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

BugLink: https://bugs.launchpad.net/bugs/2097575

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@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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Manuel Diewald <manuel.diewald@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>

This commit is contained in:

Aleksa Sarai

2024-10-10 07:40:36 +11:00

committed by

Stefan Bader

parent c257731c11

commit d99adb7a14

1 changed files with 2 additions and 0 deletions

									
										fs/open.c
									
		+2
		
												View File
												
				@@ -1446,6 +1446,8 @@ 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)