From: Heiko Carstens <hca@linux.ibm.com>
To: Bui Quang Minh <minhquangbui99@gmail.com>
Cc: Jesse Brandeburg <jesse.brandeburg@intel.com>,
Tony Nguyen <anthony.l.nguyen@intel.com>,
"David S. Miller" <davem@davemloft.net>,
Eric Dumazet <edumazet@google.com>,
Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
Paul M Stillwell Jr <paul.m.stillwell.jr@intel.com>,
Rasesh Mody <rmody@marvell.com>,
Sudarsana Kalluru <skalluru@marvell.com>,
GR-Linux-NIC-Dev@marvell.com,
Krishna Gudipati <kgudipat@brocade.com>,
Anil Gurumurthy <anil.gurumurthy@qlogic.com>,
Sudarsana Kalluru <sudarsana.kalluru@qlogic.com>,
"James E.J. Bottomley" <James.Bottomley@hansenpartnership.com>,
"Martin K. Petersen" <martin.petersen@oracle.com>,
Fabian Frederick <fabf@skynet.be>,
Saurav Kashyap <skashyap@marvell.com>,
Javed Hasan <jhasan@marvell.com>,
GR-QLogic-Storage-Upstream@marvell.com,
Nilesh Javali <nilesh.javali@cavium.com>,
Arun Easi <arun.easi@cavium.com>,
Manish Rangankar <manish.rangankar@cavium.com>,
Vineeth Vijayan <vneethv@linux.ibm.com>,
Peter Oberparleiter <oberpar@linux.ibm.com>,
Vasily Gorbik <gor@linux.ibm.com>,
Alexander Gordeev <agordeev@linux.ibm.com>,
Christian Borntraeger <borntraeger@linux.ibm.com>,
Sven Schnelle <svens@linux.ibm.com>,
intel-wired-lan@lists.osuosl.org, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org, linux-scsi@vger.kernel.org,
Saurav Kashyap <saurav.kashyap@cavium.com>,
linux-s390@vger.kernel.org, Jens Axboe <axboe@kernel.dk>
Subject: Re: [PATCH 5/5] drivers/s390/cio: ensure the copied buf is NULL terminated
Date: Wed, 24 Apr 2024 13:55:57 +0200 [thread overview]
Message-ID: <20240424115557.26193-A-hca@linux.ibm.com> (raw)
In-Reply-To: <e4f5cbd0-c803-4c3c-9703-f52e56864106@gmail.com>
On Tue, Apr 23, 2024 at 09:46:35PM +0700, Bui Quang Minh wrote:
> > > - buffer = vmemdup_user(buf, lbuf);
> > > + buffer = vmemdup_user(buf, lbuf + 1);
> > > if (IS_ERR(buffer))
> > > return -ENOMEM;
> > > + buffer[lbuf] = '\0';
> >
> > This would read one byte too much from user space, and could potentially
> > fault.
> >
> > Why isn't this simply memdup_user_nul() like all others, which would do the
> > right thing?
...
> For this case, as the original code uses vmemdup_user, which internally uses
> kvmalloc not kmalloc, so I try to keep the original behavior. And
> vmemdup_user does not have the counterpart vmemdup_user_nul. I can
> kvmalloc(lbuf + 1), then copy_to_user(lbuf) and set buffer[lbuf] = '\0' or
> do you think I should create vmemdup_user_nul?
There is no need for vmalloc() instead of kmalloc() for this particular
case. The input string is supposed to be rather short (see the sscanf()
call). So converting to memdup_user_nul() is sufficient and solves the
potential problem.
next prev parent reply other threads:[~2024-04-24 11:56 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-22 16:41 [PATCH 0/5] Ensure the copied buf is NULL terminated Bui Quang Minh
2024-04-22 16:41 ` [PATCH 1/5] drivers/net/ethernet/intel-ice: ensure " Bui Quang Minh
2024-04-23 9:20 ` Przemek Kitszel
2024-04-22 16:41 ` [PATCH 2/5] drivers/net/brocade-bnad: " Bui Quang Minh
2024-04-22 16:41 ` [PATCH 3/5] drivers/scsi/bfa/bfad: " Bui Quang Minh
2024-04-22 16:41 ` [PATCH 4/5] drivers/scsi/qedf: " Bui Quang Minh
2024-04-22 16:41 ` [PATCH 5/5] drivers/s390/cio: " Bui Quang Minh
2024-04-23 6:50 ` Heiko Carstens
2024-04-23 14:46 ` Bui Quang Minh
2024-04-24 11:55 ` Heiko Carstens [this message]
2024-04-23 11:10 ` [Intel-wired-lan] [PATCH 0/5] Ensure " Marcin Szycik
2024-04-23 11:25 ` Przemek Kitszel
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