup even if "noapic" boot parameter is added. As a result we crash later when the interrupt affinity is set due to a half initialized remapping infrastructure. Prevent remap initialization when IOAPIC is disabled. Signed-off-by:
Wanpeng Li <wanpeng.li@hotmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Joerg Roedel <joro@8bytes.org> Link: http://lkml.kernel.org/r/1471954039-3942-1-git-send-email-wanpeng.li@hotmail.comSigned-off-by:
Thomas Gleixner <tglx@linutronix.de> Signed-off-by:
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Sebastian Andrzej Siewior authored
commit 5cf0791d upstream. There's a subtle preemption race on UP kernels: Usually current->mm (and therefore mm->pgd) stays the same during the lifetime of a task so it does not matter if a task gets preempted during the read and write of the CR3. But then, there is this scenario on x86-UP: TaskA is in do_exit() and exit_mm() sets current->mm = NULL followed by: -> mmput() -> exit_mmap() -> tlb_finish_mmu() -> tlb_flush_mmu() -> tlb_flush_mmu_tlbonly() -> tlb_flush() -> flush_tlb_mm_range() -> __flush_tlb_up() -> __flush_tlb() -> __native_flush_tlb() At this point current->mm is NULL but current->active_mm still points to the "old" mm. Let's preempt taskA _after_ native_read_cr3() by taskB. TaskB has its own mm so CR3 has changed. Now preempt back to taskA. TaskA has no ->mm set so it borrows taskB's mm and so CR3 remains unchanged. Once taskA gets active it continues where it was interrupted and that means it writes its old CR3 value back. Everything is fine because userland won't need its memory anymore. Now the fun part: Let's preempt taskA one more time and get back to taskB. This time switch_mm() won't do a thing because oldmm (->active_mm) is the same as mm (as per context_switch()). So we remain with a bad CR3 / PGD and return to userland. The next thing that happens is handle_mm_fault() with an address for the execution of its code in userland. handle_mm_fault() realizes that it has a PTE with proper rights so it returns doing nothing. But the CPU looks at the wrong PGD and insists that something is wrong and faults again. And again. And one more time⦠This pagefault circle continues until the scheduler gets tired of it and puts another task on the CPU. It gets little difficult if the task is a RT task with a high priority. The system will either freeze or it gets fixed by the software watchdog thread which usually runs at RT-max prio. But waiting for the watchdog will increase the latency of the RT task which is no good. Fix this by disabling preemption across the critical code section. Signed-off-by:
Sebastian Andrzej Siewior <bigeasy@linutronix.de> Acked-by:
Rik van Riel <riel@redhat.com> Acked-by:
Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Borislav Petkov <bp@suse.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/1470404259-26290-1-git-send-email-bigeasy@linutronix.de [ Prettified the changelog. ] Signed-off-by:
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Andy Lutomirski authored
This is a backport of: commit fc0e81b2 upstream On the 80486 DX, it seems that some exceptions may leave garbage in the high bits of CS. This causes sporadic failures in which early_fixup_exception() refuses to fix up an exception. As far as I can tell, this has been buggy for a long time, but the problem seems to have been exacerbated by commits: 1e02ce4c ("x86: Store a per-cpu shadow copy of CR4") e1bfc11c ("x86/init: Fix cr4_init_shadow() on CR4-less machines") This appears to have broken for as long as we've had early exception handling. [ This backport should apply to kernels from 3.4 - 4.5. ] Fixes: 4c5023a3 ("x86-32: Handle exception table entries during early boot") Cc: H. Peter Anvin <hpa@zytor.com> Cc: stable@vger.kernel.org Reported-by:
Matthew Whitehead <tedheadster@gmail.com> Signed-off-by:
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Juergen Gross authored
commit 1cf38741 upstream. xen_cleanhighmap() is operating on level2_kernel_pgt only. The upper bound of the loop setting non-kernel-image entries to zero should not exceed the size of level2_kernel_pgt. Reported-by:
Juergen Gross <jgross@suse.com> Signed-off-by:
David Vrabel <david.vrabel@citrix.com> Signed-off-by:
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