linux-kernel - [PATCH 1/3] scsi: qedf: do not touch __user pointer in qedf_dbg_stop_io_on_error_cmd

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20230728065819.139694-2-oleksandr@redhat.com>
Date:   Fri, 28 Jul 2023 08:58:17 +0200
From:   Oleksandr Natalenko <oleksandr@...hat.com>
To:     linux-kernel@...r.kernel.org
Cc:     linux-scsi@...r.kernel.org, Saurav Kashyap <skashyap@...vell.com>,
        Johannes Thumshirn <Johannes.Thumshirn@....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: [PATCH 1/3] scsi: qedf: do not touch __user pointer in qedf_dbg_stop_io_on_error_cmd_read() directly

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.

Fixes: 61d8658b4a ("scsi: qedf: Add QLogic FastLinQ offload FCoE driver framework.")
Link: https://lore.kernel.org/lkml/20230724120241.40495-1-oleksandr@redhat.com/
Link: https://lore.kernel.org/linux-scsi/20230726101236.11922-1-skashyap@marvell.com/
Cc: Saurav Kashyap <skashyap@...vell.com>
Cc: Rob Evers <revers@...hat.com>
Cc: Johannes Thumshirn <Johannes.Thumshirn@....com>
Cc: Jozef Bacik <jobacik@...hat.com>
Cc: Laurence Oberman <loberman@...hat.com>
Cc: "James E.J. Bottomley" <jejb@...ux.ibm.com>
Cc: "Martin K. Petersen" <martin.petersen@...cle.com>
Cc: GR-QLogic-Storage-Upstream@...vell.com
Cc: linux-scsi@...r.kernel.org
Tested-by: Laurence Oberman <loberman@...hat.com>
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 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