From: Thomas Weißschuh Date: Wed, 7 Jun 2023 17:28:48 +0000 (+0200) Subject: fs: avoid empty option when generating legacy mount string X-Git-Tag: v6.6.17~4638^2~9 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=62176420274db5b5127cd7a0083a9aeb461756ee;p=platform%2Fkernel%2Flinux-rpi.git fs: avoid empty option when generating legacy mount string 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 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 --- diff --git a/fs/fs_context.c b/fs/fs_context.c index 24ce12f..851214d 100644 --- a/fs/fs_context.c +++ b/fs/fs_context.c @@ -561,7 +561,8 @@ static int legacy_parse_param(struct fs_context *fc, struct fs_parameter *param) 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;