[PATCH 5.7 160/179] vfs/xattr: mm/shmem: kernfs: release simple xattr entry in a right way

From: Greg Kroah-Hartman
Date: Mon Jul 27 2020 - 10:25:38 EST


From: Chengguang Xu <cgxu519@xxxxxxxxxxxx>

commit 3bef735ad7b7d987069181e7b58588043cbd1509 upstream.

After commit fdc85222d58e ("kernfs: kvmalloc xattr value instead of
kmalloc"), simple xattr entry is allocated with kvmalloc() instead of
kmalloc(), so we should release it with kvfree() instead of kfree().

Fixes: fdc85222d58e ("kernfs: kvmalloc xattr value instead of kmalloc")
Signed-off-by: Chengguang Xu <cgxu519@xxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Acked-by: Hugh Dickins <hughd@xxxxxxxxxx>
Acked-by: Tejun Heo <tj@xxxxxxxxxx>
Cc: Daniel Xu <dxu@xxxxxxxxx>
Cc: Chris Down <chris@xxxxxxxxxxxxxx>
Cc: Andreas Dilger <adilger@xxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx> [5.7]
Link: http://lkml.kernel.org/r/20200704051608.15043-1-cgxu519@xxxxxxxxxxxx
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
include/linux/xattr.h | 3 ++-
mm/shmem.c | 2 +-
2 files changed, 3 insertions(+), 2 deletions(-)

--- a/include/linux/xattr.h
+++ b/include/linux/xattr.h
@@ -15,6 +15,7 @@
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/spinlock.h>
+#include <linux/mm.h>
#include <uapi/linux/xattr.h>

struct inode;
@@ -94,7 +95,7 @@ static inline void simple_xattrs_free(st

list_for_each_entry_safe(xattr, node, &xattrs->head, list) {
kfree(xattr->name);
- kfree(xattr);
+ kvfree(xattr);
}
}

--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -3205,7 +3205,7 @@ static int shmem_initxattrs(struct inode
new_xattr->name = kmalloc(XATTR_SECURITY_PREFIX_LEN + len,
GFP_KERNEL);
if (!new_xattr->name) {
- kfree(new_xattr);
+ kvfree(new_xattr);
return -ENOMEM;
}