linux/drivers/tty/vt
Tetsuo Handa af77c56aa3 tty: vt: initialize unicode screen buffer
syzbot reports kernel infoleak at vcs_read() [1], for buffer can be read
immediately after resize operation. Initialize buffer using kzalloc().

  ----------
  #include <fcntl.h>
  #include <unistd.h>
  #include <sys/ioctl.h>
  #include <linux/fb.h>

  int main(int argc, char *argv[])
  {
    struct fb_var_screeninfo var = { };
    const int fb_fd = open("/dev/fb0", 3);
    ioctl(fb_fd, FBIOGET_VSCREENINFO, &var);
    var.yres = 0x21;
    ioctl(fb_fd, FBIOPUT_VSCREENINFO, &var);
    return read(open("/dev/vcsu", O_RDONLY), &var, sizeof(var)) == -1;
  }
  ----------

Link: https://syzkaller.appspot.com/bug?extid=31a641689d43387f05d3 [1]
Cc: stable <stable@vger.kernel.org>
Reported-by: syzbot <syzbot+31a641689d43387f05d3@syzkaller.appspotmail.com>
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Link: https://lore.kernel.org/r/4ef053cf-e796-fb5e-58b7-3ae58242a4ad@I-love.SAKURA.ne.jp
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-07-19 14:18:27 +02:00
..
.gitignore .gitignore: prefix local generated files with a slash 2021-05-02 00:43:35 +09:00
conmakehash.c tty: vt: move conmakehash to drivers/tty/vt/ from scripts/ 2019-12-17 14:42:46 +01:00
consolemap.c tty/vt: consolemap: use E_TABSZ for the translations size 2022-06-27 14:17:12 +02:00
cp437.uni tty: fix up a few remaining files without SPDX identifiers 2019-04-04 18:48:43 +02:00
defkeymap.c_shipped tty/vt: defkeymap.c_shipped, little unification with loadkeys 2022-06-10 13:34:17 +02:00
defkeymap.map tty: fix up a few remaining files without SPDX identifiers 2019-04-04 18:48:43 +02:00
keyboard.c tty: Fix the keyboard led light display problem 2021-12-21 09:19:14 +01:00
Makefile tty/vt: Makefile, add --unicode for loadkeys invocation 2022-06-10 13:34:18 +02:00
selection.c tty/vt: consolemap: make parameters of inverse_translate() saner 2022-06-10 13:37:01 +02:00
vc_screen.c Revert "vc_screen: extract vcs_read_buf_header" 2020-08-24 19:51:56 +02:00
vt_ioctl.c vt_ioctl: fix potential spectre v1 in VT_DISALLOCATE 2022-03-18 14:35:01 +01:00
vt.c tty: vt: initialize unicode screen buffer 2022-07-19 14:18:27 +02:00