Re: [PATCH] efivarfs: fix memory leak in efivarfs_create()

From: Ard Biesheuvel
Date: Mon Oct 26 2020 - 03:16:13 EST


On Fri, 23 Oct 2020 at 13:54, Vamshi K Sthambamkadi
<vamshi.k.sthambamkadi@xxxxxxxxx> wrote:
>
> 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.
>
> Signed-off-by: Vamshi K Sthambamkadi <vamshi.k.sthambamkadi@xxxxxxxxx>

Queued as a fix, thanks!

> ---
> fs/efivarfs/super.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/fs/efivarfs/super.c b/fs/efivarfs/super.c
> index 15880a6..f943fd0 100644
> --- 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 = {
> --
> 2.7.4
>