openat2: explicitly return -E2BIG for (usize > PAGE_SIZE)

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@vger.kernel.org # v5.6+
Fixes: fddb5d430a ("open: introduce openat2(2) syscall")
Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
Link: https://lore.kernel.org/r/20241010-extensible-structs-check_fields-v3-3-d2833dfe6edd@cyphar.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
This commit is contained in:
Aleksa Sarai 2024-10-10 07:40:36 +11:00 committed by Christian Brauner
parent 368196e501
commit f92f0a1b05
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@ -1457,6 +1457,8 @@ SYSCALL_DEFINE4(openat2, int, dfd, const char __user *, filename,
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)