[dpdk-dev] [PATCH v2] bitmap: fix buffer overrun in bitmap init function

[Andrew Rybchenko]

From: Ivan Ilchenko <ivan.ilche...@oktetlabs.ru>

Bitmap initialization function is allowed to memset()
caller-provided buffer with number of bytes exceeded
this buffer size. This happens due to wrong comparison
sign between buffer size and number of bytes required
to initialize bitmap.

Fixes: 602c9ca33a4 ("sched: bitmap is now dynamically allocated")
Cc: sta...@dpdk.org

Reported-by: Andy Moreton <amore...@xilinx.com>
Signed-off-by: Ivan Ilchenko <ivan.ilche...@oktetlabs.ru>
Reviewed-by: Andy Moreton <amore...@xilinx.com>
Signed-off-by: Andrew Rybchenko <andrew.rybche...@oktetlabs.ru>
---
 lib/eal/include/rte_bitmap.h | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/lib/eal/include/rte_bitmap.h b/lib/eal/include/rte_bitmap.h
index 9e2b8f2cbf..e4623bb176 100644
--- a/lib/eal/include/rte_bitmap.h
+++ b/lib/eal/include/rte_bitmap.h
@@ -185,9 +185,8 @@ rte_bitmap_init(uint32_t n_bits, uint8_t *mem, uint32_t 
mem_size)
        size = __rte_bitmap_get_memory_footprint(n_bits,
                &array1_byte_offset, &array1_slabs,
                &array2_byte_offset, &array2_slabs);
-       if (size < mem_size) {
+       if (size > mem_size)
                return NULL;
-       }
 
        /* Setup bitmap */
        memset(mem, 0, size);
-- 
2.30.2