1. 17 Jan, 2018 10 commits
    • Maciej W. Rozycki's avatar
      MIPS: Consistently handle buffer counter with PTRACE_SETREGSET · 323429be
      Maciej W. Rozycki authored
      commit 80b3ffce upstream.
      
      Update commit d614fd58 ("mips/ptrace: Preserve previous registers
      for short regset write") bug and consistently consume all data supplied
      to `fpr_set_msa' with the ptrace(2) PTRACE_SETREGSET request, such that
      a zero data buffer counter is returned where insufficient data has been
      given to fill a whole number of FP general registers.
      
      In reality this is not going to happen, as the caller is supposed to
      only supply data covering a whole number of registers and it is verified
      in `ptrace_regset' and again asserted in `fpr_set', however structuring
      code such that the presence of trailing partial FP general register data
      causes `fpr_set_msa' to return with a non-zero data buffer counter makes
      it appear that this trailing data will be used if there are subsequent
      writes made to FP registers, which is going to be the case with the FCSR
      once the missing write to that register has been fixed.
      
      Fixes: d614fd58 ("mips/ptrace: Preserve previous registers for short regset write")
      Signed-off-by: default avatarMaciej W. Rozycki <macro@mips.com>
      Cc: James Hogan <james.hogan@mips.com>
      Cc: Paul Burton <Paul.Burton@mips.com>
      Cc: Alex Smith <alex@alex-smith.me.uk>
      Cc: Dave Martin <Dave.Martin@arm.com>
      Cc: linux-mips@linux-mips.org
      Cc: linux-kernel@vger.kernel.org
      Patchwork: https://patchwork.linux-mips.org/patch/17927/Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      323429be
    • Maciej W. Rozycki's avatar
      MIPS: Guard against any partial write attempt with PTRACE_SETREGSET · a38f387c
      Maciej W. Rozycki authored
      commit dc24d0ed upstream.
      
      Complement commit d614fd58 ("mips/ptrace: Preserve previous
      registers for short regset write") and ensure that no partial register
      write attempt is made with PTRACE_SETREGSET, as we do not preinitialize
      any temporaries used to hold incoming register data and consequently
      random data could be written.
      
      It is the responsibility of the caller, such as `ptrace_regset', to
      arrange for writes to span whole registers only, so here we only assert
      that it has indeed happened.
      Signed-off-by: default avatarMaciej W. Rozycki <macro@mips.com>
      Fixes: 72b22bba ("MIPS: Don't assume 64-bit FP registers for FP regset")
      Cc: James Hogan <james.hogan@mips.com>
      Cc: Paul Burton <Paul.Burton@mips.com>
      Cc: Alex Smith <alex@alex-smith.me.uk>
      Cc: Dave Martin <Dave.Martin@arm.com>
      Cc: linux-mips@linux-mips.org
      Cc: linux-kernel@vger.kernel.org
      Patchwork: https://patchwork.linux-mips.org/patch/17926/Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      a38f387c
    • Maciej W. Rozycki's avatar
      MIPS: Factor out NT_PRFPREG regset access helpers · bc511ace
      Maciej W. Rozycki authored
      commit a03fe725 upstream.
      
      In preparation to fix a commit 72b22bba ("MIPS: Don't assume 64-bit
      FP registers for FP regset") FCSR access regression factor out
      NT_PRFPREG regset access helpers for the non-MSA and the MSA variants
      respectively, to avoid having to deal with excessive indentation in the
      actual fix.
      
      No functional change, however use `target->thread.fpu.fpr[0]' rather
      than `target->thread.fpu.fpr[i]' for FGR holding type size determination
      as there's no `i' variable to refer to anymore, and for the factored out
      `i' variable declaration use `unsigned int' rather than `unsigned' as
      its type, following the common style.
      Signed-off-by: default avatarMaciej W. Rozycki <macro@mips.com>
      Fixes: 72b22bba ("MIPS: Don't assume 64-bit FP registers for FP regset")
      Cc: James Hogan <james.hogan@mips.com>
      Cc: Paul Burton <Paul.Burton@mips.com>
      Cc: Alex Smith <alex@alex-smith.me.uk>
      Cc: Dave Martin <Dave.Martin@arm.com>
      Cc: linux-mips@linux-mips.org
      Cc: linux-kernel@vger.kernel.org
      Patchwork: https://patchwork.linux-mips.org/patch/17925/Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      bc511ace
    • Maciej W. Rozycki's avatar
      MIPS: Validate PR_SET_FP_MODE prctl(2) requests against the ABI of the task · a8caed01
      Maciej W. Rozycki authored
      commit b67336ee upstream.
      
      Fix an API loophole introduced with commit 9791554b ("MIPS,prctl:
      add PR_[GS]ET_FP_MODE prctl options for MIPS"), where the caller of
      prctl(2) is incorrectly allowed to make a change to CP0.Status.FR or
      CP0.Config5.FRE register bits even if CONFIG_MIPS_O32_FP64_SUPPORT has
      not been enabled, despite that an executable requesting the mode
      requested via ELF file annotation would not be allowed to run in the
      first place, or for n64 and n64 ABI tasks which do not have non-default
      modes defined at all.  Add suitable checks to `mips_set_process_fp_mode'
      and bail out if an invalid mode change has been requested for the ABI in
      effect, even if the FPU hardware or emulation would otherwise allow it.
      
      Always succeed however without taking any further action if the mode
      requested is the same as one already in effect, regardless of whether
      any mode change, should it be requested, would actually be allowed for
      the task concerned.
      Signed-off-by: default avatarMaciej W. Rozycki <macro@mips.com>
      Fixes: 9791554b ("MIPS,prctl: add PR_[GS]ET_FP_MODE prctl options for MIPS")
      Reviewed-by: default avatarPaul Burton <paul.burton@mips.com>
      Cc: James Hogan <james.hogan@mips.com>
      Cc: linux-mips@linux-mips.org
      Cc: linux-kernel@vger.kernel.org
      Patchwork: https://patchwork.linux-mips.org/patch/17800/Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      a8caed01
    • Bart Van Assche's avatar
      IB/srpt: Fix ACL lookup during login · 14af4f4c
      Bart Van Assche authored
      commit a1ffa467 upstream.
      
      Make sure that the initiator port GUID is stored in ch->ini_guid.
      Note: when initiating a connection sgid and dgid members in struct
      sa_path_rec represent the source and destination GIDs. When accepting
      a connection however sgid represents the destination GID and dgid the
      source GID.
      
      Fixes: commit 2bce1a6d ("IB/srpt: Accept GUIDs as port names")
      Signed-off-by: default avatarBart Van Assche <bart.vanassche@wdc.com>
      Signed-off-by: default avatarJason Gunthorpe <jgg@mellanox.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      14af4f4c
    • Bart Van Assche's avatar
      IB/srpt: Disable RDMA access by the initiator · 68807cb2
      Bart Van Assche authored
      commit bec40c26 upstream.
      
      With the SRP protocol all RDMA operations are initiated by the target.
      Since no RDMA operations are initiated by the initiator, do not grant
      the initiator permission to submit RDMA reads or writes to the target.
      Signed-off-by: default avatarBart Van Assche <bart.vanassche@wdc.com>
      Signed-off-by: default avatarJason Gunthorpe <jgg@mellanox.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      68807cb2
    • Wolfgang Grandegger's avatar
      can: gs_usb: fix return value of the "set_bittiming" callback · 83f8d47b
      Wolfgang Grandegger authored
      commit d5b42e66 upstream.
      
      The "set_bittiming" callback treats a positive return value as error!
      For that reason "can_changelink()" will quit silently after setting
      the bittiming values without processing ctrlmode, restart-ms, etc.
      Signed-off-by: default avatarWolfgang Grandegger <wg@grandegger.com>
      Signed-off-by: default avatarMarc Kleine-Budde <mkl@pengutronix.de>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      83f8d47b
    • Oliver Hartkopp's avatar
      can: vxcan: improve handling of missing peer name attribute · b043ea18
      Oliver Hartkopp authored
      commit b4c2951a upstream.
      
      Picking up the patch from Serhey Popovych (commit 191cdb38,
      "veth: Be more robust on network device creation when no attributes").
      
      When the peer name attribute is not provided the former implementation tries
      to register the given device name twice ... which leads to -EEXIST.
      If only one device name is given apply an automatic generated and valid name
      for the peer.
      
      Cc: Serhey Popovych <serhe.popovych@gmail.com>
      Signed-off-by: default avatarOliver Hartkopp <socketcan@hartkopp.net>
      Signed-off-by: default avatarMarc Kleine-Budde <mkl@pengutronix.de>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      b043ea18
    • Wanpeng Li's avatar
      KVM: Fix stack-out-of-bounds read in write_mmio · 653c41ac
      Wanpeng Li authored
      commit e39d200f upstream.
      
      Reported by syzkaller:
      
        BUG: KASAN: stack-out-of-bounds in write_mmio+0x11e/0x270 [kvm]
        Read of size 8 at addr ffff8803259df7f8 by task syz-executor/32298
      
        CPU: 6 PID: 32298 Comm: syz-executor Tainted: G           OE    4.15.0-rc2+ #18
        Hardware name: LENOVO ThinkCentre M8500t-N000/SHARKBAY, BIOS FBKTC1AUS 02/16/2016
        Call Trace:
         dump_stack+0xab/0xe1
         print_address_description+0x6b/0x290
         kasan_report+0x28a/0x370
         write_mmio+0x11e/0x270 [kvm]
         emulator_read_write_onepage+0x311/0x600 [kvm]
         emulator_read_write+0xef/0x240 [kvm]
         emulator_fix_hypercall+0x105/0x150 [kvm]
         em_hypercall+0x2b/0x80 [kvm]
         x86_emulate_insn+0x2b1/0x1640 [kvm]
         x86_emulate_instruction+0x39a/0xb90 [kvm]
         handle_exception+0x1b4/0x4d0 [kvm_intel]
         vcpu_enter_guest+0x15a0/0x2640 [kvm]
         kvm_arch_vcpu_ioctl_run+0x549/0x7d0 [kvm]
         kvm_vcpu_ioctl+0x479/0x880 [kvm]
         do_vfs_ioctl+0x142/0x9a0
         SyS_ioctl+0x74/0x80
         entry_SYSCALL_64_fastpath+0x23/0x9a
      
      The path of patched vmmcall will patch 3 bytes opcode 0F 01 C1(vmcall)
      to the guest memory, however, write_mmio tracepoint always prints 8 bytes
      through *(u64 *)val since kvm splits the mmio access into 8 bytes. This
      leaks 5 bytes from the kernel stack (CVE-2017-17741).  This patch fixes
      it by just accessing the bytes which we operate on.
      
      Before patch:
      
      syz-executor-5567  [007] .... 51370.561696: kvm_mmio: mmio write len 3 gpa 0x10 val 0x1ffff10077c1010f
      
      After patch:
      
      syz-executor-13416 [002] .... 51302.299573: kvm_mmio: mmio write len 3 gpa 0x10 val 0xc1010f
      Reported-by: default avatarDmitry Vyukov <dvyukov@google.com>
      Reviewed-by: default avatarDarren Kenny <darren.kenny@oracle.com>
      Reviewed-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
      Tested-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
      Cc: Paolo Bonzini <pbonzini@redhat.com>
      Cc: Radim Krčmář <rkrcmar@redhat.com>
      Cc: Marc Zyngier <marc.zyngier@arm.com>
      Cc: Christoffer Dall <christoffer.dall@linaro.org>
      Signed-off-by: default avatarWanpeng Li <wanpeng.li@hotmail.com>
      Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
      Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      653c41ac
    • Suren Baghdasaryan's avatar
      dm bufio: fix shrinker scans when (nr_to_scan < retain_target) · 883a082e
      Suren Baghdasaryan authored
      commit fbc7c07e upstream.
      
      When system is under memory pressure it is observed that dm bufio
      shrinker often reclaims only one buffer per scan. This change fixes
      the following two issues in dm bufio shrinker that cause this behavior:
      
      1. ((nr_to_scan - freed) <= retain_target) condition is used to
      terminate slab scan process. This assumes that nr_to_scan is equal
      to the LRU size, which might not be correct because do_shrink_slab()
      in vmscan.c calculates nr_to_scan using multiple inputs.
      As a result when nr_to_scan is less than retain_target (64) the scan
      will terminate after the first iteration, effectively reclaiming one
      buffer per scan and making scans very inefficient. This hurts vmscan
      performance especially because mutex is acquired/released every time
      dm_bufio_shrink_scan() is called.
      New implementation uses ((LRU size - freed) <= retain_target)
      condition for scan termination. LRU size can be safely determined
      inside __scan() because this function is called after dm_bufio_lock().
      
      2. do_shrink_slab() uses value returned by dm_bufio_shrink_count() to
      determine number of freeable objects in the slab. However dm_bufio
      always retains retain_target buffers in its LRU and will terminate
      a scan when this mark is reached. Therefore returning the entire LRU size
      from dm_bufio_shrink_count() is misleading because that does not
      represent the number of freeable objects that slab will reclaim during
      a scan. Returning (LRU size - retain_target) better represents the
      number of freeable objects in the slab. This way do_shrink_slab()
      returns 0 when (LRU size < retain_target) and vmscan will not try to
      scan this shrinker avoiding scans that will not reclaim any memory.
      
      Test: tested using Android device running
      <AOSP>/system/extras/alloc-stress that generates memory pressure
      and causes intensive shrinker scans
      Signed-off-by: default avatarSuren Baghdasaryan <surenb@google.com>
      Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      
      883a082e
  2. 10 Jan, 2018 30 commits