[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20230724120241.40495-3-oleksandr@redhat.com>
Date: Mon, 24 Jul 2023 14:02:40 +0200
From: Oleksandr Natalenko <oleksandr@...hat.com>
To: linux-kernel@...r.kernel.org
Cc: linux-scsi@...r.kernel.org, Saurav Kashyap <skashyap@...vell.com>,
Javed Hasan <jhasan@...vell.com>,
GR-QLogic-Storage-Upstream@...vell.com,
"James E.J. Bottomley" <jejb@...ux.ibm.com>,
"Martin K. Petersen" <martin.petersen@...cle.com>,
Jozef Bacik <jobacik@...hat.com>,
Laurence Oberman <loberman@...hat.com>,
Rob Evers <revers@...hat.com>
Subject: [RFC PATCH 2/3] scsi: qedf: do not touch __user pointer in qedf_dbg_debug_cmd_read() directly
The qedf_dbg_debug_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@...hat.com>
---
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 4d1b99569d490..f910af0029a2c 100644
--- a/drivers/scsi/qedf/qedf_debugfs.c
+++ b/drivers/scsi/qedf/qedf_debugfs.c
@@ -138,15 +138,14 @@ qedf_dbg_debug_cmd_read(struct file *filp, char __user *buffer, size_t count,
loff_t *ppos)
{
int cnt;
+ char cbuf[35];
struct qedf_dbg_ctx *qedf_dbg =
(struct qedf_dbg_ctx *)filp->private_data;
QEDF_INFO(qedf_dbg, QEDF_LOG_DEBUGFS, "debug mask=0x%x\n", qedf_debug);
- cnt = sprintf(buffer, "debug mask = 0x%x\n", qedf_debug);
+ cnt = sprintf(cbuf, "debug mask = 0x%x\n", qedf_debug);
- 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
Powered by blists - more mailing lists