[PATCH v5 3/3] test_firmware: fix the memory leak of the allocated firmware buffer
From: Mirsad Goran Todorovac
Date: Wed Apr 26 2023 - 09:16:32 EST
The following kernel memory leak was noticed after running
tools/testing/selftests/firmware/fw_run_tests.sh:
[root@pc-mtodorov firmware]# cat /sys/kernel/debug/kmemleak
.
.
.
unreferenced object 0xffff955389bc3400 (size 1024):
comm "test_firmware-0", pid 5451, jiffies 4294944822 (age 65.652s)
hex dump (first 32 bytes):
47 48 34 35 36 37 0a 00 00 00 00 00 00 00 00 00 GH4567..........
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<ffffffff962f5dec>] slab_post_alloc_hook+0x8c/0x3c0
[<ffffffff962fcca4>] __kmem_cache_alloc_node+0x184/0x240
[<ffffffff962704de>] kmalloc_trace+0x2e/0xc0
[<ffffffff9665b42d>] test_fw_run_batch_request+0x9d/0x180
[<ffffffff95fd813b>] kthread+0x10b/0x140
[<ffffffff95e033e9>] ret_from_fork+0x29/0x50
unreferenced object 0xffff9553c334b400 (size 1024):
comm "test_firmware-1", pid 5452, jiffies 4294944822 (age 65.652s)
hex dump (first 32 bytes):
47 48 34 35 36 37 0a 00 00 00 00 00 00 00 00 00 GH4567..........
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<ffffffff962f5dec>] slab_post_alloc_hook+0x8c/0x3c0
[<ffffffff962fcca4>] __kmem_cache_alloc_node+0x184/0x240
[<ffffffff962704de>] kmalloc_trace+0x2e/0xc0
[<ffffffff9665b42d>] test_fw_run_batch_request+0x9d/0x180
[<ffffffff95fd813b>] kthread+0x10b/0x140
[<ffffffff95e033e9>] ret_from_fork+0x29/0x50
unreferenced object 0xffff9553c334f000 (size 1024):
comm "test_firmware-2", pid 5453, jiffies 4294944822 (age 65.652s)
hex dump (first 32 bytes):
47 48 34 35 36 37 0a 00 00 00 00 00 00 00 00 00 GH4567..........
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<ffffffff962f5dec>] slab_post_alloc_hook+0x8c/0x3c0
[<ffffffff962fcca4>] __kmem_cache_alloc_node+0x184/0x240
[<ffffffff962704de>] kmalloc_trace+0x2e/0xc0
[<ffffffff9665b42d>] test_fw_run_batch_request+0x9d/0x180
[<ffffffff95fd813b>] kthread+0x10b/0x140
[<ffffffff95e033e9>] ret_from_fork+0x29/0x50
unreferenced object 0xffff9553c3348400 (size 1024):
comm "test_firmware-3", pid 5454, jiffies 4294944822 (age 65.652s)
hex dump (first 32 bytes):
47 48 34 35 36 37 0a 00 00 00 00 00 00 00 00 00 GH4567..........
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<ffffffff962f5dec>] slab_post_alloc_hook+0x8c/0x3c0
[<ffffffff962fcca4>] __kmem_cache_alloc_node+0x184/0x240
[<ffffffff962704de>] kmalloc_trace+0x2e/0xc0
[<ffffffff9665b42d>] test_fw_run_batch_request+0x9d/0x180
[<ffffffff95fd813b>] kthread+0x10b/0x140
[<ffffffff95e033e9>] ret_from_fork+0x29/0x50
[root@pc-mtodorov firmware]#
Note that the size 1024 corresponds to the size of the test firmware
buffer. The actual number of the buffers leaked is around 70-110,
depending on the test run.
The cause of the leak is the following:
request_partial_firmware_into_buf() and request_firmware_into_buf()
provided firmware buffer isn't released on release_firmware(), we
have allocated it and we are responsible for deallocating it manually.
This is introduced in a number of context where previously only
release_firmware() was called, which was insufficient.
Reported-by: Mirsad Goran Todorovac <mirsad.todorovac@xxxxxxxxxxxx>
Fixes: 7feebfa487b92 ("test_firmware: add support for request_firmware_into_buf")
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: Dan Carpenter <error27@xxxxxxxxx>
Cc: Takashi Iwai <tiwai@xxxxxxx>
Cc: Luis Chamberlain <mcgrof@xxxxxxxxxx>
Cc: Russ Weight <russell.h.weight@xxxxxxxxx>
Cc: Tianfei zhang <tianfei.zhang@xxxxxxxxx>
Cc: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
Cc: Zhengchao Shao <shaozhengchao@xxxxxxxxxx>
Cc: Colin Ian King <colin.i.king@xxxxxxxxx>
Cc: linux-kernel@xxxxxxxxxxxxxxx
Cc: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: Scott Branden <sbranden@xxxxxxxxxxxx>
Cc: Luis R. Rodriguez <mcgrof@xxxxxxxxxx>
Cc: linux-kselftest@xxxxxxxxxxxxxxx
Cc: stable@xxxxxxxxxxxxxxx # v5.4
Signed-off-by: Mirsad Goran Todorovac <mirsad.todorovac@xxxxxxxxxxxx>
---
lib/test_firmware.c | 19 ++++++++++++++++++-
1 file changed, 18 insertions(+), 1 deletion(-)
diff --git a/lib/test_firmware.c b/lib/test_firmware.c
index 91b232ed3161..1d7d480b8eeb 100644
--- a/lib/test_firmware.c
+++ b/lib/test_firmware.c
@@ -45,6 +45,7 @@ struct test_batched_req {
bool sent;
const struct firmware *fw;
const char *name;
+ const char *fw_buf;
struct completion completion;
struct task_struct *task;
struct device *dev;
@@ -175,8 +176,14 @@ static void __test_release_all_firmware(void)
for (i = 0; i < test_fw_config->num_requests; i++) {
req = &test_fw_config->reqs[i];
- if (req->fw)
+ if (req->fw) {
+ if (req->fw_buf) {
+ kfree_const(req->fw_buf);
+ req->fw_buf = NULL;
+ }
release_firmware(req->fw);
+ req->fw = NULL;
+ }
}
vfree(test_fw_config->reqs);
@@ -670,6 +677,8 @@ static ssize_t trigger_request_store(struct device *dev,
mutex_lock(&test_fw_mutex);
release_firmware(test_firmware);
+ if (test_fw_config->reqs)
+ __test_release_all_firmware();
test_firmware = NULL;
rc = request_firmware(&test_firmware, name, dev);
if (rc) {
@@ -770,6 +779,8 @@ static ssize_t trigger_async_request_store(struct device *dev,
mutex_lock(&test_fw_mutex);
release_firmware(test_firmware);
test_firmware = NULL;
+ if (test_fw_config->reqs)
+ __test_release_all_firmware();
rc = request_firmware_nowait(THIS_MODULE, 1, name, dev, GFP_KERNEL,
NULL, trigger_async_request_cb);
if (rc) {
@@ -812,6 +823,8 @@ static ssize_t trigger_custom_fallback_store(struct device *dev,
mutex_lock(&test_fw_mutex);
release_firmware(test_firmware);
+ if (test_fw_config->reqs)
+ __test_release_all_firmware();
test_firmware = NULL;
rc = request_firmware_nowait(THIS_MODULE, FW_ACTION_NOUEVENT, name,
dev, GFP_KERNEL, NULL,
@@ -874,6 +887,8 @@ static int test_fw_run_batch_request(void *data)
test_fw_config->buf_size);
if (!req->fw)
kfree(test_buf);
+ else
+ req->fw_buf = test_buf;
} else {
req->rc = test_fw_config->req_firmware(&req->fw,
req->name,
@@ -934,6 +949,7 @@ static ssize_t trigger_batched_requests_store(struct device *dev,
req->fw = NULL;
req->idx = i;
req->name = test_fw_config->name;
+ req->fw_buf = NULL;
req->dev = dev;
init_completion(&req->completion);
req->task = kthread_run(test_fw_run_batch_request, req,
@@ -1038,6 +1054,7 @@ ssize_t trigger_batched_requests_async_store(struct device *dev,
for (i = 0; i < test_fw_config->num_requests; i++) {
req = &test_fw_config->reqs[i];
req->name = test_fw_config->name;
+ req->fw_buf = NULL;
req->fw = NULL;
req->idx = i;
init_completion(&req->completion);
--
2.30.2