Messages in this thread | ![/](/images/icornerl.gif) | | Date | Thu, 29 Feb 2024 13:45:54 +0100 | Subject | Re: [PATCH v2] clk: zynq: Prevent null pointer dereference caused by kmalloc failure | From | Michal Simek <> |
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On 2/29/24 13:22, Duoming Zhou wrote: > The kmalloc() in zynq_clk_setup() will return null if the > physical memory has run out. As a result, if we use snprintf > to write data to the null address, the null pointer dereference > bug will happen. > > This patch adds a stack variable to replace the kmalloc(). > > Fixes: 0ee52b157b8e ("clk: zynq: Add clock controller driver") > Signed-off-by: Duoming Zhou <duoming@zju.edu.cn> > --- > Changes in v2: > - Use stack variable to replace kmalloc(). > > drivers/clk/zynq/clkc.c | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-) > > diff --git a/drivers/clk/zynq/clkc.c b/drivers/clk/zynq/clkc.c > index 7bdeaff2bfd..e4c4c9adf79 100644 > --- a/drivers/clk/zynq/clkc.c > +++ b/drivers/clk/zynq/clkc.c > @@ -427,7 +427,7 @@ static void __init zynq_clk_setup(struct device_node *np) > SLCR_GEM1_CLK_CTRL, 0, 0, &gem1clk_lock); > > tmp = strlen("mio_clk_00x"); > - clk_name = kmalloc(tmp, GFP_KERNEL); > + char clk_name[tmp];
I know that Stephen asked for it but variable with variable length in the middle of code doesn't look good or useful. I would allocate rather bigger array on stack with size bigger than max length which will use it.
Thanks, Michal
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