From 17854d92fa4a7d40463a83d558774b6f8ba1749a Mon Sep 17 00:00:00 2001 From: Amir Goldstein Date: Mon, 4 Sep 2023 14:17:56 +0300 Subject: [PATCH] ovl: fix failed copyup of fileattr on a symlink commit ab048302026d7701e7fbd718917e0dbcff0c4223 upstream. Some local filesystems support setting persistent fileattr flags (e.g. FS_NOATIME_FL) on directories and regular files via ioctl. Some of those persistent fileattr flags are reflected to vfs as in-memory inode flags (e.g. S_NOATIME). Overlayfs uses the in-memory inode flags (e.g. S_NOATIME) on a lower file as an indication that a the lower file may have persistent inode fileattr flags (e.g. FS_NOATIME_FL) that need to be copied to upper file. However, in some cases, the S_NOATIME in-memory flag could be a false indication for persistent FS_NOATIME_FL fileattr. For example, with NFS and FUSE lower fs, as was the case in the two bug reports, the S_NOATIME flag is set unconditionally for all inodes. Users cannot set persistent fileattr flags on symlinks and special files, but in some local fs, such as ext4/btrfs/tmpfs, the FS_NOATIME_FL fileattr flag are inheritted to symlinks and special files from parent directory. In both cases described above, when lower symlink has the S_NOATIME flag, overlayfs will try to copy the symlink's fileattrs and fail with error ENOXIO, because it could not open the symlink for the ioctl security hook. To solve this failure, do not attempt to copyup fileattrs for anything other than directories and regular files. Reported-by: Ruiwen Zhao Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217850 Fixes: 72db82115d2b ("ovl: copy up sync/noatime fileattr flags") Cc: # v5.15 Reviewed-by: Miklos Szeredi Signed-off-by: Amir Goldstein Signed-off-by: Greg Kroah-Hartman --- fs/overlayfs/copy_up.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/overlayfs/copy_up.c b/fs/overlayfs/copy_up.c index edc1ebff33f5a..e6d711f42607b 100644 --- a/fs/overlayfs/copy_up.c +++ b/fs/overlayfs/copy_up.c @@ -580,7 +580,8 @@ static int ovl_copy_up_metadata(struct ovl_copy_up_ctx *c, struct dentry *temp) if (err) return err; - if (inode->i_flags & OVL_COPY_I_FLAGS_MASK) { + if (inode->i_flags & OVL_COPY_I_FLAGS_MASK && + (S_ISREG(c->stat.mode) || S_ISDIR(c->stat.mode))) { /* * Copy the fileattr inode flags that are the source of already * copied i_flags -- 2.39.5