From 7f21735ffb2648a29e0fc79c4bdcb1b9ed8602cd Mon Sep 17 00:00:00 2001 From: Yang Yingliang Date: Thu, 27 Oct 2022 17:19:18 +0800 Subject: [PATCH] rbd: fix possible memory leak in rbd_sysfs_init() If device_register() returns error in rbd_sysfs_init(), name of kobject which is allocated in dev_set_name() called in device_add() is leaked. As comment of device_add() says, it should call put_device() to drop the reference count that was set in device_initialize() when it fails, so the name can be freed in kobject_cleanup(). Fault injection test can trigger this problem: unreferenced object 0xffff88810173aa78 (size 8): comm "modprobe", pid 247, jiffies 4294714278 (age 31.789s) hex dump (first 8 bytes): 72 62 64 00 81 88 ff ff rbd..... backtrace: [<00000000f58fae56>] __kmalloc_node_track_caller+0x44/0x1b0 [<00000000bdd44fe7>] kstrdup+0x3a/0x70 [<00000000f7844d0b>] kstrdup_const+0x63/0x80 [<000000001b0a0eeb>] kvasprintf_const+0x10b/0x190 [<00000000a47bd894>] kobject_set_name_vargs+0x56/0x150 [<00000000d5edbf18>] dev_set_name+0xab/0xe0 [<00000000f5153e80>] device_add+0x106/0x1f20 Fixes: dfc5606dc513 ("rbd: replace the rbd sysfs interface") Signed-off-by: Yang Yingliang Reviewed-by: Alex Elder Link: https://lore.kernel.org/r/20221027091918.2294132-1-yangyingliang@huawei.com Signed-off-by: Jens Axboe --- drivers/block/rbd.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c index f9e3930..04453f4 100644 --- a/drivers/block/rbd.c +++ b/drivers/block/rbd.c @@ -7222,8 +7222,10 @@ static int __init rbd_sysfs_init(void) int ret; ret = device_register(&rbd_root_dev); - if (ret < 0) + if (ret < 0) { + put_device(&rbd_root_dev); return ret; + } ret = bus_register(&rbd_bus_type); if (ret < 0) -- 2.7.4