The patch below does not apply to the 6.5-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.5.y git checkout FETCH_HEAD git cherry-pick -x c34706acf40b43dd31f67c92c5a95d39666a1eb3 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2023101542-semisweet-rogue-1c44@gregkh' --subject-prefix 'PATCH 6.5.y' HEAD^..

Possible dependencies:

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From c34706acf40b43dd31f67c92c5a95d39666a1eb3 Mon Sep 17 00:00:00 2001 From: Amir Goldstein amir73il@gmail.com Date: Thu, 12 Oct 2023 16:08:28 +0300 Subject: [PATCH] ovl: fix regression in parsing of mount options with escaped comma

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@alum.mit.edu Closes: https://lore.kernel.org/r/8da307fb-9318-cf78-8a27-ba5c5a0aef6d@alum.mit.edu/ Fixes: 1784fbc2ed9c ("ovl: port to new mount api") Signed-off-by: Amir Goldstein amir73il@gmail.com

diff --git a/fs/overlayfs/params.c b/fs/overlayfs/params.c index 95b751507ac8..17c74ef4f089 100644 --- a/fs/overlayfs/params.c +++ b/fs/overlayfs/params.c @@ -157,6 +157,34 @@ 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; @@ -682,6 +710,7 @@ 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,