From bce7698e2e6565bb765bd0522337f29f5f312624 Mon Sep 17 00:00:00 2001 From: Haojie Li Date: Tue, 25 Aug 2026 18:08:45 +0800 Subject: drm/mediatek: Add missing IS_ERR check for ovl_adaptor platform device platform_device_register_data() can fail and return an ERR_PTR, but the return value is used without checking, leading to an invalid pointer being stored in ddp_comp[].dev and passed to component_match_add() and mtk_ddp_comp_init(), which could result in a kernel crash. Add an IS_ERR() check to jump to the error handling path on failure. Fixes: 0d9eee9118b7 ("drm/mediatek: Add drm ovl_adaptor sub driver for MT8195") Cc: stable@vger.kernel.org Signed-off-by: Haojie Li Reviewed-by: CK Hu Link: https://patchwork.kernel.org/project/linux-mediatek/patch/20260825100845.438893-1-lihaojie@kylinos.cn/ Signed-off-by: Chun-Kuang Hu --- lib/check_signature.c | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) create mode 100644 lib/check_signature.c (limited to 'lib/check_signature.c') diff --git a/lib/check_signature.c b/lib/check_signature.c new file mode 100644 index 000000000..43a7301da --- /dev/null +++ b/lib/check_signature.c @@ -0,0 +1,27 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include + +/** + * check_signature - find BIOS signatures + * @io_addr: mmio address to check + * @signature: signature block + * @length: length of signature + * + * Perform a signature comparison with the mmio address io_addr. This + * address should have been obtained by ioremap. + * Returns 1 on a match. + */ + +int check_signature(const volatile void __iomem *io_addr, + const unsigned char *signature, int length) +{ + while (length--) { + if (readb(io_addr) != *signature) + return 0; + io_addr++; + signature++; + } + return 1; +} +EXPORT_SYMBOL(check_signature); -- cgit v1.3.1