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-rw-r--r--fs/overlayfs/file.c149
1 files changed, 24 insertions, 125 deletions
diff --git a/fs/overlayfs/file.c b/fs/overlayfs/file.c
index efccb7c1f9bc..077d3ad343f6 100644
--- a/fs/overlayfs/file.c
+++ b/fs/overlayfs/file.c
@@ -53,9 +53,10 @@ static struct file *ovl_open_realfile(const struct file *file,
err = inode_permission(realinode, MAY_OPEN | acc_mode);
if (err) {
realfile = ERR_PTR(err);
- } else if (!inode_owner_or_capable(realinode)) {
- realfile = ERR_PTR(-EPERM);
} else {
+ if (!inode_owner_or_capable(realinode))
+ flags &= ~O_NOATIME;
+
realfile = open_with_fake_path(&file->f_path, flags, realinode,
current_cred());
}
@@ -75,12 +76,6 @@ static int ovl_change_flags(struct file *file, unsigned int flags)
struct inode *inode = file_inode(file);
int err;
- flags |= OVL_OPEN_FLAGS;
-
- /* If some flag changed that cannot be changed then something's amiss */
- if (WARN_ON((file->f_flags ^ flags) & ~OVL_SETFL_MASK))
- return -EIO;
-
flags &= OVL_SETFL_MASK;
if (((flags ^ file->f_flags) & O_APPEND) && IS_APPEND(inode))
@@ -397,56 +392,15 @@ out_unlock:
return ret;
}
-static ssize_t ovl_splice_read(struct file *in, loff_t *ppos,
- struct pipe_inode_info *pipe, size_t len,
- unsigned int flags)
-{
- ssize_t ret;
- struct fd real;
- const struct cred *old_cred;
-
- ret = ovl_real_fdget(in, &real);
- if (ret)
- return ret;
-
- old_cred = ovl_override_creds(file_inode(in)->i_sb);
- ret = generic_file_splice_read(real.file, ppos, pipe, len, flags);
- revert_creds(old_cred);
-
- ovl_file_accessed(in);
- fdput(real);
- return ret;
-}
-
-static ssize_t
-ovl_splice_write(struct pipe_inode_info *pipe, struct file *out,
- loff_t *ppos, size_t len, unsigned int flags)
-{
- struct fd real;
- const struct cred *old_cred;
- ssize_t ret;
-
- ret = ovl_real_fdget(out, &real);
- if (ret)
- return ret;
-
- old_cred = ovl_override_creds(file_inode(out)->i_sb);
- ret = iter_file_splice_write(pipe, real.file, ppos, len, flags);
- revert_creds(old_cred);
-
- ovl_file_accessed(out);
- fdput(real);
- return ret;
-}
-
static int ovl_fsync(struct file *file, loff_t start, loff_t end, int datasync)
{
struct fd real;
const struct cred *old_cred;
int ret;
- if (!ovl_should_sync(OVL_FS(file_inode(file)->i_sb)))
- return 0;
+ ret = ovl_sync_status(OVL_FS(file_inode(file)->i_sb));
+ if (ret <= 0)
+ return ret;
ret = ovl_real_fdget_meta(file, &real, !datasync);
if (ret)
@@ -541,46 +495,31 @@ static long ovl_real_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
struct fd real;
- const struct cred *old_cred;
long ret;
ret = ovl_real_fdget(file, &real);
if (ret)
return ret;
- old_cred = ovl_override_creds(file_inode(file)->i_sb);
ret = security_file_ioctl(real.file, cmd, arg);
- if (!ret)
+ if (!ret) {
+ /*
+ * Don't override creds, since we currently can't safely check
+ * permissions before doing so.
+ */
ret = vfs_ioctl(real.file, cmd, arg);
- revert_creds(old_cred);
+ }
fdput(real);
return ret;
}
-static unsigned int ovl_iflags_to_fsflags(unsigned int iflags)
-{
- unsigned int flags = 0;
-
- if (iflags & S_SYNC)
- flags |= FS_SYNC_FL;
- if (iflags & S_APPEND)
- flags |= FS_APPEND_FL;
- if (iflags & S_IMMUTABLE)
- flags |= FS_IMMUTABLE_FL;
- if (iflags & S_NOATIME)
- flags |= FS_NOATIME_FL;
-
- return flags;
-}
-
static long ovl_ioctl_set_flags(struct file *file, unsigned int cmd,
- unsigned long arg, unsigned int flags)
+ unsigned long arg)
{
long ret;
struct inode *inode = file_inode(file);
- unsigned int oldflags;
if (!inode_owner_or_capable(inode))
return -EACCES;
@@ -591,10 +530,13 @@ static long ovl_ioctl_set_flags(struct file *file, unsigned int cmd,
inode_lock(inode);
- /* Check the capability before cred override */
- oldflags = ovl_iflags_to_fsflags(READ_ONCE(inode->i_flags));
- ret = vfs_ioc_setflags_prepare(inode, oldflags, flags);
- if (ret)
+ /*
+ * Prevent copy up if immutable and has no CAP_LINUX_IMMUTABLE
+ * capability.
+ */
+ ret = -EPERM;
+ if (!ovl_has_upperdata(inode) && IS_IMMUTABLE(inode) &&
+ !capable(CAP_LINUX_IMMUTABLE))
goto unlock;
ret = ovl_maybe_copy_up(file_dentry(file), O_WRONLY);
@@ -613,46 +555,6 @@ unlock:
}
-static long ovl_ioctl_set_fsflags(struct file *file, unsigned int cmd,
- unsigned long arg)
-{
- unsigned int flags;
-
- if (get_user(flags, (int __user *) arg))
- return -EFAULT;
-
- return ovl_ioctl_set_flags(file, cmd, arg, flags);
-}
-
-static unsigned int ovl_fsxflags_to_fsflags(unsigned int xflags)
-{
- unsigned int flags = 0;
-
- if (xflags & FS_XFLAG_SYNC)
- flags |= FS_SYNC_FL;
- if (xflags & FS_XFLAG_APPEND)
- flags |= FS_APPEND_FL;
- if (xflags & FS_XFLAG_IMMUTABLE)
- flags |= FS_IMMUTABLE_FL;
- if (xflags & FS_XFLAG_NOATIME)
- flags |= FS_NOATIME_FL;
-
- return flags;
-}
-
-static long ovl_ioctl_set_fsxflags(struct file *file, unsigned int cmd,
- unsigned long arg)
-{
- struct fsxattr fa;
-
- memset(&fa, 0, sizeof(fa));
- if (copy_from_user(&fa, (void __user *) arg, sizeof(fa)))
- return -EFAULT;
-
- return ovl_ioctl_set_flags(file, cmd, arg,
- ovl_fsxflags_to_fsflags(fa.fsx_xflags));
-}
-
long ovl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
long ret;
@@ -663,12 +565,9 @@ long ovl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
ret = ovl_real_ioctl(file, cmd, arg);
break;
- case FS_IOC_SETFLAGS:
- ret = ovl_ioctl_set_fsflags(file, cmd, arg);
- break;
-
case FS_IOC_FSSETXATTR:
- ret = ovl_ioctl_set_fsxflags(file, cmd, arg);
+ case FS_IOC_SETFLAGS:
+ ret = ovl_ioctl_set_flags(file, cmd, arg);
break;
default:
@@ -801,8 +700,8 @@ const struct file_operations ovl_file_operations = {
#ifdef CONFIG_COMPAT
.compat_ioctl = ovl_compat_ioctl,
#endif
- .splice_read = ovl_splice_read,
- .splice_write = ovl_splice_write,
+ .splice_read = generic_file_splice_read,
+ .splice_write = iter_file_splice_write,
.copy_file_range = ovl_copy_file_range,
.remap_file_range = ovl_remap_file_range,