[PATCH] soundwire: sysfs_emit() expects a buffer of size PAGE_SIZE

From: Sergio Perez Gonzalez
Date: Wed Jul 23 2025 - 19:10:27 EST


In read_buffer_show(), allocate sufficient memory to pass on to
sysfs_emit(), which expects a buffer of size PAGE_SIZE.

Link: https://scan7.scan.coverity.com/#/project-view/53936/11354?selectedIssue=1648019
Fixes: 35323d8ab811 ("soundwire: replace scnprintf() with sysfs_emit() for sysfs consistency")
Signed-off-by: Sergio Perez Gonzalez <sperezglz@xxxxxxxxx>
---
drivers/soundwire/debugfs.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/soundwire/debugfs.c b/drivers/soundwire/debugfs.c
index 825f7abbad32..08fb1e29026e 100644
--- a/drivers/soundwire/debugfs.c
+++ b/drivers/soundwire/debugfs.c
@@ -306,12 +306,12 @@ static int cmd_go(void *data, u64 value)
DEFINE_DEBUGFS_ATTRIBUTE(cmd_go_fops, NULL,
cmd_go, "%llu\n");

-#define MAX_LINE_LEN 128
-
static int read_buffer_show(struct seq_file *s_file, void *data)
{
- char buf[MAX_LINE_LEN];
int i;
+ char *buf __free(kfree) = kzalloc(PAGE_SIZE, GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;

if (num_bytes == 0 || num_bytes > MAX_CMD_BYTES)
return -EINVAL;
--
2.43.0