1. 20 Jun, 2017 40 commits
    • Felipe Balbi's avatar
      usb: gadget: composite: correctly initialize ep->maxpacket · d4dfd03c
      Felipe Balbi authored
      commit e8f29bb7 upstream.
      
      usb_endpoint_maxp() returns wMaxPacketSize in its
      raw form. Without taking into consideration that it
      also contains other bits reserved for isochronous
      endpoints.
      
      This patch fixes one occasion where this is a
      problem by making sure that we initialize
      ep->maxpacket only with lower 10 bits of the value
      returned by usb_endpoint_maxp(). Note that seperate
      patches will be necessary to audit all call sites of
      usb_endpoint_maxp() and make sure that
      usb_endpoint_maxp() only returns lower 10 bits of
      wMaxPacketSize.
      Signed-off-by: default avatarFelipe Balbi <felipe.balbi@linux.intel.com>
      Signed-off-by: default avatarWilly Tarreau <w@1wt.eu>
      d4dfd03c
    • Guenter Roeck's avatar
      usb: hub: Wait for connection to be reestablished after port reset · 1ea3d6c8
      Guenter Roeck authored
      commit 22547c4c upstream.
      
      On a system with a defective USB device connected to an USB hub,
      an endless sequence of port connect events was observed. The sequence
      of events as observed is as follows:
      
      - Port reports connected event (port status=USB_PORT_STAT_CONNECTION).
      - Event handler debounces port and resets it by calling hub_port_reset().
      - hub_port_reset() calls hub_port_wait_reset() to wait for the reset
        to complete.
      - The reset completes, but USB_PORT_STAT_CONNECTION is not immediately
        set in the port status register.
      - hub_port_wait_reset() returns -ENOTCONN.
      - Port initialization sequence is aborted.
      - A few milliseconds later, the port again reports a connected event,
        and the sequence repeats.
      
      This continues either forever or, randomly, stops if the connection
      is already re-established when the port status is read. It results in
      a high rate of udev events. This in turn destabilizes userspace since
      the above sequence holds the device mutex pretty much continuously
      and prevents userspace from actually reading the device status.
      
      To prevent the problem from happening, let's wait for the connection
      to be re-established after a port reset. If the device was actually
      disconnected, the code will still return an error, but it will do so
      only after the long reset timeout.
      
      Cc: Douglas Anderson <dianders@chromium.org>
      Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
      Acked-by: default avatarAlan Stern <stern@rowland.harvard.edu>
      Signed-off-by: default avatarSumit Semwal <sumit.semwal@linaro.org>
      Signed-off-by: default avatarWilly Tarreau <w@1wt.eu>
      1ea3d6c8
    • Janusz Dziedzic's avatar
      usb: dwc3: gadget: delay unmap of bounced requests · 91c86d70
      Janusz Dziedzic authored
      commit de288e36 upstream.
      
      In the case of bounced ep0 requests, we must delay DMA operation until
      after ->complete() otherwise we might overwrite contents of req->buf.
      
      This caused problems with RNDIS gadget.
      Signed-off-by: default avatarJanusz Dziedzic <januszx.dziedzic@intel.com>
      Signed-off-by: default avatarFelipe Balbi <felipe.balbi@linux.intel.com>
      Signed-off-by: default avatarWilly Tarreau <w@1wt.eu>
      91c86d70
    • Guenter Roeck's avatar
      usb: host: xhci-plat: Fix timeout on removal of hot pluggable xhci controllers · a3fdfc64
      Guenter Roeck authored
      commit dcc7620c upstream.
      
      Upstream commit 98d74f9c ("xhci: fix 10 second timeout on removal of
      PCI hotpluggable xhci controllers") fixes a problem with hot pluggable PCI
      xhci controllers which can result in excessive timeouts, to the point where
      the system reports a deadlock.
      
      The same problem is seen with hot pluggable xhci controllers using the
      xhci-plat driver, such as the driver used for Type-C ports on rk3399.
      Similar to hot-pluggable PCI controllers, the driver for this chip
      removes the xhci controller from the system when the Type-C cable is
      disconnected.
      
      The solution for PCI devices works just as well for non-PCI devices
      and avoids the problem.
      Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
      Signed-off-by: default avatarMathias Nyman <mathias.nyman@linux.intel.com>
      Signed-off-by: default avatarWilly Tarreau <w@1wt.eu>
      a3fdfc64
    • Felipe Balbi's avatar
      usb: dwc3: gadget: make Set Endpoint Configuration macros safe · 8cada854
      Felipe Balbi authored
      commit 7369090a upstream.
      
      Some gadget drivers are bad, bad boys. We notice
      that ADB was passing bad Burst Size which caused top
      bits of param0 to be overwritten which confused DWC3
      when running this command.
      
      In order to avoid future issues, we're going to make
      sure values passed by macros are always safe for the
      controller. Note that ADB still needs a fix to *not*
      pass bad values.
      Reported-by: default avatarMohamed Abbas <mohamed.abbas@intel.com>
      Sugested-by: default avatarAdam Andruszak <adam.andruszak@intel.com>
      Signed-off-by: default avatarFelipe Balbi <felipe.balbi@linux.intel.com>
      Signed-off-by: default avatarWilly Tarreau <w@1wt.eu>
      8cada854
    • Johan Hovold's avatar
      USB: cdc-acm: fix failed open not being detected · 817a471a
      Johan Hovold authored
      commit 8727bf68 upstream.
      
      Fix errors during open not being returned to userspace. Specifically,
      failed control-line manipulations or control or read urb submissions
      would not be detected.
      
      Fixes: 7fb57a01 ("USB: cdc-acm: Fix potential deadlock (lockdep
      warning)")
      Signed-off-by: default avatarJohan Hovold <jhovold@gmail.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      Signed-off-by: default avatarWilly Tarreau <w@1wt.eu>
      817a471a
    • Johan Hovold's avatar
      USB: cdc-acm: fix open and suspend race · 256d49ba
      Johan Hovold authored
      commit 703df329 upstream.
      
      We must not do the usb_autopm_put_interface() before submitting the read
      urbs or we might end up doing I/O to a suspended device.
      
      Fixes: 088c64f8 ("USB: cdc-acm: re-write read processing")
      Signed-off-by: default avatarJohan Hovold <jhovold@gmail.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      Signed-off-by: default avatarWilly Tarreau <w@1wt.eu>
      256d49ba
    • Alexey Khoroshilov's avatar
      USB: cdc-acm: fix double usb_autopm_put_interface() in acm_port_activate() · f8dc9ab9
      Alexey Khoroshilov authored
      commit 070c0b17 upstream.
      
      If acm_submit_read_urbs() fails in acm_port_activate(), error handling
      code calls usb_autopm_put_interface() while it is already called
      before acm_submit_read_urbs(). The patch reorganizes error handling code
      to avoid double decrement of USB interface's PM-usage counter.
      
      Found by Linux Driver Verification project (linuxtesting.org).
      Signed-off-by: default avatarAlexey Khoroshilov <khoroshilov@ispras.ru>
      Acked-by: default avatarOliver Neukum <oliver@neukum.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      Signed-off-by: default avatarWilly Tarreau <w@1wt.eu>
      f8dc9ab9
    • Felipe Balbi's avatar
      usb: gadget: composite: always set ep->mult to a sensible value · 7b1a80c8
      Felipe Balbi authored
      commit eaa496ff upstream.
      
      ep->mult is supposed to be set to Isochronous and
      Interrupt Endapoint's multiplier value. This value
      is computed from different places depending on the
      link speed.
      
      If we're dealing with HighSpeed, then it's part of
      bits [12:11] of wMaxPacketSize. This case wasn't
      taken into consideration before.
      
      While at that, also make sure the ep->mult defaults
      to one so drivers can use it unconditionally and
      assume they'll never multiply ep->maxpacket to zero.
      Signed-off-by: default avatarFelipe Balbi <felipe.balbi@linux.intel.com>
      Signed-off-by: default avatarWilly Tarreau <w@1wt.eu>
      7b1a80c8
    • Johan Hovold's avatar
      USB: serial: io_ti: bind to interface after fw download · a1bf279f
      Johan Hovold authored
      commit e35d6d7c upstream.
      
      Bind to the interface, but do not register any ports, after having
      downloaded the firmware. The device will still disconnect and
      re-enumerate, but this way we avoid an error messages from being logged
      as part of the process:
      
      io_ti: probe of 1-1.3:1.0 failed with error -5
      Signed-off-by: default avatarJohan Hovold <johan@kernel.org>
      Signed-off-by: default avatarWilly Tarreau <w@1wt.eu>
      a1bf279f
    • Mathias Nyman's avatar
      xhci: free xhci virtual devices with leaf nodes first · e233c671
      Mathias Nyman authored
      commit ee8665e2 upstream.
      
      the tt_info provided by a HS hub might be in use to by a child device
      Make sure we free the devices in the correct order.
      
      This is needed in special cases such as when xhci controller is
      reset when resuming from hibernate, and all virt_devices are freed.
      
      Also free the virt_devices starting from max slot_id as children
      more commonly have higher slot_id than parent.
      Reported-by: default avatarGuenter Roeck <groeck@chromium.org>
      Tested-by: default avatarGuenter Roeck <groeck@chromium.org>
      Signed-off-by: default avatarMathias Nyman <mathias.nyman@linux.intel.com>
      Signed-off-by: default avatarWilly Tarreau <w@1wt.eu>
      e233c671
    • Alan Stern's avatar
      USB: gadgetfs: fix checks of wTotalLength in config descriptors · bde22e32
      Alan Stern authored
      commit 1c069b05 upstream.
      
      Andrey Konovalov's fuzz testing of gadgetfs showed that we should
      improve the driver's checks for valid configuration descriptors passed
      in by the user.  In particular, the driver needs to verify that the
      wTotalLength value in the descriptor is not too short (smaller
      than USB_DT_CONFIG_SIZE).  And the check for whether wTotalLength is
      too large has to be changed, because the driver assumes there is
      always enough room remaining in the buffer to hold a device descriptor
      (at least USB_DT_DEVICE_SIZE bytes).
      
      This patch adds the additional check and fixes the existing check.  It
      may do a little more than strictly necessary, but one extra check
      won't hurt.
      Signed-off-by: default avatarAlan Stern <stern@rowland.harvard.edu>
      CC: Andrey Konovalov <andreyknvl@google.com>
      Signed-off-by: default avatarFelipe Balbi <felipe.balbi@linux.intel.com>
      Signed-off-by: default avatarWilly Tarreau <w@1wt.eu>
      bde22e32
    • Alan Stern's avatar
      USB: gadgetfs: fix use-after-free bug · 6ccec4b1
      Alan Stern authored
      commit add333a8 upstream.
      
      Andrey Konovalov reports that fuzz testing with syzkaller causes a
      KASAN use-after-free bug report in gadgetfs:
      
      BUG: KASAN: use-after-free in gadgetfs_setup+0x208a/0x20e0 at addr ffff88003dfe5bf2
      Read of size 2 by task syz-executor0/22994
      CPU: 3 PID: 22994 Comm: syz-executor0 Not tainted 4.9.0-rc7+ #16
      Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
       ffff88006df06a18 ffffffff81f96aba ffffffffe0528500 1ffff1000dbe0cd6
       ffffed000dbe0cce ffff88006df068f0 0000000041b58ab3 ffffffff8598b4c8
       ffffffff81f96828 1ffff1000dbe0ccd ffff88006df06708 ffff88006df06748
      Call Trace:
       <IRQ> [  201.343209]  [<     inline     >] __dump_stack lib/dump_stack.c:15
       <IRQ> [  201.343209]  [<ffffffff81f96aba>] dump_stack+0x292/0x398 lib/dump_stack.c:51
       [<ffffffff817e4dec>] kasan_object_err+0x1c/0x70 mm/kasan/report.c:159
       [<     inline     >] print_address_description mm/kasan/report.c:197
       [<ffffffff817e5080>] kasan_report_error+0x1f0/0x4e0 mm/kasan/report.c:286
       [<     inline     >] kasan_report mm/kasan/report.c:306
       [<ffffffff817e562a>] __asan_report_load_n_noabort+0x3a/0x40 mm/kasan/report.c:337
       [<     inline     >] config_buf drivers/usb/gadget/legacy/inode.c:1298
       [<ffffffff8322c8fa>] gadgetfs_setup+0x208a/0x20e0 drivers/usb/gadget/legacy/inode.c:1368
       [<ffffffff830fdcd0>] dummy_timer+0x11f0/0x36d0 drivers/usb/gadget/udc/dummy_hcd.c:1858
       [<ffffffff814807c1>] call_timer_fn+0x241/0x800 kernel/time/timer.c:1308
       [<     inline     >] expire_timers kernel/time/timer.c:1348
       [<ffffffff81482de6>] __run_timers+0xa06/0xec0 kernel/time/timer.c:1641
       [<ffffffff814832c1>] run_timer_softirq+0x21/0x80 kernel/time/timer.c:1654
       [<ffffffff84f4af8b>] __do_softirq+0x2fb/0xb63 kernel/softirq.c:284
      
      The cause of the bug is subtle.  The dev_config() routine gets called
      twice by the fuzzer.  The first time, the user data contains both a
      full-speed configuration descriptor and a high-speed config
      descriptor, causing dev->hs_config to be set.  But it also contains an
      invalid device descriptor, so the buffer containing the descriptors is
      deallocated and dev_config() returns an error.
      
      The second time dev_config() is called, the user data contains only a
      full-speed config descriptor.  But dev->hs_config still has the stale
      pointer remaining from the first call, causing the routine to think
      that there is a valid high-speed config.  Later on, when the driver
      dereferences the stale pointer to copy that descriptor, we get a
      use-after-free access.
      
      The fix is simple: Clear dev->hs_config if the passed-in data does not
      contain a high-speed config descriptor.
      Signed-off-by: default avatarAlan Stern <stern@rowland.harvard.edu>
      Reported-by: default avatarAndrey Konovalov <andreyknvl@google.com>
      Tested-by: default avatarAndrey Konovalov <andreyknvl@google.com>
      Signed-off-by: default avatarFelipe Balbi <felipe.balbi@linux.intel.com>
      Signed-off-by: default avatarWilly Tarreau <w@1wt.eu>
      6ccec4b1
    • Alan Stern's avatar
      USB: gadgetfs: fix unbounded memory allocation bug · 66e87b46
      Alan Stern authored
      commit faab5098 upstream.
      
      Andrey Konovalov reports that fuzz testing with syzkaller causes a
      KASAN warning in gadgetfs:
      
      BUG: KASAN: slab-out-of-bounds in dev_config+0x86f/0x1190 at addr ffff88003c47e160
      Write of size 65537 by task syz-executor0/6356
      CPU: 3 PID: 6356 Comm: syz-executor0 Not tainted 4.9.0-rc7+ #19
      Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
       ffff88003c107ad8 ffffffff81f96aba ffffffff3dc11ef0 1ffff10007820eee
       ffffed0007820ee6 ffff88003dc11f00 0000000041b58ab3 ffffffff8598b4c8
       ffffffff81f96828 ffffffff813fb4a0 ffff88003b6eadc0 ffff88003c107738
      Call Trace:
       [<     inline     >] __dump_stack lib/dump_stack.c:15
       [<ffffffff81f96aba>] dump_stack+0x292/0x398 lib/dump_stack.c:51
       [<ffffffff817e4dec>] kasan_object_err+0x1c/0x70 mm/kasan/report.c:159
       [<     inline     >] print_address_description mm/kasan/report.c:197
       [<ffffffff817e5080>] kasan_report_error+0x1f0/0x4e0 mm/kasan/report.c:286
       [<ffffffff817e5705>] kasan_report+0x35/0x40 mm/kasan/report.c:306
       [<     inline     >] check_memory_region_inline mm/kasan/kasan.c:308
       [<ffffffff817e3fb9>] check_memory_region+0x139/0x190 mm/kasan/kasan.c:315
       [<ffffffff817e4044>] kasan_check_write+0x14/0x20 mm/kasan/kasan.c:326
       [<     inline     >] copy_from_user arch/x86/include/asm/uaccess.h:689
       [<     inline     >] ep0_write drivers/usb/gadget/legacy/inode.c:1135
       [<ffffffff83228caf>] dev_config+0x86f/0x1190 drivers/usb/gadget/legacy/inode.c:1759
       [<ffffffff817fdd55>] __vfs_write+0x5d5/0x760 fs/read_write.c:510
       [<ffffffff817ff650>] vfs_write+0x170/0x4e0 fs/read_write.c:560
       [<     inline     >] SYSC_write fs/read_write.c:607
       [<ffffffff81803a5b>] SyS_write+0xfb/0x230 fs/read_write.c:599
       [<ffffffff84f47ec1>] entry_SYSCALL_64_fastpath+0x1f/0xc2
      
      Indeed, there is a comment saying that the value of len is restricted
      to a 16-bit integer, but the code doesn't actually do this.
      
      This patch fixes the warning.  It replaces the comment with a
      computation that forces the amount of data copied from the user in
      ep0_write() to be no larger than the wLength size for the control
      transfer, which is a 16-bit quantity.
      Signed-off-by: default avatarAlan Stern <stern@rowland.harvard.edu>
      Reported-by: default avatarAndrey Konovalov <andreyknvl@google.com>
      Tested-by: default avatarAndrey Konovalov <andreyknvl@google.com>
      Signed-off-by: default avatarFelipe Balbi <felipe.balbi@linux.intel.com>
      Signed-off-by: default avatarWilly Tarreau <w@1wt.eu>
      66e87b46
    • Greg Kroah-Hartman's avatar
      usb: gadgetfs: restrict upper bound on device configuration size · 133caaf5
      Greg Kroah-Hartman authored
      commit 0994b0a2 upstream.
      
      Andrey Konovalov reported that we were not properly checking the upper
      limit before of a device configuration size before calling
      memdup_user(), which could cause some problems.
      
      So set the upper limit to PAGE_SIZE * 4, which should be good enough for
      all devices.
      Reported-by: default avatarAndrey Konovalov <andreyknvl@google.com>
      Signed-off-by: default avatarFelipe Balbi <felipe.balbi@linux.intel.com>
      Signed-off-by: default avatarWilly Tarreau <w@1wt.eu>
      133caaf5
    • Con Kolivas's avatar
      ALSA: usb-audio: Add QuickCam Communicate Deluxe/S7500 to volume_control_quirks · 7563f274
      Con Kolivas authored
      commit 82ffb6fc upstream.
      
      The Logitech QuickCam Communicate Deluxe/S7500 microphone fails with the
      following warning.
      
      [    6.778995] usb 2-1.2.2.2: Warning! Unlikely big volume range (=3072),
      cval->res is probably wrong.
      [    6.778996] usb 2-1.2.2.2: [5] FU [Mic Capture Volume] ch = 1, val =
      4608/7680/1
      
      Adding it to the list of devices in volume_control_quirks makes it work
      properly, fixing related typo.
      Signed-off-by: default avatarCon Kolivas <kernel@kolivas.org>
      Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      Signed-off-by: default avatarWilly Tarreau <w@1wt.eu>
      7563f274
    • Takashi Iwai's avatar
      ALSA: seq: Don't break snd_use_lock_sync() loop by timeout · 42860dab
      Takashi Iwai authored
      commit 4e7655fd upstream.
      
      The snd_use_lock_sync() (thus its implementation
      snd_use_lock_sync_helper()) has the 5 seconds timeout to break out of
      the sync loop.  It was introduced from the beginning, just to be
      "safer", in terms of avoiding the stupid bugs.
      
      However, as Ben Hutchings suggested, this timeout rather introduces a
      potential leak or use-after-free that was apparently fixed by the
      commit 2d7d5400 ("ALSA: seq: Fix race during FIFO resize"):
      for example, snd_seq_fifo_event_in() -> snd_seq_event_dup() ->
      copy_from_user() could block for a long time, and snd_use_lock_sync()
      goes timeout and still leaves the cell at releasing the pool.
      
      For fixing such a problem, we remove the break by the timeout while
      still keeping the warning.
      Suggested-by: default avatarBen Hutchings <ben.hutchings@codethink.co.uk>
      Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      Signed-off-by: default avatarWilly Tarreau <w@1wt.eu>
      42860dab
    • Takashi Iwai's avatar
      ALSA: seq: Fix race during FIFO resize · 28e0ebdd
      Takashi Iwai authored
      commit 2d7d5400 upstream.
      
      When a new event is queued while processing to resize the FIFO in
      snd_seq_fifo_clear(), it may lead to a use-after-free, as the old pool
      that is being queued gets removed.  For avoiding this race, we need to
      close the pool to be deleted and sync its usage before actually
      deleting it.
      
      The issue was spotted by syzkaller.
      Reported-by: default avatarDmitry Vyukov <dvyukov@google.com>
      Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      Signed-off-by: default avatarWilly Tarreau <w@1wt.eu>
      28e0ebdd
    • Takashi Iwai's avatar
      ALSA: seq: Fix racy cell insertions during snd_seq_pool_done() · 2dbb155d
      Takashi Iwai authored
      commit c520ff3d upstream.
      
      When snd_seq_pool_done() is called, it marks the closing flag to
      refuse the further cell insertions.  But snd_seq_pool_done() itself
      doesn't clear the cells but just waits until all cells are cleared by
      the caller side.  That is, it's racy, and this leads to the endless
      stall as syzkaller spotted.
      
      This patch addresses the racy by splitting the setup of pool->closing
      flag out of snd_seq_pool_done(), and calling it properly before
      snd_seq_pool_done().
      
      BugLink: http://lkml.kernel.org/r/CACT4Y+aqqy8bZA1fFieifNxR2fAfFQQABcBHj801+u5ePV0URw@mail.gmail.comReported-and-tested-by: default avatarDmitry Vyukov <dvyukov@google.com>
      Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      Signed-off-by: default avatarWilly Tarreau <w@1wt.eu>
      2dbb155d
    • Takashi Iwai's avatar
      ALSA: seq: Fix link corruption by event error handling · 2dbfb5cb
      Takashi Iwai authored
      commit f3ac9f73 upstream.
      
      The sequencer FIFO management has a bug that may lead to a corruption
      (shortage) of the cell linked list.  When a sequencer client faces an
      error at the event delivery, it tries to put back the dequeued cell.
      When the first queue was put back, this forgot the tail pointer
      tracking, and the link will be screwed up.
      
      Although there is no memory corruption, the sequencer client may stall
      forever at exit while flushing the pending FIFO cells in
      snd_seq_pool_done(), as spotted by syzkaller.
      
      This patch addresses the missing tail pointer tracking at
      snd_seq_fifo_cell_putback().  Also the patch makes sure to clear the
      cell->enxt pointer at snd_seq_fifo_event_in() for avoiding a similar
      mess-up of the FIFO linked list.
      Reported-by: default avatarDmitry Vyukov <dvyukov@google.com>
      Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      Signed-off-by: default avatarWilly Tarreau <w@1wt.eu>
      2dbfb5cb
    • Takashi Iwai's avatar
      ALSA: timer: Reject user params with too small ticks · 7a3085a3
      Takashi Iwai authored
      commit 71321eb3 upstream.
      
      When a user sets a too small ticks with a fine-grained timer like
      hrtimer, the kernel tries to fire up the timer irq too frequently.
      This may lead to the condensed locks, eventually the kernel spinlock
      lockup with warnings.
      
      For avoiding such a situation, we define a lower limit of the
      resolution, namely 1ms.  When the user passes a too small tick value
      that results in less than that, the kernel returns -EINVAL now.
      Reported-by: default avatarDmitry Vyukov <dvyukov@google.com>
      Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      Signed-off-by: default avatarWilly Tarreau <w@1wt.eu>
      7a3085a3
    • Takashi Iwai's avatar
      ALSA: seq: Don't handle loop timeout at snd_seq_pool_done() · 28567fb4
      Takashi Iwai authored
      commit 37a7ea4a upstream.
      
      snd_seq_pool_done() syncs with closing of all opened threads, but it
      aborts the wait loop with a timeout, and proceeds to the release
      resource even if not all threads have been closed.  The timeout was 5
      seconds, and if you run a crazy stuff, it can exceed easily, and may
      result in the access of the invalid memory address -- this is what
      syzkaller detected in a bug report.
      
      As a fix, let the code graduate from naiveness, simply remove the loop
      timeout.
      
      BugLink: http://lkml.kernel.org/r/CACT4Y+YdhDV2H5LLzDTJDVF-qiYHUHhtRaW4rbb4gUhTCQB81w@mail.gmail.comReported-by: default avatarDmitry Vyukov <dvyukov@google.com>
      Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      Signed-off-by: default avatarWilly Tarreau <w@1wt.eu>
      28567fb4
    • Takashi Iwai's avatar
      ALSA: seq: Fix race at creating a queue · 6dd5cf43
      Takashi Iwai authored
      commit 4842e98f upstream.
      
      When a sequencer queue is created in snd_seq_queue_alloc(),it adds the
      new queue element to the public list before referencing it.  Thus the
      queue might be deleted before the call of snd_seq_queue_use(), and it
      results in the use-after-free error, as spotted by syzkaller.
      
      The fix is to reference the queue object at the right time.
      Reported-by: default avatarDmitry Vyukov <dvyukov@google.com>
      Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      Signed-off-by: default avatarWilly Tarreau <w@1wt.eu>
      6dd5cf43
    • Takashi Iwai's avatar
      ALSA: hda - Fix up GPIO for ASUS ROG Ranger · bbcdcb83
      Takashi Iwai authored
      commit 85bcf96c upstream.
      
      ASUS ROG Ranger VIII with ALC1150 codec requires the extra GPIO pin to
      up for the front panel.  Just use the existing fixup for setting up
      the GPIO pins.
      
      Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=189411Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      Signed-off-by: default avatarWilly Tarreau <w@1wt.eu>
      bbcdcb83
    • Marc Kleine-Budde's avatar
      can: usb_8dev: Fix memory leak of priv->cmd_msg_buffer · d2ab6e52
      Marc Kleine-Budde authored
      commit 7c426313 upstream.
      
      The priv->cmd_msg_buffer is allocated in the probe function, but never
      kfree()ed. This patch converts the kzalloc() to resource-managed
      kzalloc.
      Signed-off-by: default avatarMarc Kleine-Budde <mkl@pengutronix.de>
      Signed-off-by: default avatarWilly Tarreau <w@1wt.eu>
      d2ab6e52
    • Oliver Hartkopp's avatar
      can: bcm: fix hrtimer/tasklet termination in bcm op removal · d5361ee8
      Oliver Hartkopp authored
      commit a06393ed upstream.
      
      When removing a bcm tx operation either a hrtimer or a tasklet might run.
      As the hrtimer triggers its associated tasklet and vice versa we need to
      take care to mutually terminate both handlers.
      Reported-by: default avatarMichael Josenhans <michael.josenhans@web.de>
      Signed-off-by: default avatarOliver Hartkopp <socketcan@hartkopp.net>
      Tested-by: default avatarMichael Josenhans <michael.josenhans@web.de>
      Signed-off-by: default avatarMarc Kleine-Budde <mkl@pengutronix.de>
      Signed-off-by: default avatarWilly Tarreau <w@1wt.eu>
      d5361ee8
    • Yegor Yefremov's avatar
      can: ti_hecc: add missing prepare and unprepare of the clock · 2adddc0a
      Yegor Yefremov authored
      commit befa6011 upstream.
      
      In order to make the driver work with the common clock framework, this
      patch converts the clk_enable()/clk_disable() to
      clk_prepare_enable()/clk_disable_unprepare().
      
      Also add error checking for clk_prepare_enable().
      Signed-off-by: default avatarYegor Yefremov <yegorslists@googlemail.com>
      Signed-off-by: default avatarMarc Kleine-Budde <mkl@pengutronix.de>
      Signed-off-by: default avatarWilly Tarreau <w@1wt.eu>
      2adddc0a
    • Einar Jón's avatar
      can: c_can_pci: fix null-pointer-deref in c_can_start() - set device pointer · 165cc033
      Einar Jón authored
      commit c97c52be upstream.
      
      The priv->device pointer for c_can_pci is never set, but it is used
      without a NULL check in c_can_start(). Setting it in c_can_pci_probe()
      like c_can_plat_probe() prevents c_can_pci.ko from crashing, with and
      without CONFIG_PM.
      
      This might also cause the pm_runtime_*() functions in c_can.c to
      actually be executed for c_can_pci devices - they are the only other
      place where priv->device is used, but they all contain a null check.
      Signed-off-by: default avatarEinar Jón <tolvupostur@gmail.com>
      Signed-off-by: default avatarMarc Kleine-Budde <mkl@pengutronix.de>
      Signed-off-by: default avatarWilly Tarreau <w@1wt.eu>
      165cc033
    • 추지호's avatar
      can: peak: fix bad memory access and free sequence · 3e7b58a3
      추지호 authored
      commit b67d0dd7 upstream.
      
      Fix for bad memory access while disconnecting. netdev is freed before
      private data free, and dev is accessed after freeing netdev.
      
      This makes a slub problem, and it raise kernel oops with slub debugger
      config.
      Signed-off-by: default avatarJiho Chu <jiho.chu@samsung.com>
      Signed-off-by: default avatarMarc Kleine-Budde <mkl@pengutronix.de>
      Signed-off-by: default avatarWilly Tarreau <w@1wt.eu>
      3e7b58a3
    • Marc Kleine-Budde's avatar
      can: raw: raw_setsockopt: limit number of can_filter that can be set · cf796900
      Marc Kleine-Budde authored
      commit 332b05ca upstream.
      
      This patch adds a check to limit the number of can_filters that can be
      set via setsockopt on CAN_RAW sockets. Otherwise allocations > MAX_ORDER
      are not prevented resulting in a warning.
      
      Reference: https://lkml.org/lkml/2016/12/2/230Reported-by: default avatarAndrey Konovalov <andreyknvl@google.com>
      Tested-by: default avatarAndrey Konovalov <andreyknvl@google.com>
      Signed-off-by: default avatarMarc Kleine-Budde <mkl@pengutronix.de>
      Signed-off-by: default avatarWilly Tarreau <w@1wt.eu>
      cf796900
    • Tariq Saeed's avatar
      ocfs2: fix BUG_ON() in ocfs2_ci_checkpointed() · 1918581a
      Tariq Saeed authored
      commit 3d46a44a upstream.
      
      PID: 614    TASK: ffff882a739da580  CPU: 3   COMMAND: "ocfs2dc"
        #0 [ffff882ecc3759b0] machine_kexec at ffffffff8103b35d
        #1 [ffff882ecc375a20] crash_kexec at ffffffff810b95b5
        #2 [ffff882ecc375af0] oops_end at ffffffff815091d8
        #3 [ffff882ecc375b20] die at ffffffff8101868b
        #4 [ffff882ecc375b50] do_trap at ffffffff81508bb0
        #5 [ffff882ecc375ba0] do_invalid_op at ffffffff810165e5
        #6 [ffff882ecc375c40] invalid_op at ffffffff815116fb
           [exception RIP: ocfs2_ci_checkpointed+208]
           RIP: ffffffffa0a7e940  RSP: ffff882ecc375cf0  RFLAGS: 00010002
           RAX: 0000000000000001  RBX: 000000000000654b  RCX: ffff8812dc83f1f8
           RDX: 00000000000017d9  RSI: ffff8812dc83f1f8  RDI: ffffffffa0b2c318
           RBP: ffff882ecc375d20   R8: ffff882ef6ecfa60   R9: ffff88301f272200
           R10: 0000000000000000  R11: 0000000000000000  R12: ffffffffffffffff
           R13: ffff8812dc83f4f0  R14: 0000000000000000  R15: ffff8812dc83f1f8
           ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
        #7 [ffff882ecc375d28] ocfs2_check_meta_downconvert at ffffffffa0a7edbd [ocfs2]
        #8 [ffff882ecc375d38] ocfs2_unblock_lock at ffffffffa0a84af8 [ocfs2]
        #9 [ffff882ecc375dc8] ocfs2_process_blocked_lock at ffffffffa0a85285 [ocfs2]
      assert is tripped because the tran is not checkpointed and the lock level is PR.
      
      Some time ago, chmod command had been executed. As result, the following call
      chain left the inode cluster lock in PR state, latter on causing the assert.
      system_call_fastpath
        -> my_chmod
         -> sys_chmod
          -> sys_fchmodat
           -> notify_change
            -> ocfs2_setattr
             -> posix_acl_chmod
              -> ocfs2_iop_set_acl
               -> ocfs2_set_acl
                -> ocfs2_acl_set_mode
      Here is how.
      1119 int ocfs2_setattr(struct dentry *dentry, struct iattr *attr)
      1120 {
      1247         ocfs2_inode_unlock(inode, 1); <<< WRONG thing to do.
      ..
      1258         if (!status && attr->ia_valid & ATTR_MODE) {
      1259                 status =  posix_acl_chmod(inode, inode->i_mode);
      
      519 posix_acl_chmod(struct inode *inode, umode_t mode)
      520 {
      ..
      539         ret = inode->i_op->set_acl(inode, acl, ACL_TYPE_ACCESS);
      
      287 int ocfs2_iop_set_acl(struct inode *inode, struct posix_acl *acl, ...
      288 {
      289         return ocfs2_set_acl(NULL, inode, NULL, type, acl, NULL, NULL);
      
      224 int ocfs2_set_acl(handle_t *handle,
      225                          struct inode *inode, ...
      231 {
      ..
      252                                 ret = ocfs2_acl_set_mode(inode, di_bh,
      253                                                          handle, mode);
      
      168 static int ocfs2_acl_set_mode(struct inode *inode, struct buffer_head ...
      170 {
      183         if (handle == NULL) {
                          >>> BUG: inode lock not held in ex at this point <<<
      184                 handle = ocfs2_start_trans(OCFS2_SB(inode->i_sb),
      185                                            OCFS2_INODE_UPDATE_CREDITS);
      
      ocfs2_setattr.#1247 we unlock and at #1259 call posix_acl_chmod. When we reach
      ocfs2_acl_set_mode.#181 and do trans, the inode cluster lock is not held in EX
      mode (it should be). How this could have happended?
      
      We are the lock master, were holding lock EX and have released it in
      ocfs2_setattr.#1247.  Note that there are no holders of this lock at
      this point.  Another node needs the lock in PR, and we downconvert from
      EX to PR.  So the inode lock is PR when do the trans in
      ocfs2_acl_set_mode.#184.  The trans stays in core (not flushed to disc).
      Now another node want the lock in EX, downconvert thread gets kicked
      (the one that tripped assert abovt), finds an unflushed trans but the
      lock is not EX (it is PR).  If the lock was at EX, it would have flushed
      the trans ocfs2_ci_checkpointed -> ocfs2_start_checkpoint before
      downconverting (to NULL) for the request.
      
      ocfs2_setattr must not drop inode lock ex in this code path.  If it
      does, takes it again before the trans, say in ocfs2_set_acl, another
      cluster node can get in between, execute another setattr, overwriting
      the one in progress on this node, resulting in a mode acl size combo
      that is a mix of the two.
      
      Orabug: 20189959
      Signed-off-by: default avatarTariq Saeed <tariq.x.saeed@oracle.com>
      Reviewed-by: default avatarMark Fasheh <mfasheh@suse.de>
      Cc: Joel Becker <jlbec@evilplan.org>
      Cc: Joseph Qi <joseph.qi@huawei.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarWilly Tarreau <w@1wt.eu>
      1918581a
    • Eric Ren's avatar
      ocfs2: fix crash caused by stale lvb with fsdlm plugin · 4b93c1da
      Eric Ren authored
      commit e7ee2c08 upstream.
      
      The crash happens rather often when we reset some cluster nodes while
      nodes contend fiercely to do truncate and append.
      
      The crash backtrace is below:
      
         dlm: C21CBDA5E0774F4BA5A9D4F317717495: dlm_recover_grant 1 locks on 971 resources
         dlm: C21CBDA5E0774F4BA5A9D4F317717495: dlm_recover 9 generation 5 done: 4 ms
         ocfs2: Begin replay journal (node 318952601, slot 2) on device (253,18)
         ocfs2: End replay journal (node 318952601, slot 2) on device (253,18)
         ocfs2: Beginning quota recovery on device (253,18) for slot 2
         ocfs2: Finishing quota recovery on device (253,18) for slot 2
         (truncate,30154,1):ocfs2_truncate_file:470 ERROR: bug expression: le64_to_cpu(fe->i_size) != i_size_read(inode)
         (truncate,30154,1):ocfs2_truncate_file:470 ERROR: Inode 290321, inode i_size = 732 != di i_size = 937, i_flags = 0x1
         ------------[ cut here ]------------
         kernel BUG at /usr/src/linux/fs/ocfs2/file.c:470!
         invalid opcode: 0000 [#1] SMP
         Modules linked in: ocfs2_stack_user(OEN) ocfs2(OEN) ocfs2_nodemanager ocfs2_stackglue(OEN) quota_tree dlm(OEN) configfs fuse sd_mod    iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi af_packet iscsi_ibft iscsi_boot_sysfs softdog xfs libcrc32c ppdev parport_pc pcspkr parport      joydev virtio_balloon virtio_net i2c_piix4 acpi_cpufreq button processor ext4 crc16 jbd2 mbcache ata_generic cirrus virtio_blk ata_piix               drm_kms_helper ahci syscopyarea libahci sysfillrect sysimgblt fb_sys_fops ttm floppy libata drm virtio_pci virtio_ring uhci_hcd virtio ehci_hcd       usbcore serio_raw usb_common sg dm_multipath dm_mod scsi_dh_rdac scsi_dh_emc scsi_dh_alua scsi_mod autofs4
         Supported: No, Unsupported modules are loaded
         CPU: 1 PID: 30154 Comm: truncate Tainted: G           OE   N  4.4.21-69-default #1
         Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.8.1-0-g4adadbd-20151112_172657-sheep25 04/01/2014
         task: ffff88004ff6d240 ti: ffff880074e68000 task.ti: ffff880074e68000
         RIP: 0010:[<ffffffffa05c8c30>]  [<ffffffffa05c8c30>] ocfs2_truncate_file+0x640/0x6c0 [ocfs2]
         RSP: 0018:ffff880074e6bd50  EFLAGS: 00010282
         RAX: 0000000000000074 RBX: 000000000000029e RCX: 0000000000000000
         RDX: 0000000000000001 RSI: 0000000000000246 RDI: 0000000000000246
         RBP: ffff880074e6bda8 R08: 000000003675dc7a R09: ffffffff82013414
         R10: 0000000000034c50 R11: 0000000000000000 R12: ffff88003aab3448
         R13: 00000000000002dc R14: 0000000000046e11 R15: 0000000000000020
         FS:  00007f839f965700(0000) GS:ffff88007fc80000(0000) knlGS:0000000000000000
         CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
         CR2: 00007f839f97e000 CR3: 0000000036723000 CR4: 00000000000006e0
         Call Trace:
           ocfs2_setattr+0x698/0xa90 [ocfs2]
           notify_change+0x1ae/0x380
           do_truncate+0x5e/0x90
           do_sys_ftruncate.constprop.11+0x108/0x160
           entry_SYSCALL_64_fastpath+0x12/0x6d
         Code: 24 28 ba d6 01 00 00 48 c7 c6 30 43 62 a0 8b 41 2c 89 44 24 08 48 8b 41 20 48 c7 c1 78 a3 62 a0 48 89 04 24 31 c0 e8 a0 97 f9 ff <0f> 0b 3d 00 fe ff ff 0f 84 ab fd ff ff 83 f8 fc 0f 84 a2 fd ff
         RIP  [<ffffffffa05c8c30>] ocfs2_truncate_file+0x640/0x6c0 [ocfs2]
      
      It's because ocfs2_inode_lock() get us stale LVB in which the i_size is
      not equal to the disk i_size.  We mistakenly trust the LVB because the
      underlaying fsdlm dlm_lock() doesn't set lkb_sbflags with
      DLM_SBF_VALNOTVALID properly for us.  But, why?
      
      The current code tries to downconvert lock without DLM_LKF_VALBLK flag
      to tell o2cb don't update RSB's LVB if it's a PR->NULL conversion, even
      if the lock resource type needs LVB.  This is not the right way for
      fsdlm.
      
      The fsdlm plugin behaves different on DLM_LKF_VALBLK, it depends on
      DLM_LKF_VALBLK to decide if we care about the LVB in the LKB.  If
      DLM_LKF_VALBLK is not set, fsdlm will skip recovering RSB's LVB from
      this lkb and set the right DLM_SBF_VALNOTVALID appropriately when node
      failure happens.
      
      The following diagram briefly illustrates how this crash happens:
      
      RSB1 is inode metadata lock resource with LOCK_TYPE_USES_LVB;
      
      The 1st round:
      
                   Node1                                    Node2
      RSB1: PR
                                                        RSB1(master): NULL->EX
      ocfs2_downconvert_lock(PR->NULL, set_lvb==0)
        ocfs2_dlm_lock(no DLM_LKF_VALBLK)
      
      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
      
      dlm_lock(no DLM_LKF_VALBLK)
        convert_lock(overwrite lkb->lkb_exflags
                     with no DLM_LKF_VALBLK)
      
      RSB1: NULL                                        RSB1: EX
                                                        reset Node2
      dlm_recover_rsbs()
        recover_lvb()
      
      /* The LVB is not trustable if the node with EX fails and
       * no lock >= PR is left. We should set RSB_VALNOTVALID for RSB1.
       */
      
       if(!(kb_exflags & DLM_LKF_VALBLK)) /* This means we miss the chance to
                 return;                   * to invalid the LVB here.
                                           */
      
      The 2nd round:
      
               Node 1                                Node2
      RSB1(become master from recovery)
      
      ocfs2_setattr()
        ocfs2_inode_lock(NULL->EX)
          /* dlm_lock() return the stale lvb without setting DLM_SBF_VALNOTVALID */
          ocfs2_meta_lvb_is_trustable() return 1 /* so we don't refresh inode from disk */
        ocfs2_truncate_file()
            mlog_bug_on_msg(disk isize != i_size_read(inode))  /* crash! */
      
      The fix is quite straightforward.  We keep to set DLM_LKF_VALBLK flag
      for dlm_lock() if the lock resource type needs LVB and the fsdlm plugin
      is uesed.
      
      Link: http://lkml.kernel.org/r/1481275846-6604-1-git-send-email-zren@suse.comSigned-off-by: default avatarEric Ren <zren@suse.com>
      Reviewed-by: default avatarJoseph Qi <jiangqi903@gmail.com>
      Cc: Mark Fasheh <mfasheh@versity.com>
      Cc: Joel Becker <jlbec@evilplan.org>
      Cc: Junxiao Bi <junxiao.bi@oracle.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarWilly Tarreau <w@1wt.eu>
      4b93c1da
    • Sachin Prabhu's avatar
      cifs: Do not send echoes before Negotiate is complete · 4549e4af
      Sachin Prabhu authored
      commit 62a6cfdd upstream.
      
      commit 4fcd1813 ("Fix reconnect to not defer smb3 session reconnect
      long after socket reconnect") added support for Negotiate requests to
      be initiated by echo calls.
      
      To avoid delays in calling echo after a reconnect, I added the patch
      introduced by the commit b8c60012 ("Call echo service immediately
      after socket reconnect").
      
      This has however caused a regression with cifs shares which do not have
      support for echo calls to trigger Negotiate requests. On connections
      which need to call Negotiation, the echo calls trigger an error which
      triggers a reconnect which in turn triggers another echo call. This
      results in a loop which is only broken when an operation is performed on
      the cifs share. For an idle share, it can DOS a server.
      
      The patch uses the smb_operation can_echo() for cifs so that it is
      called only if connection has been already been setup.
      
      kernel bz: 194531
      Signed-off-by: default avatarSachin Prabhu <sprabhu@redhat.com>
      Tested-by: default avatarJonathan Liu <net147@gmail.com>
      Acked-by: default avatarPavel Shilovsky <pshilov@microsoft.com>
      Signed-off-by: default avatarSteve French <smfrench@gmail.com>
      Signed-off-by: default avatarWilly Tarreau <w@1wt.eu>
      4549e4af
    • Aurelien Aptel's avatar
      fs/cifs: make share unaccessible at root level mountable · a9baa441
      Aurelien Aptel authored
      commit a6b5058f upstream.
      
      if, when mounting //HOST/share/sub/dir/foo we can query /sub/dir/foo but
      not any of the path components above:
      
      - store the /sub/dir/foo prefix in the cifs super_block info
      - in the superblock, set root dentry to the subpath dentry (instead of
        the share root)
      - set a flag in the superblock to remember it
      - use prefixpath when building path from a dentry
      
      fixes bso#8950
      Signed-off-by: default avatarAurelien Aptel <aaptel@suse.com>
      Reviewed-by: default avatarPavel Shilovsky <pshilovsky@samba.org>
      Signed-off-by: default avatarSteve French <smfrench@gmail.com>
      Signed-off-by: default avatarWilly Tarreau <w@1wt.eu>
      a9baa441
    • Germano Percossi's avatar
      CIFS: remove bad_network_name flag · 60f2c2fa
      Germano Percossi authored
      commit a0918f1c upstream.
      
      STATUS_BAD_NETWORK_NAME can be received during node failover,
      causing the flag to be set and making the reconnect thread
      always unsuccessful, thereafter.
      
      Once the only place where it is set is removed, the remaining
      bits are rendered moot.
      
      Removing it does not prevent "mount" from failing when a non
      existent share is passed.
      
      What happens when the share really ceases to exist while the
      share is mounted is undefined now as much as it was before.
      Signed-off-by: default avatarGermano Percossi <germano.percossi@citrix.com>
      Reviewed-by: default avatarPavel Shilovsky <pshilov@microsoft.com>
      Signed-off-by: default avatarSteve French <smfrench@gmail.com>
      Signed-off-by: default avatarWilly Tarreau <w@1wt.eu>
      60f2c2fa
    • Pavel Shilovsky's avatar
      CIFS: Fix a possible memory corruption in push locks · f9e74c2a
      Pavel Shilovsky authored
      commit e3d240e9 upstream.
      
      If maxBuf is not 0 but less than a size of SMB2 lock structure
      we can end up with a memory corruption.
      Signed-off-by: default avatarPavel Shilovsky <pshilov@microsoft.com>
      Signed-off-by: default avatarWilly Tarreau <w@1wt.eu>
      f9e74c2a
    • Pavel Shilovsky's avatar
      CIFS: Fix missing nls unload in smb2_reconnect() · 85beff45
      Pavel Shilovsky authored
      commit 4772c795 upstream.
      Acked-by: default avatarSachin Prabhu <sprabhu@redhat.com>
      Signed-off-by: default avatarPavel Shilovsky <pshilov@microsoft.com>
      Signed-off-by: default avatarWilly Tarreau <w@1wt.eu>
      85beff45
    • Pavel Shilovsky's avatar
      CIFS: Fix a possible memory corruption during reconnect · e008a962
      Pavel Shilovsky authored
      commit 53e0e11e upstream.
      
      We can not unlock/lock cifs_tcp_ses_lock while walking through ses
      and tcon lists because it can corrupt list iterator pointers and
      a tcon structure can be released if we don't hold an extra reference.
      Fix it by moving a reconnect process to a separate delayed work
      and acquiring a reference to every tcon that needs to be reconnected.
      Also do not send an echo request on newly established connections.
      Signed-off-by: default avatarPavel Shilovsky <pshilov@microsoft.com>
      Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      Signed-off-by: default avatarWilly Tarreau <w@1wt.eu>
      e008a962
    • colyli@suse.de's avatar
      md linear: fix a race between linear_add() and linear_congested() · d45256ff
      colyli@suse.de authored
      commit 03a9e24e upstream.
      
      Recently I receive a bug report that on Linux v3.0 based kerenl, hot add
      disk to a md linear device causes kernel crash at linear_congested(). From
      the crash image analysis, I find in linear_congested(), mddev->raid_disks
      contains value N, but conf->disks[] only has N-1 pointers available. Then
      a NULL pointer deference crashes the kernel.
      
      There is a race between linear_add() and linear_congested(), RCU stuffs
      used in these two functions cannot avoid the race. Since Linuv v4.0
      RCU code is replaced by introducing mddev_suspend().  After checking the
      upstream code, it seems linear_congested() is not called in
      generic_make_request() code patch, so mddev_suspend() cannot provent it
      from being called. The possible race still exists.
      
      Here I explain how the race still exists in current code.  For a machine
      has many CPUs, on one CPU, linear_add() is called to add a hard disk to a
      md linear device; at the same time on other CPU, linear_congested() is
      called to detect whether this md linear device is congested before issuing
      an I/O request onto it.
      
      Now I use a possible code execution time sequence to demo how the possible
      race happens,
      
      seq    linear_add()                linear_congested()
       0                                 conf=mddev->private
       1   oldconf=mddev->private
       2   mddev->raid_disks++
       3                              for (i=0; i<mddev->raid_disks;i++)
       4                                bdev_get_queue(conf->disks[i].rdev->bdev)
       5   mddev->private=newconf
      
      In linear_add() mddev->raid_disks is increased in time seq 2, and on
      another CPU in linear_congested() the for-loop iterates conf->disks[i] by
      the increased mddev->raid_disks in time seq 3,4. But conf with one more
      element (which is a pointer to struct dev_info type) to conf->disks[] is
      not updated yet, accessing its structure member in time seq 4 will cause a
      NULL pointer deference fault.
      
      To fix this race, there are 2 parts of modification in the patch,
       1) Add 'int raid_disks' in struct linear_conf, as a copy of
          mddev->raid_disks. It is initialized in linear_conf(), always being
          consistent with pointers number of 'struct dev_info disks[]'. When
          iterating conf->disks[] in linear_congested(), use conf->raid_disks to
          replace mddev->raid_disks in the for-loop, then NULL pointer deference
          will not happen again.
       2) RCU stuffs are back again, and use kfree_rcu() in linear_add() to
          free oldconf memory. Because oldconf may be referenced as mddev->private
          in linear_congested(), kfree_rcu() makes sure that its memory will not
          be released until no one uses it any more.
      Also some code comments are added in this patch, to make this modification
      to be easier understandable.
      
      This patch can be applied for kernels since v4.0 after commit:
      3be260cc ("md/linear: remove rcu protections in favour of
      suspend/resume"). But this bug is reported on Linux v3.0 based kernel, for
      people who maintain kernels before Linux v4.0, they need to do some back
      back port to this patch.
      
      Changelog:
       - V3: add 'int raid_disks' in struct linear_conf, and use kfree_rcu() to
             replace rcu_call() in linear_add().
       - v2: add RCU stuffs by suggestion from Shaohua and Neil.
       - v1: initial effort.
      Signed-off-by: default avatarColy Li <colyli@suse.de>
      Cc: Shaohua Li <shli@fb.com>
      Cc: Neil Brown <neilb@suse.com>
      Signed-off-by: default avatarShaohua Li <shli@fb.com>
      Signed-off-by: default avatarWilly Tarreau <w@1wt.eu>
      d45256ff
    • Wei Fang's avatar
      md:raid1: fix a dead loop when read from a WriteMostly disk · 7a56cc09
      Wei Fang authored
      commit 816b0acf upstream.
      
      If first_bad == this_sector when we get the WriteMostly disk
      in read_balance(), valid disk will be returned with zero
      max_sectors. It'll lead to a dead loop in make_request(), and
      OOM will happen because of endless allocation of struct bio.
      
      Since we can't get data from this disk in this case, so
      continue for another disk.
      Signed-off-by: default avatarWei Fang <fangwei1@huawei.com>
      Signed-off-by: default avatarShaohua Li <shli@fb.com>
      Cc: Julia Lawall <julia.lawall@lip6.fr>
      Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      Signed-off-by: default avatarWilly Tarreau <w@1wt.eu>
      7a56cc09