Messages in this thread | | | Date | Wed, 25 Nov 2020 18:06:58 +0100 | From | Benjamin Block <> | Subject | Re: [PATCH] scsi: zfcp: fix use-after-free in zfcp_unit_remove |
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On Fri, Nov 20, 2020 at 03:48:54PM +0800, Qinglang Miao wrote: > kfree(port) is called in put_device(&port->dev) so that following > use would cause use-after-free bug. > > The former put_device is redundant for device_unregister contains > put_device already. So just remove it to fix this. > > Fixes: 86bdf218a717 ("[SCSI] zfcp: cleanup unit sysfs attribute usage") > Reported-by: Hulk Robot <hulkci@huawei.com> > Signed-off-by: Qinglang Miao <miaoqinglang@huawei.com> > --- > drivers/s390/scsi/zfcp_unit.c | 2 -- > 1 file changed, 2 deletions(-) > > diff --git a/drivers/s390/scsi/zfcp_unit.c b/drivers/s390/scsi/zfcp_unit.c > index e67bf7388..664b77853 100644 > --- a/drivers/s390/scsi/zfcp_unit.c > +++ b/drivers/s390/scsi/zfcp_unit.c > @@ -255,8 +255,6 @@ int zfcp_unit_remove(struct zfcp_port *port, u64 fcp_lun) > scsi_device_put(sdev); > } > > - put_device(&unit->dev); > - > device_unregister(&unit->dev); > > return 0;
Same as in the other mail for `zfcp_sysfs_port_remove_store()`. We explicitly get a new ref in `_zfcp_unit_find()`, so we also need to put that away again.
-- Best Regards, Benjamin Block / Linux on IBM Z Kernel Development / IBM Systems IBM Deutschland Research & Development GmbH / https://www.ibm.com/privacy Vorsitz. AufsR.: Gregor Pillen / Geschäftsführung: Dirk Wittkopp Sitz der Gesellschaft: Böblingen / Registergericht: AmtsG Stuttgart, HRB 243294
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