From: Chen Jun <chenjun102@xxxxxxxxxx>
[ Upstream commit 13721a2ac66b246f5802ba1b75ad8637e53eeecc ]
kmemleak reports memory leaks in watchdog_dev_register, as follows:
unreferenced object 0xffff888116233000 (size 2048):
comm ""modprobe"", pid 28147, jiffies 4353426116 (age 61.741s)
hex dump (first 32 bytes):
80 fa b9 05 81 88 ff ff 08 30 23 16 81 88 ff ff .........0#.....
08 30 23 16 81 88 ff ff 00 00 00 00 00 00 00 00 .0#.............
backtrace:
[<000000007f001ffd>] __kmem_cache_alloc_node+0x157/0x220
[<000000006a389304>] kmalloc_trace+0x21/0x110
[<000000008d640eea>] watchdog_dev_register+0x4e/0x780 [watchdog]
[<0000000053c9f248>] __watchdog_register_device+0x4f0/0x680 [watchdog]
[<00000000b2979824>] watchdog_register_device+0xd2/0x110 [watchdog]
[<000000001f730178>] 0xffffffffc10880ae
[<000000007a1a8bcc>] do_one_initcall+0xcb/0x4d0
[<00000000b98be325>] do_init_module+0x1ca/0x5f0
[<0000000046d08e7c>] load_module+0x6133/0x70f0
...
unreferenced object 0xffff888105b9fa80 (size 16):
comm ""modprobe"", pid 28147, jiffies 4353426116 (age 61.741s)
hex dump (first 16 bytes):
77 61 74 63 68 64 6f 67 31 00 b9 05 81 88 ff ff watchdog1.......
backtrace:
[<000000007f001ffd>] __kmem_cache_alloc_node+0x157/0x220
[<00000000486ab89b>] __kmalloc_node_track_caller+0x44/0x1b0
[<000000005a39aab0>] kvasprintf+0xb5/0x140
[<0000000024806f85>] kvasprintf_const+0x55/0x180
[<000000009276cb7f>] kobject_set_name_vargs+0x56/0x150
[<00000000a92e820b>] dev_set_name+0xab/0xe0
[<00000000cec812c6>] watchdog_dev_register+0x285/0x780 [watchdog]
[<0000000053c9f248>] __watchdog_register_device+0x4f0/0x680 [watchdog]
[<00000000b2979824>] watchdog_register_device+0xd2/0x110 [watchdog]
[<000000001f730178>] 0xffffffffc10880ae
[<000000007a1a8bcc>] do_one_initcall+0xcb/0x4d0
[<00000000b98be325>] do_init_module+0x1ca/0x5f0
[<0000000046d08e7c>] load_module+0x6133/0x70f0
...
The reason is that put_device is not be called if cdev_device_add fails
and wdd->id != 0.
watchdog_cdev_register
wd_data = kzalloc [1]
err = dev_set_name [2]
..
err = cdev_device_add
if (err) {
if (wdd->id == 0) { // wdd->id != 0
..
}
return err; // [1],[2] would be leaked
To fix it, call put_device in all wdd->id cases.
Fixes: 72139dfa2464 ("watchdog: Fix the race between the release of watchdog_core_data and cdev")
Signed-off-by: Chen Jun <chenjun102@xxxxxxxxxx>
Reviewed-by: Guenter Roeck <linux@xxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20221116012714.102066-1-chenjun102@xxxxxxxxxx
Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx>
Signed-off-by: Wim Van Sebroeck <wim@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/watchdog/watchdog_dev.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/watchdog/watchdog_dev.c b/drivers/watchdog/watchdog_dev.c
index 3a3d8b5c7ad59..5eec84fa65170 100644
--- a/drivers/watchdog/watchdog_dev.c
+++ b/drivers/watchdog/watchdog_dev.c
@@ -1044,8 +1044,8 @@ static int watchdog_cdev_register(struct watchdog_device *wdd)
if (wdd->id == 0) {
misc_deregister(&watchdog_miscdev);
old_wd_data = NULL;
- put_device(&wd_data->dev);
}
+ put_device(&wd_data->dev);
return err;
}
--
2.39.2
