Messages in this thread | | | From | Adam Ford <> | Date | Fri, 28 Jan 2022 07:47:06 -0600 | Subject | Re: [PATCH] clk: imx: Fix a NULL pointer dereference in imx_register_uart_clocks() |
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On Fri, Jan 28, 2022 at 4:16 AM Greg KH <gregkh@linuxfoundation.org> wrote: > > On Tue, Jan 25, 2022 at 12:52:06AM +0800, Zhou Qingyang wrote: > > In imx_register_uart_clocks(), the global variable imx_uart_clocks is > > assigned by kcalloc() and there is a dereference of in the next for loop, > > which could introduce a NULL pointer dereference on failure of kcalloc(). > > > > Fix this by adding a NULL check of imx_uart_clocks. > > > > This bug was found by a static analyzer. > > > > Builds with 'make allyesconfig' show no new warnings, > > and our static analyzer no longer warns about this code. > > > > Fixes: 379c9a24cc23 ("clk: imx: Fix reparenting of UARTs not associated with stdout") > > Signed-off-by: Zhou Qingyang <zhou1615@umn.edu> > > --- > > 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. > > > > drivers/clk/imx/clk.c | 2 ++ > > 1 file changed, 2 insertions(+) > > > > diff --git a/drivers/clk/imx/clk.c b/drivers/clk/imx/clk.c > > index 7cc669934253..99249ab361d2 100644 > > --- a/drivers/clk/imx/clk.c > > +++ b/drivers/clk/imx/clk.c > > @@ -173,6 +173,8 @@ void imx_register_uart_clocks(unsigned int clk_count) > > int i; > > > > imx_uart_clocks = kcalloc(clk_count, sizeof(struct clk *), GFP_KERNEL); > > + if (!imx_uart_clocks) > > + return; > > > > if (!of_stdout) > > return; > > -- > > 2.25.1 > > > > As stated before, umn.edu is still not allowed to contribute to the > Linux kernel. Please work with your administration to resolve this > issue.
Greg,
In the interest of safety, I believe this patch is reasonable. I wrote the original patch that is being fixed by this. Would it be acceptable if I submitted the same patch with "suggested-by" associated with Zhou @ umn.edu? I want to give credit where credit is due while still maintaining the rule that patches are not actually being accepted by umn.edu.
adam
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