Eric Biggers c349b233d6 fsverity: Set S_VERITY only after rollback is no longer possible ... Commit f77f281b61 ("fsverity: use a hashtable to find the fsverity_info") changed the implementation of FS_IOC_ENABLE_VERITY to make concurrent reads start going through fsverity verification slightly earlier than they did before. Instead of it happening when enable_verity() calls fsverity_set_info(), it now happens when ->end_enable_verity() sets S_VERITY. However, ext4 and btrfs can roll back verity after they set S_VERITY, causing a use-after-free. Fix that by making ext4 and btrfs set S_VERITY only after rollback is no longer possible. On failure, don't roll back S_VERITY, but do roll back the filesystem-specific verity flag. Also update enable_verity() to handle any future instances of this bug more safely by warning and *not* freeing the fsverity_info. Finally, tweak some comments. Clarify one, and move information from another to its proper place in the comment for ->end_enable_verity(). Fixes: f77f281b61 ("fsverity: use a hashtable to find the fsverity_info") Cc: stable@vger.kernel.org Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://patch.msgid.link/20261025204807.122875-1-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@kernel.org>		2026-10-28 10:53:43 -07:00
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enable.c	fsverity: Set S_VERITY only after rollback is no longer possible	2026-10-28 10:53:43 -07:00
fsverity_private.h	fsverity: Tell LSMs about signature only after verity is enabled	2026-10-28 10:53:43 -07:00
hash_algs.c	fsverity: Remove inode parameter from fsverity_hash_block()	2025-09-17 13:09:40 -05:00
init.c	treewide: change inode->i_ino from unsigned long to u64	2026-03-06 14:31:28 +01:00
Kconfig	fsverity: add dependency on 64K or smaller pages	2026-03-02 21:05:34 -08:00
Makefile	fsverity: start consolidating pagecache code	2026-01-29 09:39:41 -08:00
measure.c	fsverity: Explicitly require FMODE_READ to retrieve hashes	2026-10-28 10:52:54 -07:00
open.c	fsverity: Tell LSMs about signature only after verity is enabled	2026-10-28 10:53:43 -07:00
pagecache.c	fsverity: hoist pagecache_read from f2fs/ext4 to fsverity	2026-10-04 19:47:47 +02:00
read_metadata.c	fsverity: Explicitly require FMODE_READ to retrieve hashes	2026-10-28 10:52:54 -07:00
signature.c	fsverity: Tell LSMs about signature only after verity is enabled	2026-10-28 10:53:43 -07:00
verify.c	fsverity: report validation errors through fserror to fsnotify	2026-10-04 19:30:50 +02:00