* [PATCH 6.6 1/2] fs,fsverity: reject size changes on fsverity files in setattr_prepare
2026-10-06 21:38 [PATCH 6.6 0/2] Forbid truncate of fsverity files on btrfs Eric Biggers
@ 2026-10-06 21:38 ` Eric Biggers
2026-10-06 21:38 ` [PATCH 6.6 2/2] fs,fsverity: remove check for fsverity being enabled in setattr_prepare() Eric Biggers
2026-10-07 21:03 ` [PATCH 6.6 0/2] Forbid truncate of fsverity files on btrfs Sasha Levin
2 siblings, 0 replies; 4+ messages in thread
From: Eric Biggers @ 2026-10-06 21:38 UTC (permalink / raw)
To: stable
Cc: fsverity, linux-btrfs, Christoph Hellwig, Jan Kara,
Darrick J. Wong, Eric Biggers
From: Christoph Hellwig <hch@lst.de>
commit e9734653c523c744f03333ece6ae7a315187f05c upstream.
Add the check to reject truncates of fsverity files directly to
setattr_prepare instead of requiring the file system to handle it.
Besides removing boilerplate code, this also fixes the complete lack of
such check in btrfs.
Fixes: 146054090b08 ("btrfs: initial fsverity support")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Link: https://lore.kernel.org/r/20260128152630.627409-2-hch@lst.de
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
---
fs/attr.c | 12 +++++++++++-
fs/ext4/inode.c | 4 ----
fs/f2fs/file.c | 4 ----
fs/verity/open.c | 8 --------
include/linux/fsverity.h | 25 -------------------------
5 files changed, 11 insertions(+), 42 deletions(-)
diff --git a/fs/attr.c b/fs/attr.c
index a8ae5f6d9b16..c2302fc4b333 100644
--- a/fs/attr.c
+++ b/fs/attr.c
@@ -173,7 +173,17 @@ int setattr_prepare(struct mnt_idmap *idmap, struct dentry *dentry,
* ATTR_FORCE.
*/
if (ia_valid & ATTR_SIZE) {
- int error = inode_newsize_ok(inode, attr->ia_size);
+ int error;
+
+ /*
+ * Verity files are immutable, so deny truncates. This isn't
+ * covered by the open-time check because sys_truncate() takes a
+ * path, not an open file.
+ */
+ if (IS_ENABLED(CONFIG_FS_VERITY) && IS_VERITY(inode))
+ return -EPERM;
+
+ error = inode_newsize_ok(inode, attr->ia_size);
if (error)
return error;
}
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index dea6d27e5028..9ff2958509ed 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -5484,10 +5484,6 @@ int ext4_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
if (error)
return error;
- error = fsverity_prepare_setattr(dentry, attr);
- if (error)
- return error;
-
if (is_quota_modification(idmap, inode, attr)) {
error = dquot_initialize(inode);
if (error)
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 7125117b6322..c1cd6dadabfe 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -1065,10 +1065,6 @@ int f2fs_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
if (err)
return err;
- err = fsverity_prepare_setattr(dentry, attr);
- if (err)
- return err;
-
if (unlikely(IS_IMMUTABLE(inode)))
return -EPERM;
diff --git a/fs/verity/open.c b/fs/verity/open.c
index 6c31a871b84b..5342a8e1f781 100644
--- a/fs/verity/open.c
+++ b/fs/verity/open.c
@@ -393,14 +393,6 @@ int __fsverity_file_open(struct inode *inode, struct file *filp)
}
EXPORT_SYMBOL_GPL(__fsverity_file_open);
-int __fsverity_prepare_setattr(struct dentry *dentry, struct iattr *attr)
-{
- if (attr->ia_valid & ATTR_SIZE)
- return -EPERM;
- return 0;
-}
-EXPORT_SYMBOL_GPL(__fsverity_prepare_setattr);
-
void __fsverity_cleanup_inode(struct inode *inode)
{
fsverity_free_info(inode->i_verity_info);
diff --git a/include/linux/fsverity.h b/include/linux/fsverity.h
index 1eb7eae580be..139a6f5c6217 100644
--- a/include/linux/fsverity.h
+++ b/include/linux/fsverity.h
@@ -149,7 +149,6 @@ int fsverity_get_digest(struct inode *inode,
/* open.c */
int __fsverity_file_open(struct inode *inode, struct file *filp);
-int __fsverity_prepare_setattr(struct dentry *dentry, struct iattr *attr);
void __fsverity_cleanup_inode(struct inode *inode);
/**
@@ -214,12 +213,6 @@ static inline int __fsverity_file_open(struct inode *inode, struct file *filp)
return -EOPNOTSUPP;
}
-static inline int __fsverity_prepare_setattr(struct dentry *dentry,
- struct iattr *attr)
-{
- return -EOPNOTSUPP;
-}
-
static inline void fsverity_cleanup_inode(struct inode *inode)
{
}
@@ -301,22 +294,4 @@ static inline int fsverity_file_open(struct inode *inode, struct file *filp)
return 0;
}
-/**
- * fsverity_prepare_setattr() - prepare to change a verity inode's attributes
- * @dentry: dentry through which the inode is being changed
- * @attr: attributes to change
- *
- * Verity files are immutable, so deny truncates. This isn't covered by the
- * open-time check because sys_truncate() takes a path, not a file descriptor.
- *
- * Return: 0 on success, -errno on failure
- */
-static inline int fsverity_prepare_setattr(struct dentry *dentry,
- struct iattr *attr)
-{
- if (IS_VERITY(d_inode(dentry)))
- return __fsverity_prepare_setattr(dentry, attr);
- return 0;
-}
-
#endif /* _LINUX_FSVERITY_H */
--
2.56.0
^ permalink raw reply related [flat|nested] 4+ messages in thread* [PATCH 6.6 2/2] fs,fsverity: remove check for fsverity being enabled in setattr_prepare()
2026-10-06 21:38 [PATCH 6.6 0/2] Forbid truncate of fsverity files on btrfs Eric Biggers
2026-10-06 21:38 ` [PATCH 6.6 1/2] fs,fsverity: reject size changes on fsverity files in setattr_prepare Eric Biggers
@ 2026-10-06 21:38 ` Eric Biggers
2026-10-07 21:03 ` [PATCH 6.6 0/2] Forbid truncate of fsverity files on btrfs Sasha Levin
2 siblings, 0 replies; 4+ messages in thread
From: Eric Biggers @ 2026-10-06 21:38 UTC (permalink / raw)
To: stable
Cc: fsverity, linux-btrfs, Andrey Albershteyn, Christoph Hellwig,
Eric Biggers
From: Andrey Albershteyn <aalbersh@kernel.org>
commit d2f96bcb89d36d488a10e3bcf819b98536968286 upstream.
The check that fs-verity is available in the kernel is not necessary
here. Filesystems could have fsverity files even without fs-verity
enabled. In that case, truncate on fsverity file will succeed, what this
check is trying to prevent.
Fixes: e9734653c523 ("fs,fsverity: reject size changes on fsverity files in setattr_prepare")
Cc: stable@vger.kernel.org
Signed-off-by: Andrey Albershteyn <aalbersh@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://patch.msgid.link/20260727094352.1734826-1-aalbersh@kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
---
fs/attr.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/attr.c b/fs/attr.c
index c2302fc4b333..dd3b0b5115af 100644
--- a/fs/attr.c
+++ b/fs/attr.c
@@ -180,7 +180,7 @@ int setattr_prepare(struct mnt_idmap *idmap, struct dentry *dentry,
* covered by the open-time check because sys_truncate() takes a
* path, not an open file.
*/
- if (IS_ENABLED(CONFIG_FS_VERITY) && IS_VERITY(inode))
+ if (IS_VERITY(inode))
return -EPERM;
error = inode_newsize_ok(inode, attr->ia_size);
--
2.56.0
^ permalink raw reply related [flat|nested] 4+ messages in thread