Eric Biggers 0483913921 fsverity: reject FS_IOC_ENABLE_VERITY on mode 3 fds ... Commit 56124d6c87 ("fsverity: support enabling with tree block size < PAGE_SIZE") changed FS_IOC_ENABLE_VERITY to use __kernel_read() to read the file's data, instead of direct pagecache accesses. An unintended consequence of this is that the 'WARN_ON_ONCE(!(file->f_mode & FMODE_READ))' in __kernel_read() became reachable by fuzz tests. This happens if FS_IOC_ENABLE_VERITY is called on a fd opened with access mode 3, which means "ioctl access only". Arguably, FS_IOC_ENABLE_VERITY should work on ioctl-only fds. But ioctl-only fds are a weird Linux extension that is rarely used and that few people even know about. (The documentation for FS_IOC_ENABLE_VERITY even specifically says it requires O_RDONLY.) It's probably not worthwhile to make the ioctl internally open a new fd just to handle this case. Thus, just reject the ioctl on such fds for now. Fixes: 56124d6c87 ("fsverity: support enabling with tree block size < PAGE_SIZE") Reported-by: syzbot+51177e4144d764827c45@syzkaller.appspotmail.com Link: https://syzkaller.appspot.com/bug?id=2281afcbbfa8fdb92f9887479cc0e4180f1c6b28 Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20230406215106.235829-1-ebiggers@kernel.org Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Eric Biggers <ebiggers@google.com>		2023-04-11 19:23:23 -07:00
..
Kconfig	fsverity: remove debug messages and CONFIG_FS_VERITY_DEBUG	2023-01-01 15:46:48 -08:00
Makefile	fs-verity: add FS_IOC_READ_VERITY_METADATA ioctl	2021-02-07 14:51:11 -08:00
enable.c	fsverity: reject FS_IOC_ENABLE_VERITY on mode 3 fds	2023-04-11 19:23:23 -07:00
fsverity_private.h	fsverity: support verification with tree block size < PAGE_SIZE	2023-01-09 19:06:03 -08:00
hash_algs.c	fsverity: use WARN_ON_ONCE instead of WARN_ON	2023-04-11 19:23:15 -07:00
init.c	fsverity: remove debug messages and CONFIG_FS_VERITY_DEBUG	2023-01-01 15:46:48 -08:00
measure.c	fsverity: simplify fsverity_get_digest()	2022-11-29 21:07:41 -08:00
open.c	fsverity: use WARN_ON_ONCE instead of WARN_ON	2023-04-11 19:23:15 -07:00
read_metadata.c	fs-verity: use kmap_local_page() instead of kmap()	2022-08-19 15:19:55 -07:00
signature.c	fs-verity: simplify sysctls with register_sysctl()	2023-03-27 21:17:02 -07:00
verify.c	fsverity: Remove WQ_UNBOUND from fsverity read workqueue	2023-03-14 16:16:36 -07:00