5.10-stable review patch. If anyone has any objections, please let me know.
------------------
From: Aleksa Sarai <cyphar@xxxxxxxxxx>
commit f92f0a1b05698340836229d791b3ffecc71b265a upstream.
While we do currently return -EFAULT in this case, it seems prudent to
follow the behaviour of other syscalls like clone3. It seems quite
unlikely that anyone depends on this error code being EFAULT, but we can
always revert this if it turns out to be an issue.
Cc: stable@xxxxxxxxxxxxxxx # v5.6+
Fixes: fddb5d430ad9 ("open: introduce openat2(2) syscall")
Signed-off-by: Aleksa Sarai <cyphar@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20241010-extensible-structs-check_fields-v3-3-d2833dfe6edd@xxxxxxxxxx
Signed-off-by: Christian Brauner <brauner@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/open.c | 2 ++
1 file changed, 2 insertions(+)
--- a/fs/open.c
+++ b/fs/open.c
@@ -1270,6 +1270,8 @@ SYSCALL_DEFINE4(openat2, int, dfd, const
if (unlikely(usize < OPEN_HOW_SIZE_VER0))
return -EINVAL;
+ if (unlikely(usize > PAGE_SIZE))
+ return -E2BIG;
err = copy_struct_from_user(&tmp, sizeof(tmp), how, usize);
if (err)
