From: Yong Wu Date: Wed, 24 Nov 2021 08:50:42 +0000 (+0100) Subject: memory: mtk-smi: Fix a null dereference for the ostd X-Git-Tag: v6.6.17~8744^2 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=383a44aec91c327ef4a9d03cfa65d1eaf3746c06;p=platform%2Fkernel%2Flinux-rpi.git memory: mtk-smi: Fix a null dereference for the ostd We add the ostd setting for mt8195. It introduces a KE for the previous SoC which doesn't have ostd setting. This is the log: Unable to handle kernel NULL pointer dereference at virtual address 0000000000000080 ... pc : mtk_smi_larb_config_port_gen2_general+0x64/0x130 lr : mtk_smi_larb_resume+0x54/0x98 ... Call trace: mtk_smi_larb_config_port_gen2_general+0x64/0x130 pm_generic_runtime_resume+0x2c/0x48 __genpd_runtime_resume+0x30/0xa8 genpd_runtime_resume+0x94/0x2c8 __rpm_callback+0x44/0x150 rpm_callback+0x6c/0x78 rpm_resume+0x310/0x558 __pm_runtime_resume+0x3c/0x88 In the code: larbostd = larb->larb_gen->ostd[larb->larbid], if "larb->larb_gen->ostd" is null, the "larbostd" is the offset(e.g. 0x80 above), it's also a valid value, then accessing "larbostd[i]" in the "for" loop will cause the KE above. To avoid this issue, initialize "larbostd" to NULL when the SoC doesn't have ostd setting. Fixes: fe6dd2a4017d ("memory: mtk-smi: mt8195: Add initial setting for smi-larb") Signed-off-by: Yong Wu Signed-off-by: Krzysztof Kozlowski Link: https://lore.kernel.org/r/20211108082429.15080-1-yong.wu@mediatek.com Link: https://lore.kernel.org/r/20211124085042.9649-3-krzysztof.kozlowski@canonical.com' Signed-off-by: Arnd Bergmann --- diff --git a/drivers/memory/mtk-smi.c b/drivers/memory/mtk-smi.c index b883dcc..e201e59 100644 --- a/drivers/memory/mtk-smi.c +++ b/drivers/memory/mtk-smi.c @@ -241,7 +241,7 @@ static void mtk_smi_larb_config_port_gen2_general(struct device *dev) { struct mtk_smi_larb *larb = dev_get_drvdata(dev); u32 reg, flags_general = larb->larb_gen->flags_general; - const u8 *larbostd = larb->larb_gen->ostd[larb->larbid]; + const u8 *larbostd = larb->larb_gen->ostd ? larb->larb_gen->ostd[larb->larbid] : NULL; int i; if (BIT(larb->larbid) & larb->larb_gen->larb_direct_to_common_mask)