[PATCH] ubifs: fix memory leak from c->sup_node

From: quanyang.wang
Date: Tue Jan 14 2020 - 00:43:35 EST


From: Quanyang Wang <quanyang.wang@xxxxxxxxxxxxx>

The c->sup_node is allocated in function ubifs_read_sb_node but
is not freed. This will cause memory leak as below:

unreferenced object 0xbc9ce000 (size 4096):
comm "mount", pid 500, jiffies 4294952946 (age 315.820s)
hex dump (first 32 bytes):
31 18 10 06 06 7b f1 11 02 00 00 00 00 00 00 00 1....{..........
00 10 00 00 06 00 00 00 00 00 00 00 08 00 00 00 ................
backtrace:
[<d1c503cd>] ubifs_read_superblock+0x48/0xebc
[<a20e14bd>] ubifs_mount+0x974/0x1420
[<8589ecc3>] legacy_get_tree+0x2c/0x50
[<5f1fb889>] vfs_get_tree+0x28/0xfc
[<bbfc7939>] do_mount+0x4f8/0x748
[<4151f538>] ksys_mount+0x78/0xa0
[<d59910a9>] ret_fast_syscall+0x0/0x54
[<1cc40005>] 0x7ea02790

Free it in ubifs_umount and in the error path of mount_ubifs.

Fixes: fd6150051bec ("ubifs: Store read superblock node")
Signed-off-by: Quanyang Wang <quanyang.wang@xxxxxxxxxxxxx>
---
fs/ubifs/super.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c
index 7d4547e5202d..a4412c259bb3 100644
--- a/fs/ubifs/super.c
+++ b/fs/ubifs/super.c
@@ -1599,6 +1599,7 @@ static int mount_ubifs(struct ubifs_info *c)
vfree(c->ileb_buf);
vfree(c->sbuf);
kfree(c->bottom_up_buf);
+ kfree(c->sup_node);
ubifs_debugging_exit(c);
return err;
}
@@ -1641,6 +1642,7 @@ static void ubifs_umount(struct ubifs_info *c)
vfree(c->ileb_buf);
vfree(c->sbuf);
kfree(c->bottom_up_buf);
+ kfree(c->sup_node);
ubifs_debugging_exit(c);
}

--
2.17.1