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From:   "Fabio M. De Francesco" <fmdefrancesco@gmail.com>
To:     axboe@kernel.dk, linux-block@vger.kernel.org,
        linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com,
        "James E.J. Bottomley" <jejb@linux.ibm.com>,
        "Martin K. Petersen" <martin.petersen@oracle.com>,
        linux-scsi@vger.kernel.org
Cc:     "Fabio M. De Francesco" <fmdefrancesco@gmail.com>,
        syzbot+f08c77040fa163a75a46@syzkaller.appspotmail.com
Subject: [PATCH] scsi: sd: Jump to out_free_index if device_add{,_disk}() fail
Date:   Mon, 28 Mar 2022 10:44:52 +0200
Message-Id: <20220328084452.11479-1-fmdefrancesco@gmail.com>
MIME-Version: 1.0
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Currently, if device_add() or device_add_disk() fail, the code jumps to
the "out" label. Doing so we get a memory leak as Syzbot reports.[1]

Fix this bug by jumping to the "out_free_index" label.

[1] https://groups.google.com/g/syzkaller-bugs/c/BvuqG6YGb6I

Reported-and-tested-by: syzbot+f08c77040fa163a75a46@syzkaller.appspotmail.com
Fixes: 2a7a891f4c40 ("scsi: sd: Add error handling support for add_disk()")
Fixes: 265dfe8ebbab ("scsi: sd: Free scsi_disk device via put_device()")
Signed-off-by: Fabio M. De Francesco <fmdefrancesco@gmail.com>
---
 drivers/scsi/sd.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index a390679cf458..61fcf653ef5a 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -3434,7 +3434,7 @@ static int sd_probe(struct device *dev)
 	error = device_add(&sdkp->disk_dev);
 	if (error) {
 		put_device(&sdkp->disk_dev);
-		goto out;
+		goto out_free_index;
 	}
 
 	dev_set_drvdata(dev, sdkp);
@@ -3475,7 +3475,7 @@ static int sd_probe(struct device *dev)
 	error = device_add_disk(dev, gd, NULL);
 	if (error) {
 		put_device(&sdkp->disk_dev);
-		goto out;
+		goto out_free_index;
 	}
 
 	if (sdkp->capacity)
-- 
2.34.1