[PATCH 5.9 201/252] efivarfs: fix memory leak in efivarfs_create()

Greg Kroah-Hartman
2020-11-23T12:57:07Z

From: Vamshi K Sthambamkadi <vamshi.k.sthambamkadi@gmail.com>

commit fe5186cf12e30facfe261e9be6c7904a170bd822 upstream.

kmemleak report:
unreferenced object 0xffff9b8915fcb000 (size 4096):
comm "efivarfs.sh", pid 2360, jiffies 4294920096 (age 48.264s)
hex dump (first 32 bytes):
2d 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:
[<00000000cc4d897c>] kmem_cache_alloc_trace+0x155/0x4b0
[<000000007d1dfa72>] efivarfs_create+0x6e/0x1a0
[<00000000e6ee18fc>] path_openat+0xe4b/0x1120
[<000000000ad0414f>] do_filp_open+0x91/0x100
[<00000000ce93a198>] do_sys_openat2+0x20c/0x2d0
[<000000002a91be6d>] do_sys_open+0x46/0x80
[<000000000a854999>] __x64_sys_openat+0x20/0x30
[<00000000c50d89c9>] do_syscall_64+0x38/0x90
[<00000000cecd6b5f>] entry_SYSCALL_64_after_hwframe+0x44/0xa9

In efivarfs_create(), inode->i_private is setup with efivar_entry
object which is never freed.

Cc: <stable@vger.kernel.org>
Signed-off-by: Vamshi K Sthambamkadi <vamshi.k.sthambamkadi@gmail.com>
Link: https://lore.kernel.org/r/20201023115429.GA2479@cosmos
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
fs/efivarfs/super.c | 1 +
1 file changed, 1 insertion(+)

--- a/fs/efivarfs/super.c
+++ b/fs/efivarfs/super.c
@@ -21,6 +21,7 @@ LIST_HEAD(efivarfs_list);
static void efivarfs_evict_inode(struct inode *inode)
{
clear_inode(inode);
+ kfree(inode->i_private);
}

static const struct super_operations efivarfs_ops = {