• Tao Liu's avatar
    RDMA/cma: Fix listener leak in rdma_cma_listen_on_all() failure · ca465e1f
    Tao Liu authored
    If cma_listen_on_all() fails it leaves the per-device ID still on the
    listen_list but the state is not set to RDMA_CM_ADDR_BOUND.
    
    When the cmid is eventually destroyed cma_cancel_listens() is not called
    due to the wrong state, however the per-device IDs are still holding the
    refcount preventing the ID from being destroyed, thus deadlocking:
    
     task:rping state:D stack:   0 pid:19605 ppid: 47036 flags:0x00000084
     Call Trace:
      __schedule+0x29a/0x780
      ? free_unref_page_commit+0x9b/0x110
      schedule+0x3c/0xa0
      schedule_timeout+0x215/0x2b0
      ? __flush_work+0x19e/0x1e0
      wait_for_completion+0x8d/0xf0
      _destroy_id+0x144/0x210 [rdma_cm]
      ucma_close_id+0x2b/0x40 [rdma_ucm]
      __destroy_id+0x93/0x2c0 [rdma_ucm]
      ? __xa_erase+0x4a/0xa0
      ucma_destroy_id+0x9a/0x120 [rdma_ucm]
      ucma_write+0xb8/0x130 [rdma_ucm]
      vfs_write+0xb4/0x250
      ksys_write+0xb5/0xd0
      ? syscall_trace_enter.isra.19+0x123/0x190
      do_syscall_64+0x33/0x40
      entry_SYSCALL_64_after_hwframe+0x44/0xa9
    
    Ensure that cma_listen_on_all() atomically unwinds its action under the
    lock during error.
    
    Fixes: c80a0c52 ("RDMA/cma: Add missing error handling of listen_id")
    Link: https://lore.kernel.org/r/20210913093344.17230-1-thomas.liu@ucloud.cnSigned-off-by: default avatarTao Liu <thomas.liu@ucloud.cn>
    Reviewed-by: default avatarLeon Romanovsky <leonro@nvidia.com>
    Signed-off-by: default avatarJason Gunthorpe <jgg@nvidia.com>
    ca465e1f
cma.c 134 KB