From: Dan Carpenter <dan.carpenter@oracle.com>
To: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr>,
selvin.xavier@broadcom.com, devesh.sharma@broadcom.com,
dledford@redhat.com, leon@kernel.org, colin.king@canonical.com,
roland@purestorage.com, linux-rdma@vger.kernel.org,
linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org
Subject: Re: [PATCH] RDMA/ocrdma: Fix an off-by-one issue in 'ocrdma_add_stat'
Date: Thu, 16 Apr 2020 13:08:47 +0000 [thread overview]
Message-ID: <20200416130847.GP1163@kadam> (raw)
In-Reply-To: <20200414183441.GA28870@ziepe.ca>
On Tue, Apr 14, 2020 at 03:34:41PM -0300, Jason Gunthorpe wrote:
> The memcpy is still kind of silly right? What about this:
>
> static int ocrdma_add_stat(char *start, char *pcur, char *name, u64 count)
> {
> size_t len = (start + OCRDMA_MAX_DBGFS_MEM) - pcur;
> int cpy_len;
>
> cpy_len = snprintf(pcur, len, "%s: %llu\n", name, count);
> if (cpy_len >= len || cpy_len < 0) {
The kernel version of snprintf() doesn't and will never return
negatives. It would cause a huge security headache if it started
returning negatives.
> pr_err("%s: No space in stats buff\n", __func__);
> return 0;
> }
regards,
dan carpenter
WARNING: multiple messages have this Message-ID (diff)
From: Dan Carpenter <dan.carpenter@oracle.com>
To: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr>,
selvin.xavier@broadcom.com, devesh.sharma@broadcom.com,
dledford@redhat.com, leon@kernel.org, colin.king@canonical.com,
roland@purestorage.com, linux-rdma@vger.kernel.org,
linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org
Subject: Re: [PATCH] RDMA/ocrdma: Fix an off-by-one issue in 'ocrdma_add_stat'
Date: Thu, 16 Apr 2020 16:08:47 +0300 [thread overview]
Message-ID: <20200416130847.GP1163@kadam> (raw)
In-Reply-To: <20200414183441.GA28870@ziepe.ca>
On Tue, Apr 14, 2020 at 03:34:41PM -0300, Jason Gunthorpe wrote:
> The memcpy is still kind of silly right? What about this:
>
> static int ocrdma_add_stat(char *start, char *pcur, char *name, u64 count)
> {
> size_t len = (start + OCRDMA_MAX_DBGFS_MEM) - pcur;
> int cpy_len;
>
> cpy_len = snprintf(pcur, len, "%s: %llu\n", name, count);
> if (cpy_len >= len || cpy_len < 0) {
The kernel version of snprintf() doesn't and will never return
negatives. It would cause a huge security headache if it started
returning negatives.
> pr_err("%s: No space in stats buff\n", __func__);
> return 0;
> }
regards,
dan carpenter
next prev parent reply other threads:[~2020-04-16 13:08 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-28 7:30 [PATCH] RDMA/ocrdma: Fix an off-by-one issue in 'ocrdma_add_stat' Christophe JAILLET
2020-03-28 7:30 ` Christophe JAILLET
2020-04-14 18:34 ` Jason Gunthorpe
2020-04-14 18:34 ` Jason Gunthorpe
2020-04-16 13:08 ` Dan Carpenter [this message]
2020-04-16 13:08 ` Dan Carpenter
2020-04-16 18:47 ` Jason Gunthorpe
2020-04-16 18:47 ` Jason Gunthorpe
2020-04-17 11:26 ` Dan Carpenter
2020-04-17 11:26 ` Dan Carpenter
2020-04-17 12:25 ` Jason Gunthorpe
2020-04-17 12:25 ` Jason Gunthorpe
2020-04-17 13:09 ` Dan Carpenter
2020-04-17 13:09 ` Dan Carpenter
2020-04-17 13:48 ` Jason Gunthorpe
2020-04-17 13:48 ` Jason Gunthorpe
2020-04-17 15:13 ` Dan Carpenter
2020-04-17 15:13 ` Dan Carpenter
2020-04-17 15:56 ` Jason Gunthorpe
2020-04-17 15:56 ` Jason Gunthorpe
2020-04-17 13:28 ` Marion & Christophe JAILLET
2020-04-17 13:28 ` Marion & Christophe JAILLET
2020-04-17 13:50 ` Jason Gunthorpe
2020-04-17 13:50 ` Jason Gunthorpe
2020-04-17 14:39 ` Christophe JAILLET
2020-04-17 14:39 ` Christophe JAILLET
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