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3b0c406124
This issue happens when a userspace program does an ioctl FBIOPUT_VSCREENINFO passing the fb_var_screeninfo struct containing only the fields xres, yres, and bits_per_pixel with values. If this struct is the same as the previous ioctl, the vc_resize() detects it and doesn't call the resize_screen(), leaving the fb_var_screeninfo incomplete. And this leads to the updatescrollmode() calculates a wrong value to fbcon_display->vrows, which makes the real_y() return a wrong value of y, and that value, eventually, causes the imageblit to access an out-of-bound address value. To solve this issue I made the resize_screen() be called even if the screen does not need any resizing, so it will "fix and fill" the fb_var_screeninfo independently. Cc: stable <stable@vger.kernel.org> # after 5.15-rc2 is out, give it time to bake Reported-and-tested-by: syzbot+858dc7a2f7ef07c2c219@syzkaller.appspotmail.com Signed-off-by: Igor Matheus Andrade Torrente <igormtorrente@gmail.com> Link: https://lore.kernel.org/r/20210628134509.15895-1-igormtorrente@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
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| .gitignore | ||
| conmakehash.c | ||
| consolemap.c | ||
| cp437.uni | ||
| defkeymap.c_shipped | ||
| defkeymap.map | ||
| keyboard.c | ||
| Makefile | ||
| selection.c | ||
| vc_screen.c | ||
| vt.c | ||
| vt_ioctl.c | ||