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authorAnand Jain <anand.jain@oracle.com>2020-09-05 01:34:21 +0800
committerDavid Sterba <dsterba@suse.com>2020-09-22 15:57:52 +0200
commitb5ddcffa37778244d5e786fe32f778edf2bfc93e (patch)
tree2d27703d4fe628cc317f5f308d643f3a74e0c861 /fs
parent35be8851d172c6e3db836c0f28c19087b10c9e00 (diff)
downloadlinux-b5ddcffa37778244d5e786fe32f778edf2bfc93e.tar.bz2
btrfs: fix put of uninitialized kobject after seed device delete
The following test case leads to NULL kobject free error: mount seed /mnt add sprout to /mnt umount /mnt mount sprout to /mnt delete seed kobject: '(null)' (00000000dd2b87e4): is not initialized, yet kobject_put() is being called. WARNING: CPU: 1 PID: 15784 at lib/kobject.c:736 kobject_put+0x80/0x350 RIP: 0010:kobject_put+0x80/0x350 :: Call Trace: btrfs_sysfs_remove_devices_dir+0x6e/0x160 [btrfs] btrfs_rm_device.cold+0xa8/0x298 [btrfs] btrfs_ioctl+0x206c/0x22a0 [btrfs] ksys_ioctl+0xe2/0x140 __x64_sys_ioctl+0x1e/0x29 do_syscall_64+0x96/0x150 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7f4047c6288b :: This is because, at the end of the seed device-delete, we try to remove the seed's devid sysfs entry. But for the seed devices under the sprout fs, we don't initialize the devid kobject yet. So add a kobject state check, which takes care of the bug. Fixes: 668e48af7a94 ("btrfs: sysfs, add devid/dev_state kobject and device attributes") CC: stable@vger.kernel.org # 5.6+ Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'fs')
-rw-r--r--fs/btrfs/sysfs.c16
1 files changed, 10 insertions, 6 deletions
diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c
index c8df2edafd85..5be30066563c 100644
--- a/fs/btrfs/sysfs.c
+++ b/fs/btrfs/sysfs.c
@@ -1170,10 +1170,12 @@ int btrfs_sysfs_remove_devices_dir(struct btrfs_fs_devices *fs_devices,
disk_kobj->name);
}
- kobject_del(&one_device->devid_kobj);
- kobject_put(&one_device->devid_kobj);
+ if (one_device->devid_kobj.state_initialized) {
+ kobject_del(&one_device->devid_kobj);
+ kobject_put(&one_device->devid_kobj);
- wait_for_completion(&one_device->kobj_unregister);
+ wait_for_completion(&one_device->kobj_unregister);
+ }
return 0;
}
@@ -1186,10 +1188,12 @@ int btrfs_sysfs_remove_devices_dir(struct btrfs_fs_devices *fs_devices,
sysfs_remove_link(fs_devices->devices_kobj,
disk_kobj->name);
}
- kobject_del(&one_device->devid_kobj);
- kobject_put(&one_device->devid_kobj);
+ if (one_device->devid_kobj.state_initialized) {
+ kobject_del(&one_device->devid_kobj);
+ kobject_put(&one_device->devid_kobj);
- wait_for_completion(&one_device->kobj_unregister);
+ wait_for_completion(&one_device->kobj_unregister);
+ }
}
return 0;