• David Daney's avatar
    MIPS: Make virt_to_phys() work for all unmapped addresses. · 49c426ba
    David Daney authored
    As reported:
      This problem was discovered when doing BGP traffic with the TCP MD5 option
      activated, where the following call chain caused a crash:
    
       * tcp_v4_rcv
       *  tcp_v4_timewait_ack
       *   tcp_v4_send_ack -> follow stack variable rep.th
       *    tcp_v4_md5_hash_hdr
       *     tcp_md5_hash_header
       *      sg_init_one
       *       sg_set_buf
       *        virt_to_page
    
      I noticed that tcp_v4_send_reset uses a similar stack variable and
      also calls tcp_v4_md5_hash_hdr, so it has the same problem.
    
    The networking core can indirectly call virt_to_phys() on stack
    addresses, if this is done from PID 0, the stack will usually be in
    CKSEG0, so virt_to_phys() needs to work there as well
    Signed-off-by: default avatarDavid Daney <david.daney@cavium.com>
    Cc: linux-mips@linux-mips.org
    Cc: Jiang Liu <liuj97@gmail.com>
    Cc: eunb.song@samsung.com
    Cc: linux-kernel@vger.kernel.org
    Patchwork: https://patchwork.linux-mips.org/patch/5220/Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
    49c426ba
io.h 18.4 KB