From: Sebastian <sebastian.scherbel@fau.de>
To: clm@fb.com
Cc: josef@toxicpanda.com, dsterba@suse.com,
linux-btrfs@vger.kernel.org, linux-kernel@i4.cs.fau.de,
Sebastian Scherbel <sebastian.scherbel@fau.de>,
Ole Wiedemann <ole.wiedemann@fau.de>
Subject: [PATCH 2/2] btrfs: Move dereference behind null check in check volumes
Date: Sat, 7 Dec 2019 23:18:18 +0100 [thread overview]
Message-ID: <20191207221818.3641-3-sebastian.scherbel@fau.de> (raw)
In-Reply-To: <20191207221818.3641-1-sebastian.scherbel@fau.de>
From: Sebastian Scherbel <sebastian.scherbel@fau.de>
Regarding Bug 205003, point 2
The struct "tgtdev" is currently dereferenced before being checked
for null later on. This patch moves the derefernce after the null
check to avoid a possible null pointer dereference.
Furthermore WARN_ON is replaced by BUG_ON to prevent the subsequent
dereference of the null pointer.
Signed-off-by: Sebastian Scherbel <sebastian.scherbel@fau.de>
Co-developed-by: Ole Wiedemann <ole.wiedemann@fau.de>
Signed-off-by: Ole Wiedemann <ole.wiedemann@fau.de>
---
fs/btrfs/volumes.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index d8e5560db285..12015f60f50d 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -2128,9 +2128,11 @@ void btrfs_rm_dev_replace_free_srcdev(struct btrfs_device *srcdev)
void btrfs_destroy_dev_replace_tgtdev(struct btrfs_device *tgtdev)
{
- struct btrfs_fs_devices *fs_devices = tgtdev->fs_info->fs_devices;
+ struct btrfs_fs_devices *fs_devices;
+
+ BUG_ON(!tgtdev);
+ fs_devices = tgtdev->fs_info->fs_devices;
- WARN_ON(!tgtdev);
mutex_lock(&fs_devices->device_list_mutex);
btrfs_sysfs_rm_device_link(fs_devices, tgtdev);
--
2.20.1
next prev parent reply other threads:[~2019-12-07 22:29 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-07 22:18 [PATCH 0/2] btrfs: Move dereference behind null checks Sebastian
2019-12-07 22:18 ` [PATCH 1/2] btrfs: Move dereference behind null check in check integrity Sebastian
2019-12-07 22:18 ` Sebastian [this message]
2019-12-09 9:30 ` [PATCH 0/2] btrfs: Move dereference behind null checks Johannes Thumshirn
2019-12-09 16:11 ` David Sterba
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