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| author | Jocelyn Falempe <jfalempe@redhat.com> | 2025-10-09 14:24:50 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-10-29 14:10:28 +0100 |
| commit | 53e5c5ef2f0c04b237f011b18841dc0249fadcac (patch) | |
| tree | 120f34aca39d693273a0455b7d27a4458db3f26b | |
| parent | 9a0daa17381993de3158a593edea0d6ad54f47c8 (diff) | |
| download | linux-53e5c5ef2f0c04b237f011b18841dc0249fadcac.tar.gz linux-53e5c5ef2f0c04b237f011b18841dc0249fadcac.tar.bz2 linux-53e5c5ef2f0c04b237f011b18841dc0249fadcac.zip | |
drm/panic: Fix qr_code, ensure vmargin is positive
[ Upstream commit 4fcffb5e5c8c0c8e2ad9c99a22305a0afbecc294 ]
Depending on qr_code size and screen size, the vertical margin can
be negative, that means there is not enough room to draw the qr_code.
So abort early, to avoid a segfault by trying to draw at negative
coordinates.
Fixes: cb5164ac43d0f ("drm/panic: Add a QR code panic screen")
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://lore.kernel.org/r/20251009122955.562888-4-jfalempe@redhat.com
Signed-off-by: Jocelyn Falempe <jfalempe@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | drivers/gpu/drm/drm_panic.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/drivers/gpu/drm/drm_panic.c b/drivers/gpu/drm/drm_panic.c index 23ba791c6131..1bc15c44207b 100644 --- a/drivers/gpu/drm/drm_panic.c +++ b/drivers/gpu/drm/drm_panic.c @@ -736,7 +736,10 @@ static int _draw_panic_static_qr_code(struct drm_scanout_buffer *sb) pr_debug("QR width %d and scale %d\n", qr_width, scale); r_qr_canvas = DRM_RECT_INIT(0, 0, qr_canvas_width * scale, qr_canvas_width * scale); - v_margin = (sb->height - drm_rect_height(&r_qr_canvas) - drm_rect_height(&r_msg)) / 5; + v_margin = sb->height - drm_rect_height(&r_qr_canvas) - drm_rect_height(&r_msg); + if (v_margin < 0) + return -ENOSPC; + v_margin /= 5; drm_rect_translate(&r_qr_canvas, (sb->width - r_qr_canvas.x2) / 2, 2 * v_margin); r_qr = DRM_RECT_INIT(r_qr_canvas.x1 + QR_MARGIN * scale, r_qr_canvas.y1 + QR_MARGIN * scale, |