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

[Andrew Rybchenko]

From: Ivan Ilchenko <ivan.ilchenko at 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: stable at dpdk.org

Reported-by: Andy Moreton <amoreton at xilinx.com>
Signed-off-by: Ivan Ilchenko <ivan.ilchenko at oktetlabs.ru>
Reviewed-by: Andy Moreton <amoreton at xilinx.com>
Signed-off-by: Andrew Rybchenko <andrew.rybchenko at 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