• Michael Chan's avatar
    bnxt_en: Fix RX consumer index logic in the error path. · bbd6f0a9
    Michael Chan authored
    In bnxt_rx_pkt(), the RX buffers are expected to complete in order.
    If the RX consumer index indicates an out of order buffer completion,
    it means we are hitting a hardware bug and the driver will abort all
    remaining RX packets and reset the RX ring.  The RX consumer index
    that we pass to bnxt_discard_rx() is not correct.  We should be
    passing the current index (tmp_raw_cons) instead of the old index
    (raw_cons).  This bug can cause us to be at the wrong index when
    trying to abort the next RX packet.  It can crash like this:
    
     #0 [ffff9bbcdf5c39a8] machine_kexec at ffffffff9b05e007
     #1 [ffff9bbcdf5c3a00] __crash_kexec at ffffffff9b111232
     #2 [ffff9bbcdf5c3ad0] panic at ffffffff9b07d61e
     #3 [ffff9bbcdf5c3b50] oops_end at ffffffff9b030978
     #4 [ffff9bbcdf5c3b78] no_context at ffffffff9b06aaf0
     #5 [ffff9bbcdf5c3bd8] __bad_area_nosemaphore at ffffffff9b06ae2e
     #6 [ffff9bbcdf5c3c28] bad_area_nosemaphore at ffffffff9b06af24
     #7 [ffff9bbcdf5c3c38] __do_page_fault at ffffffff9b06b67e
     #8 [ffff9bbcdf5c3cb0] do_page_fault at ffffffff9b06bb12
     #9 [ffff9bbcdf5c3ce0] page_fault at ffffffff9bc015c5
        [exception RIP: bnxt_rx_pkt+237]
        RIP: ffffffffc0259cdd  RSP: ffff9bbcdf5c3d98  RFLAGS: 00010213
        RAX: 000000005dd8097f  RBX: ffff9ba4cb11b7e0  RCX: ffffa923cf6e9000
        RDX: 0000000000000fff  RSI: 0000000000000627  RDI: 0000000000001000
        RBP: ffff9bbcdf5c3e60   R8: 0000000000420003   R9: 000000000000020d
        R10: ffffa923cf6ec138  R11: ffff9bbcdf5c3e83  R12: ffff9ba4d6f928c0
        R13: ffff9ba4cac28080  R14: ffff9ba4cb11b7f0  R15: ffff9ba4d5a30000
        ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
    
    Fixes: a1b0e4e6 ("bnxt_en: Improve RX consumer index validity check.")
    Reviewed-by: default avatarPavan Chebbi <pavan.chebbi@broadcom.com>
    Reviewed-by: default avatarAndy Gospodarek <gospo@broadcom.com>
    Signed-off-by: default avatarMichael Chan <michael.chan@broadcom.com>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    bbd6f0a9
bnxt.c 349 KB