drm/sysfb: ofdrm: Fix integer overflow in fb_size calculation

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The framebuffer size calculation `fb_size = linebytes * height` can
overflow when both values are large (e.g., 46341 * 46341 > INT_MAX).
Since linebytes and height are both int types, the multiplication is
performed as int * int, which results in undefined behavior on overflow.

Use check_mul_overflow() to detect and prevent this overflow, consistent
with the approach used in simpledrm.c and corebootdrm.c.

Signed-off-by: Shixiong Ou <oushixiong@kylinos.cn>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Fixes: c8a17756c4 ("drm/ofdrm: Add ofdrm for Open Firmware framebuffers")
Cc: <stable@vger.kernel.org> # v6.2+
Link: https://patch.msgid.link/20260825104134.669676-1-oushixiong1025@163.com

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Shixiong Ou 2026-08-25 18:41:34 +08:00 • committed by Thomas Zimmermann

parent 5bb489b333

commit c6f48e59ec

1 changed files with 5 additions and 1 deletions

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drivers/gpu/drm/sysfb/ofdrm.c

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