From: Hemant Agrawal <[email protected]>
In lsx_ccsr_map_region, PAGE_SIZE is a macro defined as
sysconf(_SC_PAGESIZE), which returns a signed long and may be negative
on error. The value was used directly in size_t comparisons and passed
to mmap, causing an integer overflow (Coverity CID 49765682).
The old round-down "len & PAGE_MASK" ignored the in-page offset: for a
4096-byte or 6656-byte len on a 64K-page kernel the masked result is 0,
causing the mapping to fail, where the old code would have bumped len up
to PAGE_SIZE. The correct mapping size must cover the region from the
page-aligned start through offset + len.
Fix by calling sysconf(_SC_PAGESIZE) explicitly into a signed long,
checking for a non-positive return before use, computing page_mask from
the verified value, and using RTE_ALIGN_CEIL(offset + len, page_size)
for map_len so that the mmap covers the full requested region regardless
of page size. The page-aligned start address and the back-pointer offset
are both derived from the same page_mask, keeping the three values
consistent.
Coverity issue: 49765682
Fixes: f023d059769f ("net/dpaa2: support recycle loopback port")
Cc: [email protected]
Signed-off-by: Hemant Agrawal <[email protected]>
---
drivers/net/dpaa2/dpaa2_recycle.c | 23 +++++++++++++++--------
1 file changed, 15 insertions(+), 8 deletions(-)
diff --git a/drivers/net/dpaa2/dpaa2_recycle.c
b/drivers/net/dpaa2/dpaa2_recycle.c
index f78d12362e..9b6ae3f515 100644
--- a/drivers/net/dpaa2/dpaa2_recycle.c
+++ b/drivers/net/dpaa2/dpaa2_recycle.c
@@ -176,6 +176,9 @@ static void *lsx_ccsr_map_region(uint64_t addr, size_t len)
void *tmp;
uint64_t start;
uint64_t offset;
+ uint64_t page_mask;
+ long page_size;
+ size_t map_len;
fd = open("/dev/mem", O_RDWR);
if (fd < 0) {
@@ -183,20 +186,24 @@ static void *lsx_ccsr_map_region(uint64_t addr, size_t
len)
return NULL;
}
- start = addr & PAGE_MASK;
+ page_size = sysconf(_SC_PAGESIZE);
+ if (page_size <= 0) {
+ close(fd);
+ return NULL;
+ }
+ page_mask = ~((uint64_t)page_size - 1);
+ start = addr & page_mask;
offset = addr - start;
- len = len & PAGE_MASK;
- if (len < (size_t)PAGE_SIZE)
- len = PAGE_SIZE;
+ map_len = RTE_ALIGN_CEIL(offset + len, (size_t)page_size);
- tmp = mmap(NULL, len, PROT_READ | PROT_WRITE, MAP_SHARED, fd, start);
+ tmp = mmap(NULL, map_len, PROT_READ | PROT_WRITE, MAP_SHARED, fd,
start);
close(fd);
- if (tmp != MAP_FAILED)
- return (uint8_t *)tmp + offset;
- else
+ if (tmp == MAP_FAILED)
return NULL;
+
+ return (uint8_t *)tmp + offset;
}
static const uint8_t ls_sd1_prot_idx_map[] = {
--
2.43.0
