[PATCH 2/2] livepatch: handle kzalloc failure

From: Nicholas Mc Guire
Date: Thu Dec 13 2018 - 06:14:06 EST


kzalloc() return should be checked. On dummy_alloc() failing
in kzalloc() NULL should be returned.

Signed-off-by: Nicholas Mc Guire <hofrat@xxxxxxxxx>
---

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 a number of unrelated sparse warnings on symbols not being static)

Patch is against 4.20-rc6 (localversion-next is next-20181213)

samples/livepatch/livepatch-shadow-mod.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/samples/livepatch/livepatch-shadow-mod.c b/samples/livepatch/livepatch-shadow-mod.c
index 4c54b25..57d5cde 100644
--- a/samples/livepatch/livepatch-shadow-mod.c
+++ b/samples/livepatch/livepatch-shadow-mod.c
@@ -118,6 +118,8 @@ noinline struct dummy *dummy_alloc(void)

/* Oops, forgot to save leak! */
leak = kzalloc(sizeof(int), GFP_KERNEL);
+ if (!leak)
+ return NULL;

pr_info("%s: dummy @ %p, expires @ %lx\n",
__func__, d, d->jiffies_expire);
--
2.1.4