• Jens Axboe's avatar
    io_uring/net: fix sr->len for IORING_OP_RECV with MSG_WAITALL and buffers · 72bd8025
    Jens Axboe authored
    If we use IORING_OP_RECV with provided buffers and pass in '0' as the
    length of the request, the length is retrieved from the selected buffer.
    If MSG_WAITALL is also set and we get a short receive, then we may hit
    the retry path which decrements sr->len and increments the buffer for
    a retry. However, the length is still zero at this point, which means
    that sr->len now becomes huge and import_ubuf() will cap it to
    MAX_RW_COUNT and subsequently return -EFAULT for the range as a whole.
    
    Fix this by always assigning sr->len once the buffer has been selected.
    
    Cc: stable@vger.kernel.org
    Fixes: 7ba89d2a ("io_uring: ensure recv and recvmsg handle MSG_WAITALL correctly")
    Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
    72bd8025
net.c 38.8 KB