Re: [PATCH] ubi: fix memory leak from ubi->fm_anchor

[Quanyang Wang]

Ping?

On 1/14/20 5:33 PM, quanyang.wang@xxxxxxxxxxxxx wrote:
> From: Quanyang Wang <quanyang.wang@xxxxxxxxxxxxx>
>
> Some ubi_wl_entry are allocated in erase_aeb() and one of them is
> assigned to ubi->fm_anchor in __erase_worker(). And it should be freed
> like others which are freed in tree_destroy(). Otherwise, it will
> cause a memory leak:
>
> unreferenced object 0xbc094318 (size 24):
>    comm "ubiattach", pid 491, jiffies 4294954015 (age 420.110s)
>    hex dump (first 24 bytes):
>      30 43 09 bc 00 00 00 00 00 00 00 00 01 00 00 00  0C..............
>      02 00 00 00 04 00 00 00                          ........
>    backtrace:
>      [<6c2d5089>] erase_aeb+0x28/0xc8
>      [<a1c68fb1>] ubi_wl_init+0x1d8/0x4a8
>      [<d4f408f8>] ubi_attach+0xffc/0x10d0
>      [<add3b5d8>] ubi_attach_mtd_dev+0x5b4/0x9fc
>      [<d375a11c>] ctrl_cdev_ioctl+0xb8/0x1d8
>      [<72b250f2>] vfs_ioctl+0x28/0x3c
>      [<b80095d7>] do_vfs_ioctl+0xb0/0x798
>      [<bf9ef69e>] ksys_ioctl+0x58/0x74
>      [<5355bdbe>] ret_fast_syscall+0x0/0x54
>      [<90c6c3ca>] 0x7eadf854
>
> Signed-off-by: Quanyang Wang <quanyang.wang@xxxxxxxxxxxxx>
> ---
>   drivers/mtd/ubi/wl.c | 2 ++
>   1 file changed, 2 insertions(+)
>
> diff --git a/drivers/mtd/ubi/wl.c b/drivers/mtd/ubi/wl.c
> index 5d77a38dba54..a5e9d1e4dc34 100644
> --- a/drivers/mtd/ubi/wl.c
> +++ b/drivers/mtd/ubi/wl.c
> @@ -1885,6 +1885,7 @@ int ubi_wl_init(struct ubi_device *ubi, struct ubi_attach_info *ai)
>   	tree_destroy(ubi, &ubi->used);
>   	tree_destroy(ubi, &ubi->free);
>   	tree_destroy(ubi, &ubi->scrub);
> +	wl_entry_destroy(ubi, ubi->fm_anchor);
>   	kfree(ubi->lookuptbl);
>   	return err;
>   }
> @@ -1920,6 +1921,7 @@ void ubi_wl_close(struct ubi_device *ubi)
>   	tree_destroy(ubi, &ubi->erroneous);
>   	tree_destroy(ubi, &ubi->free);
>   	tree_destroy(ubi, &ubi->scrub);
> +	wl_entry_destroy(ubi, ubi->fm_anchor);
>   	kfree(ubi->lookuptbl);
>   }
>