6.6-stable review patch. If anyone has any objections, please let me know.
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From: Miklos Szeredi mszeredi@redhat.com
commit 004b8d1491b4bcbb7da1a3206d1e7e66822d47c6 upstream.
ovl_check_encode_origin() should return a positive number if the lower dentry is to be encoded, zero otherwise. If there's no upper layer at all (read-only overlay), then it obviously needs to return positive.
This was broken by commit 16aac5ad1fa9 ("ovl: support encoding non-decodable file handles"), which didn't take the lower-only configuration into account.
Fix by checking the no-upper-layer case up-front.
Reported-and-tested-by: Youzhong Yang youzhong@gmail.com Closes: https://lore.kernel.org/all/CADpNCvaBimi+zCYfRJHvCOhMih8OU0rmZkwLuh24MKKroRu... Fixes: 16aac5ad1fa9 ("ovl: support encoding non-decodable file handles") Cc: stable@vger.kernel.org # v6.6 Signed-off-by: Miklos Szeredi mszeredi@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/overlayfs/export.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)
--- a/fs/overlayfs/export.c +++ b/fs/overlayfs/export.c @@ -186,6 +186,10 @@ static int ovl_check_encode_origin(struc struct ovl_fs *ofs = OVL_FS(dentry->d_sb); bool decodable = ofs->config.nfs_export;
+ /* No upper layer? */ + if (!ovl_upper_mnt(ofs)) + return 1; + /* Lower file handle for non-upper non-decodable */ if (!ovl_dentry_upper(dentry) && !decodable) return 1; @@ -214,7 +218,7 @@ static int ovl_check_encode_origin(struc * ovl_connect_layer() will try to make origin's layer "connected" by * copying up a "connectable" ancestor. */ - if (d_is_dir(dentry) && ovl_upper_mnt(ofs) && decodable) + if (d_is_dir(dentry) && decodable) return ovl_connect_layer(dentry);
/* Lower file handle for indexed and non-upper dir/non-dir */