2020-12-29 01:52:58

by Xiaolei Wang

Subject: [PATCH v2] regmap: debugfs: Fix a memory leak when calling regmap_attach_dev

Fixes: 9b947a13e7f6 ("regmap: use debugfs even when no device")

After initializing the regmap through
syscon_regmap_lookup_by_compatible, then regmap_attach_dev to the
device, because the debugfs_name has been allocated, there is no
need to redistribute it again

unreferenced object 0xd8399b80 (size 64):
comm "swapper/0", pid 1, jiffies 4294937641 (age 278.590s)
hex dump (first 32 bytes):
64 75 6d 6d 79 2d 69 6f 6d 75 78 63 2d 67 70 72
dummy-iomuxc-gpr
40 32 30 65 34 30 30 30 00 7f 52 5b d8 7e 42 69
@20e4000..R[.~Bi
backtrace:
[<ca384d6f>] kasprintf+0x2c/0x54
[<6ad3bbc2>] regmap_debugfs_init+0xdc/0x2fc
[<bc4181da>] __regmap_init+0xc38/0xd88
[<1f7e0609>] of_syscon_register+0x168/0x294
[<735e8766>] device_node_get_regmap+0x6c/0x98
[<d96c8982>] imx6ul_init_machine+0x20/0x88
[<0456565b>] customize_machine+0x1c/0x30
[<d07393d8>] do_one_initcall+0x80/0x3ac
[<7e584867>] kernel_init_freeable+0x170/0x1f0
[<80074741>] kernel_init+0x8/0x120
[<285d6f28>] ret_from_fork+0x14/0x20
[<00000000>] 0x0

Signed-off-by: Xiaolei Wang <[email protected]>
---
drivers/base/regmap/regmap-debugfs.c | 11 +++++++++--
1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/drivers/base/regmap/regmap-debugfs.c b/drivers/base/regmap/regmap-debugfs.c
index 8dfac7f3ed7a..bf03cd343be2 100644
--- a/drivers/base/regmap/regmap-debugfs.c
+++ b/drivers/base/regmap/regmap-debugfs.c
@@ -582,18 +582,25 @@ void regmap_debugfs_init(struct regmap *map)
devname = dev_name(map->dev);

if (name) {
- map->debugfs_name = kasprintf(GFP_KERNEL, "%s-%s",
+ if (!map->debugfs_name) {
+ map->debugfs_name = kasprintf(GFP_KERNEL, "%s-%s",
devname, name);
+ if (!map->debugfs_name)
+ return;
+ }
name = map->debugfs_name;
} else {
name = devname;
}

if (!strcmp(name, "dummy")) {
- kfree(map->debugfs_name);
+ if (!map->debugfs_name)
+ kfree(map->debugfs_name);

map->debugfs_name = kasprintf(GFP_KERNEL, "dummy%d",
dummy_index);
+ if (!map->debugfs_name)
+ return;
name = map->debugfs_name;
dummy_index++;
}
--
2.25.1

2020-12-29 10:20:20

by Greg Kroah-Hartman

Subject: Re: [PATCH v2] regmap: debugfs: Fix a memory leak when calling regmap_attach_dev

On Tue, Dec 29, 2020 at 09:16:17AM +0800, Xiaolei Wang wrote:
> Fixes: 9b947a13e7f6 ("regmap: use debugfs even when no device")

This line goes down next to your signed-off-by line in the changelog
please.

thanks,

greg k-h