user/sven/linux.git/arch, branch stable/5.2.y

KVM: hyperv: Fix Direct Synthetic timers assert an interrupt w/o lapic_in_kernel

2019-10-07T16:59:41Z

commit a073d7e3ad687a7ef32b65affe80faa7ce89bf92 upstream. Reported by syzkaller: kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] PREEMPT SMP KASAN RIP: 0010:__apic_accept_irq+0x46/0x740 arch/x86/kvm/lapic.c:1029 Call Trace: kvm_apic_set_irq+0xb4/0x140 arch/x86/kvm/lapic.c:558 stimer_notify_direct arch/x86/kvm/hyperv.c:648 [inline] stimer_expiration arch/x86/kvm/hyperv.c:659 [inline] kvm_hv_process_stimers+0x594/0x1650 arch/x86/kvm/hyperv.c:686 vcpu_enter_guest+0x2b2a/0x54b0 arch/x86/kvm/x86.c:7896 vcpu_run+0x393/0xd40 arch/x86/kvm/x86.c:8152 kvm_arch_vcpu_ioctl_run+0x636/0x900 arch/x86/kvm/x86.c:8360 kvm_vcpu_ioctl+0x6cf/0xaf0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2765 The testcase programs HV_X64_MSR_STIMERn_CONFIG/HV_X64_MSR_STIMERn_COUNT, in addition, there is no lapic in the kernel, the counters value are small enough in order that kvm_hv_process_stimers() inject this already-expired timer interrupt into the guest through lapic in the kernel which triggers the NULL deferencing. This patch fixes it by don't advertise direct mode synthetic timers and discarding the inject when lapic is not in kernel. syzkaller source: https://syzkaller.appspot.com/x/repro.c?x=1752fe0a600000 Reported-by: syzbot+dff25ee91f0c7d5c1695@syzkaller.appspotmail.com Cc: Paolo Bonzini Cc: Radim Krčmář Signed-off-by: Wanpeng Li Reviewed-by: Vitaly Kuznetsov Signed-off-by: Paolo Bonzini Signed-off-by: Greg Kroah-Hartman

arm: use STACK_TOP when computing mmap base address

2019-10-07T16:59:39Z

[ Upstream commit 86e568e9c0525fc40e76d827212d5e9721cf7504 ] mmap base address must be computed wrt stack top address, using TASK_SIZE is wrong since STACK_TOP and TASK_SIZE are not equivalent. Link: http://lkml.kernel.org/r/20190730055113.23635-8-alex@ghiti.fr Signed-off-by: Alexandre Ghiti Acked-by: Kees Cook Reviewed-by: Luis Chamberlain Cc: Albert Ou Cc: Alexander Viro Cc: Catalin Marinas Cc: Christoph Hellwig Cc: Christoph Hellwig Cc: James Hogan Cc: Palmer Dabbelt Cc: Paul Burton Cc: Ralf Baechle Cc: Russell King Cc: Will Deacon Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin

arm: properly account for stack randomization and stack guard gap

2019-10-07T16:59:38Z

[ Upstream commit af0f4297286f13a75edf93677b1fb2fc16c412a7 ] This commit takes care of stack randomization and stack guard gap when computing mmap base address and checks if the task asked for randomization. This fixes the problem uncovered and not fixed for arm here: https://lkml.kernel.org/r/20170622200033.25714-1-riel@redhat.com Link: http://lkml.kernel.org/r/20190730055113.23635-7-alex@ghiti.fr Signed-off-by: Alexandre Ghiti Acked-by: Kees Cook Reviewed-by: Luis Chamberlain Cc: Albert Ou Cc: Alexander Viro Cc: Catalin Marinas Cc: Christoph Hellwig Cc: Christoph Hellwig Cc: James Hogan Cc: Palmer Dabbelt Cc: Paul Burton Cc: Ralf Baechle Cc: Russell King Cc: Will Deacon Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin

mips: properly account for stack randomization and stack guard gap

2019-10-07T16:59:38Z

[ Upstream commit b1f61b5bde3a1f50392c97b4c8513d1b8efb1cf2 ] This commit takes care of stack randomization and stack guard gap when computing mmap base address and checks if the task asked for randomization. This fixes the problem uncovered and not fixed for arm here: https://lkml.kernel.org/r/20170622200033.25714-1-riel@redhat.com Link: http://lkml.kernel.org/r/20190730055113.23635-10-alex@ghiti.fr Signed-off-by: Alexandre Ghiti Acked-by: Kees Cook Acked-by: Paul Burton Reviewed-by: Luis Chamberlain Cc: Albert Ou Cc: Alexander Viro Cc: Catalin Marinas Cc: Christoph Hellwig Cc: Christoph Hellwig Cc: James Hogan Cc: Palmer Dabbelt Cc: Ralf Baechle Cc: Russell King Cc: Will Deacon Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin

arm64: consider stack randomization for mmap base only when necessary

2019-10-07T16:59:37Z

[ Upstream commit e8d54b62c55ab6201de6d195fc2c276294c1f6ae ] Do not offset mmap base address because of stack randomization if current task does not want randomization. Note that x86 already implements this behaviour. Link: http://lkml.kernel.org/r/20190730055113.23635-4-alex@ghiti.fr Signed-off-by: Alexandre Ghiti Acked-by: Catalin Marinas Acked-by: Kees Cook Reviewed-by: Christoph Hellwig Reviewed-by: Luis Chamberlain Cc: Albert Ou Cc: Alexander Viro Cc: Christoph Hellwig Cc: James Hogan Cc: Palmer Dabbelt Cc: Paul Burton Cc: Ralf Baechle Cc: Russell King Cc: Will Deacon Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin

hypfs: Fix error number left in struct pointer member

2019-10-07T16:59:35Z

[ Upstream commit b54c64f7adeb241423cd46598f458b5486b0375e ] In hypfs_fill_super(), if hypfs_create_update_file() fails, sbi->update_file is left holding an error number. This is passed to hypfs_kill_super() which doesn't check for this. Fix this by not setting sbi->update_value until after we've checked for error. Fixes: 24bbb1faf3f0 ("[PATCH] s390_hypfs filesystem") Signed-off-by: David Howells cc: Martin Schwidefsky cc: Heiko Carstens cc: linux-s390@vger.kernel.org Signed-off-by: Al Viro Signed-off-by: Sasha Levin

ARM: 8903/1: ensure that usable memory in bank 0 starts from a PMD-aligned address

2019-10-07T16:59:34Z

[ Upstream commit 00d2ec1e6bd82c0538e6dd3e4a4040de93ba4fef ] The calculation of memblock_limit in adjust_lowmem_bounds() assumes that bank 0 starts from a PMD-aligned address. However, the beginning of the first bank may be NOMAP memory and the start of usable memory will be not aligned to PMD boundary. In such case the memblock_limit will be set to the end of the NOMAP region, which will prevent any memblock allocations. Mark the region between the end of the NOMAP area and the next PMD-aligned address as NOMAP as well, so that the usable memory will start at PMD-aligned address. Signed-off-by: Mike Rapoport Signed-off-by: Russell King Signed-off-by: Sasha Levin

ARM: 8905/1: Emit __gnu_mcount_nc when using Clang 10.0.0 or newer

2019-10-07T16:59:34Z

[ Upstream commit b0fe66cf095016e0b238374c10ae366e1f087d11 ] Currently, multi_v7_defconfig + CONFIG_FUNCTION_TRACER fails to build with clang: arm-linux-gnueabi-ld: kernel/softirq.o: in function `_local_bh_enable': softirq.c:(.text+0x504): undefined reference to `mcount' arm-linux-gnueabi-ld: kernel/softirq.o: in function `__local_bh_enable_ip': softirq.c:(.text+0x58c): undefined reference to `mcount' arm-linux-gnueabi-ld: kernel/softirq.o: in function `do_softirq': softirq.c:(.text+0x6c8): undefined reference to `mcount' arm-linux-gnueabi-ld: kernel/softirq.o: in function `irq_enter': softirq.c:(.text+0x75c): undefined reference to `mcount' arm-linux-gnueabi-ld: kernel/softirq.o: in function `irq_exit': softirq.c:(.text+0x840): undefined reference to `mcount' arm-linux-gnueabi-ld: kernel/softirq.o:softirq.c:(.text+0xa50): more undefined references to `mcount' follow clang can emit a working mcount symbol, __gnu_mcount_nc, when '-meabi gnu' is passed to it. Until r369147 in LLVM, this was broken and caused the kernel not to boot with '-pg' because the calling convention was not correct. Always build with '-meabi gnu' when using clang but ensure that '-pg' (which is added with CONFIG_FUNCTION_TRACER and its prereq CONFIG_HAVE_FUNCTION_TRACER) cannot be added with it unless this is fixed (which means using clang 10.0.0 and newer). Link: https://github.com/ClangBuiltLinux/linux/issues/35 Link: https://bugs.llvm.org/show_bug.cgi?id=33845 Link: https://github.com/llvm/llvm-project/commit/16fa8b09702378bacfa3d07081afe6b353b99e60 Reviewed-by: Matthias Kaehlcke Reviewed-by: Nick Desaulniers Reviewed-by: Stefan Agner Signed-off-by: Nathan Chancellor Signed-off-by: Russell King Signed-off-by: Sasha Levin

ARM: 8875/1: Kconfig: default to AEABI w/ Clang

2019-10-07T16:59:30Z

[ Upstream commit a05b9608456e0d4464c6f7ca8572324ace57a3f4 ] Clang produces references to __aeabi_uidivmod and __aeabi_idivmod for arm-linux-gnueabi and arm-linux-gnueabihf targets incorrectly when AEABI is not selected (such as when OABI_COMPAT is selected). While this means that OABI userspaces wont be able to upgraded to kernels built with Clang, it means that boards that don't enable AEABI like s3c2410_defconfig will stop failing to link in KernelCI when built with Clang. Link: https://github.com/ClangBuiltLinux/linux/issues/482 Link: https://groups.google.com/forum/#!msg/clang-built-linux/yydsAAux5hk/GxjqJSW-AQAJ Suggested-by: Arnd Bergmann Signed-off-by: Nick Desaulniers Reviewed-by: Arnd Bergmann Reviewed-by: Linus Walleij Signed-off-by: Russell King Signed-off-by: Sasha Levin

ARM: 8898/1: mm: Don't treat faults reported from cache maintenance as writes

2019-10-07T16:59:29Z

[ Upstream commit 834020366da9ab3fb87d1eb9a3160eb22dbed63a ] Translation faults arising from cache maintenance instructions are rather unhelpfully reported with an FSR value where the WnR field is set to 1, indicating that the faulting access was a write. Since cache maintenance instructions on 32-bit ARM do not require any particular permissions, this can cause our private 'cacheflush' system call to fail spuriously if a translation fault is generated due to page aging when targetting a read-only VMA. In this situation, we will return -EFAULT to userspace, although this is unfortunately suppressed by the popular '__builtin___clear_cache()' intrinsic provided by GCC, which returns void. Although it's tempting to write this off as a userspace issue, we can actually do a little bit better on CPUs that support LPAE, even if the short-descriptor format is in use. On these CPUs, cache maintenance faults additionally set the CM field in the FSR, which we can use to suppress the write permission checks in the page fault handler and succeed in performing cache maintenance to read-only areas even in the presence of a translation fault. Reported-by: Orion Hodson Signed-off-by: Will Deacon Signed-off-by: Russell King Signed-off-by: Sasha Levin