The qedf_dbg_stop_io_on_error_cmd_read() function invokes sprintf() directly on a __user pointer, which may crash the kernel. Avoid doing that by using a small on-stack buffer for sprintf() and then calling simple_read_from_buffer() which does a proper copy_to_user() call. Signed-off-by: Oleksandr Natalenko <oleksandr@xxxxxxxxxx> --- drivers/scsi/qedf/qedf_debugfs.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/drivers/scsi/qedf/qedf_debugfs.c b/drivers/scsi/qedf/qedf_debugfs.c index a3ed681c8ce3f..4d1b99569d490 100644 --- a/drivers/scsi/qedf/qedf_debugfs.c +++ b/drivers/scsi/qedf/qedf_debugfs.c @@ -185,18 +185,17 @@ qedf_dbg_stop_io_on_error_cmd_read(struct file *filp, char __user *buffer, size_t count, loff_t *ppos) { int cnt; + char cbuf[7]; struct qedf_dbg_ctx *qedf_dbg = (struct qedf_dbg_ctx *)filp->private_data; struct qedf_ctx *qedf = container_of(qedf_dbg, struct qedf_ctx, dbg_ctx); QEDF_INFO(qedf_dbg, QEDF_LOG_DEBUGFS, "entered\n"); - cnt = sprintf(buffer, "%s\n", + cnt = sprintf(cbuf, "%s\n", qedf->stop_io_on_error ? "true" : "false"); - cnt = min_t(int, count, cnt - *ppos); - *ppos += cnt; - return cnt; + return simple_read_from_buffer(buffer, count, ppos, cbuf, cnt); } static ssize_t -- 2.41.0