From: Zheyu Ma <zheyuma97@gmail.com> To: dri-devel@lists.freedesktop.org Cc: linux-fbdev@vger.kernel.org, linux-kernel@vger.kernel.org, sam@ravnborg.org, Zheyu Ma <zheyuma97@gmail.com> Subject: [PATCH v2] video: fbdev: kyro: fix a DoS bug by restricting user input Date: Wed, 14 Jul 2021 04:09:22 +0000 [thread overview] Message-ID: <1626235762-2590-1-git-send-email-zheyuma97@gmail.com> (raw) The user can pass in any value to the driver through the 'ioctl' interface. The driver dost not check, which may cause DoS bugs. The following log reveals it: divide error: 0000 [#1] PREEMPT SMP KASAN PTI RIP: 0010:SetOverlayViewPort+0x133/0x5f0 drivers/video/fbdev/kyro/STG4000OverlayDevice.c:476 Call Trace: kyro_dev_overlay_viewport_set drivers/video/fbdev/kyro/fbdev.c:378 [inline] kyrofb_ioctl+0x2eb/0x330 drivers/video/fbdev/kyro/fbdev.c:603 do_fb_ioctl+0x1f3/0x700 drivers/video/fbdev/core/fbmem.c:1171 fb_ioctl+0xeb/0x130 drivers/video/fbdev/core/fbmem.c:1185 vfs_ioctl fs/ioctl.c:48 [inline] __do_sys_ioctl fs/ioctl.c:753 [inline] __se_sys_ioctl fs/ioctl.c:739 [inline] __x64_sys_ioctl+0x19b/0x220 fs/ioctl.c:739 do_syscall_64+0x32/0x80 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xae Signed-off-by: Zheyu Ma <zheyuma97@gmail.com> --- Changes in v2: - Validate the inputs on a higher level --- drivers/video/fbdev/kyro/fbdev.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/video/fbdev/kyro/fbdev.c b/drivers/video/fbdev/kyro/fbdev.c index 8fbde92ae8b9..eb0cbd1d12d5 100644 --- a/drivers/video/fbdev/kyro/fbdev.c +++ b/drivers/video/fbdev/kyro/fbdev.c @@ -372,6 +372,11 @@ static int kyro_dev_overlay_viewport_set(u32 x, u32 y, u32 ulWidth, u32 ulHeight /* probably haven't called CreateOverlay yet */ return -EINVAL; + if (ulWidth == 0 || ulWidth == 0xffffffff || + ulHeight == 0 || ulHeight == 0xffffffff || + (x < 2 && ulWidth + 2 == 0)) + return -EINVAL; + /* Stop Ramdac Output */ DisableRamdacOutput(deviceInfo.pSTGReg); -- 2.17.6
WARNING: multiple messages have this Message-ID (diff)
From: Zheyu Ma <zheyuma97@gmail.com> To: dri-devel@lists.freedesktop.org Cc: linux-fbdev@vger.kernel.org, Zheyu Ma <zheyuma97@gmail.com>, sam@ravnborg.org, linux-kernel@vger.kernel.org Subject: [PATCH v2] video: fbdev: kyro: fix a DoS bug by restricting user input Date: Wed, 14 Jul 2021 04:09:22 +0000 [thread overview] Message-ID: <1626235762-2590-1-git-send-email-zheyuma97@gmail.com> (raw) The user can pass in any value to the driver through the 'ioctl' interface. The driver dost not check, which may cause DoS bugs. The following log reveals it: divide error: 0000 [#1] PREEMPT SMP KASAN PTI RIP: 0010:SetOverlayViewPort+0x133/0x5f0 drivers/video/fbdev/kyro/STG4000OverlayDevice.c:476 Call Trace: kyro_dev_overlay_viewport_set drivers/video/fbdev/kyro/fbdev.c:378 [inline] kyrofb_ioctl+0x2eb/0x330 drivers/video/fbdev/kyro/fbdev.c:603 do_fb_ioctl+0x1f3/0x700 drivers/video/fbdev/core/fbmem.c:1171 fb_ioctl+0xeb/0x130 drivers/video/fbdev/core/fbmem.c:1185 vfs_ioctl fs/ioctl.c:48 [inline] __do_sys_ioctl fs/ioctl.c:753 [inline] __se_sys_ioctl fs/ioctl.c:739 [inline] __x64_sys_ioctl+0x19b/0x220 fs/ioctl.c:739 do_syscall_64+0x32/0x80 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xae Signed-off-by: Zheyu Ma <zheyuma97@gmail.com> --- Changes in v2: - Validate the inputs on a higher level --- drivers/video/fbdev/kyro/fbdev.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/video/fbdev/kyro/fbdev.c b/drivers/video/fbdev/kyro/fbdev.c index 8fbde92ae8b9..eb0cbd1d12d5 100644 --- a/drivers/video/fbdev/kyro/fbdev.c +++ b/drivers/video/fbdev/kyro/fbdev.c @@ -372,6 +372,11 @@ static int kyro_dev_overlay_viewport_set(u32 x, u32 y, u32 ulWidth, u32 ulHeight /* probably haven't called CreateOverlay yet */ return -EINVAL; + if (ulWidth == 0 || ulWidth == 0xffffffff || + ulHeight == 0 || ulHeight == 0xffffffff || + (x < 2 && ulWidth + 2 == 0)) + return -EINVAL; + /* Stop Ramdac Output */ DisableRamdacOutput(deviceInfo.pSTGReg); -- 2.17.6
next reply other threads:[~2021-07-14 4:09 UTC|newest] Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-07-14 4:09 Zheyu Ma [this message] 2021-07-14 4:09 ` [PATCH v2] video: fbdev: kyro: fix a DoS bug by restricting user input Zheyu Ma 2021-07-19 18:50 ` Sam Ravnborg 2021-07-20 6:45 ` Zheyu Ma 2021-07-20 6:45 ` Zheyu Ma
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