From mboxrd@z Thu Jan 1 00:00:00 1970 From: Randy Dunlap Subject: Re: [PATCH v2] scsi: require CAP_SYS_ADMIN to write to procfs interface Date: Sat, 4 Nov 2017 13:50:22 -0700 Message-ID: References: <20171104202624.6605-1-asarai@suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20171104202624.6605-1-asarai-l3A5Bk7waGM@public.gmane.org> Content-Language: en-US List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: Aleksa Sarai , "James E.J. Bottomley" , "Martin K. Petersen" Cc: linux-scsi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, stable-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, cyphar-gVpy/LI/lHzQT0dZR+AlfA@public.gmane.org, "Eric W. Biederman" List-Id: containers.vger.kernel.org On 11/04/2017 01:26 PM, Aleksa Sarai wrote: > Previously, the only capability effectively required to operate on the > /proc/scsi interface was CAP_DAC_OVERRIDE (or for some other files, > having an fsuid of GLOBAL_ROOT_UID was enough). This means that > semi-privileged processes could interfere with core components of a > system (such as causing a DoS by removing the underlying SCSI device of > the host's / mount). > > Cc: > Cc: "Eric W. Biederman" > Signed-off-by: Aleksa Sarai There should be an #include somewhere... even if some other header file is dragging it in (which it must be), the preferred style is to always explicitly #include header files that are used. > --- > drivers/scsi/scsi_proc.c | 8 +++++++- > 1 file changed, 7 insertions(+), 1 deletion(-) > > diff --git a/drivers/scsi/scsi_proc.c b/drivers/scsi/scsi_proc.c > index 480a597b3877..8c891ab16b11 100644 > --- a/drivers/scsi/scsi_proc.c > +++ b/drivers/scsi/scsi_proc.c > @@ -51,7 +51,10 @@ static ssize_t proc_scsi_host_write(struct file *file, const char __user *buf, > struct Scsi_Host *shost = PDE_DATA(file_inode(file)); > ssize_t ret = -ENOMEM; > char *page; > - > + > + if (!capable(CAP_SYS_ADMIN)) > + return -EPERM; > + > if (count > PROC_BLOCK_SIZE) > return -EOVERFLOW; > > @@ -313,6 +316,9 @@ static ssize_t proc_scsi_write(struct file *file, const char __user *buf, > char *buffer, *p; > int err; > > + if (!capable(CAP_SYS_ADMIN)) > + return -EPERM; > + > if (!buf || length > PAGE_SIZE) > return -EINVAL; > > -- ~Randy