[PATCH AUTOSEL 5.18 37/93] rcutorture: Fix memory leak in rcu_test_debug_objects()

Sasha Levin
2022-08-11T15:57:28Z

From: Zqiang <qiang1.zhang@intel.com>

[ Upstream commit 98ea20328786372cbbc90c601be168f5fe1f8845 ]

The kernel memory leak detector located the following:

unreferenced object 0xffff95d941135b50 (size 16):
comm "swapper/0", pid 1, jiffies 4294667610 (age 1367.451s)
hex dump (first 16 bytes):
f0 c6 c2 bd d9 95 ff ff 00 00 00 00 00 00 00 00 ................
backtrace:
[<00000000bc81d9b1>] kmem_cache_alloc_trace+0x2f6/0x500
[<00000000d28be229>] rcu_torture_init+0x1235/0x1354
[<0000000032c3acd9>] do_one_initcall+0x51/0x210
[<000000003c117727>] kernel_init_freeable+0x205/0x259
[<000000003961f965>] kernel_init+0x1a/0x120
[<000000001998f890>] ret_from_fork+0x22/0x30

This is caused by the rcu_test_debug_objects() function allocating an
rcu_head structure, then failing to free it. This commit therefore adds
the needed kfree() after the last use of this structure.

Signed-off-by: Zqiang <qiang1.zhang@intel.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
kernel/rcu/rcutorture.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index 55d049c39608..4df46bede467 100644
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -3074,6 +3074,7 @@ static void rcu_test_debug_objects(void)
pr_alert("%s: WARN: Duplicate call_rcu() test complete.\n", KBUILD_MODNAME);
destroy_rcu_head_on_stack(&rh1);
destroy_rcu_head_on_stack(&rh2);
+ kfree(rhp);
#else /* #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */
pr_alert("%s: !CONFIG_DEBUG_OBJECTS_RCU_HEAD, not testing duplicate call_rcu()\n", KBUILD_MODNAME);
#endif /* #else #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */
--
2.35.1