* [PATCH] libnvdimm, pmem: fix a possible OOB access when read and write pmem
@ 2019-04-04 2:58 Li RongQing
2019-04-04 16:54 ` Ira Weiny
2019-04-05 15:43 ` Jeff Moyer
0 siblings, 2 replies; 3+ messages in thread
From: Li RongQing @ 2019-04-04 2:58 UTC (permalink / raw)
To: dan.j.williams, vishal.l.verma, dave.jiang, keith.busch,
ira.weiny, linux-nvdimm
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>
---
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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^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [PATCH] libnvdimm, pmem: fix a possible OOB access when read and write pmem
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
2019-04-05 15:43 ` Jeff Moyer
1 sibling, 0 replies; 3+ messages in thread
From: Ira Weiny @ 2019-04-04 16:54 UTC (permalink / raw)
To: Li RongQing; +Cc: linux-nvdimm
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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^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH] libnvdimm, pmem: fix a possible OOB access when read and write pmem
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
@ 2019-04-05 15:43 ` Jeff Moyer
1 sibling, 0 replies; 3+ messages in thread
From: Jeff Moyer @ 2019-04-05 15:43 UTC (permalink / raw)
To: Li RongQing; +Cc: linux-nvdimm
Li RongQing <lirongqing@baidu.com> writes:
> If offset is not zero and length is bigger than PAGE_SIZE,
> this will cause to out of boundary access to a page memory
Agreed, though I don't think this can be triggered in practice.
> 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: Jeff Moyer <jmoyer@redhat.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;
> }
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^ permalink raw reply [flat|nested] 3+ messages in thread
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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
2019-04-05 15:43 ` Jeff Moyer
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