linux-stable.git/drivers/char, branch v4.4.205 Linux kernel stable tree virtio_console: move removal code 2019-11-28T17:26:23+00:00 Michael S. Tsirkin mst@redhat.com 2018-04-20T17:51:18+00:00 b12818d70879ffa0ac5f40672ef502445c1a3368 [ Upstream commit aa44ec867030a72e8aa127977e37dec551d8df19 ] Will make it reusable for error handling. Cc: stable@vger.kernel.org Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit aa44ec867030a72e8aa127977e37dec551d8df19 ]

Will make it reusable for error handling.

Cc: stable@vger.kernel.org
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
virtio_console: drop custom control queue cleanup 2019-11-28T17:26:23+00:00 Michael S. Tsirkin mst@redhat.com 2018-04-20T17:49:04+00:00 fa3c628897e62909ea10a8a12de3b9d4492669ed [ Upstream commit 61a8950c5c5708cf2068b29ffde94e454e528208 ] We now cleanup all VQs on device removal - no need to handle the control VQ specially. Cc: stable@vger.kernel.org Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 61a8950c5c5708cf2068b29ffde94e454e528208 ]

We now cleanup all VQs on device removal - no need
to handle the control VQ specially.

Cc: stable@vger.kernel.org
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
virtio_console: fix uninitialized variable use 2019-11-28T17:26:22+00:00 Michael S. Tsirkin mst@redhat.com 2017-03-29T20:22:04+00:00 ba9e2c1190a6b193ba2256a6810c8204ee5d08c3 [ Upstream commit 2055997f983c6db7b5c3940ce5f8f822657d5bc3 ] We try to disable callbacks on c_ivq even without multiport even though that vq is not initialized in this configuration. Fixes: c743d09dbd01 ("virtio: console: Disable callbacks for virtqueues at start of S4 freeze") Suggested-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 2055997f983c6db7b5c3940ce5f8f822657d5bc3 ]

We try to disable callbacks on c_ivq even without multiport
even though that vq is not initialized in this configuration.

Fixes: c743d09dbd01 ("virtio: console: Disable callbacks for virtqueues at start of S4 freeze")
Suggested-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
virtio_console: allocate inbufs in add_port() only if it is needed 2019-11-28T17:26:22+00:00 Laurent Vivier lvivier@redhat.com 2019-11-14T12:25:48+00:00 abdd31f3744ef8b6c7aa4178ed7fec3070ef29d3 [ Upstream commit d791cfcbf98191122af70b053a21075cb450d119 ] When we hot unplug a virtserialport and then try to hot plug again, it fails: (qemu) chardev-add socket,id=serial0,path=/tmp/serial0,server,nowait (qemu) device_add virtserialport,bus=virtio-serial0.0,nr=2,\ chardev=serial0,id=serial0,name=serial0 (qemu) device_del serial0 (qemu) device_add virtserialport,bus=virtio-serial0.0,nr=2,\ chardev=serial0,id=serial0,name=serial0 kernel error: virtio-ports vport2p2: Error allocating inbufs qemu error: virtio-serial-bus: Guest failure in adding port 2 for device \ virtio-serial0.0 This happens because buffers for the in_vq are allocated when the port is added but are not released when the port is unplugged. They are only released when virtconsole is removed (see a7a69ec0d8e4) To avoid the problem and to be symmetric, we could allocate all the buffers in init_vqs() as they are released in remove_vqs(), but it sounds like a waste of memory. Rather than that, this patch changes add_port() logic to ignore ENOSPC error in fill_queue(), which means queue has already been filled. Fixes: a7a69ec0d8e4 ("virtio_console: free buffers after reset") Cc: mst@redhat.com Cc: stable@vger.kernel.org Signed-off-by: Laurent Vivier <lvivier@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit d791cfcbf98191122af70b053a21075cb450d119 ]

When we hot unplug a virtserialport and then try to hot plug again,
it fails:

(qemu) chardev-add socket,id=serial0,path=/tmp/serial0,server,nowait
(qemu) device_add virtserialport,bus=virtio-serial0.0,nr=2,\
                  chardev=serial0,id=serial0,name=serial0
(qemu) device_del serial0
(qemu) device_add virtserialport,bus=virtio-serial0.0,nr=2,\
                  chardev=serial0,id=serial0,name=serial0
kernel error:
  virtio-ports vport2p2: Error allocating inbufs
qemu error:
  virtio-serial-bus: Guest failure in adding port 2 for device \
                     virtio-serial0.0

This happens because buffers for the in_vq are allocated when the port is
added but are not released when the port is unplugged.

They are only released when virtconsole is removed (see a7a69ec0d8e4)

To avoid the problem and to be symmetric, we could allocate all the buffers
in init_vqs() as they are released in remove_vqs(), but it sounds like
a waste of memory.

Rather than that, this patch changes add_port() logic to ignore ENOSPC
error in fill_queue(), which means queue has already been filled.

Fixes: a7a69ec0d8e4 ("virtio_console: free buffers after reset")
Cc: mst@redhat.com
Cc: stable@vger.kernel.org
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
virtio_console: don't tie bufs to a vq 2019-11-28T17:26:21+00:00 Michael S. Tsirkin mst@redhat.com 2018-04-20T16:54:23+00:00 809ff9a14bdea2c70440f1f4479d29a179ea6682 [ Upstream commit 2855b33514d290c51d52d94e25d3ef942cd4d578 ] an allocated buffer doesn't need to be tied to a vq - only vq->vdev is ever used. Pass the function the just what it needs - the vdev. Cc: stable@vger.kernel.org Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 2855b33514d290c51d52d94e25d3ef942cd4d578 ]

an allocated buffer doesn't need to be tied to a vq -
only vq->vdev is ever used. Pass the function the
just what it needs - the vdev.

Cc: stable@vger.kernel.org
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
virtio_console: reset on out of memory 2019-11-28T17:26:21+00:00 Michael S. Tsirkin mst@redhat.com 2018-04-20T18:00:13+00:00 4cad8c2d8f8b50638dc5da357b5f2e42b5860f19 [ Upstream commit 5c60300d68da32ca77f7f978039dc72bfc78b06b ] When out of memory and we can't add ctrl vq buffers, probe fails. Unfortunately the error handling is out of spec: it calls del_vqs without bothering to reset the device first. To fix, call the full cleanup function in this case. Cc: stable@vger.kernel.org Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 5c60300d68da32ca77f7f978039dc72bfc78b06b ]

When out of memory and we can't add ctrl vq buffers,
probe fails. Unfortunately the error handling is
out of spec: it calls del_vqs without bothering
to reset the device first.

To fix, call the full cleanup function in this case.

Cc: stable@vger.kernel.org
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
ipmi_si: Only schedule continuously in the thread in maintenance mode 2019-10-07T19:00:59+00:00 Corey Minyard cminyard@mvista.com 2019-08-02T12:31:36+00:00 d9e87b4415c7a81986f440e32f628325f79ae533 [ Upstream commit 340ff31ab00bca5c15915e70ad9ada3030c98cf8 ] ipmi_thread() uses back-to-back schedule() to poll for command completion which, on some machines, can push up CPU consumption and heavily tax the scheduler locks leading to noticeable overall performance degradation. This was originally added so firmware updates through IPMI would complete in a timely manner. But we can't kill the scheduler locks for that one use case. Instead, only run schedule() continuously in maintenance mode, where firmware updates should run. Signed-off-by: Corey Minyard <cminyard@mvista.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 340ff31ab00bca5c15915e70ad9ada3030c98cf8 ]

ipmi_thread() uses back-to-back schedule() to poll for command
completion which, on some machines, can push up CPU consumption and
heavily tax the scheduler locks leading to noticeable overall
performance degradation.

This was originally added so firmware updates through IPMI would
complete in a timely manner.  But we can't kill the scheduler
locks for that one use case.

Instead, only run schedule() continuously in maintenance mode,
where firmware updates should run.

Signed-off-by: Corey Minyard <cminyard@mvista.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
hwrng: core - don't wait on add_early_randomness() 2019-10-05T10:27:55+00:00 Laurent Vivier lvivier@redhat.com 2019-09-17T09:54:50+00:00 c648d4350015ab238c0b1ba35616adfb72f5d76b commit 78887832e76541f77169a24ac238fccb51059b63 upstream. add_early_randomness() is called by hwrng_register() when the hardware is added. If this hardware and its module are present at boot, and if there is no data available the boot hangs until data are available and can't be interrupted. For instance, in the case of virtio-rng, in some cases the host can be not able to provide enough entropy for all the guests. We can have two easy ways to reproduce the problem but they rely on misconfiguration of the hypervisor or the egd daemon: - if virtio-rng device is configured to connect to the egd daemon of the host but when the virtio-rng driver asks for data the daemon is not connected, - if virtio-rng device is configured to connect to the egd daemon of the host but the egd daemon doesn't provide data. The guest kernel will hang at boot until the virtio-rng driver provides enough data. To avoid that, call rng_get_data() in non-blocking mode (wait=0) from add_early_randomness(). Signed-off-by: Laurent Vivier <lvivier@redhat.com> Fixes: d9e797261933 ("hwrng: add randomness to system from rng...") Cc: <stable@vger.kernel.org> Reviewed-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 78887832e76541f77169a24ac238fccb51059b63 upstream.

add_early_randomness() is called by hwrng_register() when the
hardware is added. If this hardware and its module are present
at boot, and if there is no data available the boot hangs until
data are available and can't be interrupted.

For instance, in the case of virtio-rng, in some cases the host can be
not able to provide enough entropy for all the guests.

We can have two easy ways to reproduce the problem but they rely on
misconfiguration of the hypervisor or the egd daemon:

- if virtio-rng device is configured to connect to the egd daemon of the
host but when the virtio-rng driver asks for data the daemon is not
connected,

- if virtio-rng device is configured to connect to the egd daemon of the
host but the egd daemon doesn't provide data.

The guest kernel will hang at boot until the virtio-rng driver provides
enough data.

To avoid that, call rng_get_data() in non-blocking mode (wait=0)
from add_early_randomness().

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Fixes: d9e797261933 ("hwrng: add randomness to system from rng...")
Cc: <stable@vger.kernel.org>
Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
/dev/mem: Bail out upon SIGKILL. 2019-10-05T10:27:54+00:00 Tetsuo Handa penguin-kernel@I-love.SAKURA.ne.jp 2019-08-26T13:13:25+00:00 4e9518d21cf0244247b2386f11949fb4ccf38667 commit 8619e5bdeee8b2c685d686281f2d2a6017c4bc15 upstream. syzbot found that a thread can stall for minutes inside read_mem() or write_mem() after that thread was killed by SIGKILL [1]. Reading from iomem areas of /dev/mem can be slow, depending on the hardware. While reading 2GB at one read() is legal, delaying termination of killed thread for minutes is bad. Thus, allow reading/writing /dev/mem and /dev/kmem to be preemptible and killable. [ 1335.912419][T20577] read_mem: sz=4096 count=2134565632 [ 1335.943194][T20577] read_mem: sz=4096 count=2134561536 [ 1335.978280][T20577] read_mem: sz=4096 count=2134557440 [ 1336.011147][T20577] read_mem: sz=4096 count=2134553344 [ 1336.041897][T20577] read_mem: sz=4096 count=2134549248 Theoretically, reading/writing /dev/mem and /dev/kmem can become "interruptible". But this patch chose "killable". Future patch will make them "interruptible" so that we can revert to "killable" if some program regressed. [1] https://syzkaller.appspot.com/bug?id=a0e3436829698d5824231251fad9d8e998f94f5e Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: stable <stable@vger.kernel.org> Reported-by: syzbot <syzbot+8ab2d0f39fb79fe6ca40@syzkaller.appspotmail.com> Link: https://lore.kernel.org/r/1566825205-10703-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 8619e5bdeee8b2c685d686281f2d2a6017c4bc15 upstream.

syzbot found that a thread can stall for minutes inside read_mem() or
write_mem() after that thread was killed by SIGKILL [1]. Reading from
iomem areas of /dev/mem can be slow, depending on the hardware.
While reading 2GB at one read() is legal, delaying termination of killed
thread for minutes is bad. Thus, allow reading/writing /dev/mem and
/dev/kmem to be preemptible and killable.

  [ 1335.912419][T20577] read_mem: sz=4096 count=2134565632
  [ 1335.943194][T20577] read_mem: sz=4096 count=2134561536
  [ 1335.978280][T20577] read_mem: sz=4096 count=2134557440
  [ 1336.011147][T20577] read_mem: sz=4096 count=2134553344
  [ 1336.041897][T20577] read_mem: sz=4096 count=2134549248

Theoretically, reading/writing /dev/mem and /dev/kmem can become
"interruptible". But this patch chose "killable". Future patch will make
them "interruptible" so that we can revert to "killable" if some program
regressed.

[1] https://syzkaller.appspot.com/bug?id=a0e3436829698d5824231251fad9d8e998f94f5e

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: stable <stable@vger.kernel.org>
Reported-by: syzbot <syzbot+8ab2d0f39fb79fe6ca40@syzkaller.appspotmail.com>
Link: https://lore.kernel.org/r/1566825205-10703-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
hpet: Fix division by zero in hpet_time_div() 2019-08-04T07:35:00+00:00 Kefeng Wang wangkefeng.wang@huawei.com 2019-07-11T13:27:57+00:00 fe7d7592df205c3ca74ace8cd5a73078652c6a64 commit 0c7d37f4d9b8446956e97b7c5e61173cdb7c8522 upstream. The base value in do_div() called by hpet_time_div() is truncated from unsigned long to uint32_t, resulting in a divide-by-zero exception. UBSAN: Undefined behaviour in ../drivers/char/hpet.c:572:2 division by zero CPU: 1 PID: 23682 Comm: syz-executor.3 Not tainted 4.4.184.x86_64+ #4 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014 0000000000000000 b573382df1853d00 ffff8800a3287b98 ffffffff81ad7561 ffff8800a3287c00 ffffffff838b35b0 ffffffff838b3860 ffff8800a3287c20 0000000000000000 ffff8800a3287bb0 ffffffff81b8f25e ffffffff838b35a0 Call Trace: [<ffffffff81ad7561>] __dump_stack lib/dump_stack.c:15 [inline] [<ffffffff81ad7561>] dump_stack+0xc1/0x120 lib/dump_stack.c:51 [<ffffffff81b8f25e>] ubsan_epilogue+0x12/0x8d lib/ubsan.c:166 [<ffffffff81b900cb>] __ubsan_handle_divrem_overflow+0x282/0x2c8 lib/ubsan.c:262 [<ffffffff823560dd>] hpet_time_div drivers/char/hpet.c:572 [inline] [<ffffffff823560dd>] hpet_ioctl_common drivers/char/hpet.c:663 [inline] [<ffffffff823560dd>] hpet_ioctl_common.cold+0xa8/0xad drivers/char/hpet.c:577 [<ffffffff81e63d56>] hpet_ioctl+0xc6/0x180 drivers/char/hpet.c:676 [<ffffffff81711590>] vfs_ioctl fs/ioctl.c:43 [inline] [<ffffffff81711590>] file_ioctl fs/ioctl.c:470 [inline] [<ffffffff81711590>] do_vfs_ioctl+0x6e0/0xf70 fs/ioctl.c:605 [<ffffffff81711eb4>] SYSC_ioctl fs/ioctl.c:622 [inline] [<ffffffff81711eb4>] SyS_ioctl+0x94/0xc0 fs/ioctl.c:613 [<ffffffff82846003>] tracesys_phase2+0x90/0x95 The main C reproducer autogenerated by syzkaller, syscall(__NR_mmap, 0x20000000, 0x1000000, 3, 0x32, -1, 0); memcpy((void*)0x20000100, "/dev/hpet\000", 10); syscall(__NR_openat, 0xffffffffffffff9c, 0x20000100, 0, 0); syscall(__NR_ioctl, r[0], 0x40086806, 0x40000000000000); Fix it by using div64_ul(). Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Signed-off-by: Zhang HongJun <zhanghongjun2@huawei.com> Cc: stable <stable@vger.kernel.org> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Link: https://lore.kernel.org/r/20190711132757.130092-1-wangkefeng.wang@huawei.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 0c7d37f4d9b8446956e97b7c5e61173cdb7c8522 upstream.

The base value in do_div() called by hpet_time_div() is truncated from
unsigned long to uint32_t, resulting in a divide-by-zero exception.

UBSAN: Undefined behaviour in ../drivers/char/hpet.c:572:2
division by zero
CPU: 1 PID: 23682 Comm: syz-executor.3 Not tainted 4.4.184.x86_64+ #4
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014
 0000000000000000 b573382df1853d00 ffff8800a3287b98 ffffffff81ad7561
 ffff8800a3287c00 ffffffff838b35b0 ffffffff838b3860 ffff8800a3287c20
 0000000000000000 ffff8800a3287bb0 ffffffff81b8f25e ffffffff838b35a0
Call Trace:
 [<ffffffff81ad7561>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81ad7561>] dump_stack+0xc1/0x120 lib/dump_stack.c:51
 [<ffffffff81b8f25e>] ubsan_epilogue+0x12/0x8d lib/ubsan.c:166
 [<ffffffff81b900cb>] __ubsan_handle_divrem_overflow+0x282/0x2c8 lib/ubsan.c:262
 [<ffffffff823560dd>] hpet_time_div drivers/char/hpet.c:572 [inline]
 [<ffffffff823560dd>] hpet_ioctl_common drivers/char/hpet.c:663 [inline]
 [<ffffffff823560dd>] hpet_ioctl_common.cold+0xa8/0xad drivers/char/hpet.c:577
 [<ffffffff81e63d56>] hpet_ioctl+0xc6/0x180 drivers/char/hpet.c:676
 [<ffffffff81711590>] vfs_ioctl fs/ioctl.c:43 [inline]
 [<ffffffff81711590>] file_ioctl fs/ioctl.c:470 [inline]
 [<ffffffff81711590>] do_vfs_ioctl+0x6e0/0xf70 fs/ioctl.c:605
 [<ffffffff81711eb4>] SYSC_ioctl fs/ioctl.c:622 [inline]
 [<ffffffff81711eb4>] SyS_ioctl+0x94/0xc0 fs/ioctl.c:613
 [<ffffffff82846003>] tracesys_phase2+0x90/0x95

The main C reproducer autogenerated by syzkaller,

  syscall(__NR_mmap, 0x20000000, 0x1000000, 3, 0x32, -1, 0);
  memcpy((void*)0x20000100, "/dev/hpet\000", 10);
  syscall(__NR_openat, 0xffffffffffffff9c, 0x20000100, 0, 0);
  syscall(__NR_ioctl, r[0], 0x40086806, 0x40000000000000);

Fix it by using div64_ul().

Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Zhang HongJun <zhanghongjun2@huawei.com>
Cc: stable <stable@vger.kernel.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20190711132757.130092-1-wangkefeng.wang@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>