On Thu, Dec 13, 2018 at 01:31:39PM +0100, Petr Mladek wrote: > On Thu 2018-12-13 12:09:49, Nicholas Mc Guire wrote: > > kzalloc() return should always be checked - notably in example code > > where this may be seen as reference. On failure of allocation > > livepatch_fix1_dummy_alloc() should return NULL. > > > > Signed-off-by: Nicholas Mc Guire <[email protected]> > > --- > > > > Problem was located with an experimental coccinelle script > > > > Patch was compile tested with: x86_64_defconfig + FTRACE=y > > FUNCTION_TRACER=y, EXPERT=y, LATENCYTOP=y, SAMPLES=y, SAMPLE_LIVEPATCH=y > > (with some unrelated sparse warnings on symbols not being static) > > > > Patch is against 4.20-rc6 (localversion-next is next-20181213) > > > > samples/livepatch/livepatch-shadow-fix1.c | 3 +++ > > 1 file changed, 3 insertions(+) > > > > diff --git a/samples/livepatch/livepatch-shadow-fix1.c > > b/samples/livepatch/livepatch-shadow-fix1.c > > index 49b1355..a0e8f04 100644 > > --- a/samples/livepatch/livepatch-shadow-fix1.c > > +++ b/samples/livepatch/livepatch-shadow-fix1.c > > @@ -89,6 +89,9 @@ struct dummy *livepatch_fix1_dummy_alloc(void) > > * pointer to handle resource release. > > */ > > leak = kzalloc(sizeof(int), GFP_KERNEL); > > + if (!leak) > > + return NULL; > > It should be: > > if (!leak) { > kfree(d); > return NULL; > } > > Note that The check is not strictly needed in this artificial > example because we never read/write any data there. But I agree > that we should add the check to promote the the right programming > patterns. > thanks for catching this ! will send a V2.
thx! hofrat
