1. 09 Dec, 2021 6 commits
    • Xie Yongji's avatar
      aio: Fix incorrect usage of eventfd_signal_allowed() · 4b374986
      Xie Yongji authored
      We should defer eventfd_signal() to the workqueue when
      eventfd_signal_allowed() return false rather than return
      true.
      
      Fixes: b542e383 ("eventfd: Make signal recursion protection a task bit")
      Signed-off-by: default avatarXie Yongji <xieyongji@bytedance.com>
      Link: https://lore.kernel.org/r/20210913111928.98-1-xieyongji@bytedance.comReviewed-by: default avatarEric Biggers <ebiggers@google.com>
      Signed-off-by: default avatarEric Biggers <ebiggers@google.com>
      4b374986
    • Eric Biggers's avatar
      aio: fix use-after-free due to missing POLLFREE handling · 50252e4b
      Eric Biggers authored
      signalfd_poll() and binder_poll() are special in that they use a
      waitqueue whose lifetime is the current task, rather than the struct
      file as is normally the case.  This is okay for blocking polls, since a
      blocking poll occurs within one task; however, non-blocking polls
      require another solution.  This solution is for the queue to be cleared
      before it is freed, by sending a POLLFREE notification to all waiters.
      
      Unfortunately, only eventpoll handles POLLFREE.  A second type of
      non-blocking poll, aio poll, was added in kernel v4.18, and it doesn't
      handle POLLFREE.  This allows a use-after-free to occur if a signalfd or
      binder fd is polled with aio poll, and the waitqueue gets freed.
      
      Fix this by making aio poll handle POLLFREE.
      
      A patch by Ramji Jiyani <ramjiyani@google.com>
      (https://lore.kernel.org/r/20211027011834.2497484-1-ramjiyani@google.com)
      tried to do this by making aio_poll_wake() always complete the request
      inline if POLLFREE is seen.  However, that solution had two bugs.
      First, it introduced a deadlock, as it unconditionally locked the aio
      context while holding the waitqueue lock, which inverts the normal
      locking order.  Second, it didn't consider that POLLFREE notifications
      are missed while the request has been temporarily de-queued.
      
      The second problem was solved by my previous patch.  This patch then
      properly fixes the use-after-free by handling POLLFREE in a
      deadlock-free way.  It does this by taking advantage of the fact that
      freeing of the waitqueue is RCU-delayed, similar to what eventpoll does.
      
      Fixes: 2c14fa83 ("aio: implement IOCB_CMD_POLL")
      Cc: <stable@vger.kernel.org> # v4.18+
      Link: https://lore.kernel.org/r/20211209010455.42744-6-ebiggers@kernel.orgSigned-off-by: default avatarEric Biggers <ebiggers@google.com>
      50252e4b
    • Eric Biggers's avatar
      aio: keep poll requests on waitqueue until completed · 363bee27
      Eric Biggers authored
      Currently, aio_poll_wake() will always remove the poll request from the
      waitqueue.  Then, if aio_poll_complete_work() sees that none of the
      polled events are ready and the request isn't cancelled, it re-adds the
      request to the waitqueue.  (This can easily happen when polling a file
      that doesn't pass an event mask when waking up its waitqueue.)
      
      This is fundamentally broken for two reasons:
      
        1. If a wakeup occurs between vfs_poll() and the request being
           re-added to the waitqueue, it will be missed because the request
           wasn't on the waitqueue at the time.  Therefore, IOCB_CMD_POLL
           might never complete even if the polled file is ready.
      
        2. When the request isn't on the waitqueue, there is no way to be
           notified that the waitqueue is being freed (which happens when its
           lifetime is shorter than the struct file's).  This is supposed to
           happen via the waitqueue entries being woken up with POLLFREE.
      
      Therefore, leave the requests on the waitqueue until they are actually
      completed (or cancelled).  To keep track of when aio_poll_complete_work
      needs to be scheduled, use new fields in struct poll_iocb.  Remove the
      'done' field which is now redundant.
      
      Note that this is consistent with how sys_poll() and eventpoll work;
      their wakeup functions do *not* remove the waitqueue entries.
      
      Fixes: 2c14fa83 ("aio: implement IOCB_CMD_POLL")
      Cc: <stable@vger.kernel.org> # v4.18+
      Link: https://lore.kernel.org/r/20211209010455.42744-5-ebiggers@kernel.orgSigned-off-by: default avatarEric Biggers <ebiggers@google.com>
      363bee27
    • Eric Biggers's avatar
      signalfd: use wake_up_pollfree() · 9537bae0
      Eric Biggers authored
      wake_up_poll() uses nr_exclusive=1, so it's not guaranteed to wake up
      all exclusive waiters.  Yet, POLLFREE *must* wake up all waiters.  epoll
      and aio poll are fortunately not affected by this, but it's very
      fragile.  Thus, the new function wake_up_pollfree() has been introduced.
      
      Convert signalfd to use wake_up_pollfree().
      Reported-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Fixes: d80e731e ("epoll: introduce POLLFREE to flush ->signalfd_wqh before kfree()")
      Cc: stable@vger.kernel.org
      Link: https://lore.kernel.org/r/20211209010455.42744-4-ebiggers@kernel.orgSigned-off-by: default avatarEric Biggers <ebiggers@google.com>
      9537bae0
    • Eric Biggers's avatar
      binder: use wake_up_pollfree() · a880b28a
      Eric Biggers authored
      wake_up_poll() uses nr_exclusive=1, so it's not guaranteed to wake up
      all exclusive waiters.  Yet, POLLFREE *must* wake up all waiters.  epoll
      and aio poll are fortunately not affected by this, but it's very
      fragile.  Thus, the new function wake_up_pollfree() has been introduced.
      
      Convert binder to use wake_up_pollfree().
      Reported-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Fixes: f5cb779b ("ANDROID: binder: remove waitqueue when thread exits.")
      Cc: stable@vger.kernel.org
      Link: https://lore.kernel.org/r/20211209010455.42744-3-ebiggers@kernel.orgSigned-off-by: default avatarEric Biggers <ebiggers@google.com>
      a880b28a
    • Eric Biggers's avatar
      wait: add wake_up_pollfree() · 42288cb4
      Eric Biggers authored
      Several ->poll() implementations are special in that they use a
      waitqueue whose lifetime is the current task, rather than the struct
      file as is normally the case.  This is okay for blocking polls, since a
      blocking poll occurs within one task; however, non-blocking polls
      require another solution.  This solution is for the queue to be cleared
      before it is freed, using 'wake_up_poll(wq, EPOLLHUP | POLLFREE);'.
      
      However, that has a bug: wake_up_poll() calls __wake_up() with
      nr_exclusive=1.  Therefore, if there are multiple "exclusive" waiters,
      and the wakeup function for the first one returns a positive value, only
      that one will be called.  That's *not* what's needed for POLLFREE;
      POLLFREE is special in that it really needs to wake up everyone.
      
      Considering the three non-blocking poll systems:
      
      - io_uring poll doesn't handle POLLFREE at all, so it is broken anyway.
      
      - aio poll is unaffected, since it doesn't support exclusive waits.
        However, that's fragile, as someone could add this feature later.
      
      - epoll doesn't appear to be broken by this, since its wakeup function
        returns 0 when it sees POLLFREE.  But this is fragile.
      
      Although there is a workaround (see epoll), it's better to define a
      function which always sends POLLFREE to all waiters.  Add such a
      function.  Also make it verify that the queue really becomes empty after
      all waiters have been woken up.
      Reported-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Cc: stable@vger.kernel.org
      Link: https://lore.kernel.org/r/20211209010455.42744-2-ebiggers@kernel.orgSigned-off-by: default avatarEric Biggers <ebiggers@google.com>
      42288cb4
  2. 05 Dec, 2021 12 commits
    • Linus Torvalds's avatar
      Linux 5.16-rc4 · 0fcfb00b
      Linus Torvalds authored
      0fcfb00b
    • Linus Torvalds's avatar
      Merge tag 'for-5.16/parisc-6' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux · 268ba095
      Linus Torvalds authored
      Pull parisc fixes from Helge Deller:
       "Some bug and warning fixes:
      
         - Fix "make install" to use debians "installkernel" script which is
           now in /usr/sbin
      
         - Fix the bindeb-pkg make target by giving the correct KBUILD_IMAGE
           file name
      
         - Fix compiler warnings by annotating parisc agp init functions with
           __init
      
         - Fix timekeeping on SMP machines with dual-core CPUs
      
         - Enable some more config options in the 64-bit defconfig"
      
      * tag 'for-5.16/parisc-6' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
        parisc: Mark cr16 CPU clocksource unstable on all SMP machines
        parisc: Fix "make install" on newer debian releases
        parisc/agp: Annotate parisc agp init functions with __init
        parisc: Enable sata sil, audit and usb support on 64-bit defconfig
        parisc: Fix KBUILD_IMAGE for self-extracting kernel
      268ba095
    • Linus Torvalds's avatar
      Merge tag 'usb-5.16-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb · 94420704
      Linus Torvalds authored
      Pull USB fixes from Greg KH:
       "Here are some small USB fixes for a few reported issues. Included in
        here are:
      
         - xhci fix for a _much_ reported regression. I don't think there's a
           community distro that has not reported this problem yet :(
      
         - new USB quirk addition
      
         - cdns3 minor fixes
      
         - typec regression fix.
      
        All of these have been in linux-next with no reported problems, and
        the xhci fix has been reported by many to resolve their reported
        problem"
      
      * tag 'usb-5.16-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
        usb: cdnsp: Fix a NULL pointer dereference in cdnsp_endpoint_init()
        usb: cdns3: gadget: fix new urb never complete if ep cancel previous requests
        usb: typec: tcpm: Wait in SNK_DEBOUNCED until disconnect
        USB: NO_LPM quirk Lenovo Powered USB-C Travel Hub
        xhci: Fix commad ring abort, write all 64 bits to CRCR register.
      94420704
    • Linus Torvalds's avatar
      Merge tag 'tty-5.16-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty · 51639539
      Linus Torvalds authored
      Pull tty/serial fixes from Greg KH:
       "Here are some small TTY and Serial driver fixes for 5.16-rc4 to
        resolve a number of reported problems.
      
        They include:
      
         - liteuart serial driver fixes
      
         - 8250_pci serial driver fixes for pericom devices
      
         - 8250 RTS line control fix while in RS-485 mode
      
         - tegra serial driver fix
      
         - msm_serial driver fix
      
         - pl011 serial driver new id
      
         - fsl_lpuart revert of broken change
      
         - 8250_bcm7271 serial driver fix
      
         - MAINTAINERS file update for rpmsg tty driver that came in 5.16-rc1
      
         - vgacon fix for reported problem
      
        All of these, except for the 8250_bcm7271 fix have been in linux-next
        with no reported problem. The 8250_bcm7271 fix was added to the tree
        on Friday so no chance to be linux-next yet. But it should be fine as
        the affected developers submitted it"
      
      * tag 'tty-5.16-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
        serial: 8250_bcm7271: UART errors after resuming from S2
        serial: 8250_pci: rewrite pericom_do_set_divisor()
        serial: 8250_pci: Fix ACCES entries in pci_serial_quirks array
        serial: 8250: Fix RTS modem control while in rs485 mode
        Revert "tty: serial: fsl_lpuart: drop earlycon entry for i.MX8QXP"
        serial: tegra: Change lower tolerance baud rate limit for tegra20 and tegra30
        serial: liteuart: relax compile-test dependencies
        serial: liteuart: fix minor-number leak on probe errors
        serial: liteuart: fix use-after-free and memleak on unbind
        serial: liteuart: Fix NULL pointer dereference in ->remove()
        vgacon: Propagate console boot parameters before calling `vc_resize'
        tty: serial: msm_serial: Deactivate RX DMA for polling support
        serial: pl011: Add ACPI SBSA UART match id
        serial: core: fix transmit-buffer reset and memleak
        MAINTAINERS: Add rpmsg tty driver maintainer
      51639539
    • Linus Torvalds's avatar
      Merge tag 'timers_urgent_for_v5.16_rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · 7587a4a5
      Linus Torvalds authored
      Pull timer fix from Borislav Petkov:
      
       - Prevent a tick storm when a dedicated timekeeper CPU in nohz_full
         mode runs for prolonged periods with interrupts disabled and ends up
         programming the next tick in the past, leading to that storm
      
      * tag 'timers_urgent_for_v5.16_rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
        timers/nohz: Last resort update jiffies on nohz_full IRQ entry
      7587a4a5
    • Linus Torvalds's avatar
      Merge tag 'sched_urgent_for_v5.16_rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · 1d213767
      Linus Torvalds authored
      Pull scheduler fixes from Borislav Petkov:
      
       - Properly init uclamp_flags of a runqueue, on first enqueuing
      
       - Fix preempt= callback return values
      
       - Correct utime/stime resource usage reporting on nohz_full to return
         the proper times instead of shorter ones
      
      * tag 'sched_urgent_for_v5.16_rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
        sched/uclamp: Fix rq->uclamp_max not set on first enqueue
        preempt/dynamic: Fix setup_preempt_mode() return value
        sched/cputime: Fix getrusage(RUSAGE_THREAD) with nohz_full
      1d213767
    • Linus Torvalds's avatar
      Merge tag 'x86_urgent_for_v5.16_rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · f5d54a42
      Linus Torvalds authored
      Pull x86 fixes from Borislav Petkov:
      
       - Fix a couple of SWAPGS fencing issues in the x86 entry code
      
       - Use the proper operand types in __{get,put}_user() to prevent
         truncation in SEV-ES string io
      
       - Make sure the kernel mappings are present in trampoline_pgd in order
         to prevent any potential accesses to unmapped memory after switching
         to it
      
       - Fix a trivial list corruption in objtool's pv_ops validation
      
       - Disable the clocksource watchdog for TSC on platforms which claim
         that the TSC is constant, doesn't stop in sleep states, CPU has TSC
         adjust and the number of sockets of the platform are max 2, to
         prevent erroneous markings of the TSC as unstable.
      
       - Make sure TSC adjust is always checked not only when going idle
      
       - Prevent a stack leak by initializing struct _fpx_sw_bytes properly in
         the FPU code
      
       - Fix INTEL_FAM6_RAPTORLAKE define naming to adhere to the convention
      
      * tag 'x86_urgent_for_v5.16_rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
        x86/xen: Add xenpv_restore_regs_and_return_to_usermode()
        x86/entry: Use the correct fence macro after swapgs in kernel CR3
        x86/entry: Add a fence for kernel entry SWAPGS in paranoid_entry()
        x86/sev: Fix SEV-ES INS/OUTS instructions for word, dword, and qword
        x86/64/mm: Map all kernel memory into trampoline_pgd
        objtool: Fix pv_ops noinstr validation
        x86/tsc: Disable clocksource watchdog for TSC on qualified platorms
        x86/tsc: Add a timer to make sure TSC_adjust is always checked
        x86/fpu/signal: Initialize sw_bytes in save_xstate_epilog()
        x86/cpu: Drop spurious underscore from RAPTOR_LAKE #define
      f5d54a42
    • Linus Torvalds's avatar
      Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm · 90bf8d98
      Linus Torvalds authored
      Pull more kvm fixes from Paolo Bonzini:
      
       - Static analysis fix
      
       - New SEV-ES protocol for communicating invalid VMGEXIT requests
      
       - Ensure APICv is considered inactive if there is no APIC
      
       - Fix reserved bits for AMD PerfEvtSeln register
      
      * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
        KVM: SVM: Do not terminate SEV-ES guests on GHCB validation failure
        KVM: SEV: Fall back to vmalloc for SEV-ES scratch area if necessary
        KVM: SEV: Return appropriate error codes if SEV-ES scratch setup fails
        KVM: x86/mmu: Retry page fault if root is invalidated by memslot update
        KVM: VMX: Set failure code in prepare_vmcs02()
        KVM: ensure APICv is considered inactive if there is no APIC
        KVM: x86/pmu: Fix reserved bits for AMD PerfEvtSeln register
      90bf8d98
    • Tom Lendacky's avatar
      KVM: SVM: Do not terminate SEV-ES guests on GHCB validation failure · ad5b3532
      Tom Lendacky authored
      Currently, an SEV-ES guest is terminated if the validation of the VMGEXIT
      exit code or exit parameters fails.
      
      The VMGEXIT instruction can be issued from userspace, even though
      userspace (likely) can't update the GHCB. To prevent userspace from being
      able to kill the guest, return an error through the GHCB when validation
      fails rather than terminating the guest. For cases where the GHCB can't be
      updated (e.g. the GHCB can't be mapped, etc.), just return back to the
      guest.
      
      The new error codes are documented in the lasest update to the GHCB
      specification.
      
      Fixes: 291bd20d ("KVM: SVM: Add initial support for a VMGEXIT VMEXIT")
      Signed-off-by: default avatarTom Lendacky <thomas.lendacky@amd.com>
      Message-Id: <b57280b5562893e2616257ac9c2d4525a9aeeb42.1638471124.git.thomas.lendacky@amd.com>
      Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
      ad5b3532
    • Sean Christopherson's avatar
      KVM: SEV: Fall back to vmalloc for SEV-ES scratch area if necessary · a655276a
      Sean Christopherson authored
      Use kvzalloc() to allocate KVM's buffer for SEV-ES's GHCB scratch area so
      that KVM falls back to __vmalloc() if physically contiguous memory isn't
      available.  The buffer is purely a KVM software construct, i.e. there's
      no need for it to be physically contiguous.
      
      Cc: Tom Lendacky <thomas.lendacky@amd.com>
      Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
      Message-Id: <20211109222350.2266045-3-seanjc@google.com>
      Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
      a655276a
    • Sean Christopherson's avatar
      KVM: SEV: Return appropriate error codes if SEV-ES scratch setup fails · 75236f5f
      Sean Christopherson authored
      Return appropriate error codes if setting up the GHCB scratch area for an
      SEV-ES guest fails.  In particular, returning -EINVAL instead of -ENOMEM
      when allocating the kernel buffer could be confusing as userspace would
      likely suspect a guest issue.
      
      Fixes: 8f423a80 ("KVM: SVM: Support MMIO for an SEV-ES guest")
      Cc: Tom Lendacky <thomas.lendacky@amd.com>
      Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
      Message-Id: <20211109222350.2266045-2-seanjc@google.com>
      Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
      75236f5f
    • Linus Torvalds's avatar
      Merge tag 'xfs-5.16-fixes-2' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux · 79a72162
      Linus Torvalds authored
      Pull xfs fix from Darrick Wong:
       "Remove an unnecessary (and backwards) rename flags check that
        duplicates a VFS level check"
      
      * tag 'xfs-5.16-fixes-2' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
        xfs: remove incorrect ASSERT in xfs_rename
      79a72162
  3. 04 Dec, 2021 9 commits
  4. 03 Dec, 2021 13 commits