nvd-json-data-feeds/CVE-2021/CVE-2021-476xx/CVE-2021-47615.json

{
  "id": "CVE-2021-47615",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2024-06-19T15:15:56.030",
  "lastModified": "2024-06-20T12:43:25.663",
  "vulnStatus": "Awaiting Analysis",
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nRDMA/mlx5: Fix releasing unallocated memory in dereg MR flow\n\nFor the case of IB_MR_TYPE_DM the mr does doesn't have a umem, even though\nit is a user MR. This causes function mlx5_free_priv_descs() to think that\nit is a kernel MR, leading to wrongly accessing mr->descs that will get\nwrong values in the union which leads to attempt to release resources that\nwere not allocated in the first place.\n\nFor example:\n DMA-API: mlx5_core 0000:08:00.1: device driver tries to free DMA memory it has not allocated [device address=0x0000000000000000] [size=0 bytes]\n WARNING: CPU: 8 PID: 1021 at kernel/dma/debug.c:961 check_unmap+0x54f/0x8b0\n RIP: 0010:check_unmap+0x54f/0x8b0\n Call Trace:\n  debug_dma_unmap_page+0x57/0x60\n  mlx5_free_priv_descs+0x57/0x70 [mlx5_ib]\n  mlx5_ib_dereg_mr+0x1fb/0x3d0 [mlx5_ib]\n  ib_dereg_mr_user+0x60/0x140 [ib_core]\n  uverbs_destroy_uobject+0x59/0x210 [ib_uverbs]\n  uobj_destroy+0x3f/0x80 [ib_uverbs]\n  ib_uverbs_cmd_verbs+0x435/0xd10 [ib_uverbs]\n  ? uverbs_finalize_object+0x50/0x50 [ib_uverbs]\n  ? lock_acquire+0xc4/0x2e0\n  ? lock_acquired+0x12/0x380\n  ? lock_acquire+0xc4/0x2e0\n  ? lock_acquire+0xc4/0x2e0\n  ? ib_uverbs_ioctl+0x7c/0x140 [ib_uverbs]\n  ? lock_release+0x28a/0x400\n  ib_uverbs_ioctl+0xc0/0x140 [ib_uverbs]\n  ? ib_uverbs_ioctl+0x7c/0x140 [ib_uverbs]\n  __x64_sys_ioctl+0x7f/0xb0\n  do_syscall_64+0x38/0x90\n\nFix it by reorganizing the dereg flow and mlx5_ib_mr structure:\n - Move the ib_umem field into the user MRs structure in the union as it's\n   applicable only there.\n - Function mlx5_ib_dereg_mr() will now call mlx5_free_priv_descs() only\n   in case there isn't udata, which indicates that this isn't a user MR."
    },
    {
      "lang": "es",
      "value": "En el kernel de Linux, se resolvi\u00f3 la siguiente vulnerabilidad: RDMA/mlx5: Se corrigi\u00f3 la liberaci\u00f3n de memoria no asignada en el flujo de MR dereg. Para el caso de IB_MR_TYPE_DM, mr no tiene un umem, aunque sea un usuario MR. Esto hace que la funci\u00f3n mlx5_free_priv_descs() piense que es un MR del kernel, lo que lleva a un acceso incorrecto a mr->descs que obtendr\u00e1 valores incorrectos en la uni\u00f3n, lo que lleva a intentar liberar recursos que no fueron asignados en primer lugar. Por ejemplo: DMA-API: mlx5_core 0000:08:00.1: el controlador de dispositivo intenta liberar la memoria DMA que no ha asignado [direcci\u00f3n del dispositivo=0x0000000000000000] [tama\u00f1o=0 bytes] ADVERTENCIA: CPU: 8 PID: 1021 en kernel/dma/ debug.c:961 check_unmap+0x54f/0x8b0 RIP: 0010:check_unmap+0x54f/0x8b0 Seguimiento de llamadas: debug_dma_unmap_page+0x57/0x60 mlx5_free_priv_descs+0x57/0x70 [mlx5_ib] [mlx5_ib] ib_dereg_mr_user+0x60/0x140 [ib_core ] uverbs_destroy_uobject+0x59/0x210 [ib_uverbs] uobj_destroy+0x3f/0x80 [ib_uverbs] ib_uverbs_cmd_verbs+0x435/0xd10 [ib_uverbs] ? uverbs_finalize_object+0x50/0x50 [ib_uverbs] ? lock_acquire+0xc4/0x2e0? lock_adquirido+0x12/0x380? lock_acquire+0xc4/0x2e0? lock_acquire+0xc4/0x2e0? ib_uverbs_ioctl+0x7c/0x140 [ib_uverbs] ? lock_release+0x28a/0x400 ib_uverbs_ioctl+0xc0/0x140 [ib_uverbs]? ib_uverbs_ioctl+0x7c/0x140 [ib_uverbs] __x64_sys_ioctl+0x7f/0xb0 do_syscall_64+0x38/0x90 Soluci\u00f3nelo reorganizando el flujo de dereg y la estructura mlx5_ib_mr: - Mueva el campo ib_umem a la estructura MRs del usuario en la uni\u00f3n, ya que solo se aplica all\u00ed. - La funci\u00f3n mlx5_ib_dereg_mr() ahora llamar\u00e1 a mlx5_free_priv_descs() solo en caso de que no haya udata, lo que indica que no se trata de un usuario MR."
    }
  ],
  "metrics": {},
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/c44979ace49b4aede3cc7cb5542316e53a4005c9",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/e3bc4d4b50cae7db08e50dbe43f771c906e97701",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/f0ae4afe3d35e67db042c58a52909e06262b740f",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ]
}