[PATCH 4.1 59/86] ovl: free stack of paths in ovl_fill_super

From: Greg Kroah-Hartman
Date: Fri Nov 06 2015 - 15:06:05 EST

4.1-stable review patch. If anyone has any objections, please let me know.


From: Konstantin Khlebnikov <khlebnikov@xxxxxxxxxxxxxx>

commit 0f95502ad84874b3c05fc7cdd9d4d9d5cddf7859 upstream.

This fixes small memory leak after mount.

Kmemleak report:

unreferenced object 0xffff88003683fe00 (size 16):
comm "mount", pid 2029, jiffies 4294909563 (age 33.380s)
hex dump (first 16 bytes):
20 27 1f bb 00 88 ff ff 40 4b 0f 36 02 88 ff ff '......@xxxxxxx
[<ffffffff811f8cd4>] create_object+0x124/0x2c0
[<ffffffff817a059b>] kmemleak_alloc+0x7b/0xc0
[<ffffffff811dffe6>] __kmalloc+0x106/0x340
[<ffffffffa01b7a29>] ovl_fill_super+0x389/0x9a0 [overlay]
[<ffffffff81200ac4>] mount_nodev+0x54/0xa0
[<ffffffffa01b7118>] ovl_mount+0x18/0x20 [overlay]
[<ffffffff81201ab3>] mount_fs+0x43/0x170
[<ffffffff81220d34>] vfs_kern_mount+0x74/0x170
[<ffffffff812233ad>] do_mount+0x22d/0xdf0
[<ffffffff812242cb>] SyS_mount+0x7b/0xc0
[<ffffffff817b6bee>] entry_SYSCALL_64_fastpath+0x12/0x76
[<ffffffffffffffff>] 0xffffffffffffffff

Signed-off-by: Konstantin Khlebnikov <khlebnikov@xxxxxxxxxxxxxx>
Signed-off-by: Miklos Szeredi <miklos@xxxxxxxxxx>
Fixes: a78d9f0d5d5c ("ovl: support multiple lower layers")
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

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

--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -981,6 +981,7 @@ static int ovl_fill_super(struct super_b
oe->lowerstack[i].dentry = stack[i].dentry;
oe->lowerstack[i].mnt = ufs->lower_mnt[i];
+ kfree(stack);

root_dentry->d_fsdata = oe;

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