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| author | Moritz Fischer <mdf@kernel.org> | 2020-02-04 15:01:18 -0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2020-02-05 14:21:31 +0100 |
| commit | 33e2b32b5df2b544ac5d43c4de2194bcc822b1b5 (patch) | |
| tree | d6a1cb4363e7c15cf6ad8772ee9aaeeffbe2f94e /drivers/net/ethernet/dec/tulip/de2104x.c | |
| parent | 7bb77d4b8567b35aadd57f3154a08d873572ae20 (diff) | |
| download | lwn-33e2b32b5df2b544ac5d43c4de2194bcc822b1b5.tar.gz lwn-33e2b32b5df2b544ac5d43c4de2194bcc822b1b5.zip | |
net: ethernet: dec: tulip: Fix length mask in receive length calculation
The receive frame length calculation uses a wrong mask to calculate the
length of the received frames.
Per spec table 4-1 the length is contained in the FL (Frame Length)
field in bits 30:16.
This didn't show up as an issue so far since frames were limited to
1500 bytes which falls within the 11 bit window.
Signed-off-by: Moritz Fischer <mdf@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/ethernet/dec/tulip/de2104x.c')
| -rw-r--r-- | drivers/net/ethernet/dec/tulip/de2104x.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/drivers/net/ethernet/dec/tulip/de2104x.c b/drivers/net/ethernet/dec/tulip/de2104x.c index d305d1b24b0a..42b798a3fad4 100644 --- a/drivers/net/ethernet/dec/tulip/de2104x.c +++ b/drivers/net/ethernet/dec/tulip/de2104x.c @@ -417,7 +417,10 @@ static void de_rx (struct de_private *de) if (status & DescOwn) break; - len = ((status >> 16) & 0x7ff) - 4; + /* the length is actually a 15 bit value here according + * to Table 4-1 in the DE2104x spec so mask is 0x7fff + */ + len = ((status >> 16) & 0x7fff) - 4; mapping = de->rx_skb[rx_tail].mapping; if (unlikely(drop)) { |