4.20-stable review patch. If anyone has any objections, please let me know.
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[ Upstream commit 5f30b2e823484ce6a79f2b59901b6351c15effa6 ]
kzalloc() return should always be checked - notably in example code where this may be seen as reference. On failure of allocation in livepatch_fix1_dummy_alloc() respectively dummy_alloc() previous allocation is freed (thanks to Petr Mladek pmladek@suse.com for catching this) and NULL returned.
Signed-off-by: Nicholas Mc Guire hofrat@osadl.org Fixes: 439e7271dc2b ("livepatch: introduce shadow variable API") Acked-by: Joe Lawrence joe.lawrence@redhat.com Reviewed-by: Petr Mladek pmladek@suse.com Acked-by: Miroslav Benes mbenes@suse.cz Signed-off-by: Jiri Kosina jkosina@suse.cz Signed-off-by: Sasha Levin sashal@kernel.org --- samples/livepatch/livepatch-shadow-fix1.c | 5 +++++ samples/livepatch/livepatch-shadow-mod.c | 4 ++++ 2 files changed, 9 insertions(+)
diff --git a/samples/livepatch/livepatch-shadow-fix1.c b/samples/livepatch/livepatch-shadow-fix1.c index 49b13553eaae..e8f1bd6b29b1 100644 --- a/samples/livepatch/livepatch-shadow-fix1.c +++ b/samples/livepatch/livepatch-shadow-fix1.c @@ -89,6 +89,11 @@ struct dummy *livepatch_fix1_dummy_alloc(void) * pointer to handle resource release. */ leak = kzalloc(sizeof(int), GFP_KERNEL); + if (!leak) { + kfree(d); + return NULL; + } + klp_shadow_alloc(d, SV_LEAK, sizeof(leak), GFP_KERNEL, shadow_leak_ctor, leak);
diff --git a/samples/livepatch/livepatch-shadow-mod.c b/samples/livepatch/livepatch-shadow-mod.c index 4c54b250332d..4aa8a88d3cd6 100644 --- a/samples/livepatch/livepatch-shadow-mod.c +++ b/samples/livepatch/livepatch-shadow-mod.c @@ -118,6 +118,10 @@ noinline struct dummy *dummy_alloc(void)
/* Oops, forgot to save leak! */ leak = kzalloc(sizeof(int), GFP_KERNEL); + if (!leak) { + kfree(d); + return NULL; + }
pr_info("%s: dummy @ %p, expires @ %lx\n", __func__, d, d->jiffies_expire);