[PATCH] fbcon: Fix a NULL pointer dereference issue in fbcon_putcs
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STALE746d
From: Qianqiang Liu <hidden>
Date: 2024-09-16 01:11:08
Also in:
dri-devel, lkml, stable
Subsystem:
framebuffer console, framebuffer core, framebuffer layer, the rest · Maintainers:
Helge Deller, Thomas Zimmermann, Simona Vetter, Linus Torvalds
syzbot has found a NULL pointer dereference bug in fbcon [1]. This issue is caused by ops->putcs being a NULL pointer. We need to check the pointer before using it. [1] https://syzkaller.appspot.com/bug?extid=3d613ae53c031502687a Cc: stable@vger.kernel.org Reported-and-tested-by: syzbot+3d613ae53c031502687a@syzkaller.appspotmail.com Signed-off-by: Qianqiang Liu <redacted> --- drivers/video/fbdev/core/fbcon.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/video/fbdev/core/fbcon.c b/drivers/video/fbdev/core/fbcon.c
index 3f7333dca508..96c1262cc981 100644
--- a/drivers/video/fbdev/core/fbcon.c
+++ b/drivers/video/fbdev/core/fbcon.c@@ -1284,7 +1284,7 @@ static void fbcon_putcs(struct vc_data *vc, const u16 *s, unsigned int count, struct fbcon_display *p = &fb_display[vc->vc_num]; struct fbcon_ops *ops = info->fbcon_par; - if (!fbcon_is_inactive(vc, info)) + if (!fbcon_is_inactive(vc, info) && ops->putcs) ops->putcs(vc, info, s, count, real_y(p, ypos), xpos, get_color(vc, info, scr_readw(s), 1), get_color(vc, info, scr_readw(s), 0));
--
2.39.2