[PATCH v2] net/bnxt/tf_core: fix SRAM block allocation failure handling

[Manish Kurup]

In tf_sram_mgr_alloc(), two sequential 64B blocks are allocated from
the resource manager before the tf_sram_block tracking structure is
created with tf_sram_alloc_block(). If that allocation fails it
returns NULL, but the NULL result was not checked: the RM indices
stayed marked in use and could never be reused, and the NULL block
was then dereferenced via block->block_id.

Release both RM indices and return -ENOMEM when the block structure
cannot be allocated, as is already done when the two indices are not
sequential.

Fixes: 37ff91c158a3 ("net/bnxt: add SRAM manager model")
Cc: stable at dpdk.org

Signed-off-by: Manish Kurup <manish.kurup at broadcom.com>
---
v2:
* Split out of "net/bnxt: fix multiple truflow defects" (one fix per
  patch); this is the tf_sram_mgr_alloc() fix.
* New subject and commit message (also notes the NULL dereference);
  single Fixes: tag.

 drivers/net/bnxt/tf_core/tf_sram_mgr.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/net/bnxt/tf_core/tf_sram_mgr.c b/drivers/net/bnxt/tf_core/tf_sram_mgr.c
index 0dffd74cd5..70bdb0ba1b 100644
--- a/drivers/net/bnxt/tf_core/tf_sram_mgr.c
+++ b/drivers/net/bnxt/tf_core/tf_sram_mgr.c
@@ -710,6 +710,15 @@ int tf_sram_mgr_alloc(void *sram_handle,
 		}
 		block_id = index;
 		block = tf_sram_alloc_block(slice_list, block_id);
+		if (unlikely(!block)) {
+			fparms.index = index;
+			fparms.subtype = parms->tbl_type;
+			fparms.rm_db = parms->rm_db;
+			tf_rm_free(&fparms);
+			fparms.index = next_index;
+			tf_rm_free(&fparms);
+			return -ENOMEM;
+		}
 
 	} else {
 		/* Block exists
-- 
2.31.1