CentOS Linux 8.4 ホストには、TuxCare CENTOS8.4:CLSA-2024:1707478061アドバイザリに記載されている複数の脆弱性の影響を受けるパッケージがインストールされています。

  - Linux カーネルでは、以下の脆弱性が解決されています: RDMA/cma: Ensure rdma_addr_cancel() happens before issuing more requests The FSM can run in a circle allowing rdma_resolve_ip() to be called twice on the same id_priv. While this cannot happen without going through the work, it violates the invariant that the same address resolution background request cannot be active twice. CPU 1 CPU 2 rdma_resolve_addr(): RDMA_CM_IDLE -> RDMA_CM_ADDR_QUERY rdma_resolve_ip(addr_handler) #1 process_one_req(): for #1 addr_handler(): RDMA_CM_ADDR_QUERY -> RDMA_CM_ADDR_BOUND mutex_unlock(&id_priv->handler_mutex); [.. handler still running ..] rdma_resolve_addr():
    RDMA_CM_ADDR_BOUND -> RDMA_CM_ADDR_QUERY rdma_resolve_ip(addr_handler) !! two requests are now on the req_list rdma_destroy_id(): destroy_id_handler_unlock(): _destroy_id(): cma_cancel_operation():
    rdma_addr_cancel() // process_one_req() self removes it spin_lock_bh(&lock);
    cancel_delayed_work(&req->work); if (!list_empty(&req->list)) == true ! rdma_addr_cancel() returns after process_on_req #1 is done kfree(id_priv) process_one_req(): for #2 addr_handler():
    mutex_lock(&id_priv->handler_mutex); !! Use after free on id_priv rdma_addr_cancel() expects there to be one req on the list and only cancels the first one. The self-removal behavior of the work only happens after the handler has returned. This yields a situations where the req_list can have two reqs for the same handle but rdma_addr_cancel() only cancels the first one. The second req remains active beyond rdma_destroy_id() and will use-after-free id_priv once it inevitably triggers. Fix this by remembering if the id_priv has called rdma_resolve_ip() and always cancel before calling it again. This ensures the req_list never gets more than one item in it and doesn't cost anything in the normal flow that never uses this strange error path. (CVE-2021-47391)

  - Linux カーネルでは、以下の脆弱性が解決されています: writeback: avoid use-after-free after removing device When a disk is removed, bdi_unregister gets called to stop further writeback and wait for associated delayed work to complete. However, wb_inode_writeback_end() may schedule bandwidth estimation dwork after this has completed, which can result in the timer attempting to access the just freed bdi_writeback. Fix this by checking if the bdi_writeback is alive, similar to when scheduling writeback work. Since this requires wb->work_lock, and wb_inode_writeback_end() may get called from interrupt, switch wb->work_lock to an irqsafe lock. (CVE-2022-49995)

  - 6.4.12 より前の Linux カーネルでは、drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c の amdgpu_cs_wait_all_fences にメモリ解放後使用 (use-after-free) があります。(CVE-2023-51042)

  - 6.4.5 より前の Linux カーネルでは、非ブロッキングアトミックコミットとドライバーアンロードの間の競合状態の間、drivers/gpu/drm/drm_atomic.c にメモリ解放後使用 (Use After Free) があります。(CVE-2023-51043)

  - 6.6.8 より前の Linux カーネルで問題が発見されました。net/atm/ioctl.c の do_vcc_ioctl に、vcc_recvmsg の競合状態によるメモリ解放後使用 (Use After Free) があります。(CVE-2023-51780)

Nessus はこれらの問題をテストしておらず、代わりにアプリケーションが自己報告するバージョン番号にのみ依存していることに注意してください。

検出

CentOS Linux 8.4 [TuxCare] セキュリティ更新プログラム:bpftool/kernel/kernel-core/kernel-cross-headers/etcの複数の脆弱性(CENTOS8.4:CLSA-2024:1707478061)

high Nessus プラグイン ID 366965