livepatch: check kzalloc return values

[ 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: 439e7271dc ("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>
This commit is contained in:
Nicholas Mc Guire 2018-12-14 17:56:10 +01:00 committed by Greg Kroah-Hartman
parent 1157c2683c
commit 086ed19ecf
2 changed files with 9 additions and 0 deletions

View file

@ -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);

View file

@ -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);