In the Linux kernel, the following vulnerability has been resolved:
drivers: staging: rtl8192eu: Fix deadlock in rtw_joinbss_event_prehandle
There is a deadlock in rtw_joinbss_event_prehandle(), which is shown below:
(Thread 1) | (Thread 2)
| _set_timer()
rtw_joinbss_event_prehandle()| mod_timer()
spin_lock_bh() //(1) | (wait a time)
... | rtw_join_timeout_handler()
| _rtw_join_timeout_handler()
del_timer_sync() | spin_lock_bh() //(2)
(wait timer to stop) | ...
We hold pmlmepriv->lock in position (1) of thread 1 and
use del_timer_sync() to wait timer to stop, but timer handler
also need pmlmepriv->lock in position (2) of thread 2.
As a result, rtw_joinbss_event_prehandle() will block forever.
This patch extracts del_timer_sync() from the protection of
spin_lock_bh(), which could let timer handler to obtain
the needed lock. What`s more, we change spin_lock_bh() to
spin_lock_irq() in _rtw_join_timeout_handler() in order to
prevent deadlock.
In the Linux kernel, the following vulnerability has been resolved:
drivers: tty: serial: Fix deadlock in sa1100_set_termios()
There is a deadlock in sa1100_set_termios(), which is shown
below:
(Thread 1) | (Thread 2)
| sa1100_enable_ms()
sa1100_set_termios() | mod_timer()
spin_lock_irqsave() //(1) | (wait a time)
... | sa1100_timeout()
del_timer_sync() | spin_lock_irqsave() //(2)
(wait timer to stop) | ...
We hold sport->port.lock in position (1) of thread 1 and
use del_timer_sync() to wait timer to stop, but timer handler
also need sport->port.lock in position (2) of thread 2. As a result,
sa1100_set_termios() will block forever.
This patch moves del_timer_sync() before spin_lock_irqsave()
in order to prevent the deadlock.
In the Linux kernel, the following vulnerability has been resolved:
drivers: staging: rtl8192u: Fix deadlock in ieee80211_beacons_stop()
There is a deadlock in ieee80211_beacons_stop(), which is shown below:
(Thread 1) | (Thread 2)
| ieee80211_send_beacon()
ieee80211_beacons_stop() | mod_timer()
spin_lock_irqsave() //(1) | (wait a time)
... | ieee80211_send_beacon_cb()
del_timer_sync() | spin_lock_irqsave() //(2)
(wait timer to stop) | ...
We hold ieee->beacon_lock in position (1) of thread 1 and use
del_timer_sync() to wait timer to stop, but timer handler
also need ieee->beacon_lock in position (2) of thread 2.
As a result, ieee80211_beacons_stop() will block forever.
This patch extracts del_timer_sync() from the protection of
spin_lock_irqsave(), which could let timer handler to obtain
the needed lock.
In the Linux kernel, the following vulnerability has been resolved:
tty: synclink_gt: Fix null-pointer-dereference in slgt_clean()
When the driver fails at alloc_hdlcdev(), and then we remove the driver
module, we will get the following splat:
[ 25.065966] general protection fault, probably for non-canonical address 0xdffffc0000000182: 0000 [#1] PREEMPT SMP KASAN PTI
[ 25.066914] KASAN: null-ptr-deref in range [0x0000000000000c10-0x0000000000000c17]
[ 25.069262] RIP: 0010:detach_hdlc_protocol+0x2a/0x3e0
[ 25.077709] Call Trace:
[ 25.077924] <TASK>
[ 25.078108] unregister_hdlc_device+0x16/0x30
[ 25.078481] slgt_cleanup+0x157/0x9f0 [synclink_gt]
Fix this by checking whether the 'info->netdev' is a null pointer first.
In the Linux kernel, the following vulnerability has been resolved:
extcon: Modify extcon device to be created after driver data is set
Currently, someone can invoke the sysfs such as state_show()
intermittently before dev_set_drvdata() is done.
And it can be a cause of kernel Oops because of edev is Null at that time.
So modified the driver registration to after setting drviver data.
- Oops's backtrace.
Backtrace:
[<c067865c>] (state_show) from [<c05222e8>] (dev_attr_show)
[<c05222c0>] (dev_attr_show) from [<c02c66e0>] (sysfs_kf_seq_show)
[<c02c6648>] (sysfs_kf_seq_show) from [<c02c496c>] (kernfs_seq_show)
[<c02c4938>] (kernfs_seq_show) from [<c025e2a0>] (seq_read)
[<c025e11c>] (seq_read) from [<c02c50a0>] (kernfs_fop_read)
[<c02c5064>] (kernfs_fop_read) from [<c0231cac>] (__vfs_read)
[<c0231c5c>] (__vfs_read) from [<c0231ee0>] (vfs_read)
[<c0231e34>] (vfs_read) from [<c0232464>] (ksys_read)
[<c02323f0>] (ksys_read) from [<c02324fc>] (sys_read)
[<c02324e4>] (sys_read) from [<c00091d0>] (__sys_trace_return)
In the Linux kernel, the following vulnerability has been resolved:
drivers: staging: rtl8723bs: Fix deadlock in rtw_surveydone_event_callback()
There is a deadlock in rtw_surveydone_event_callback(),
which is shown below:
(Thread 1) | (Thread 2)
| _set_timer()
rtw_surveydone_event_callback()| mod_timer()
spin_lock_bh() //(1) | (wait a time)
... | rtw_scan_timeout_handler()
del_timer_sync() | spin_lock_bh() //(2)
(wait timer to stop) | ...
We hold pmlmepriv->lock in position (1) of thread 1 and use
del_timer_sync() to wait timer to stop, but timer handler
also need pmlmepriv->lock in position (2) of thread 2.
As a result, rtw_surveydone_event_callback() will block forever.
This patch extracts del_timer_sync() from the protection of
spin_lock_bh(), which could let timer handler to obtain
the needed lock. What`s more, we change spin_lock_bh() in
rtw_scan_timeout_handler() to spin_lock_irq(). Otherwise,
spin_lock_bh() will also cause deadlock() in timer handler.
In the Linux kernel, the following vulnerability has been resolved:
drivers: staging: rtl8192bs: Fix deadlock in rtw_joinbss_event_prehandle()
There is a deadlock in rtw_joinbss_event_prehandle(), which is shown
below:
(Thread 1) | (Thread 2)
| _set_timer()
rtw_joinbss_event_prehandle()| mod_timer()
spin_lock_bh() //(1) | (wait a time)
... | _rtw_join_timeout_handler()
del_timer_sync() | spin_lock_bh() //(2)
(wait timer to stop) | ...
We hold pmlmepriv->lock in position (1) of thread 1 and
use del_timer_sync() to wait timer to stop, but timer handler
also need pmlmepriv->lock in position (2) of thread 2.
As a result, rtw_joinbss_event_prehandle() will block forever.
This patch extracts del_timer_sync() from the protection of
spin_lock_bh(), which could let timer handler to obtain
the needed lock. What`s more, we change spin_lock_bh() to
spin_lock_irq() in _rtw_join_timeout_handler() in order to
prevent deadlock.
In the Linux kernel, the following vulnerability has been resolved:
staging: rtl8712: fix a potential memory leak in r871xu_drv_init()
In r871xu_drv_init(), if r8712_init_drv_sw() fails, then the memory
allocated by r8712_alloc_io_queue() in r8712_usb_dvobj_init() is not
properly released as there is no action will be performed by
r8712_usb_dvobj_deinit().
To properly release it, we should call r8712_free_io_queue() in
r8712_usb_dvobj_deinit().
Besides, in r871xu_dev_remove(), r8712_usb_dvobj_deinit() will be called
by r871x_dev_unload() under condition `padapter->bup` and
r8712_free_io_queue() is called by r8712_free_drv_sw().
However, r8712_usb_dvobj_deinit() does not rely on `padapter->bup` and
calling r8712_free_io_queue() in r8712_free_drv_sw() is negative for
better understading the code.
So I move r8712_usb_dvobj_deinit() into r871xu_dev_remove(), and remove
r8712_free_io_queue() from r8712_free_drv_sw().
In the Linux kernel, the following vulnerability has been resolved:
ALSA: oss: Fix PCM OSS buffer allocation overflow
We've got syzbot reports hitting INT_MAX overflow at vmalloc()
allocation that is called from snd_pcm_plug_alloc(). Although we
apply the restrictions to input parameters, it's based only on the
hw_params of the underlying PCM device. Since the PCM OSS layer
allocates a temporary buffer for the data conversion, the size may
become unexpectedly large when more channels or higher rates is given;
in the reported case, it went over INT_MAX, hence it hits WARN_ON().
This patch is an attempt to avoid such an overflow and an allocation
for too large buffers. First off, it adds the limit of 1MB as the
upper bound for period bytes. This must be large enough for all use
cases, and we really don't want to handle a larger temporary buffer
than this size. The size check is performed at two places, where the
original period bytes is calculated and where the plugin buffer size
is calculated.
In addition, the driver uses array_size() and array3_size() for
multiplications to catch overflows for the converted period size and
buffer bytes.
In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Check if modulo is 0 before dividing.
[How & Why]
If a value of 0 is read, then this will cause a divide-by-0 panic.