treewide: Change list_sort to use const pointers
list_sort() internally casts the comparison function passed to it
to a different type with constant struct list_head pointers, and
uses this pointer to call the functions, which trips indirect call
Control-Flow Integrity (CFI) checking.
Instead of removing the consts, this change defines the
list_cmp_func_t type and changes the comparison function types of
all list_sort() callers to use const pointers, thus avoiding type
mismatches.
Suggested-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20210408182843.1754385-10-samitolvanen@google.com
diff --git a/fs/xfs/xfs_extfree_item.c b/fs/xfs/xfs_extfree_item.c
index 93223eb..2424230 100644
--- a/fs/xfs/xfs_extfree_item.c
+++ b/fs/xfs/xfs_extfree_item.c
@@ -397,8 +397,8 @@ xfs_trans_free_extent(
static int
xfs_extent_free_diff_items(
void *priv,
- struct list_head *a,
- struct list_head *b)
+ const struct list_head *a,
+ const struct list_head *b)
{
struct xfs_mount *mp = priv;
struct xfs_extent_free_item *ra;
