Messages in this thread Patch in this message | | | From | Yong Wu <> | Subject | [PATCH v2] memory: mtk-smi: Fix a null dereference for the ostd | Date | Mon, 8 Nov 2021 16:24:29 +0800 |
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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.
Signed-off-by: Yong Wu <yong.wu@mediatek.com> --- change note: Reword the commit message to show why it KE. and update the solution via initializing "larbostd" is NULL explicitly in the non-ostd case. --- drivers/memory/mtk-smi.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/memory/mtk-smi.c b/drivers/memory/mtk-smi.c index b883dcc0bbfa..e201e5976f34 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) -- 2.18.0
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