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    Subject[38/45] b44 WOL setup: one-bit-off stack corruption kernel panic fix
    2.6.27-stable review patch.  If anyone has any objections, please let us know.


    From: Stanislav Brabec <>

    commit e0188829cb724e7d12a2d4e343b368ff1d6e1471 upstream.

    About 50% of shutdowns of b44 Ethernet adapter ends by kernel panic
    with kernels compiled with stack-protector.

    Checking b44_magic_pattern() return values, one call of
    b44_magic_pattern() returns 127. It means, that set_bit(128, pmask)
    was called on line 1509. It means that bit 0 of 17th byte of pmask was
    overwritten. But pmask has only 16 bytes. Stack corruption happens.

    It seems that set_bit() on line 1509 always writes one bit off.

    The fix does not only solve the stack corruption, but also makes Wake
    On LAN working on my onboard B44 on Asus A7V-333X mainboard.

    It seems that this problem affects all kernel versions since commit
    725ad800 ([PATCH] b44: add wol for old nic) on 2006-06-20.

    Signed-off-by: Stanislav Brabec <>
    Signed-off-by: David S. Miller <>
    Signed-off-by: Greg Kroah-Hartman <>

    drivers/net/b44.c | 3 +--
    1 file changed, 1 insertion(+), 2 deletions(-)

    --- a/drivers/net/b44.c
    +++ b/drivers/net/b44.c
    @@ -1502,8 +1502,7 @@ static int b44_magic_pattern(u8 *macaddr
    for (k = 0; k< ethaddr_bytes; k++) {
    ppattern[offset + magicsync +
    (j * ETH_ALEN) + k] = macaddr[k];
    - len++;
    - set_bit(len, (unsigned long *) pmask);
    + set_bit(len++, (unsigned long *) pmask);
    return len - 1;

     \ /
      Last update: 2010-03-31 01:15    [W:4.189 / U:0.012 seconds]
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