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

From: Quanyang Wang
Date: Mon Feb 03 2020 - 03:39:56 EST


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);
}