rcutorture: Fix memory leak in rcu_test_debug_objects()
authorZqiang <qiang1.zhang@intel.com>
Wed, 27 Apr 2022 07:15:20 +0000 (15:15 +0800)
committerPaul E. McKenney <paulmck@kernel.org>
Tue, 21 Jun 2022 22:57:04 +0000 (15:57 -0700)
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>
kernel/rcu/rcutorture.c

index eed32cea938bbbb13184d27607781f90f21557ce..62841e9cd2686d34555b8f96240b1cd2c84f3423 100644 (file)
@@ -3116,6 +3116,7 @@ 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 */