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-rw-r--r--fs/overlayfs/copy_up.c51
-rw-r--r--fs/overlayfs/inode.c44
-rw-r--r--fs/overlayfs/overlayfs.h15
3 files changed, 89 insertions, 21 deletions
diff --git a/fs/overlayfs/copy_up.c b/fs/overlayfs/copy_up.c
index 3fa68a5cc16e..daf2afa603d3 100644
--- a/fs/overlayfs/copy_up.c
+++ b/fs/overlayfs/copy_up.c
@@ -8,6 +8,7 @@
#include <linux/fs.h>
#include <linux/slab.h>
#include <linux/file.h>
+#include <linux/fileattr.h>
#include <linux/splice.h>
#include <linux/xattr.h>
#include <linux/security.h>
@@ -130,6 +131,31 @@ out:
return error;
}
+static int ovl_copy_fileattr(struct path *old, struct path *new)
+{
+ struct fileattr oldfa = { .flags_valid = true };
+ struct fileattr newfa = { .flags_valid = true };
+ int err;
+
+ err = ovl_real_fileattr_get(old, &oldfa);
+ if (err)
+ return err;
+
+ err = ovl_real_fileattr_get(new, &newfa);
+ if (err)
+ return err;
+
+ BUILD_BUG_ON(OVL_COPY_FS_FLAGS_MASK & ~FS_COMMON_FL);
+ newfa.flags &= ~OVL_COPY_FS_FLAGS_MASK;
+ newfa.flags |= (oldfa.flags & OVL_COPY_FS_FLAGS_MASK);
+
+ BUILD_BUG_ON(OVL_COPY_FSX_FLAGS_MASK & ~FS_XFLAG_COMMON);
+ newfa.fsx_xflags &= ~OVL_COPY_FSX_FLAGS_MASK;
+ newfa.fsx_xflags |= (oldfa.fsx_xflags & OVL_COPY_FSX_FLAGS_MASK);
+
+ return ovl_real_fileattr_set(new, &newfa);
+}
+
static int ovl_copy_up_data(struct ovl_fs *ofs, struct path *old,
struct path *new, loff_t len)
{
@@ -493,20 +519,21 @@ static int ovl_link_up(struct ovl_copy_up_ctx *c)
static int ovl_copy_up_inode(struct ovl_copy_up_ctx *c, struct dentry *temp)
{
struct ovl_fs *ofs = OVL_FS(c->dentry->d_sb);
+ struct inode *inode = d_inode(c->dentry);
+ struct path upperpath, datapath;
int err;
+ ovl_path_upper(c->dentry, &upperpath);
+ if (WARN_ON(upperpath.dentry != NULL))
+ return -EIO;
+
+ upperpath.dentry = temp;
+
/*
* Copy up data first and then xattrs. Writing data after
* xattrs will remove security.capability xattr automatically.
*/
if (S_ISREG(c->stat.mode) && !c->metacopy) {
- struct path upperpath, datapath;
-
- ovl_path_upper(c->dentry, &upperpath);
- if (WARN_ON(upperpath.dentry != NULL))
- return -EIO;
- upperpath.dentry = temp;
-
ovl_path_lowerdata(c->dentry, &datapath);
err = ovl_copy_up_data(ofs, &datapath, &upperpath,
c->stat.size);
@@ -518,6 +545,16 @@ static int ovl_copy_up_inode(struct ovl_copy_up_ctx *c, struct dentry *temp)
if (err)
return err;
+ if (inode->i_flags & OVL_COPY_I_FLAGS_MASK) {
+ /*
+ * Copy the fileattr inode flags that are the source of already
+ * copied i_flags
+ */
+ err = ovl_copy_fileattr(&c->lowerpath, &upperpath);
+ if (err)
+ return err;
+ }
+
/*
* Store identifier of lower inode in upper inode xattr to
* allow lookup of the copy up origin inode.
diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
index 5e828a1c98a8..b288843e6b42 100644
--- a/fs/overlayfs/inode.c
+++ b/fs/overlayfs/inode.c
@@ -503,16 +503,14 @@ static int ovl_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
* Introducing security_inode_fileattr_get/set() hooks would solve this issue
* properly.
*/
-static int ovl_security_fileattr(struct dentry *dentry, struct fileattr *fa,
+static int ovl_security_fileattr(struct path *realpath, struct fileattr *fa,
bool set)
{
- struct path realpath;
struct file *file;
unsigned int cmd;
int err;
- ovl_path_real(dentry, &realpath);
- file = dentry_open(&realpath, O_RDONLY, current_cred());
+ file = dentry_open(realpath, O_RDONLY, current_cred());
if (IS_ERR(file))
return PTR_ERR(file);
@@ -527,11 +525,22 @@ static int ovl_security_fileattr(struct dentry *dentry, struct fileattr *fa,
return err;
}
+int ovl_real_fileattr_set(struct path *realpath, struct fileattr *fa)
+{
+ int err;
+
+ err = ovl_security_fileattr(realpath, fa, true);
+ if (err)
+ return err;
+
+ return vfs_fileattr_set(&init_user_ns, realpath->dentry, fa);
+}
+
int ovl_fileattr_set(struct user_namespace *mnt_userns,
struct dentry *dentry, struct fileattr *fa)
{
struct inode *inode = d_inode(dentry);
- struct dentry *upperdentry;
+ struct path upperpath;
const struct cred *old_cred;
int err;
@@ -541,12 +550,10 @@ int ovl_fileattr_set(struct user_namespace *mnt_userns,
err = ovl_copy_up(dentry);
if (!err) {
- upperdentry = ovl_dentry_upper(dentry);
+ ovl_path_real(dentry, &upperpath);
old_cred = ovl_override_creds(inode->i_sb);
- err = ovl_security_fileattr(dentry, fa, true);
- if (!err)
- err = vfs_fileattr_set(&init_user_ns, upperdentry, fa);
+ err = ovl_real_fileattr_set(&upperpath, fa);
revert_creds(old_cred);
ovl_copyflags(ovl_inode_real(inode), inode);
}
@@ -555,17 +562,28 @@ out:
return err;
}
+int ovl_real_fileattr_get(struct path *realpath, struct fileattr *fa)
+{
+ int err;
+
+ err = ovl_security_fileattr(realpath, fa, false);
+ if (err)
+ return err;
+
+ return vfs_fileattr_get(realpath->dentry, fa);
+}
+
int ovl_fileattr_get(struct dentry *dentry, struct fileattr *fa)
{
struct inode *inode = d_inode(dentry);
- struct dentry *realdentry = ovl_dentry_real(dentry);
+ struct path realpath;
const struct cred *old_cred;
int err;
+ ovl_path_real(dentry, &realpath);
+
old_cred = ovl_override_creds(inode->i_sb);
- err = ovl_security_fileattr(dentry, fa, false);
- if (!err)
- err = vfs_fileattr_get(realdentry, fa);
+ err = ovl_real_fileattr_get(&realpath, fa);
revert_creds(old_cred);
return err;
diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h
index e5dabf7ef339..2cbebe06d9ad 100644
--- a/fs/overlayfs/overlayfs.h
+++ b/fs/overlayfs/overlayfs.h
@@ -518,9 +518,20 @@ static inline void ovl_copyattr(struct inode *from, struct inode *to)
i_size_write(to, i_size_read(from));
}
+/* vfs inode flags copied from real to ovl inode */
+#define OVL_COPY_I_FLAGS_MASK (S_SYNC | S_NOATIME | S_APPEND | S_IMMUTABLE)
+
+/*
+ * fileattr flags copied from lower to upper inode on copy up.
+ * We cannot copy immutable/append-only flags, because that would prevevnt
+ * linking temp inode to upper dir.
+ */
+#define OVL_COPY_FS_FLAGS_MASK (FS_SYNC_FL | FS_NOATIME_FL)
+#define OVL_COPY_FSX_FLAGS_MASK (FS_XFLAG_SYNC | FS_XFLAG_NOATIME)
+
static inline void ovl_copyflags(struct inode *from, struct inode *to)
{
- unsigned int mask = S_SYNC | S_IMMUTABLE | S_APPEND | S_NOATIME;
+ unsigned int mask = OVL_COPY_I_FLAGS_MASK;
inode_set_flags(to, from->i_flags & mask, mask);
}
@@ -548,6 +559,8 @@ struct dentry *ovl_create_temp(struct dentry *workdir, struct ovl_cattr *attr);
extern const struct file_operations ovl_file_operations;
int __init ovl_aio_request_cache_init(void);
void ovl_aio_request_cache_destroy(void);
+int ovl_real_fileattr_get(struct path *realpath, struct fileattr *fa);
+int ovl_real_fileattr_set(struct path *realpath, struct fileattr *fa);
int ovl_fileattr_get(struct dentry *dentry, struct fileattr *fa);
int ovl_fileattr_set(struct user_namespace *mnt_userns,
struct dentry *dentry, struct fileattr *fa);
generated by cgit (git 2.34.1) at 2024-06-01 21:31:01 +0000