linux/drivers/video/fbdev/riva
Zheyu Ma f92763cb0f video: fbdev: riva: Error out if 'pixclock' equals zero
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 error.

Fix this by checking whether 'pixclock' is zero first.

The following log reveals it:

[   33.396850] divide error: 0000 [#1] PREEMPT SMP KASAN PTI
[   33.396864] CPU: 5 PID: 11754 Comm: i740 Not tainted 5.14.0-rc2-00513-gac532c9bbcfb-dirty #222
[   33.396883] RIP: 0010:riva_load_video_mode+0x417/0xf70
[   33.396969] Call Trace:
[   33.396973]  ? debug_smp_processor_id+0x1c/0x20
[   33.396984]  ? tick_nohz_tick_stopped+0x1a/0x90
[   33.396996]  ? rivafb_copyarea+0x3c0/0x3c0
[   33.397003]  ? wake_up_klogd.part.0+0x99/0xd0
[   33.397014]  ? vprintk_emit+0x110/0x4b0
[   33.397024]  ? vprintk_default+0x26/0x30
[   33.397033]  ? vprintk+0x9c/0x1f0
[   33.397041]  ? printk+0xba/0xed
[   33.397054]  ? record_print_text.cold+0x16/0x16
[   33.397063]  ? __kasan_check_read+0x11/0x20
[   33.397074]  ? profile_tick+0xc0/0x100
[   33.397084]  ? __sanitizer_cov_trace_const_cmp4+0x24/0x80
[   33.397094]  ? riva_set_rop_solid+0x2a0/0x2a0
[   33.397102]  rivafb_set_par+0xbe/0x610
[   33.397111]  ? riva_set_rop_solid+0x2a0/0x2a0
[   33.397119]  fb_set_var+0x5bf/0xeb0
[   33.397127]  ? fb_blank+0x1a0/0x1a0
[   33.397134]  ? lock_acquire+0x1ef/0x530
[   33.397143]  ? lock_release+0x810/0x810
[   33.397151]  ? lock_is_held_type+0x100/0x140
[   33.397159]  ? ___might_sleep+0x1ee/0x2d0
[   33.397170]  ? __mutex_lock+0x620/0x1190
[   33.397180]  ? trace_hardirqs_on+0x6a/0x1c0
[   33.397190]  do_fb_ioctl+0x31e/0x700

Signed-off-by: Zheyu Ma <zheyuma97@gmail.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/1627293835-17441-4-git-send-email-zheyuma97@gmail.com
2021-07-26 20:06:03 +02:00
..
fbdev.c video: fbdev: riva: Error out if 'pixclock' equals zero 2021-07-26 20:06:03 +02:00
Makefile License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
nv_driver.c video: fbdev: riva: deprecate pci_get_bus_and_slot() 2018-01-17 08:16:46 -06:00
nv_type.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
nvreg.h
riva_hw.c video: fbdev: riva: Fix kernel-doc and set but not used warnings 2020-11-30 20:04:36 +01:00
riva_hw.h video: fbdev: riva: deprecate pci_get_bus_and_slot() 2018-01-17 08:16:46 -06:00
riva_tbl.h
rivafb-i2c.c
rivafb.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00