[PATCH 6.0 0993/1073] orangefs: Fix kmemleak in orangefs_{kernel,client}_debug_init()

Greg Kroah-Hartman
2022-12-28T16:46:36Z

From: Zhang Xiaoxu <zhangxiaoxu5@huawei.com>

[ Upstream commit 31720a2b109b3080eb77e97b8f6f50a27b4ae599 ]

When insert and remove the orangefs module, there are memory leaked
as below:

unreferenced object 0xffff88816b0cc000 (size 2048):
comm "insmod", pid 783, jiffies 4294813439 (age 65.512s)
hex dump (first 32 bytes):
6e 6f 6e 65 0a 00 00 00 00 00 00 00 00 00 00 00 none............
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<0000000031ab7788>] kmalloc_trace+0x27/0xa0
[<000000005b405fee>] orangefs_debugfs_init.cold+0xaf/0x17f
[<00000000e5a0085b>] 0xffffffffa02780f9
[<000000004232d9f7>] do_one_initcall+0x87/0x2a0
[<0000000054f22384>] do_init_module+0xdf/0x320
[<000000003263bdea>] load_module+0x2f98/0x3330
[<0000000052cd4153>] __do_sys_finit_module+0x113/0x1b0
[<00000000250ae02b>] do_syscall_64+0x35/0x80
[<00000000f11c03c7>] entry_SYSCALL_64_after_hwframe+0x46/0xb0

Use the golbal variable as the buffer rather than dynamic allocate to
slove the problem.

Signed-off-by: Zhang Xiaoxu <zhangxiaoxu5@huawei.com>
Signed-off-by: Mike Marshall <hubcap@omnibond.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/orangefs/orangefs-debugfs.c | 26 +++-----------------------
1 file changed, 3 insertions(+), 23 deletions(-)

diff --git a/fs/orangefs/orangefs-debugfs.c b/fs/orangefs/orangefs-debugfs.c
index a848b6ef9599..1b508f543384 100644
--- a/fs/orangefs/orangefs-debugfs.c
+++ b/fs/orangefs/orangefs-debugfs.c
@@ -194,15 +194,10 @@ void orangefs_debugfs_init(int debug_mask)
*/
static void orangefs_kernel_debug_init(void)
{
- int rc = -ENOMEM;
- char *k_buffer = NULL;
+ static char k_buffer[ORANGEFS_MAX_DEBUG_STRING_LEN] = { };

gossip_debug(GOSSIP_DEBUGFS_DEBUG, "%s: start\n", __func__);

- k_buffer = kzalloc(ORANGEFS_MAX_DEBUG_STRING_LEN, GFP_KERNEL);
- if (!k_buffer)
- goto out;
-
if (strlen(kernel_debug_string) + 1 < ORANGEFS_MAX_DEBUG_STRING_LEN) {
strcpy(k_buffer, kernel_debug_string);
strcat(k_buffer, "\n");
@@ -213,9 +208,6 @@ static void orangefs_kernel_debug_init(void)

debugfs_create_file(ORANGEFS_KMOD_DEBUG_FILE, 0444, debug_dir, k_buffer,
&kernel_debug_fops);
-
-out:
- gossip_debug(GOSSIP_DEBUGFS_DEBUG, "%s: rc:%d:\n", __func__, rc);
}

@@ -299,18 +291,13 @@ static int help_show(struct seq_file *m, void *v)
/*
* initialize the client-debug file.
*/
-static int orangefs_client_debug_init(void)
+static void orangefs_client_debug_init(void)
{

- int rc = -ENOMEM;
- char *c_buffer = NULL;
+ static char c_buffer[ORANGEFS_MAX_DEBUG_STRING_LEN] = { };

gossip_debug(GOSSIP_DEBUGFS_DEBUG, "%s: start\n", __func__);

- c_buffer = kzalloc(ORANGEFS_MAX_DEBUG_STRING_LEN, GFP_KERNEL);
- if (!c_buffer)
- goto out;
-
if (strlen(client_debug_string) + 1 < ORANGEFS_MAX_DEBUG_STRING_LEN) {
strcpy(c_buffer, client_debug_string);
strcat(c_buffer, "\n");
@@ -324,13 +311,6 @@ static int orangefs_client_debug_init(void)
debug_dir,
c_buffer,
&kernel_debug_fops);
-
- rc = 0;
-
-out:
-
- gossip_debug(GOSSIP_DEBUGFS_DEBUG, "%s: rc:%d:\n", __func__, rc);
- return rc;
}

/* open ORANGEFS_KMOD_DEBUG_FILE or ORANGEFS_CLIENT_DEBUG_FILE.*/
--
2.35.1