[ Upstream commit c2d953276b ]
The expression htotal * vtotal can have a zero value on
overflow. It is necessary to prevent division by zero like in
fb_var_to_videomode().
Found by Linux Verification Center (linuxtesting.org) with Svace.
Signed-off-by: Roman Smirnov <r.smirnov@omp.ru>
Reviewed-by: Sergey Shtylyov <s.shtylyov@omp.ru>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit bc87bb342f ]
There are some actions with value 'tmp' but 'dst_addr' is checked instead.
It is obvious that a copy-paste error was made here and the value
of variable 'tmp' should be checked here.
Found by Linux Verification Center (linuxtesting.org) with SVACE.
Signed-off-by: Aleksandr Burakov <a.burakov@rosalinux.ru>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit e421946be7 ]
The userspace program could pass any values to the driver through
ioctl() interface. If the driver doesn't check the value of pixclock,
it may cause divide-by-zero error.
In sisfb_check_var(), var->pixclock is used as a divisor to caculate
drate before it is checked against zero. Fix this by checking it
at the beginning.
This is similar to CVE-2022-3061 in i740fb which was fixed by
commit 15cf0b8.
Signed-off-by: Fullway Wang <fullwaywang@outlook.com>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 04e5eac8f3 ]
The userspace program could pass any values to the driver through
ioctl() interface. If the driver doesn't check the value of pixclock,
it may cause divide-by-zero error.
Although pixclock is checked in savagefb_decode_var(), but it is not
checked properly in savagefb_probe(). Fix this by checking whether
pixclock is zero in the function savagefb_check_var() before
info->var.pixclock is used as the divisor.
This is similar to CVE-2022-3061 in i740fb which was fixed by
commit 15cf0b8.
Signed-off-by: Fullway Wang <fullwaywang@outlook.com>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 15e4c1f462 upstream.
The driver's fsync() is supposed to flush any pending operation to
hardware. It is implemented in this driver by cancelling the queued
deferred IO first, then schedule it for "immediate execution" by calling
schedule_delayed_work() again with delay=0. However, setting delay=0
only means the work is scheduled immediately, it does not mean the work
is executed immediately. There is no guarantee that the work is finished
after schedule_delayed_work() returns. After this driver's fsync()
returns, there can still be pending work. Furthermore, if close() is
called by users immediately after fsync(), the pending work gets
cancelled and fsync() may do nothing.
To ensure that the deferred IO completes, use flush_delayed_work()
instead. Write operations to this driver either write to the device
directly, or invoke schedule_delayed_work(); so by flushing the
workqueue, it can be guaranteed that all previous writes make it to the
device.
Fixes: 5e841b88d2 ("fb: fsync() method for deferred I/O flush.")
Cc: stable@vger.kernel.org
Signed-off-by: Nam Cao <namcao@linutronix.de>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 8a32aa17c1 ]
The pointer to the next STI font is actually a signed 32-bit
offset. With this change the 64-bit kernel will correctly subract
the (signed 32-bit) offset instead of adding a (unsigned 32-bit)
offset. It has no effect on 32-bit kernels.
This fixes the stifb driver with a 64-bit kernel on qemu.
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit a5035c8184 ]
wr_reg_wa() is not an appropriate name for a global function, and doesn't need
to be global anyway, so mark it static and avoid the warning:
drivers/video/fbdev/fsl-diu-fb.c:493:6: error: no previous prototype for 'wr_reg_wa' [-Werror=missing-prototypes]
Fixes: 0d9dab39fb ("powerpc/5121: fsl-diu-fb: fix issue with re-enabling DIU area descriptor")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit aba6ab57a9 ]
I've re-written the error handling but the bug is that if init_imstt()
fails we need to call iounmap(par->cmap_regs).
Fixes: c75f5a5506 ("fbdev: imsttfb: Fix use after free bug in imsttfb_probe")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 1022e7e2f4 ]
Delete the v86d netlink only after all the VBE tasks have been
completed.
Fixes initial state restore on module unload:
uvesafb: VBE state restore call failed (eax=0x4f04, err=-19)
Signed-off-by: Jorge Maidana <jorgem.linux@gmail.com>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit c1a8d1d0ed ]
ioremap_uc() is only meaningful on old x86-32 systems with the PAT
extension, and on ia64 with its slightly unconventional ioremap()
behavior, everywhere else this is the same as ioremap() anyway.
Change the only driver that still references ioremap_uc() to only do so
on x86-32/ia64 in order to allow removing that interface at some
point in the future for the other architectures.
On some architectures, ioremap_uc() just returns NULL, changing
the driver to call ioremap() means that they now have a chance
of working correctly.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Baoquan He <bhe@redhat.com>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Cc: Helge Deller <deller@gmx.de>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: linux-fbdev@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit f75f71b2c4 ]
Fix linker error if FB=m about missing fb_io_read and fb_io_write. The
linker's error message suggests that this config setting has already
been broken for other symbols.
All errors (new ones prefixed by >>):
sh4-linux-ld: drivers/video/fbdev/sh7760fb.o: in function `sh7760fb_probe':
sh7760fb.c:(.text+0x374): undefined reference to `framebuffer_alloc'
sh4-linux-ld: sh7760fb.c:(.text+0x394): undefined reference to `fb_videomode_to_var'
sh4-linux-ld: sh7760fb.c:(.text+0x39c): undefined reference to `fb_alloc_cmap'
sh4-linux-ld: sh7760fb.c:(.text+0x3a4): undefined reference to `register_framebuffer'
sh4-linux-ld: sh7760fb.c:(.text+0x3ac): undefined reference to `fb_dealloc_cmap'
sh4-linux-ld: sh7760fb.c:(.text+0x434): undefined reference to `framebuffer_release'
sh4-linux-ld: drivers/video/fbdev/sh7760fb.o: in function `sh7760fb_remove':
sh7760fb.c:(.text+0x800): undefined reference to `unregister_framebuffer'
sh4-linux-ld: sh7760fb.c:(.text+0x804): undefined reference to `fb_dealloc_cmap'
sh4-linux-ld: sh7760fb.c:(.text+0x814): undefined reference to `framebuffer_release'
>> sh4-linux-ld: drivers/video/fbdev/sh7760fb.o:(.rodata+0xc): undefined reference to `fb_io_read'
>> sh4-linux-ld: drivers/video/fbdev/sh7760fb.o:(.rodata+0x10): undefined reference to `fb_io_write'
sh4-linux-ld: drivers/video/fbdev/sh7760fb.o:(.rodata+0x2c): undefined reference to `cfb_fillrect'
sh4-linux-ld: drivers/video/fbdev/sh7760fb.o:(.rodata+0x30): undefined reference to `cfb_copyarea'
sh4-linux-ld: drivers/video/fbdev/sh7760fb.o:(.rodata+0x34): undefined reference to `cfb_imageblit'
Suggested-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202309130632.LS04CPWu-lkp@intel.com/
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Acked-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20230918090400.13264-1-tzimmermann@suse.de
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 6f29e04938 ]
Improve the performance of sys_imageblit() by manually unrolling
the inner blitting loop and moving some invariants out. The compiler
failed to do this automatically. The resulting binary code was even
slower than the cfb_imageblit() helper, which uses the same algorithm,
but operates on I/O memory.
A microbenchmark measures the average number of CPU cycles
for sys_imageblit() after a stabilizing period of a few minutes
(i7-4790, FullHD, simpledrm, kernel with debugging). The value
for CFB is given as a reference.
sys_imageblit(), new: 25934 cycles
sys_imageblit(), old: 35944 cycles
cfb_imageblit(): 30566 cycles
In the optimized case, sys_imageblit() is now ~30% faster than before
and ~20% faster than cfb_imageblit().
v2:
* move switch out of inner loop (Gerd)
* remove test for alignment of dst1 (Sam)
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220223193804.18636-3-tzimmermann@suse.de
Stable-dep-of: c2d22806ae ("fbdev: fix potential OOB read in fast_imageblit()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 0872b2c0ab upstream.
in mmphw_probe(), check the return value of clk_prepare_enable()
and return the error code if clk_prepare_enable() returns an
unexpected value.
Fixes: d63028c389 ("video: mmp display controller support")
Signed-off-by: Yuanjun Gong <ruc_gongyuanjun@163.com>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 4e88761f5f ]
This func misses checking for platform_get_irq()'s call and may passes the
negative error codes to request_irq(), which takes unsigned IRQ #,
causing it to fail with -EINVAL, overriding an original error code.
Fix this by stop calling request_irq() with invalid IRQ #s.
Fixes: 1630d85a83 ("au1200fb: fix hardcoded IRQ")
Signed-off-by: Zhang Shurong <zhang_shurong@foxmail.com>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 4e47382fbc ]
Warn about invalid var->left_margin or var->right_margin. Their values
are read from the device tree.
We store var->left_margin-3 and var->right_margin-1 in register
fields. These fields should be >= 0.
Fixes: 7e8549bcee ("imxfb: Fix margin settings")
Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit c75f5a5506 upstream.
A use-after-free bug may occur if init_imstt invokes framebuffer_release
and free the info ptr. The caller, imsttfb_probe didn't notice that and
still keep the ptr as private data in pdev.
If we remove the driver which will call imsttfb_remove to make cleanup,
UAF happens.
Fix it by return error code if bad case happens in init_imstt.
Signed-off-by: Zheng Wang <zyytlz.wz@163.com>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 0bdf1ad8d1 ]
Minor fix to reset the info field to NULL in case of error.
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 44a3b36b42 ]
var->pixclock can be assigned to zero by user. Without
proper check, divide by zero would occur when invoking
macro PICOS2KHZ in au1200fb_fb_check_var.
Error out if var->pixclock is zero.
Signed-off-by: Wei Chen <harperchen1110@gmail.com>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 61ac4b86a4 ]
var->pixclock can be assigned to zero by user. Without proper
check, divide by zero would occur in lx_set_clock.
Error out if var->pixclock is zero.
Signed-off-by: Wei Chen <harperchen1110@gmail.com>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit d823685486 ]
Variable var->pixclock is controlled by user and can be assigned
to zero. Without proper check, divide by zero would occur in
intelfbhw_validate_mode and intelfbhw_mode_to_hw.
Error out if var->pixclock is zero.
Signed-off-by: Wei Chen <harperchen1110@gmail.com>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 92e2a00f29 ]
variable var->pixclock can be set by user. In case it
equals to zero, divide by zero would occur in nvidiafb_set_par.
Similar crashes have happened in other fbdev drivers. There
is no check and modification on var->pixclock along the call
chain to nvidia_check_var and nvidiafb_set_par. We believe it
could also be triggered in driver nvidia from user site.
Signed-off-by: Wei Chen <harperchen1110@gmail.com>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit f90bd245de ]
fb_set_var would by called when user invokes ioctl with cmd
FBIOPUT_VSCREENINFO. User-provided data would finally reach
tgafb_check_var. In case var->pixclock is assigned to zero,
divide by zero would occur when checking whether reciprocal
of var->pixclock is too high.
Similar crashes have happened in other fbdev drivers. There
is no check and modification on var->pixclock along the call
chain to tgafb_check_var. We believe it could also be triggered
in driver tgafb from user site.
Signed-off-by: Wei Chen <harperchen1110@gmail.com>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 203873a535 upstream.
Find a valid modeline depending on the machine graphic card
configuration and add the fb_check_var() function to validate
Xorg provided graphics settings.
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit a943710407 ]
If an error occurs after a successful uvesafb_init_mtrr() call, it must be
undone by a corresponding arch_phys_wc_del() call, as already done in the
remove function.
This has been added in the remove function in commit 63e28a7a5f
("uvesafb: Clean up MTRR code")
Fixes: 8bdb3a2d7d ("uvesafb: the driver core")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 001f2cdb95 ]
pci_get_device() will increase the reference count for the returned
pci_dev. For the error path, we need to use pci_dev_put() to decrease
the reference count.
Fixes: dbe7e429fe ("vmlfb: framebuffer driver for Intel Vermilion Range")
Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 025e3b507a ]
Only a single out of three devices need a PWM, so from driver it's
optional. Moreover it's a single driver in the entire kernel that
currently selects PWM. Unfortunately this selection is a root cause
of the circular dependencies when we want to enable optional PWM
for some other drivers that select GPIOLIB.
Fixes: a2ed00da50 ("drivers/video: add support for the Solomon SSD1307 OLED Controller")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 5610bcfe86 upstream.
A race condition may occur if the user physically removes the
USB device while calling open() for this device node.
This is a race condition between the ufx_ops_open() function and
the ufx_usb_disconnect() function, which may eventually result in UAF.
So, add a mutex to the ufx_ops_open() and ufx_usb_disconnect() functions
to avoid race contidion of krefs.
Signed-off-by: Hyunwoo Kim <imv4bel@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit aca7c13d3b upstream.
Independend of the current graphics resolution, adjust the reported
graphics card memory size to the next 4MB boundary.
This fixes the fbtest program which expects a naturally aligned size.
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit a09d2d00af ]
In pxa3xx_gcu_write, a count parameter of type size_t is passed to words of
type int. Then, copy_from_user() may cause a heap overflow because it is used
as the third argument of copy_from_user().
Signed-off-by: Hyunwoo Kim <imv4bel@gmail.com>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 19f953e743 upstream.
In `do_fb_ioctl()` of fbmem.c, if cmd is FBIOPUT_VSCREENINFO, var will be
copied from user, then go through `fb_set_var()` and
`info->fbops->fb_check_var()` which could may be `pm2fb_check_var()`.
Along the path, `var->pixclock` won't be modified. This function checks
whether reciprocal of `var->pixclock` is too high. If `var->pixclock` is
zero, there will be a divide by zero error. So, it is necessary to check
whether denominator is zero to avoid crash. As this bug is found by
Syzkaller, logs are listed below.
divide error in pm2fb_check_var
Call Trace:
<TASK>
fb_set_var+0x367/0xeb0 drivers/video/fbdev/core/fbmem.c:1015
do_fb_ioctl+0x234/0x670 drivers/video/fbdev/core/fbmem.c:1110
fb_ioctl+0xdd/0x130 drivers/video/fbdev/core/fbmem.c:1189
Reported-by: Zheyu Ma <zheyuma97@gmail.com>
Signed-off-by: Letu Ren <fantasquex@gmail.com>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 40bf722f80 ]
Since the user can control the arguments of the ioctl() from the user
space, under special arguments that may result in a divide-by-zero bug.
If the user provides an improper 'pixclock' value that makes the argumet
of i740_calc_vclk() less than 'I740_RFREQ_FIX', it will cause a
divide-by-zero bug in:
drivers/video/fbdev/i740fb.c:353 p_best = min(15, ilog2(I740_MAX_VCO_FREQ / (freq / I740_RFREQ_FIX)));
The following log can reveal it:
divide error: 0000 [#1] PREEMPT SMP KASAN PTI
RIP: 0010:i740_calc_vclk drivers/video/fbdev/i740fb.c:353 [inline]
RIP: 0010:i740fb_decode_var drivers/video/fbdev/i740fb.c:646 [inline]
RIP: 0010:i740fb_set_par+0x163f/0x3b70 drivers/video/fbdev/i740fb.c:742
Call Trace:
fb_set_var+0x604/0xeb0 drivers/video/fbdev/core/fbmem.c:1034
do_fb_ioctl+0x234/0x670 drivers/video/fbdev/core/fbmem.c:1110
fb_ioctl+0xdd/0x130 drivers/video/fbdev/core/fbmem.c:1189
Fix this by checking the argument of i740_calc_vclk() first.
Signed-off-by: Zheyu Ma <zheyuma97@gmail.com>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 6ba592fa01 ]
In the function s3fb_set_par(), the value of 'screen_size' is
calculated by the user input. If the user provides the improper value,
the value of 'screen_size' may larger than 'info->screen_size', which
may cause the following bug:
[ 54.083733] BUG: unable to handle page fault for address: ffffc90003000000
[ 54.083742] #PF: supervisor write access in kernel mode
[ 54.083744] #PF: error_code(0x0002) - not-present page
[ 54.083760] RIP: 0010:memset_orig+0x33/0xb0
[ 54.083782] Call Trace:
[ 54.083788] s3fb_set_par+0x1ec6/0x4040
[ 54.083806] fb_set_var+0x604/0xeb0
[ 54.083836] do_fb_ioctl+0x234/0x670
Fix the this by checking the value of 'screen_size' before memset_io().
Fixes: a268422de8 ("fbdev driver for S3 Trio/Virge")
Signed-off-by: Zheyu Ma <zheyuma97@gmail.com>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 96b550971c ]
In the function arkfb_set_par(), the value of 'screen_size' is
calculated by the user input. If the user provides the improper value,
the value of 'screen_size' may larger than 'info->screen_size', which
may cause the following bug:
[ 659.399066] BUG: unable to handle page fault for address: ffffc90003000000
[ 659.399077] #PF: supervisor write access in kernel mode
[ 659.399079] #PF: error_code(0x0002) - not-present page
[ 659.399094] RIP: 0010:memset_orig+0x33/0xb0
[ 659.399116] Call Trace:
[ 659.399122] arkfb_set_par+0x143f/0x24c0
[ 659.399130] fb_set_var+0x604/0xeb0
[ 659.399161] do_fb_ioctl+0x234/0x670
[ 659.399189] fb_ioctl+0xdd/0x130
Fix the this by checking the value of 'screen_size' before memset_io().
Fixes: 681e14730c ("arkfb: new framebuffer driver for ARK Logic cards")
Signed-off-by: Zheyu Ma <zheyuma97@gmail.com>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit ec0754c602 ]
In the function vt8623fb_set_par(), the value of 'screen_size' is
calculated by the user input. If the user provides the improper value,
the value of 'screen_size' may larger than 'info->screen_size', which
may cause the following bug:
[ 583.339036] BUG: unable to handle page fault for address: ffffc90005000000
[ 583.339049] #PF: supervisor write access in kernel mode
[ 583.339052] #PF: error_code(0x0002) - not-present page
[ 583.339074] RIP: 0010:memset_orig+0x33/0xb0
[ 583.339110] Call Trace:
[ 583.339118] vt8623fb_set_par+0x11cd/0x21e0
[ 583.339146] fb_set_var+0x604/0xeb0
[ 583.339181] do_fb_ioctl+0x234/0x670
[ 583.339209] fb_ioctl+0xdd/0x130
Fix the this by checking the value of 'screen_size' before memset_io().
Fixes: 558b7bd86c ("vt8623fb: new framebuffer driver for VIA VT8623")
Signed-off-by: Zheyu Ma <zheyuma97@gmail.com>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 2f1c4523f7 ]
Since the user can control the arguments of the ioctl() from the user
space, under special arguments that may result in a divide-by-zero bug
in:
drivers/video/fbdev/arkfb.c:784: ark_set_pixclock(info, (hdiv * info->var.pixclock) / hmul);
with hdiv=1, pixclock=1 and hmul=2 you end up with (1*1)/2 = (int) 0.
and then in:
drivers/video/fbdev/arkfb.c:504: rv = dac_set_freq(par->dac, 0, 1000000000 / pixclock);
we'll get a division-by-zero.
The following log can reveal it:
divide error: 0000 [#1] PREEMPT SMP KASAN PTI
RIP: 0010:ark_set_pixclock drivers/video/fbdev/arkfb.c:504 [inline]
RIP: 0010:arkfb_set_par+0x10fc/0x24c0 drivers/video/fbdev/arkfb.c:784
Call Trace:
fb_set_var+0x604/0xeb0 drivers/video/fbdev/core/fbmem.c:1034
do_fb_ioctl+0x234/0x670 drivers/video/fbdev/core/fbmem.c:1110
fb_ioctl+0xdd/0x130 drivers/video/fbdev/core/fbmem.c:1189
Fix this by checking the argument of ark_set_pixclock() first.
Fixes: 681e14730c ("arkfb: new framebuffer driver for ARK Logic cards")
Signed-off-by: Zheyu Ma <zheyuma97@gmail.com>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Roman Smirnov