[PATCH -next] jffs2: fix memory leak in jffs2_do_fill_super

From: Baokun Li
Date: Tue Apr 12 2022 - 06:20:00 EST


If jffs2_iget() or d_make_root() in jffs2_do_fill_super() returns
an error, we can observe the following kmemleak report:

--------------------------------------------
unreferenced object 0xffff888105a65340 (size 64):
comm "mount", pid 710, jiffies 4302851558 (age 58.239s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<ffffffff859c45e5>] kmem_cache_alloc_trace+0x475/0x8a0
[<ffffffff86160146>] jffs2_sum_init+0x96/0x1a0
[<ffffffff86140e25>] jffs2_do_mount_fs+0x745/0x2120
[<ffffffff86149fec>] jffs2_do_fill_super+0x35c/0x810
[<ffffffff8614aae9>] jffs2_fill_super+0x2b9/0x3b0
[...]
unreferenced object 0xffff8881bd7f0000 (size 65536):
comm "mount", pid 710, jiffies 4302851558 (age 58.239s)
hex dump (first 32 bytes):
bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb ................
bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb ................
backtrace:
[<ffffffff858579ba>] kmalloc_order+0xda/0x110
[<ffffffff85857a11>] kmalloc_order_trace+0x21/0x130
[<ffffffff859c2ed1>] __kmalloc+0x711/0x8a0
[<ffffffff86160189>] jffs2_sum_init+0xd9/0x1a0
[<ffffffff86140e25>] jffs2_do_mount_fs+0x745/0x2120
[<ffffffff86149fec>] jffs2_do_fill_super+0x35c/0x810
[<ffffffff8614aae9>] jffs2_fill_super+0x2b9/0x3b0
[...]
--------------------------------------------

This is because the resources allocated in jffs2_sum_init() are not
released. Call jffs2_sum_exit() to release these resources to solve
the problem.

Fixes: e631ddba5887 ("[JFFS2] Add erase block summary support (mount time improvement)")
Signed-off-by: Baokun Li <libaokun1@xxxxxxxxxx>
---
fs/jffs2/fs.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/fs/jffs2/fs.c b/fs/jffs2/fs.c
index 71f03a5d36ed..f83a468b6488 100644
--- a/fs/jffs2/fs.c
+++ b/fs/jffs2/fs.c
@@ -604,6 +604,7 @@ int jffs2_do_fill_super(struct super_block *sb, struct fs_context *fc)
jffs2_free_raw_node_refs(c);
kvfree(c->blocks);
jffs2_clear_xattr_subsystem(c);
+ jffs2_sum_exit(c);
out_inohash:
kfree(c->inocache_list);
out_wbuf:
--
2.31.1