4.19-stable review patch. If anyone has any objections, please let me know.
------------------
From: Oleksandr Natalenko <oleksandr@xxxxxxxxxx>
[ Upstream commit 7d3d20dee4f648ec44e9717d5f647d594d184433 ]
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 scnprintf() and then
calling simple_read_from_buffer() which does a proper copy_to_user() call.
Fixes: 61d8658b4a43 ("scsi: qedf: Add QLogic FastLinQ offload FCoE driver framework.")
Link: https://lore.kernel.org/lkml/20230724120241.40495-1-oleksandr@xxxxxxxxxx/
Link: https://lore.kernel.org/linux-scsi/20230726101236.11922-1-skashyap@xxxxxxxxxxx/
Cc: Saurav Kashyap <skashyap@xxxxxxxxxxx>
Cc: Rob Evers <revers@xxxxxxxxxx>
Cc: Johannes Thumshirn <Johannes.Thumshirn@xxxxxxx>
Cc: David Laight <David.Laight@xxxxxxxxxx>
Cc: Jozef Bacik <jobacik@xxxxxxxxxx>
Cc: Laurence Oberman <loberman@xxxxxxxxxx>
Cc: "James E.J. Bottomley" <jejb@xxxxxxxxxxxxx>
Cc: "Martin K. Petersen" <martin.petersen@xxxxxxxxxx>
Cc: GR-QLogic-Storage-Upstream@xxxxxxxxxxx
Cc: linux-scsi@xxxxxxxxxxxxxxx
Reviewed-by: Laurence Oberman <loberman@xxxxxxxxxx>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@xxxxxxx>
Tested-by: Laurence Oberman <loberman@xxxxxxxxxx>
Acked-by: Saurav Kashyap <skashyap@xxxxxxxxxxx>
Signed-off-by: Oleksandr Natalenko <oleksandr@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20230731084034.37021-2-oleksandr@xxxxxxxxxx
Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@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 c29c162a494ff..917b047f66f10 100644
--- a/drivers/scsi/qedf/qedf_debugfs.c
+++ b/drivers/scsi/qedf/qedf_debugfs.c
@@ -204,18 +204,17 @@ 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 = scnprintf(cbuf, sizeof(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
--
2.40.1
