From: Ira Weiny <ira.weiny@intel.com>
To: Li RongQing <lirongqing@baidu.com>
Cc: linux-nvdimm@lists.01.org
Subject: Re: [PATCH] libnvdimm, pmem: fix a possible OOB access when read and write pmem
Date: Thu, 4 Apr 2019 09:54:31 -0700 [thread overview]
Message-ID: <20190404165431.GC1857@iweiny-DESK2.sc.intel.com> (raw)
In-Reply-To: <1554346681-31163-1-git-send-email-lirongqing@baidu.com>
On Thu, Apr 04, 2019 at 10:58:01AM +0800, Li RongQing wrote:
> If offset is not zero and length is bigger than PAGE_SIZE,
> this will cause to out of boundary access to a page memory
>
> Fixes: 98cc093cba1e "(block, THP: make block_device_operations.rw_page support THP)"
> Co-developed-by: Liang ZhiCheng <liangzhicheng@baidu.com>
> Signed-off-by: Liang ZhiCheng <liangzhicheng@baidu.com>
> Signed-off-by: Li RongQing <lirongqing@baidu.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
> ---
> drivers/nvdimm/pmem.c | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
> index bc2f700feef8..0279eb1da3ef 100644
> --- a/drivers/nvdimm/pmem.c
> +++ b/drivers/nvdimm/pmem.c
> @@ -113,13 +113,13 @@ static void write_pmem(void *pmem_addr, struct page *page,
>
> while (len) {
> mem = kmap_atomic(page);
> - chunk = min_t(unsigned int, len, PAGE_SIZE);
> + chunk = min_t(unsigned int, len, PAGE_SIZE - off);
> memcpy_flushcache(pmem_addr, mem + off, chunk);
> kunmap_atomic(mem);
> len -= chunk;
> off = 0;
> page++;
> - pmem_addr += PAGE_SIZE;
> + pmem_addr += chunk;
> }
> }
>
> @@ -132,7 +132,7 @@ static blk_status_t read_pmem(struct page *page, unsigned int off,
>
> while (len) {
> mem = kmap_atomic(page);
> - chunk = min_t(unsigned int, len, PAGE_SIZE);
> + chunk = min_t(unsigned int, len, PAGE_SIZE - off);
> rem = memcpy_mcsafe(mem + off, pmem_addr, chunk);
> kunmap_atomic(mem);
> if (rem)
> @@ -140,7 +140,7 @@ static blk_status_t read_pmem(struct page *page, unsigned int off,
> len -= chunk;
> off = 0;
> page++;
> - pmem_addr += PAGE_SIZE;
> + pmem_addr += chunk;
> }
> return BLK_STS_OK;
> }
> --
> 2.16.2
>
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next prev parent reply other threads:[~2019-04-04 16:54 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-04 2:58 [PATCH] libnvdimm, pmem: fix a possible OOB access when read and write pmem Li RongQing
2019-04-04 16:54 ` Ira Weiny [this message]
2019-04-05 15:43 ` Jeff Moyer
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