[ Upstream commit 9dc6488e84b0f64df17672271664752488cd6a25 ]
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 Reviewed-by: Jeff Moyer jmoyer@redhat.com Signed-off-by: Dan Williams dan.j.williams@intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- 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 1d432c5ed2753..cff027fc26761 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; }