Messages in this thread Patch in this message | | | From | Zhou Qingyang <> | Subject | [PATCH] clk: mediatek: mt2701: Fix a NULL pointer dereference in mtk_infrasys_init_early() | Date | Tue, 30 Nov 2021 16:54:54 +0800 |
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In mtk_infrasys_init_early(), the return value of mtk_alloc_clk_data() is assigned to infra_clk_data and there is a dereference of it in mtk_infrasys_init_early(), which could lead to a NULL pointer dereference on failure of mtk_alloc_clk_data().
Fix this bug by adding a check of infra_clk_data.
This bug was found by a static analyzer. The analysis employs differential checking to identify inconsistent security operations (e.g., checks or kfrees) between two code paths and confirms that the inconsistent operations are not recovered in the current function or the callers, so they constitute bugs.
Note that, as a bug found by static analysis, it can be a false positive or hard to trigger. Multiple researchers have cross-reviewed the bug.
Builds with CONFIG_COMMON_CLK_MT2701=y show no new warnings, and our static analyzer no longer warns about this code.
Fixes: e9862118272a ("clk: mediatek: Add MT2701 clock support") Signed-off-by: Zhou Qingyang <zhou1615@umn.edu> --- drivers/clk/mediatek/clk-mt2701.c | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/drivers/clk/mediatek/clk-mt2701.c b/drivers/clk/mediatek/clk-mt2701.c index 695be0f77427..9ba30089cb9a 100644 --- a/drivers/clk/mediatek/clk-mt2701.c +++ b/drivers/clk/mediatek/clk-mt2701.c @@ -742,6 +742,11 @@ static void __init mtk_infrasys_init_early(struct device_node *node) if (!infra_clk_data) { infra_clk_data = mtk_alloc_clk_data(CLK_INFRA_NR); + if (!infra_clk_data) { + pr_err("%s(): could not register clock provider: %d\n", + __func__, -ENOMEM); + return; + } for (i = 0; i < CLK_INFRA_NR; i++) infra_clk_data->clks[i] = ERR_PTR(-EPROBE_DEFER); -- 2.25.1
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