Messages in this thread | | | Date | Thu, 20 Jan 2022 07:31:09 +0100 | From | Greg KH <> | Subject | Re: [PATCH v3] lkdtm/bugs: Check for the NULL pointer after calling kmalloc |
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On Thu, Jan 20, 2022 at 09:25:51AM +0800, Jiasheng Jiang wrote: > As the possible failure of the kmalloc(), the not_checked and checked > could be NULL pointer. > Therefore, it should be better to check it in order to avoid the > dereference of the NULL pointer. > Also, we need to explicitly yell about the memory failure and then > kfree the 'not_checked' and 'checked' to avoid the memory leak if fails. > And since it is just a test, it may directly return without error > number. > > Fixes: ae2e1aad3e48 ("drivers/misc/lkdtm/bugs.c: add arithmetic overflow and array bounds checks") > Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn> > --- > Changelog > > v1 -> v2 > > * Change 1. Add the kfree if fails. > > v2 -> v3 > > * Change 1. Add pr_err if fails. > --- > drivers/misc/lkdtm/bugs.c | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/drivers/misc/lkdtm/bugs.c b/drivers/misc/lkdtm/bugs.c > index f4cb94a9aa9c..c64ab6f387eb 100644 > --- a/drivers/misc/lkdtm/bugs.c > +++ b/drivers/misc/lkdtm/bugs.c > @@ -325,6 +325,12 @@ void lkdtm_ARRAY_BOUNDS(void) > > not_checked = kmalloc(sizeof(*not_checked) * 2, GFP_KERNEL); > checked = kmalloc(sizeof(*checked) * 2, GFP_KERNEL); > + if (!not_checked || !checked) { > + pr_err("FAIL: could not allocate required buffers!\n");
As was pointed out, this is now a checkpatch failure :(
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