linux-stable.git, branch v5.4.4

Linux 5.4.4

2019-12-17T18:56:55+00:00

EDAC/ghes: Do not warn when incrementing refcount on 0

2019-12-17T18:56:54+00:00

[ Upstream commit 16214bd9e43a31683a7073664b000029bba00354 ]

The following warning from the refcount framework is seen during ghes
initialization:

  EDAC MC0: Giving out device to module ghes_edac.c controller ghes_edac: DEV ghes (INTERRUPT)
  ------------[ cut here ]------------
  refcount_t: increment on 0; use-after-free.
  WARNING: CPU: 36 PID: 1 at lib/refcount.c:156 refcount_inc_checked
 [...]
  Call trace:
   refcount_inc_checked
   ghes_edac_register
   ghes_probe
   ...

It warns if the refcount is incremented from zero. This warning is
reasonable as a kernel object is typically created with a refcount of
one and freed once the refcount is zero. Afterwards the object would be
"used-after-free".

For GHES, the refcount is initialized with zero, and that is why this
message is seen when initializing the first instance. However, whenever
the refcount is zero, the device will be allocated and registered. Since
the ghes_reg_mutex protects the refcount and serializes allocation and
freeing of ghes devices, a use-after-free cannot happen here.

Instead of using refcount_inc() for the first instance, use
refcount_set(). This can be used here because the refcount is zero at
this point and can not change due to its protection by the mutex.

Fixes: 23f61b9fc5cc ("EDAC/ghes: Fix locking and memory barrier issues")
Reported-by: John Garry 
Signed-off-by: Robert Richter 
Signed-off-by: Borislav Petkov 
Tested-by: John Garry 
Cc: 
Cc: James Morse 
Cc: 
Cc: linux-edac 
Cc: Mauro Carvalho Chehab 
Cc: 
Cc: Tony Luck 
Cc: 
Link: https://lkml.kernel.org/r/20191121213628.21244-1-rrichter@marvell.com
Signed-off-by: Sasha Levin

r8169: fix rtl_hw_jumbo_disable for RTL8168evl

2019-12-17T18:56:54+00:00

[ Upstream commit 0fc75219fe9a3c90631453e9870e4f6d956f0ebc ]

In referenced fix we removed the RTL8168e-specific jumbo config for
RTL8168evl in rtl_hw_jumbo_enable(). We have to do the same in
rtl_hw_jumbo_disable().

v2: fix referenced commit id

Fixes: 14012c9f3bb9 ("r8169: fix jumbo configuration for RTL8168evl")
Signed-off-by: Heiner Kallweit 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

workqueue: Fix missing kfree(rescuer) in destroy_workqueue()

2019-12-17T18:56:54+00:00

commit 8efe1223d73c218ce7e8b2e0e9aadb974b582d7f upstream.

Signed-off-by: Tejun Heo 
Reported-by: Qian Cai 
Fixes: def98c84b6cd ("workqueue: Fix spurious sanity check failures in destroy_workqueue()")
Cc: Nobuhiro Iwamatsu 
Signed-off-by: Greg Kroah-Hartman

blk-mq: make sure that line break can be printed

2019-12-17T18:56:53+00:00

commit d2c9be89f8ebe7ebcc97676ac40f8dec1cf9b43a upstream.

8962842ca5ab ("blk-mq: avoid sysfs buffer overflow with too many CPU cores")
avoids sysfs buffer overflow, and reserves one character for line break.
However, the last snprintf() doesn't get correct 'size' parameter passed
in, so fixed it.

Fixes: 8962842ca5ab ("blk-mq: avoid sysfs buffer overflow with too many CPU cores")
Signed-off-by: Ming Lei 
Signed-off-by: Jens Axboe 
Cc: Nobuhiro Iwamatsu 
Signed-off-by: Greg Kroah-Hartman

ext4: fix leak of quota reservations

2019-12-17T18:56:53+00:00

commit f4c2d372b89a1e504ebb7b7eb3e29b8306479366 upstream.

Commit 8fcc3a580651 ("ext4: rework reserved cluster accounting when
invalidating pages") moved freeing of delayed allocation reservations
from dirty page invalidation time to time when we evict corresponding
status extent from extent status tree. For inodes which don't have any
blocks allocated this may actually happen only in ext4_clear_blocks()
which is after we've dropped references to quota structures from the
inode. Thus reservation of quota leaked. Fix the problem by clearing
quota information from the inode only after evicting extent status tree
in ext4_clear_inode().

Link: https://lore.kernel.org/r/20191108115420.GI20863@quack2.suse.cz
Reported-by: Konstantin Khlebnikov 
Fixes: 8fcc3a580651 ("ext4: rework reserved cluster accounting when invalidating pages")
Signed-off-by: Jan Kara 
Signed-off-by: Theodore Ts'o 
Signed-off-by: Greg Kroah-Hartman

ext4: fix a bug in ext4_wait_for_tail_page_commit

2019-12-17T18:56:53+00:00

commit 565333a1554d704789e74205989305c811fd9c7a upstream.

No need to wait for any commit once the page is fully truncated.
Besides, it may confuse e.g. concurrent ext4_writepage() with the page
still be dirty (will be cleared by truncate_pagecache() in
ext4_setattr()) but buffers has been freed; and then trigger a bug
show as below:

[   26.057508] ------------[ cut here ]------------
[   26.058531] kernel BUG at fs/ext4/inode.c:2134!
...
[   26.088130] Call trace:
[   26.088695]  ext4_writepage+0x914/0xb28
[   26.089541]  writeout.isra.4+0x1b4/0x2b8
[   26.090409]  move_to_new_page+0x3b0/0x568
[   26.091338]  __unmap_and_move+0x648/0x988
[   26.092241]  unmap_and_move+0x48c/0xbb8
[   26.093096]  migrate_pages+0x220/0xb28
[   26.093945]  kernel_mbind+0x828/0xa18
[   26.094791]  __arm64_sys_mbind+0xc8/0x138
[   26.095716]  el0_svc_common+0x190/0x490
[   26.096571]  el0_svc_handler+0x60/0xd0
[   26.097423]  el0_svc+0x8/0xc

Run the procedure (generate by syzkaller) parallel with ext3.

void main()
{
	int fd, fd1, ret;
	void *addr;
	size_t length = 4096;
	int flags;
	off_t offset = 0;
	char *str = "12345";

	fd = open("a", O_RDWR | O_CREAT);
	assert(fd >= 0);

	/* Truncate to 4k */
	ret = ftruncate(fd, length);
	assert(ret == 0);

	/* Journal data mode */
	flags = 0xc00f;
	ret = ioctl(fd, _IOW('f', 2, long), &flags);
	assert(ret == 0);

	/* Truncate to 0 */
	fd1 = open("a", O_TRUNC | O_NOATIME);
	assert(fd1 >= 0);

	addr = mmap(NULL, length, PROT_WRITE | PROT_READ,
					MAP_SHARED, fd, offset);
	assert(addr != (void *)-1);

	memcpy(addr, str, 5);
	mbind(addr, length, 0, 0, 0, MPOL_MF_MOVE);
}

And the bug will be triggered once we seen the below order.

reproduce1                         reproduce2

...                            |   ...
truncate to 4k                 |
change to journal data mode    |
                               |   memcpy(set page dirty)
truncate to 0:                 |
ext4_setattr:                  |
...                            |
ext4_wait_for_tail_page_commit |
                               |   mbind(trigger bug)
truncate_pagecache(clean dirty)|   ...
...                            |

mbind will call ext4_writepage() since the page still be dirty, and then
report the bug since the buffers has been free. Fix it by return
directly once offset equals to 0 which means the page has been fully
truncated.

Reported-by: Hulk Robot 
Signed-off-by: yangerkun 
Link: https://lore.kernel.org/r/20190919063508.1045-1-yangerkun@huawei.com
Reviewed-by: Jan Kara 
Signed-off-by: Theodore Ts'o 
Signed-off-by: Greg Kroah-Hartman

splice: only read in as much information as there is pipe buffer space

2019-12-17T18:56:52+00:00

commit 3253d9d093376d62b4a56e609f15d2ec5085ac73 upstream.

Andreas Grünbacher reports that on the two filesystems that support
iomap directio, it's possible for splice() to return -EAGAIN (instead of
a short splice) if the pipe being written to has less space available in
its pipe buffers than the length supplied by the calling process.

Months ago we fixed splice_direct_to_actor to clamp the length of the
read request to the size of the splice pipe.  Do the same to do_splice.

Fixes: 17614445576b6 ("splice: don't read more than available pipe space")
Reported-by: syzbot+3c01db6025f26530cf8d@syzkaller.appspotmail.com
Reported-by: Andreas Grünbacher 
Reviewed-by: Andreas Grünbacher 
Signed-off-by: Darrick J. Wong 
Signed-off-by: Greg Kroah-Hartman

rtc: disable uie before setting time and enable after

2019-12-17T18:56:52+00:00

commit 7e7c005b4b1f1f169bcc4b2c3a40085ecc663df2 upstream.

When setting the time in the future with the uie timer enabled,
rtc_timer_do_work will loop for a while because the expiration of the uie
timer was way before the current RTC time and a new timer will be enqueued
until the current rtc time is reached.

If the uie timer is enabled, disable it before setting the time and enable
it after expiring current timers (which may actually be an alarm).

This is the safest thing to do to ensure the uie timer is still
synchronized with the RTC, especially in the UIE emulation case.

Reported-by: syzbot+08116743f8ad6f9a6de7@syzkaller.appspotmail.com
Fixes: 6610e0893b8b ("RTC: Rework RTC code to use timerqueue for events")
Link: https://lore.kernel.org/r/20191020231320.8191-1-alexandre.belloni@bootlin.com
Signed-off-by: Alexandre Belloni 
Signed-off-by: Greg Kroah-Hartman

USB: dummy-hcd: increase max number of devices to 32

2019-12-17T18:56:52+00:00

commit 8442b02bf3c6770e0d7e7ea17be36c30e95987b6 upstream.

When fuzzing the USB subsystem with syzkaller, we currently use 8 testing
processes within one VM. To isolate testing processes from one another it
is desirable to assign a dedicated USB bus to each of those, which means
we need at least 8 Dummy UDC/HCD devices.

This patch increases the maximum number of Dummy UDC/HCD devices to 32
(more than 8 in case we need more of them in the future).

Signed-off-by: Andrey Konovalov 
Link: https://lore.kernel.org/r/665578f904484069bb6100fb20283b22a046ad9b.1571667489.git.andreyknvl@google.com
Signed-off-by: Greg Kroah-Hartman