[PATCH 5.15 186/731] mtd: Fix device name leak when register device failed in add_mtd_device()

Greg Kroah-Hartman
2022-12-28T14:54:10Z

From: Zhang Xiaoxu <zhangxiaoxu5@huawei.com>

[ Upstream commit 895d68a39481a75c680aa421546931fb11942fa6 ]

There is a kmemleak when register device failed:
unreferenced object 0xffff888101aab550 (size 8):
comm "insmod", pid 3922, jiffies 4295277753 (age 925.408s)
hex dump (first 8 bytes):
6d 74 64 30 00 88 ff ff mtd0....
backtrace:
[<00000000bde26724>] __kmalloc_node_track_caller+0x4e/0x150
[<000000003c32b416>] kvasprintf+0xb0/0x130
[<000000001f7a8f15>] kobject_set_name_vargs+0x2f/0xb0
[<000000006e781163>] dev_set_name+0xab/0xe0
[<00000000e30d0c78>] add_mtd_device+0x4bb/0x700
[<00000000f3d34de7>] mtd_device_parse_register+0x2ac/0x3f0
[<00000000c0d88488>] 0xffffffffa0238457
[<00000000b40d0922>] 0xffffffffa02a008f
[<0000000023d17b9d>] do_one_initcall+0x87/0x2a0
[<00000000770f6ca6>] do_init_module+0xdf/0x320
[<000000007b6768fe>] load_module+0x2f98/0x3330
[<00000000346bed5a>] __do_sys_finit_module+0x113/0x1b0
[<00000000674c2290>] do_syscall_64+0x35/0x80
[<000000004c6a8d97>] entry_SYSCALL_64_after_hwframe+0x46/0xb0

If register device failed, should call put_device() to give up the
reference.

Fixes: 1f24b5a8ecbb ("[MTD] driver model updates")
Signed-off-by: Zhang Xiaoxu <zhangxiaoxu5@huawei.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20221022121352.2534682-1-zhangxiaoxu5@huawei.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/mtd/mtdcore.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
index 61f236e0378a..3abaac109e75 100644
--- a/drivers/mtd/mtdcore.c
+++ b/drivers/mtd/mtdcore.c
@@ -671,8 +671,10 @@ int add_mtd_device(struct mtd_info *mtd)
dev_set_drvdata(&mtd->dev, mtd);
of_node_get(mtd_get_of_node(mtd));
error = device_register(&mtd->dev);
- if (error)
+ if (error) {
+ put_device(&mtd->dev);
goto fail_added;
+ }

/* Add the nvmem provider */
error = mtd_nvmem_add(mtd);
--
2.35.1