linux-stable.git/drivers, branch v4.9.216

dm cache: fix a crash due to incorrect work item cancelling

2020-03-11T06:53:14+00:00

commit 7cdf6a0aae1cccf5167f3f04ecddcf648b78e289 upstream.

The crash can be reproduced by running the lvm2 testsuite test
lvconvert-thin-external-cache.sh for several minutes, e.g.:
  while :; do make check T=shell/lvconvert-thin-external-cache.sh; done

The crash happens in this call chain:
do_waker -> policy_tick -> smq_tick -> end_hotspot_period -> clear_bitset
-> memset -> __memset -- which accesses an invalid pointer in the vmalloc
area.

The work entry on the workqueue is executed even after the bitmap was
freed. The problem is that cancel_delayed_work doesn't wait for the
running work item to finish, so the work item can continue running and
re-submitting itself even after cache_postsuspend. In order to make sure
that the work item won't be running, we must use cancel_delayed_work_sync.

Also, change flush_workqueue to drain_workqueue, so that if some work item
submits itself or another work item, we are properly waiting for both of
them.

Fixes: c6b4fcbad044 ("dm: add cache target")
Cc: stable@vger.kernel.org # v3.9
Signed-off-by: Mikulas Patocka 
Signed-off-by: Mike Snitzer 
Signed-off-by: Greg Kroah-Hartman

dmaengine: coh901318: Fix a double lock bug in dma_tc_handle()

2020-03-11T06:53:13+00:00

commit 36d5d22090d13fd3a7a8c9663a711cbe6970aac8 upstream.

The caller is already holding the lock so this will deadlock.

Fixes: 0b58828c923e ("DMAENGINE: COH 901 318 remove irq counting")
Signed-off-by: Dan Carpenter 
Link: https://lore.kernel.org/r/20200217144050.3i4ymbytogod4ijn@kili.mountain
Signed-off-by: Vinod Koul 
Signed-off-by: Greg Kroah-Hartman

hwmon: (adt7462) Fix an error return in ADT7462_REG_VOLT()

2020-03-11T06:53:13+00:00

commit 44f2f882909fedfc3a56e4b90026910456019743 upstream.

This is only called from adt7462_update_device().  The caller expects it
to return zero on error.  I fixed a similar issue earlier in commit
a4bf06d58f21 ("hwmon: (adt7462) ADT7462_REG_VOLT_MAX() should return 0")
but I missed this one.

Fixes: c0b4e3ab0c76 ("adt7462: new hwmon driver")
Signed-off-by: Dan Carpenter 
Reviewed-by: Darrick J. Wong 
Link: https://lore.kernel.org/r/20200303101608.kqjwfcazu2ylhi2a@kili.mountain
Signed-off-by: Guenter Roeck 
Signed-off-by: Greg Kroah-Hartman

RMDA/cm: Fix missing ib_cm_destroy_id() in ib_cm_insert_listen()

2020-03-11T06:53:13+00:00

commit c14dfddbd869bf0c2bafb7ef260c41d9cebbcfec upstream.

The algorithm pre-allocates a cm_id since allocation cannot be done while
holding the cm.lock spinlock, however it doesn't free it on one error
path, leading to a memory leak.

Fixes: 067b171b8679 ("IB/cm: Share listening CM IDs")
Link: https://lore.kernel.org/r/20200221152023.GA8680@ziepe.ca
Signed-off-by: Jason Gunthorpe 
Signed-off-by: Greg Kroah-Hartman

RDMA/iwcm: Fix iwcm work deallocation

2020-03-11T06:53:13+00:00

commit 810dbc69087b08fd53e1cdd6c709f385bc2921ad upstream.

The dealloc_work_entries() function must update the work_free_list pointer
while freeing its entries, since potentially called again on same list. A
second iteration of the work list caused system crash. This happens, if
work allocation fails during cma_iw_listen() and free_cm_id() tries to
free the list again during cleanup.

Fixes: 922a8e9fb2e0 ("RDMA: iWARP Connection Manager.")
Link: https://lore.kernel.org/r/20200302181614.17042-1-bmt@zurich.ibm.com
Reported-by: syzbot+cb0c054eabfba4342146@syzkaller.appspotmail.com
Signed-off-by: Bernard Metzler 
Reviewed-by: Jason Gunthorpe 
Signed-off-by: Jason Gunthorpe 
Signed-off-by: Greg Kroah-Hartman

dmaengine: tegra-apb: Prevent race conditions of tasklet vs free list

2020-03-11T06:53:12+00:00

commit c33ee1301c393a241d6424e36eff1071811b1064 upstream.

The interrupt handler puts a half-completed DMA descriptor on a free list
and then schedules tasklet to process bottom half of the descriptor that
executes client's callback, this creates possibility to pick up the busy
descriptor from the free list. Thus, let's disallow descriptor's re-use
until it is fully processed.

Signed-off-by: Dmitry Osipenko 
Acked-by: Jon Hunter 
Cc: 
Link: https://lore.kernel.org/r/20200209163356.6439-3-digetx@gmail.com
Signed-off-by: Vinod Koul 
Signed-off-by: Greg Kroah-Hartman

dmaengine: tegra-apb: Fix use-after-free

2020-03-11T06:53:12+00:00

commit 94788af4ed039476ff3527b0e6a12c1dc42cb022 upstream.

I was doing some experiments with I2C and noticed that Tegra APB DMA
driver crashes sometime after I2C DMA transfer termination. The crash
happens because tegra_dma_terminate_all() bails out immediately if pending
list is empty, and thus, it doesn't release the half-completed descriptors
which are getting re-used before ISR tasklet kicks-in.

 tegra-i2c 7000c400.i2c: DMA transfer timeout
 elants_i2c 0-0010: elants_i2c_irq: failed to read data: -110
 ------------[ cut here ]------------
 WARNING: CPU: 0 PID: 142 at lib/list_debug.c:45 __list_del_entry_valid+0x45/0xac
 list_del corruption, ddbaac44->next is LIST_POISON1 (00000100)
 Modules linked in:
 CPU: 0 PID: 142 Comm: kworker/0:2 Not tainted 5.5.0-rc2-next-20191220-00175-gc3605715758d-dirty #538
 Hardware name: NVIDIA Tegra SoC (Flattened Device Tree)
 Workqueue: events_freezable_power_ thermal_zone_device_check
 [] (unwind_backtrace) from [] (show_stack+0x11/0x14)
 [] (show_stack) from [] (dump_stack+0x85/0x94)
 [] (dump_stack) from [] (__warn+0xc1/0xc4)
 [] (__warn) from [] (warn_slowpath_fmt+0x61/0x78)
 [] (warn_slowpath_fmt) from [] (__list_del_entry_valid+0x45/0xac)
 [] (__list_del_entry_valid) from [] (tegra_dma_tasklet+0x5b/0x154)
 [] (tegra_dma_tasklet) from [] (tasklet_action_common.constprop.0+0x41/0x7c)
 [] (tasklet_action_common.constprop.0) from [] (__do_softirq+0xd3/0x2a8)
 [] (__do_softirq) from [] (irq_exit+0x7b/0x98)
 [] (irq_exit) from [] (__handle_domain_irq+0x45/0x80)
 [] (__handle_domain_irq) from [] (gic_handle_irq+0x45/0x7c)
 [] (gic_handle_irq) from [] (__irq_svc+0x65/0x94)
 Exception stack(0xde2ebb90 to 0xde2ebbd8)

Signed-off-by: Dmitry Osipenko 
Acked-by: Jon Hunter 
Cc: 
Link: https://lore.kernel.org/r/20200209163356.6439-2-digetx@gmail.com
Signed-off-by: Vinod Koul 
Signed-off-by: Greg Kroah-Hartman

vt: selection, push sel_lock up

2020-03-11T06:53:12+00:00

commit e8c75a30a23c6ba63f4ef6895cbf41fd42f21aa2 upstream.

sel_lock cannot nest in the console lock. Thanks to syzkaller, the
kernel states firmly:

> WARNING: possible circular locking dependency detected
> 5.6.0-rc3-syzkaller #0 Not tainted
> ------------------------------------------------------
> syz-executor.4/20336 is trying to acquire lock:
> ffff8880a2e952a0 (&tty->termios_rwsem){++++}, at: tty_unthrottle+0x22/0x100 drivers/tty/tty_ioctl.c:136
>
> but task is already holding lock:
> ffffffff89462e70 (sel_lock){+.+.}, at: paste_selection+0x118/0x470 drivers/tty/vt/selection.c:374
>
> which lock already depends on the new lock.
>
> the existing dependency chain (in reverse order) is:
>
> -> #2 (sel_lock){+.+.}:
>        mutex_lock_nested+0x1b/0x30 kernel/locking/mutex.c:1118
>        set_selection_kernel+0x3b8/0x18a0 drivers/tty/vt/selection.c:217
>        set_selection_user+0x63/0x80 drivers/tty/vt/selection.c:181
>        tioclinux+0x103/0x530 drivers/tty/vt/vt.c:3050
>        vt_ioctl+0x3f1/0x3a30 drivers/tty/vt/vt_ioctl.c:364

This is ioctl(TIOCL_SETSEL).
Locks held on the path: console_lock -> sel_lock

> -> #1 (console_lock){+.+.}:
>        console_lock+0x46/0x70 kernel/printk/printk.c:2289
>        con_flush_chars+0x50/0x650 drivers/tty/vt/vt.c:3223
>        n_tty_write+0xeae/0x1200 drivers/tty/n_tty.c:2350
>        do_tty_write drivers/tty/tty_io.c:962 [inline]
>        tty_write+0x5a1/0x950 drivers/tty/tty_io.c:1046

This is write().
Locks held on the path: termios_rwsem -> console_lock

> -> #0 (&tty->termios_rwsem){++++}:
>        down_write+0x57/0x140 kernel/locking/rwsem.c:1534
>        tty_unthrottle+0x22/0x100 drivers/tty/tty_ioctl.c:136
>        mkiss_receive_buf+0x12aa/0x1340 drivers/net/hamradio/mkiss.c:902
>        tty_ldisc_receive_buf+0x12f/0x170 drivers/tty/tty_buffer.c:465
>        paste_selection+0x346/0x470 drivers/tty/vt/selection.c:389
>        tioclinux+0x121/0x530 drivers/tty/vt/vt.c:3055
>        vt_ioctl+0x3f1/0x3a30 drivers/tty/vt/vt_ioctl.c:364

This is ioctl(TIOCL_PASTESEL).
Locks held on the path: sel_lock -> termios_rwsem

> other info that might help us debug this:
>
> Chain exists of:
>   &tty->termios_rwsem --> console_lock --> sel_lock

Clearly. From the above, we have:
 console_lock -> sel_lock
 sel_lock -> termios_rwsem
 termios_rwsem -> console_lock

Fix this by reversing the console_lock -> sel_lock dependency in
ioctl(TIOCL_SETSEL). First, lock sel_lock, then console_lock.

Signed-off-by: Jiri Slaby 
Reported-by: syzbot+26183d9746e62da329b8@syzkaller.appspotmail.com
Fixes: 07e6124a1a46 ("vt: selection, close sel_buffer race")
Cc: stable 
Link: https://lore.kernel.org/r/20200228115406.5735-2-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman

vt: selection, push console lock down

2020-03-11T06:53:12+00:00

commit 4b70dd57a15d2f4685ac6e38056bad93e81e982f upstream.

We need to nest the console lock in sel_lock, so we have to push it down
a bit. Fortunately, the callers of set_selection_* just lock the console
lock around the function call. So moving it down is easy.

In the next patch, we switch the order.

Signed-off-by: Jiri Slaby 
Fixes: 07e6124a1a46 ("vt: selection, close sel_buffer race")
Cc: stable 
Link: https://lore.kernel.org/r/20200228115406.5735-1-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman

vt: selection, close sel_buffer race

2020-03-11T06:53:11+00:00

commit 07e6124a1a46b4b5a9b3cacc0c306b50da87abf5 upstream.

syzkaller reported this UAF:
BUG: KASAN: use-after-free in n_tty_receive_buf_common+0x2481/0x2940 drivers/tty/n_tty.c:1741
Read of size 1 at addr ffff8880089e40e9 by task syz-executor.1/13184

CPU: 0 PID: 13184 Comm: syz-executor.1 Not tainted 5.4.7 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
Call Trace:
...
 kasan_report+0xe/0x20 mm/kasan/common.c:634
 n_tty_receive_buf_common+0x2481/0x2940 drivers/tty/n_tty.c:1741
 tty_ldisc_receive_buf+0xac/0x190 drivers/tty/tty_buffer.c:461
 paste_selection+0x297/0x400 drivers/tty/vt/selection.c:372
 tioclinux+0x20d/0x4e0 drivers/tty/vt/vt.c:3044
 vt_ioctl+0x1bcf/0x28d0 drivers/tty/vt/vt_ioctl.c:364
 tty_ioctl+0x525/0x15a0 drivers/tty/tty_io.c:2657
 vfs_ioctl fs/ioctl.c:47 [inline]

It is due to a race between parallel paste_selection (TIOCL_PASTESEL)
and set_selection_user (TIOCL_SETSEL) invocations. One uses sel_buffer,
while the other frees it and reallocates a new one for another
selection. Add a mutex to close this race.

The mutex takes care properly of sel_buffer and sel_buffer_lth only. The
other selection global variables (like sel_start, sel_end, and sel_cons)
are protected only in set_selection_user. The other functions need quite
some more work to close the races of the variables there. This is going
to happen later.

This likely fixes (I am unsure as there is no reproducer provided) bug
206361 too. It was marked as CVE-2020-8648.

Signed-off-by: Jiri Slaby 
Reported-by: syzbot+59997e8d5cbdc486e6f6@syzkaller.appspotmail.com
References: https://bugzilla.kernel.org/show_bug.cgi?id=206361
Cc: stable 
Link: https://lore.kernel.org/r/20200210081131.23572-2-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman