From: Thomas Weißschuh linux@weissschuh.net
commit 62176420274db5b5127cd7a0083a9aeb461756ee upstream.
As each option string fragment is always prepended with a comma it would happen that the whole string always starts with a comma. This could be interpreted by filesystem drivers as an empty option and may produce errors.
For example the NTFS driver from ntfs.ko behaves like this and fails when mounted via the new API.
Link: https://github.com/util-linux/util-linux/issues/2298 Signed-off-by: Thomas Weißschuh linux@weissschuh.net Fixes: 3e1aeb00e6d1 ("vfs: Implement a filesystem superblock creation/configuration context") Cc: stable@vger.kernel.org Message-Id: 20230607-fs-empty-option-v1-1-20c8dbf4671b@weissschuh.net Signed-off-by: Christian Brauner brauner@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/fs_context.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/fs/fs_context.c +++ b/fs/fs_context.c @@ -598,7 +598,8 @@ static int legacy_parse_param(struct fs_ return -ENOMEM; }
- ctx->legacy_data[size++] = ','; + if (size) + ctx->legacy_data[size++] = ','; len = strlen(param->key); memcpy(ctx->legacy_data + size, param->key, len); size += len;