1. 11 Feb, 2022 1 commit
  2. 03 Feb, 2022 3 commits
    • James Morse's avatar
      KVM: arm64: Workaround Cortex-A510's single-step and PAC trap errata · 1dd498e5
      James Morse authored
      Cortex-A510's erratum #2077057 causes SPSR_EL2 to be corrupted when
      single-stepping authenticated ERET instructions. A single step is
      expected, but a pointer authentication trap is taken instead. The
      erratum causes SPSR_EL1 to be copied to SPSR_EL2, which could allow
      EL1 to cause a return to EL2 with a guest controlled ELR_EL2.
      
      Because the conditions require an ERET into active-not-pending state,
      this is only a problem for the EL2 when EL2 is stepping EL1. In this case
      the previous SPSR_EL2 value is preserved in struct kvm_vcpu, and can be
      restored.
      
      Cc: stable@vger.kernel.org # 53960faf: arm64: Add Cortex-A510 CPU part definition
      Cc: stable@vger.kernel.org
      Signed-off-by: default avatarJames Morse <james.morse@arm.com>
      [maz: fixup cpucaps ordering]
      Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
      Link: https://lore.kernel.org/r/20220127122052.1584324-5-james.morse@arm.com
      1dd498e5
    • James Morse's avatar
      KVM: arm64: Stop handle_exit() from handling HVC twice when an SError occurs · 1229630a
      James Morse authored
      Prior to commit defe21f4 ("KVM: arm64: Move PC rollback on SError to
      HYP"), when an SError is synchronised due to another exception, KVM
      handles the SError first. If the guest survives, the instruction that
      triggered the original exception is re-exectued to handle the first
      exception. HVC is treated as a special case as the instruction wouldn't
      normally be re-exectued, as its not a trap.
      
      Commit defe21f4 didn't preserve the behaviour of the 'return 1'
      that skips the rest of handle_exit().
      
      Since commit defe21f4, KVM will try to handle the SError and the
      original exception at the same time. When the exception was an HVC,
      fixup_guest_exit() has already rolled back ELR_EL2, meaning if the
      guest has virtual SError masked, it will execute and handle the HVC
      twice.
      
      Restore the original behaviour.
      
      Fixes: defe21f4 ("KVM: arm64: Move PC rollback on SError to HYP")
      Cc: stable@vger.kernel.org
      Signed-off-by: default avatarJames Morse <james.morse@arm.com>
      Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
      Link: https://lore.kernel.org/r/20220127122052.1584324-4-james.morse@arm.com
      1229630a
    • James Morse's avatar
      KVM: arm64: Avoid consuming a stale esr value when SError occur · 1c71dbc8
      James Morse authored
      When any exception other than an IRQ occurs, the CPU updates the ESR_EL2
      register with the exception syndrome. An SError may also become pending,
      and will be synchronised by KVM. KVM notes the exception type, and whether
      an SError was synchronised in exit_code.
      
      When an exception other than an IRQ occurs, fixup_guest_exit() updates
      vcpu->arch.fault.esr_el2 from the hardware register. When an SError was
      synchronised, the vcpu esr value is used to determine if the exception
      was due to an HVC. If so, ELR_EL2 is moved back one instruction. This
      is so that KVM can process the SError first, and re-execute the HVC if
      the guest survives the SError.
      
      But if an IRQ synchronises an SError, the vcpu's esr value is stale.
      If the previous non-IRQ exception was an HVC, KVM will corrupt ELR_EL2,
      causing an unrelated guest instruction to be executed twice.
      
      Check ARM_EXCEPTION_CODE() before messing with ELR_EL2, IRQs don't
      update this register so don't need to check.
      
      Fixes: defe21f4 ("KVM: arm64: Move PC rollback on SError to HYP")
      Cc: stable@vger.kernel.org
      Reported-by: default avatarSteven Price <steven.price@arm.com>
      Signed-off-by: default avatarJames Morse <james.morse@arm.com>
      Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
      Link: https://lore.kernel.org/r/20220127122052.1584324-3-james.morse@arm.com
      1c71dbc8
  3. 30 Jan, 2022 18 commits
  4. 29 Jan, 2022 12 commits
    • Thomas Gleixner's avatar
      Merge tag 'irqchip-fixes-5.17-1' of... · 243d3080
      Thomas Gleixner authored
      Merge tag 'irqchip-fixes-5.17-1' of git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms into irq/urgent
      
      Pull irqchip fixes from Marc Zyngier:
      
        - Drop an unused private data field in the AIC driver
      
        - Various fixes to the realtek-rtl driver
      
        - Make the GICv3 ITS driver compile again in !SMP configurations
      
        - Force reset of the GICv3 ITSs at probe time to avoid issues during kexec
      
        - Yet another kfree/bitmap_free conversion
      
        - Various DT updates (Renesas, SiFive)
      
      Link: https://lore.kernel.org/r/20220128174217.517041-1-maz@kernel.org
      243d3080
    • Linus Torvalds's avatar
      Merge tag 'pci-v5.17-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci · f8c7e4ed
      Linus Torvalds authored
      Pull pci fixes from Bjorn Helgaas:
      
       - Fix compilation warnings in new mt7621 driver (Sergio Paracuellos)
      
       - Restore the sysfs "rom" file for VGA shadow ROMs, which was broken
         when converting "rom" to be a static attribute (Bjorn Helgaas)
      
      * tag 'pci-v5.17-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci:
        PCI/sysfs: Find shadow ROM before static attribute initialization
        PCI: mt7621: Remove unused function pcie_rmw()
        PCI: mt7621: Drop of_match_ptr() to avoid unused variable
      f8c7e4ed
    • Linus Torvalds's avatar
      Merge tag 'gpio-fixes-for-v5.17-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux · 4cd90083
      Linus Torvalds authored
      Pull gpio fixes from Bartosz Golaszewski:
       "Two fixes for the gpio-simulator:
      
         - fix a bug with hogs not being set-up in gpio-sim when user-space
           sets the chip label to an empty string
      
         - include the gpio-sim documentation in the index"
      
      * tag 'gpio-fixes-for-v5.17-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux:
        gpio: sim: add doc file to index file
        gpio: sim: check the label length when setting up device properties
      4cd90083
    • Linus Torvalds's avatar
      Merge tag 'char-misc-5.17-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc · e255759e
      Linus Torvalds authored
      Pull char/misc driver fixes from Greg KH:
       "Here are two small char/misc driver fixes for 5.17-rc2 that fix some
        reported issues. They are:
      
         - fix up a merge issue in the at25.c driver that ended up dropping
           some lines in the driver. The removed lines ended being needed, so
           this restores it and the driver works again.
      
         - counter core fix where the wrong error was being returned, NULL
           should be the correct error for when memory is gone here, like the
           kmalloc() core does.
      
        Both of these have been in linux-next this week with no reported
        issues"
      
      * tag 'char-misc-5.17-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
        counter: fix an IS_ERR() vs NULL bug
        eeprom: at25: Restore missing allocation
      e255759e
    • Linus Torvalds's avatar
      Merge tag 'tty-5.17-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty · bb37101b
      Linus Torvalds authored
      Pull tty/serial driver fixes from Greg KH:
       "Here are some small bug fixes and reverts for reported problems with
        the tty core and drivers. They include:
      
         - revert the fifo use for the 8250 console mode. It caused too many
           regressions and problems, and had a bug in it as well. This is
           being reworked and should show up in a later -rc1 release, but it's
           not ready for 5.17
      
         - rpmsg tty race fix
      
         - restore the cyclades.h uapi header file. Turns out a compiler test
           suite used it for some unknown reason. Bring it back just for the
           parts that are used by the builder test so they continue to build.
           No functionality is restored as no one actually has this hardware
           anymore, nor is it really tested.
      
         - stm32 driver fixes
      
         - n_gsm flow control fixes
      
         - pl011 driver fix
      
         - rs485 initialization fix
      
        All of these have been in linux-next this week with no reported
        problems"
      
      * tag 'tty-5.17-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
        kbuild: remove include/linux/cyclades.h from header file check
        serial: core: Initialize rs485 RTS polarity already on probe
        serial: pl011: Fix incorrect rs485 RTS polarity on set_mctrl
        serial: stm32: fix software flow control transfer
        serial: stm32: prevent TDR register overwrite when sending x_char
        tty: n_gsm: fix SW flow control encoding/handling
        serial: 8250: of: Fix mapped region size when using reg-offset property
        tty: rpmsg: Fix race condition releasing tty port
        tty: Partially revert the removal of the Cyclades public API
        tty: Add support for Brainboxes UC cards.
        Revert "tty: serial: Use fifo in 8250 console driver"
      bb37101b
    • Linus Torvalds's avatar
      Merge tag 'usb-5.17-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb · 44aa31a2
      Linus Torvalds authored
      Pull USB driver fixes from Greg KH:
       "Here are some small USB driver fixes for 5.17-rc2 that resolve a
        number of reported problems. These include:
      
         - typec driver fixes
      
         - xhci platform driver fixes for suspending
      
         - ulpi core fix
      
         - role.h build fix
      
         - new device ids
      
         - syzbot-reported bugfixes
      
         - gadget driver fixes
      
         - dwc3 driver fixes
      
         - other small fixes
      
        All of these have been in linux-next this week with no reported
        issues"
      
      * tag 'usb-5.17-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
        usb: cdnsp: Fix segmentation fault in cdns_lost_power function
        usb: dwc2: gadget: don't try to disable ep0 in dwc2_hsotg_suspend
        usb: gadget: at91_udc: fix incorrect print type
        usb: dwc3: xilinx: Fix error handling when getting USB3 PHY
        usb: dwc3: xilinx: Skip resets and USB3 register settings for USB2.0 mode
        usb: xhci-plat: fix crash when suspend if remote wake enable
        usb: common: ulpi: Fix crash in ulpi_match()
        usb: gadget: f_sourcesink: Fix isoc transfer for USB_SPEED_SUPER_PLUS
        ucsi_ccg: Check DEV_INT bit only when starting CCG4
        USB: core: Fix hang in usb_kill_urb by adding memory barriers
        usb-storage: Add unusual-devs entry for VL817 USB-SATA bridge
        usb: typec: tcpm: Do not disconnect when receiving VSAFE0V
        usb: typec: tcpm: Do not disconnect while receiving VBUS off
        usb: typec: Don't try to register component master without components
        usb: typec: Only attempt to link USB ports if there is fwnode
        usb: typec: tcpci: don't touch CC line if it's Vconn source
        usb: roles: fix include/linux/usb/role.h compile issue
      44aa31a2
    • Linus Torvalds's avatar
      Merge tag 'block-5.17-2022-01-28' of git://git.kernel.dk/linux-block · cb323ee7
      Linus Torvalds authored
      Pull block fixes from Jens Axboe:
      
       - NVMe pull request
            - add the IGNORE_DEV_SUBNQN quirk for Intel P4500/P4600 SSDs (Wu
              Zheng)
            - remove the unneeded ret variable in nvmf_dev_show (Changcheng
              Deng)
      
       - Fix for a hang regression introduced with a patch in the merge
         window, where low queue depth devices would not always get woken
         correctly (Laibin)
      
       - Small series fixing an IO accounting issue with bio backed dm devices
         (Mike, Yu)
      
      * tag 'block-5.17-2022-01-28' of git://git.kernel.dk/linux-block:
        dm: properly fix redundant bio-based IO accounting
        dm: revert partial fix for redundant bio-based IO accounting
        block: add bio_start_io_acct_time() to control start_time
        blk-mq: Fix wrong wakeup batch configuration which will cause hang
        nvme-fabrics: remove the unneeded ret variable in nvmf_dev_show
        nvme-pci: add the IGNORE_DEV_SUBNQN quirk for Intel P4500/P4600 SSDs
        blk-mq: fix missing blk_account_io_done() in error path
        block: fix memory leak in disk_register_independent_access_ranges
      cb323ee7
    • Linus Torvalds's avatar
      Merge tag 'io_uring-5.17-2022-01-28' of git://git.kernel.dk/linux-block · 3b58e9f3
      Linus Torvalds authored
      Pull io_uring fixes from Jens Axboe:
       "Just two small fixes this time:
      
         - Fix a bug that can lead to node registration taking 1 second, when
           it should finish much quicker (Dylan)
      
         - Remove an unused argument from a function (Usama)"
      
      * tag 'io_uring-5.17-2022-01-28' of git://git.kernel.dk/linux-block:
        io_uring: remove unused argument from io_rsrc_node_alloc
        io_uring: fix bug in slow unregistering of nodes
      3b58e9f3
    • Linus Torvalds's avatar
      Merge tag 'powerpc-5.17-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux · d66c1e79
      Linus Torvalds authored
      Pull powerpc fixes from Michael Ellerman:
      
       - Fix VM debug warnings on boot triggered via __set_fixmap().
      
       - Fix a debug warning in the 64-bit Book3S PMU handling code.
      
       - Fix nested guest HFSCR handling with multiple vCPUs on Power9 or
         later.
      
       - Fix decrementer storm caused by a recent change, seen with some
         configs.
      
      Thanks to Alexey Kardashevskiy, Athira Rajeev, Christophe Leroy,
      Fabiano Rosas, Maxime Bizon, Nicholas Piggin, and Sachin Sant.
      
      * tag 'powerpc-5.17-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
        powerpc/64s/interrupt: Fix decrementer storm
        KVM: PPC: Book3S HV Nested: Fix nested HFSCR being clobbered with multiple vCPUs
        powerpc/perf: Fix power_pmu_disable to call clear_pmi_irq_pending only if PMI is pending
        powerpc/fixmap: Fix VM debug warning on unmap
      d66c1e79
    • Linus Torvalds's avatar
      Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux · 216e2aed
      Linus Torvalds authored
      Pull arm64 fixes from Catalin Marinas:
      
       - Errata workarounds for Cortex-A510: broken hardware dirty bit
         management, detection code for the TRBE (tracing) bugs with the
         actual fixes going in via the CoreSight tree.
      
       - Cortex-X2 errata handling for TRBE (inheriting the workarounds from
         Cortex-A710).
      
       - Fix ex_handler_load_unaligned_zeropad() to use the correct struct
         members.
      
       - A couple of kselftest fixes for FPSIMD.
      
       - Silence the vdso "no previous prototype" warning.
      
       - Mark start_backtrace() notrace and NOKPROBE_SYMBOL.
      
      * tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
        arm64: cpufeature: List early Cortex-A510 parts as having broken dbm
        kselftest/arm64: Correct logging of FPSIMD register read via ptrace
        kselftest/arm64: Skip VL_INHERIT tests for unsupported vector types
        arm64: errata: Add detection for TRBE trace data corruption
        arm64: errata: Add detection for TRBE invalid prohibited states
        arm64: errata: Add detection for TRBE ignored system register writes
        arm64: Add Cortex-A510 CPU part definition
        arm64: extable: fix load_unaligned_zeropad() reg indices
        arm64: Mark start_backtrace() notrace and NOKPROBE_SYMBOL
        arm64: errata: Update ARM64_ERRATUM_[2119858|2224489] with Cortex-X2 ranges
        arm64: Add Cortex-X2 CPU part definition
        arm64: vdso: Fix "no previous prototype" warning
      216e2aed
    • Linus Torvalds's avatar
      Merge tag 'fixes-v5.17-lsm-ceph-null' of... · d1e7f091
      Linus Torvalds authored
      Merge tag 'fixes-v5.17-lsm-ceph-null' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
      
      Pull security sybsystem fix from James Morris:
       "Fix NULL pointer crash in LSM via Ceph, from Vivek Goyal"
      
      * tag 'fixes-v5.17-lsm-ceph-null' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
        security, lsm: dentry_init_security() Handle multi LSM registration
      d1e7f091
    • Linus Torvalds's avatar
      Merge tag 'docs-5.17-3' of git://git.lwn.net/linux · 246e179d
      Linus Torvalds authored
      Pull documentation fixes from Jonathan Corbet:
       "A few documentation fixes for 5.17"
      
      * tag 'docs-5.17-3' of git://git.lwn.net/linux:
        docs/vm: Fix typo in *harden*
        Documentation: arm: marvell: Extend Avanta list
        docs: fix typo in Documentation/kernel-hacking/locking.rst
        docs: Hook the RTLA documents into the kernel docs build
      246e179d
  5. 28 Jan, 2022 6 commits
    • Mike Snitzer's avatar
      dm: properly fix redundant bio-based IO accounting · b879f915
      Mike Snitzer authored
      Record the start_time for a bio but defer the starting block core's IO
      accounting until after IO is submitted using bio_start_io_acct_time().
      
      This approach avoids the need to mess around with any of the
      individual IO stats in response to a bio_split() that follows bio
      submission.
      Reported-by: default avatarBud Brown <bubrown@redhat.com>
      Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
      Cc: stable@vger.kernel.org
      Depends-on: e45c47d1 ("block: add bio_start_io_acct_time() to control start_time")
      Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
      Link: https://lore.kernel.org/r/20220128155841.39644-4-snitzer@redhat.comSigned-off-by: default avatarJens Axboe <axboe@kernel.dk>
      b879f915
    • Mike Snitzer's avatar
      dm: revert partial fix for redundant bio-based IO accounting · f524d9c9
      Mike Snitzer authored
      Reverts a1e1cb72 ("dm: fix redundant IO accounting for bios that
      need splitting") because it was too narrow in scope (only addressed
      redundant 'sectors[]' accounting and not ios, nsecs[], etc).
      
      Cc: stable@vger.kernel.org
      Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
      Link: https://lore.kernel.org/r/20220128155841.39644-3-snitzer@redhat.comSigned-off-by: default avatarJens Axboe <axboe@kernel.dk>
      f524d9c9
    • Mike Snitzer's avatar
      block: add bio_start_io_acct_time() to control start_time · e45c47d1
      Mike Snitzer authored
      bio_start_io_acct_time() interface is like bio_start_io_acct() that
      allows start_time to be passed in. This gives drivers the ability to
      defer starting accounting until after IO is issued (but possibily not
      entirely due to bio splitting).
      Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
      Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
      Link: https://lore.kernel.org/r/20220128155841.39644-2-snitzer@redhat.comSigned-off-by: default avatarJens Axboe <axboe@kernel.dk>
      e45c47d1
    • Linus Torvalds's avatar
      Merge tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi · 169387e2
      Linus Torvalds authored
      Pull SCSI fixes from James Bottomley:
       "Sixteen patches, mostly minor fixes and updates; however there are
        substantive driver bug fixes in pm8001, bnx2fc, zfcp, myrs and qedf"
      
      * tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
        scsi: myrs: Fix crash in error case
        scsi: 53c700: Remove redundant assignment to pointer SCp
        scsi: ufs: Treat link loss as fatal error
        scsi: ufs: Use generic error code in ufshcd_set_dev_pwr_mode()
        scsi: bfa: Remove useless DMA-32 fallback configuration
        scsi: hisi_sas: Remove useless DMA-32 fallback configuration
        scsi: 3w-sas: Remove useless DMA-32 fallback configuration
        scsi: bnx2fc: Flush destroy_work queue before calling bnx2fc_interface_put()
        scsi: zfcp: Fix failed recovery on gone remote port with non-NPIV FCP devices
        scsi: pm8001: Fix bogus FW crash for maxcpus=1
        scsi: qedf: Change context reset messages to ratelimited
        scsi: qedf: Fix refcount issue when LOGO is received during TMF
        scsi: qedf: Add stag_work to all the vports
        scsi: ufs: ufshcd-pltfrm: Check the return value of devm_kstrdup()
        scsi: target: iscsi: Make sure the np under each tpg is unique
        scsi: elx: efct: Don't use GFP_KERNEL under spin lock
      169387e2
    • Linus Torvalds's avatar
      Merge tag 'efi-urgent-for-v5.17-1' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi · 073819e0
      Linus Torvalds authored
      Pull EFI fixes from Ard Biesheuvel:
      
       - avoid UEFI v2.00+ runtime services on Apple Mac systems, as they have
         been reported to cause crashes, and most Macs claim to be EFI v1.10
         anyway
      
       - avoid a spurious boot time warning on arm64 systems with 64k pages
      
      * tag 'efi-urgent-for-v5.17-1' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi:
        efi: runtime: avoid EFIv2 runtime services on Apple x86 machines
        efi/libstub: arm64: Fix image check alignment at entry
      073819e0
    • Vivek Goyal's avatar
      security, lsm: dentry_init_security() Handle multi LSM registration · 7f5056b9
      Vivek Goyal authored
      A ceph user has reported that ceph is crashing with kernel NULL pointer
      dereference. Following is the backtrace.
      
      /proc/version: Linux version 5.16.2-arch1-1 (linux@archlinux) (gcc (GCC)
      11.1.0, GNU ld (GNU Binutils) 2.36.1) #1 SMP PREEMPT Thu, 20 Jan 2022
      16:18:29 +0000
      distro / arch: Arch Linux / x86_64
      SELinux is not enabled
      ceph cluster version: 16.2.7 (dd0603118f56ab514f133c8d2e3adfc983942503)
      
      relevant dmesg output:
      [   30.947129] BUG: kernel NULL pointer dereference, address:
      0000000000000000
      [   30.947206] #PF: supervisor read access in kernel mode
      [   30.947258] #PF: error_code(0x0000) - not-present page
      [   30.947310] PGD 0 P4D 0
      [   30.947342] Oops: 0000 [#1] PREEMPT SMP PTI
      [   30.947388] CPU: 5 PID: 778 Comm: touch Not tainted 5.16.2-arch1-1 #1
      86fbf2c313cc37a553d65deb81d98e9dcc2a3659
      [   30.947486] Hardware name: Gigabyte Technology Co., Ltd. B365M
      DS3H/B365M DS3H, BIOS F5 08/13/2019
      [   30.947569] RIP: 0010:strlen+0x0/0x20
      [   30.947616] Code: b6 07 38 d0 74 16 48 83 c7 01 84 c0 74 05 48 39 f7 75
      ec 31 c0 31 d2 89 d6 89 d7 c3 48 89 f8 31 d2 89 d6 89 d7 c3 0
      f 1f 40 00 <80> 3f 00 74 12 48 89 f8 48 83 c0 01 80 38 00 75 f7 48 29 f8 31
      ff
      [   30.947782] RSP: 0018:ffffa4ed80ffbbb8 EFLAGS: 00010246
      [   30.947836] RAX: 0000000000000000 RBX: ffffa4ed80ffbc60 RCX:
      0000000000000000
      [   30.947904] RDX: 0000000000000000 RSI: 0000000000000000 RDI:
      0000000000000000
      [   30.947971] RBP: ffff94b0d15c0ae0 R08: 0000000000000000 R09:
      0000000000000000
      [   30.948040] R10: 0000000000000000 R11: 0000000000000000 R12:
      0000000000000000
      [   30.948106] R13: 0000000000000001 R14: ffffa4ed80ffbc60 R15:
      0000000000000000
      [   30.948174] FS:  00007fc7520f0740(0000) GS:ffff94b7ced40000(0000)
      knlGS:0000000000000000
      [   30.948252] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
      [   30.948308] CR2: 0000000000000000 CR3: 0000000104a40001 CR4:
      00000000003706e0
      [   30.948376] Call Trace:
      [   30.948404]  <TASK>
      [   30.948431]  ceph_security_init_secctx+0x7b/0x240 [ceph
      49f9c4b9bf5be8760f19f1747e26da33920bce4b]
      [   30.948582]  ceph_atomic_open+0x51e/0x8a0 [ceph
      49f9c4b9bf5be8760f19f1747e26da33920bce4b]
      [   30.948708]  ? get_cached_acl+0x4d/0xa0
      [   30.948759]  path_openat+0x60d/0x1030
      [   30.948809]  do_filp_open+0xa5/0x150
      [   30.948859]  do_sys_openat2+0xc4/0x190
      [   30.948904]  __x64_sys_openat+0x53/0xa0
      [   30.948948]  do_syscall_64+0x5c/0x90
      [   30.948989]  ? exc_page_fault+0x72/0x180
      [   30.949034]  entry_SYSCALL_64_after_hwframe+0x44/0xae
      [   30.949091] RIP: 0033:0x7fc7521e25bb
      [   30.950849] Code: 25 00 00 41 00 3d 00 00 41 00 74 4b 64 8b 04 25 18 00
      00 00 85 c0 75 67 44 89 e2 48 89 ee bf 9c ff ff ff b8 01 01 0
      0 00 0f 05 <48> 3d 00 f0 ff ff 0f 87 91 00 00 00 48 8b 54 24 28 64 48 2b 14
      25
      
      Core of the problem is that ceph checks for return code from
      security_dentry_init_security() and if return code is 0, it assumes
      everything is fine and continues to call strlen(name), which crashes.
      
      Typically SELinux LSM returns 0 and sets name to "security.selinux" and
      it is not a problem. Or if selinux is not compiled in or disabled, it
      returns -EOPNOTSUP and ceph deals with it.
      
      But somehow in this configuration, 0 is being returned and "name" is
      not being initialized and that's creating the problem.
      
      Our suspicion is that BPF LSM is registering a hook for
      dentry_init_security() and returns hook default of 0.
      
      LSM_HOOK(int, 0, dentry_init_security, struct dentry *dentry,...)
      
      I have not been able to reproduce it just by doing CONFIG_BPF_LSM=y.
      Stephen has tested the patch though and confirms it solves the problem
      for him.
      
      dentry_init_security() is written in such a way that it expects only one
      LSM to register the hook. Atleast that's the expectation with current code.
      
      If another LSM returns a hook and returns default, it will simply return
      0 as of now and that will break ceph.
      
      Hence, suggestion is that change semantics of this hook a bit. If there
      are no LSMs or no LSM is taking ownership and initializing security context,
      then return -EOPNOTSUP. Also allow at max one LSM to initialize security
      context. This hook can't deal with multiple LSMs trying to init security
      context. This patch implements this new behavior.
      Reported-by: default avatarStephen Muth <smuth4@gmail.com>
      Tested-by: default avatarStephen Muth <smuth4@gmail.com>
      Suggested-by: default avatarCasey Schaufler <casey@schaufler-ca.com>
      Acked-by: default avatarCasey Schaufler <casey@schaufler-ca.com>
      Reviewed-by: default avatarSerge Hallyn <serge@hallyn.com>
      Cc: Jeff Layton <jlayton@kernel.org>
      Cc: Christian Brauner <brauner@kernel.org>
      Cc: Paul Moore <paul@paul-moore.com>
      Cc: <stable@vger.kernel.org> # 5.16.0
      Signed-off-by: default avatarVivek Goyal <vgoyal@redhat.com>
      Reviewed-by: default avatarJeff Layton <jlayton@kernel.org>
      Acked-by: default avatarPaul Moore <paul@paul-moore.com>
      Acked-by: default avatarChristian Brauner <brauner@kernel.org>
      Signed-off-by: default avatarJames Morris <jmorris@namei.org>
      7f5056b9