[for-linus][PATCH 13/17] proc/bootconfig: Fix to use correct quotes for value

Steven Rostedt
2020-06-18T23:57:25Z

From: Masami Hiramatsu <mhiramat@kernel.org>

Fix /proc/bootconfig to select double or single quotes
corrctly according to the value.

If a bootconfig value includes a double quote character,
we must use single-quotes to quote that value.

This modifies if() condition and blocks for avoiding
double-quote in value check in 2 places. Anyway, since
xbc_array_for_each_value() can handle the array which
has a single node correctly.
Thus,

if (vnode && xbc_node_is_array(vnode)) {
xbc_array_for_each_value(vnode) /* vnode->next != NULL */
...
} else {
snprintf(val); /* val is an empty string if !vnode */
}

is equivalent to

if (vnode) {
xbc_array_for_each_value(vnode) /* vnode->next can be NULL */
...
} else {
snprintf(""); /* value is always empty */
}

Link: http://lkml.kernel.org/r/159230244786.65555.3763894451251622488.stgit@devnote2

Cc: stable@vger.kernel.org
Fixes: c1a3c36017d4 ("proc: bootconfig: Add /proc/bootconfig to show boot config list")
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
fs/proc/bootconfig.c | 15 ++++++++++-----
1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/fs/proc/bootconfig.c b/fs/proc/bootconfig.c
index 9955d75c0585..ad31ec4ad627 100644
--- a/fs/proc/bootconfig.c
+++ b/fs/proc/bootconfig.c
@@ -26,8 +26,9 @@ static int boot_config_proc_show(struct seq_file *m, void *v)
static int __init copy_xbc_key_value_list(char *dst, size_t size)
{
struct xbc_node *leaf, *vnode;
- const char *val;
char *key, *end = dst + size;
+ const char *val;
+ char q;
int ret = 0;

key = kzalloc(XBC_KEYLEN_MAX, GFP_KERNEL);
@@ -41,16 +42,20 @@ static int __init copy_xbc_key_value_list(char *dst, size_t size)
break;
dst += ret;
vnode = xbc_node_get_child(leaf);
- if (vnode && xbc_node_is_array(vnode)) {
+ if (vnode) {
xbc_array_for_each_value(vnode, val) {
- ret = snprintf(dst, rest(dst, end), "\"%s\"%s",
- val, vnode->next ? ", " : "\n");
+ if (strchr(val, '"'))
+ q = '\'';
+ else
+ q = '"';
+ ret = snprintf(dst, rest(dst, end), "%c%s%c%s",
+ q, val, q, vnode->next ? ", " : "\n");
if (ret < 0)
goto out;
dst += ret;
}
} else {
- ret = snprintf(dst, rest(dst, end), "\"%s\"\n", val);
+ ret = snprintf(dst, rest(dst, end), "\"\"\n");
if (ret < 0)
break;
dst += ret;
--
2.26.2