1. 09 Mar, 2018 5 commits
    • Dave Martin's avatar
      arm64: signal: Ensure si_code is valid for all fault signals · af40ff68
      Dave Martin authored
      Currently, as reported by Eric, an invalid si_code value 0 is
      passed in many signals delivered to userspace in response to faults
      and other kernel errors.  Typically 0 is passed when the fault is
      insufficiently diagnosable or when there does not appear to be any
      sensible alternative value to choose.
      
      This appears to violate POSIX, and is intuitively wrong for at
      least two reasons arising from the fact that 0 == SI_USER:
      
       1) si_code is a union selector, and SI_USER (and si_code <= 0 in
          general) implies the existence of a different set of fields
          (siginfo._kill) from that which exists for a fault signal
          (siginfo._sigfault).  However, the code raising the signal
          typically writes only the _sigfault fields, and the _kill
          fields make no sense in this case.
      
          Thus when userspace sees si_code == 0 (SI_USER) it may
          legitimately inspect fields in the inactive union member _kill
          and obtain garbage as a result.
      
          There appears to be software in the wild relying on this,
          albeit generally only for printing diagnostic messages.
      
       2) Software that wants to be robust against spurious signals may
          discard signals where si_code == SI_USER (or <= 0), or may
          filter such signals based on the si_uid and si_pid fields of
          siginfo._sigkill.  In the case of fault signals, this means
          that important (and usually fatal) error conditions may be
          silently ignored.
      
      In practice, many of the faults for which arm64 passes si_code == 0
      are undiagnosable conditions such as exceptions with syndrome
      values in ESR_ELx to which the architecture does not yet assign any
      meaning, or conditions indicative of a bug or error in the kernel
      or system and thus that are unrecoverable and should never occur in
      normal operation.
      
      The approach taken in this patch is to translate all such
      undiagnosable or "impossible" synchronous fault conditions to
      SIGKILL, since these are at least probably localisable to a single
      process.  Some of these conditions should really result in a kernel
      panic, but due to the lack of diagnostic information it is
      difficult to be certain: this patch does not add any calls to
      panic(), but this could change later if justified.
      
      Although si_code will not reach userspace in the case of SIGKILL,
      it is still desirable to pass a nonzero value so that the common
      siginfo handling code can detect incorrect use of si_code == 0
      without false positives.  In this case the si_code dependent
      siginfo fields will not be correctly initialised, but since they
      are not passed to userspace I deem this not to matter.
      
      A few faults can reasonably occur in realistic userspace scenarios,
      and _should_ raise a regular, handleable (but perhaps not
      ignorable/blockable) signal: for these, this patch attempts to
      choose a suitable standard si_code value for the raised signal in
      each case instead of 0.
      
      arm64 was the only arch to define a BUS_FIXME code, so after this
      patch nobody defines it.  This patch therefore also removes the
      relevant code from siginfo_layout().
      
      Cc: James Morse <james.morse@arm.com>
      Reported-by: default avatarEric W. Biederman <ebiederm@xmission.com>
      Signed-off-by: default avatarDave Martin <Dave.Martin@arm.com>
      Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
      af40ff68
    • Shanker Donthineni's avatar
      arm64: Add support for new control bits CTR_EL0.DIC and CTR_EL0.IDC · 6ae4b6e0
      Shanker Donthineni authored
      The DCache clean & ICache invalidation requirements for instructions
      to be data coherence are discoverable through new fields in CTR_EL0.
      The following two control bits DIC and IDC were defined for this
      purpose. No need to perform point of unification cache maintenance
      operations from software on systems where CPU caches are transparent.
      
      This patch optimize the three functions __flush_cache_user_range(),
      clean_dcache_area_pou() and invalidate_icache_range() if the hardware
      reports CTR_EL0.IDC and/or CTR_EL0.IDC. Basically it skips the two
      instructions 'DC CVAU' and 'IC IVAU', and the associated loop logic
      in order to avoid the unnecessary overhead.
      
      CTR_EL0.DIC: Instruction cache invalidation requirements for
       instruction to data coherence. The meaning of this bit[29].
        0: Instruction cache invalidation to the point of unification
           is required for instruction to data coherence.
        1: Instruction cache cleaning to the point of unification is
            not required for instruction to data coherence.
      
      CTR_EL0.IDC: Data cache clean requirements for instruction to data
       coherence. The meaning of this bit[28].
        0: Data cache clean to the point of unification is required for
           instruction to data coherence, unless CLIDR_EL1.LoC == 0b000
           or (CLIDR_EL1.LoUIS == 0b000 && CLIDR_EL1.LoUU == 0b000).
        1: Data cache clean to the point of unification is not required
           for instruction to data coherence.
      Co-authored-by: default avatarPhilip Elcan <pelcan@codeaurora.org>
      Reviewed-by: default avatarMark Rutland <mark.rutland@arm.com>
      Signed-off-by: default avatarShanker Donthineni <shankerd@codeaurora.org>
      Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
      6ae4b6e0
    • Ard Biesheuvel's avatar
      arm64/kernel: enable A53 erratum #8434319 handling at runtime · ca79acca
      Ard Biesheuvel authored
      Omit patching of ADRP instruction at module load time if the current
      CPUs are not susceptible to the erratum.
      Signed-off-by: default avatarArd Biesheuvel <ard.biesheuvel@linaro.org>
      [will: Drop duplicate initialisation of .def_scope field]
      Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
      ca79acca
    • Ard Biesheuvel's avatar
      arm64/errata: add REVIDR handling to framework · e8002e02
      Ard Biesheuvel authored
      In some cases, core variants that are affected by a certain erratum
      also exist in versions that have the erratum fixed, and this fact is
      recorded in a dedicated bit in system register REVIDR_EL1.
      
      Since the architecture does not require that a certain bit retains
      its meaning across different variants of the same model, each such
      REVIDR bit is tightly coupled to a certain revision/variant value,
      and so we need a list of revidr_mask/midr pairs to carry this
      information.
      
      So add the struct member and the associated macros and handling to
      allow REVIDR fixes to be taken into account.
      Signed-off-by: default avatarArd Biesheuvel <ard.biesheuvel@linaro.org>
      Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
      e8002e02
    • Ard Biesheuvel's avatar
      arm64/kernel: don't ban ADRP to work around Cortex-A53 erratum #843419 · a257e025
      Ard Biesheuvel authored
      Working around Cortex-A53 erratum #843419 involves special handling of
      ADRP instructions that end up in the last two instruction slots of a
      4k page, or whose output register gets overwritten without having been
      read. (Note that the latter instruction sequence is never emitted by
      a properly functioning compiler, which is why it is disregarded by the
      handling of the same erratum in the bfd.ld linker which we rely on for
      the core kernel)
      
      Normally, this gets taken care of by the linker, which can spot such
      sequences at final link time, and insert a veneer if the ADRP ends up
      at a vulnerable offset. However, linux kernel modules are partially
      linked ELF objects, and so there is no 'final link time' other than the
      runtime loading of the module, at which time all the static relocations
      are resolved.
      
      For this reason, we have implemented the #843419 workaround for modules
      by avoiding ADRP instructions altogether, by using the large C model,
      and by passing -mpc-relative-literal-loads to recent versions of GCC
      that may emit adrp/ldr pairs to perform literal loads. However, this
      workaround forces us to keep literal data mixed with the instructions
      in the executable .text segment, and literal data may inadvertently
      turn into an exploitable speculative gadget depending on the relative
      offsets of arbitrary symbols.
      
      So let's reimplement this workaround in a way that allows us to switch
      back to the small C model, and to drop the -mpc-relative-literal-loads
      GCC switch, by patching affected ADRP instructions at runtime:
      - ADRP instructions that do not appear at 4k relative offset 0xff8 or
        0xffc are ignored
      - ADRP instructions that are within 1 MB of their target symbol are
        converted into ADR instructions
      - remaining ADRP instructions are redirected via a veneer that performs
        the load using an unaffected movn/movk sequence.
      Signed-off-by: default avatarArd Biesheuvel <ard.biesheuvel@linaro.org>
      [will: tidied up ADRP -> ADR instruction patching.]
      [will: use ULL suffix for 64-bit immediate]
      Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
      a257e025
  2. 08 Mar, 2018 2 commits
    • Ard Biesheuvel's avatar
      arm64/kernel: kaslr: reduce module randomization range to 4 GB · f2b9ba87
      Ard Biesheuvel authored
      We currently have to rely on the GCC large code model for KASLR for
      two distinct but related reasons:
      - if we enable full randomization, modules will be loaded very far away
        from the core kernel, where they are out of range for ADRP instructions,
      - even without full randomization, the fact that the 128 MB module region
        is now no longer fully reserved for kernel modules means that there is
        a very low likelihood that the normal bottom-up allocation of other
        vmalloc regions may collide, and use up the range for other things.
      
      Large model code is suboptimal, given that each symbol reference involves
      a literal load that goes through the D-cache, reducing cache utilization.
      But more importantly, literals are not instructions but part of .text
      nonetheless, and hence mapped with executable permissions.
      
      So let's get rid of our dependency on the large model for KASLR, by:
      - reducing the full randomization range to 4 GB, thereby ensuring that
        ADRP references between modules and the kernel are always in range,
      - reduce the spillover range to 4 GB as well, so that we fallback to a
        region that is still guaranteed to be in range
      - move the randomization window of the core kernel to the middle of the
        VMALLOC space
      
      Note that KASAN always uses the module region outside of the vmalloc space,
      so keep the kernel close to that if KASAN is enabled.
      Signed-off-by: default avatarArd Biesheuvel <ard.biesheuvel@linaro.org>
      Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
      f2b9ba87
    • Ard Biesheuvel's avatar
      arm64: module: don't BUG when exceeding preallocated PLT count · 5e8307b9
      Ard Biesheuvel authored
      When PLTs are emitted at relocation time, we really should not exceed
      the number that we counted when parsing the relocation tables, and so
      currently, we BUG() on this condition. However, even though this is a
      clear bug in this particular piece of code, we can easily recover by
      failing to load the module.
      
      So instead, return 0 from module_emit_plt_entry() if this condition
      occurs, which is not a valid kernel address, and can hence serve as
      a flag value that makes the relocation routine bail out.
      Signed-off-by: default avatarArd Biesheuvel <ard.biesheuvel@linaro.org>
      Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
      5e8307b9
  3. 06 Mar, 2018 15 commits
  4. 05 Mar, 2018 4 commits
  5. 26 Feb, 2018 6 commits
  6. 25 Feb, 2018 2 commits
    • Linus Torvalds's avatar
      Merge tag 'nfs-for-4.16-3' of git://git.linux-nfs.org/projects/trondmy/linux-nfs · c89be524
      Linus Torvalds authored
      Pull NFS client bugfixes from Trond Myklebust:
      
       - fix a broken cast in nfs4_callback_recallany()
      
       - fix an Oops during NFSv4 migration events
      
       - make struct nlmclnt_fl_close_lock_ops static
      
      * tag 'nfs-for-4.16-3' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
        NFS: make struct nlmclnt_fl_close_lock_ops static
        nfs: system crashes after NFS4ERR_MOVED recovery
        NFSv4: Fix broken cast in nfs4_callback_recallany()
      c89be524
    • Linus Torvalds's avatar
      Merge tag 'powerpc-4.16-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux · 3664ce2d
      Linus Torvalds authored
      Pull powerpc fixes from Michael Ellerman:
      
       - Add handling for a missing instruction in our 32-bit BPF JIT so that
         it can be used for seccomp filtering.
      
       - Add a missing NULL pointer check before a function call in new EEH
         code.
      
       - Fix an error path in the new ocxl driver to correctly return EFAULT.
      
       - The support for the new ibm,drc-info device tree property turns out
         to need several fixes, so for now we just stop advertising to
         firmware that we support it until the bugs can be ironed out.
      
       - One fix for the new drmem code which was incorrectly modifying the
         device tree in place.
      
       - Finally two fixes for the RFI flush support, so that firmware can
         advertise to us that it should be disabled entirely so as not to
         affect performance.
      
      Thanks to: Bharata B Rao, Frederic Barrat, Juan J. Alvarez, Mark Lord,
      Michael Bringmann.
      
      * tag 'powerpc-4.16-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
        powerpc/powernv: Support firmware disable of RFI flush
        powerpc/pseries: Support firmware disable of RFI flush
        powerpc/mm/drmem: Fix unexpected flag value in ibm,dynamic-memory-v2
        powerpc/bpf/jit: Fix 32-bit JIT for seccomp_data access
        powerpc/pseries: Revert support for ibm,drc-info devtree property
        powerpc/pseries: Fix duplicate firmware feature for DRC_INFO
        ocxl: Fix potential bad errno on irq allocation
        powerpc/eeh: Fix crashes in eeh_report_resume()
      3664ce2d
  7. 23 Feb, 2018 6 commits
    • Linus Torvalds's avatar
      Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net · 9cb9c07d
      Linus Torvalds authored
      Pull networking fixes from David Miller:
      
       1) Fix TTL offset calculation in mac80211 mesh code, from Peter Oh.
      
       2) Fix races with procfs in ipt_CLUSTERIP, from Cong Wang.
      
       3) Memory leak fix in lpm_trie BPF map code, from Yonghong Song.
      
       4) Need to use GFP_ATOMIC in BPF cpumap allocations, from Jason Wang.
      
       5) Fix potential deadlocks in netfilter getsockopt() code paths, from
          Paolo Abeni.
      
       6) Netfilter stackpointer size checks really are needed to validate
          user input, from Florian Westphal.
      
       7) Missing timer init in x_tables, from Paolo Abeni.
      
       8) Don't use WQ_MEM_RECLAIM in mac80211 hwsim, from Johannes Berg.
      
       9) When an ibmvnic device is brought down then back up again, it can be
          sent queue entries from a previous session, handle this properly
          instead of crashing. From Thomas Falcon.
      
      10) Fix TCP checksum on LRO buffers in mlx5e, from Gal Pressman.
      
      11) When we are dumping filters in cls_api, the output SKB is empty, and
          the filter we are dumping is too large for the space in the SKB, we
          should return -EMSGSIZE like other netlink dump operations do.
          Otherwise userland has no signal that is needs to increase the size
          of its read buffer. From Roman Kapl.
      
      12) Several XDP fixes for virtio_net, from Jesper Dangaard Brouer.
      
      13) Module refcount leak in netlink when a dump start fails, from Jason
          Donenfeld.
      
      14) Handle sub-optimal GSO sizes better in TCP BBR congestion control,
          from Eric Dumazet.
      
      15) Releasing bpf per-cpu arraymaps can take a long time, add a
          condtional scheduling point. From Eric Dumazet.
      
      16) Implement retpolines for tail calls in x64 and arm64 bpf JITs. From
          Daniel Borkmann.
      
      17) Fix page leak in gianfar driver, from Andy Spencer.
      
      18) Missed clearing of estimator scratch buffer, from Eric Dumazet.
      
      * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (76 commits)
        net_sched: gen_estimator: fix broken estimators based on percpu stats
        gianfar: simplify FCS handling and fix memory leak
        ipv6 sit: work around bogus gcc-8 -Wrestrict warning
        macvlan: fix use-after-free in macvlan_common_newlink()
        bpf, arm64: fix out of bounds access in tail call
        bpf, x64: implement retpoline for tail call
        rxrpc: Fix send in rxrpc_send_data_packet()
        net: aquantia: Fix error handling in aq_pci_probe()
        bpf: fix rcu lockdep warning for lpm_trie map_free callback
        bpf: add schedule points in percpu arrays management
        regulatory: add NUL to request alpha2
        ibmvnic: Fix early release of login buffer
        net/smc9194: Remove bogus CONFIG_MAC reference
        net: ipv4: Set addr_type in hash_keys for forwarded case
        tcp_bbr: better deal with suboptimal GSO
        smsc75xx: fix smsc75xx_set_features()
        netlink: put module reference if dump start fails
        selftests/bpf/test_maps: exit child process without error in ENOMEM case
        selftests/bpf: update gitignore with test_libbpf_open
        selftests/bpf: tcpbpf_kern: use in6_* macros from glibc
        ..
      9cb9c07d
    • Linus Torvalds's avatar
      Merge branch 'fixes-v4.16-rc3' of... · 2eb02aa9
      Linus Torvalds authored
      Merge branch 'fixes-v4.16-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
      
      Pull security subsystem fixes from James Morris:
      
       - keys fixes via David Howells:
            "A collection of fixes for Linux keyrings, mostly thanks to Eric
             Biggers:
      
              - Fix some PKCS#7 verification issues.
      
              - Fix handling of unsupported crypto in X.509.
      
              - Fix too-large allocation in big_key"
      
       - Seccomp updates via Kees Cook:
            "These are fixes for the get_metadata interface that landed during
             -rc1. While the new selftest is strictly not a bug fix, I think
             it's in the same spirit of avoiding bugs"
      
       - an IMA build fix from Randy Dunlap
      
      * 'fixes-v4.16-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
        integrity/security: fix digsig.c build error with header file
        KEYS: Use individual pages in big_key for crypto buffers
        X.509: fix NULL dereference when restricting key with unsupported_sig
        X.509: fix BUG_ON() when hash algorithm is unsupported
        PKCS#7: fix direct verification of SignerInfo signature
        PKCS#7: fix certificate blacklisting
        PKCS#7: fix certificate chain verification
        seccomp: add a selftest for get_metadata
        ptrace, seccomp: tweak get_metadata behavior slightly
        seccomp, ptrace: switch get_metadata types to arch independent
      2eb02aa9
    • Linus Torvalds's avatar
      Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux · 65738c6b
      Linus Torvalds authored
      Pull arm64 fixes from Catalin Marinas:
       "arm64 and perf fixes:
      
         - build error when accessing MPIDR_HWID_BITMASK from .S
      
         - fix CTR_EL0 field definitions
      
         - remove/disable some kernel messages on user faults (unhandled
           signals, unimplemented syscalls)
      
         - fix kernel page fault in unwind_frame() with function graph tracing
      
         - fix perf sleeping while atomic errors when booting with ACPI"
      
      * tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
        arm64: fix unwind_frame() for filtered out fn for function graph tracing
        arm64: Enforce BBM for huge IO/VMAP mappings
        arm64: perf: correct PMUVer probing
        arm_pmu: acpi: request IRQs up-front
        arm_pmu: note IRQs and PMUs per-cpu
        arm_pmu: explicitly enable/disable SPIs at hotplug
        arm_pmu: acpi: check for mismatched PPIs
        arm_pmu: add armpmu_alloc_atomic()
        arm_pmu: fold platform helpers into platform code
        arm_pmu: kill arm_pmu_platdata
        ARM: ux500: remove PMU IRQ bouncer
        arm64: __show_regs: Only resolve kernel symbols when running at EL1
        arm64: Remove unimplemented syscall log message
        arm64: Disable unhandled signal log messages by default
        arm64: cpufeature: Fix CTR_EL0 field definitions
        arm64: uaccess: Formalise types for access_ok()
        arm64: Fix compilation error while accessing MPIDR_HWID_BITMASK from .S files
      65738c6b
    • Linus Torvalds's avatar
      Merge tag 'mips_fixes_4.16_3' of git://git.kernel.org/pub/scm/linux/kernel/git/jhogan/mips · 2bd06ce7
      Linus Torvalds authored
      Pull MIPS fix from James Hogan:
       "A single MIPS fix for mismatching struct compat_flock, resulting in
        bus errors starting Firefox on Debian 8 since 4.13"
      
      * tag 'mips_fixes_4.16_3' of git://git.kernel.org/pub/scm/linux/kernel/git/jhogan/mips:
        MIPS: Drop spurious __unused in struct compat_flock
      2bd06ce7
    • Linus Torvalds's avatar
      Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk · 13f514be
      Linus Torvalds authored
      Pull printk fixlet from Petr Mladek:
       "People expect to see the real pointer value for %px.
      
        Let's substitute '(null)' only for the other %p? format modifiers that
        need to deference the pointer"
      
      * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk:
        vsprintf: avoid misleading "(null)" for %px
      13f514be
    • Linus Torvalds's avatar
      Merge branch 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux · 938e1426
      Linus Torvalds authored
      Pull i2c fixes from Wolfram Sang:
       "Two bugfixes, one v4.16 regression fix, and two documentation fixes"
      
      * 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
        i2c: designware: Consider SCL GPIO optional
        i2c: busses: i2c-sirf: Fix spelling: "formular" -> "formula".
        i2c: bcm2835: Set up the rising/falling edge delays
        i2c: i801: Add missing documentation entries for Braswell and Kaby Lake
        i2c: designware: must wait for enable
      938e1426