qed: fix double free in qed_cxt_tables_alloc()

If one of the later PF or VF CID bitmap allocations fails,
qed_cid_map_alloc() jumps to cid_map_fail and frees the previously
allocated CID bitmaps before returning an error. qed_cxt_tables_alloc()
then calls qed_cxt_mngr_free(), which invokes qed_cid_map_free()
again.

Fix this by setting each CID bitmap pointer to NULL after bitmap_free()
to avoid double free.

The bug was first flagged by an experimental analysis tool we are
developing for kernel memory-management bugs while analyzing
v6.13-rc1. The tool is still under development and is not yet publicly
available. Manual inspection confirms that the bug is still
present in v7.1-rc3.

Runtime reproduction was not attempted because exercising the failing
allocation path requires device-specific setup.

Fixes: fe56b9e6a8d9 ("qed: Add module with basic common support")
Cc: stable@vger.kernel.org
Signed-off-by: Zilin Guan <zilin@seu.edu.cn>
Signed-off-by: Dawei Feng <dawei.feng@seu.edu.cn>
Link: https://patch.msgid.link/20260520070323.2762379-1-dawei.feng@seu.edu.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/ethernet/qlogic/qed/qed_cxt.c b/drivers/net/ethernet/qlogic/qed/qed_cxt.c
index 9861daa82d9e85b61802b01632314541b6b00474..b70262e70baf6e7deb48a4a700968eef12e73b20 100644 (file)
--- a/drivers/net/ethernet/qlogic/qed/qed_cxt.c
+++ b/drivers/net/ethernet/qlogic/qed/qed_cxt.c
@@ -1036,11 +1036,13 @@ static void qed_cid_map_free(struct qed_hwfn *p_hwfn)
 
        for (type = 0; type < MAX_CONN_TYPES; type++) {
                bitmap_free(p_mngr->acquired[type].cid_map);
+               p_mngr->acquired[type].cid_map = NULL;
                p_mngr->acquired[type].max_count = 0;
                p_mngr->acquired[type].start_cid = 0;
 
                for (vf = 0; vf < MAX_NUM_VFS; vf++) {
                        bitmap_free(p_mngr->acquired_vf[type][vf].cid_map);
+                       p_mngr->acquired_vf[type][vf].cid_map = NULL;
                        p_mngr->acquired_vf[type][vf].max_count = 0;
                        p_mngr->acquired_vf[type][vf].start_cid = 0;
                }