[PATCH] fix NULL pointer deference crash

Hassan Shahbazi
2021-03-31T16:44:10Z

The patch has fixed a NULL pointer deference crash in hiding the cursor. It
is verified by syzbot patch tester.

Reported by: syzbot
https://syzkaller.appspot.com/bug?id=defb47bf56e1c14d5687280c7bb91ce7b608b94b

Signed-off-by: Hassan Shahbazi <h.shahbazi.git@gmail.com>
---
drivers/video/fbdev/core/fbcon.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/video/fbdev/core/fbcon.c b/drivers/video/fbdev/core/fbcon.c
index 44a5cd2f54cc..ee252d1c43c6 100644
--- a/drivers/video/fbdev/core/fbcon.c
+++ b/drivers/video/fbdev/core/fbcon.c
@@ -1333,8 +1333,9 @@ static void fbcon_cursor(struct vc_data *vc, int mode)

ops->cursor_flash = (mode == CM_ERASE) ? 0 : 1;

- ops->cursor(vc, info, mode, get_color(vc, info, c, 1),
- get_color(vc, info, c, 0));
+ if (ops && ops->cursor)
+ ops->cursor(vc, info, mode, get_color(vc, info, c, 1),
+ get_color(vc, info, c, 0));
}

static int scrollback_phys_max = 0;
--
2.26.3