6.5-stable review patch. If anyone has any objections, please let me know.
------------------
From: Amir Goldstein <amir73il@xxxxxxxxx>
[ Upstream commit c34706acf40b43dd31f67c92c5a95d39666a1eb3 ]
Ever since commit 91c77947133f ("ovl: allow filenames with comma"), the
following example was legit overlayfs mount options:
mount -t overlay overlay -o 'lowerdir=/tmp/a\,b/lower' /mnt
The conversion to new mount api moved to using the common helper
generic_parse_monolithic() and discarded the specialized ovl_next_opt()
option separator.
Bring back ovl_next_opt() and use vfs_parse_monolithic_sep() to fix the
regression.
Reported-by: Ryan Hendrickson <ryan.hendrickson@xxxxxxxxxxxx>
Closes: https://lore.kernel.org/r/8da307fb-9318-cf78-8a27-ba5c5a0aef6d@xxxxxxxxxxxx/
Fixes: 1784fbc2ed9c ("ovl: port to new mount api")
Signed-off-by: Amir Goldstein <amir73il@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
fs/overlayfs/params.c | 29 +++++++++++++++++++++++++++++
1 file changed, 29 insertions(+)
diff --git a/fs/overlayfs/params.c b/fs/overlayfs/params.c
index c69d97aef2cf9..c0f70af422d6c 100644
--- a/fs/overlayfs/params.c
+++ b/fs/overlayfs/params.c
@@ -120,6 +120,34 @@ const struct fs_parameter_spec ovl_parameter_spec[] = {
{}
};
+static char *ovl_next_opt(char **s)
+{
+ char *sbegin = *s;
+ char *p;
+
+ if (sbegin == NULL)
+ return NULL;
+
+ for (p = sbegin; *p; p++) {
+ if (*p == '\\') {
+ p++;
+ if (!*p)
+ break;
+ } else if (*p == ',') {
+ *p = '\0';
+ *s = p + 1;
+ return sbegin;
+ }
+ }
+ *s = NULL;
+ return sbegin;
+}
+
+static int ovl_parse_monolithic(struct fs_context *fc, void *data)
+{
+ return vfs_parse_monolithic_sep(fc, data, ovl_next_opt);
+}
+
static ssize_t ovl_parse_param_split_lowerdirs(char *str)
{
ssize_t nr_layers = 1, nr_colons = 0;
@@ -596,6 +624,7 @@ static int ovl_reconfigure(struct fs_context *fc)
}
static const struct fs_context_operations ovl_context_ops = {
+ .parse_monolithic = ovl_parse_monolithic,
.parse_param = ovl_parse_param,
.get_tree = ovl_get_tree,
.reconfigure = ovl_reconfigure,
--
2.40.1
