diff options
| author | Xie He <xie.he.0141@gmail.com> | 2021-01-31 21:57:06 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-02-10 09:12:08 +0100 |
| commit | f40e70f117276b35714feb4a573bf15d022dc7c7 (patch) | |
| tree | 497d5549ab813f5ff109c3e6aa72ae1383cc5e2c /tools | |
| parent | d99f2fa0d02b3acb78342031e7bb525b501be7cb (diff) | |
net: lapb: Copy the skb before sending a packet
[ Upstream commit 88c7a9fd9bdd3e453f04018920964c6f848a591a ]
When sending a packet, we will prepend it with an LAPB header.
This modifies the shared parts of a cloned skb, so we should copy the
skb rather than just clone it, before we prepend the header.
In "Documentation/networking/driver.rst" (the 2nd point), it states
that drivers shouldn't modify the shared parts of a cloned skb when
transmitting.
The "dev_queue_xmit_nit" function in "net/core/dev.c", which is called
when an skb is being sent, clones the skb and sents the clone to
AF_PACKET sockets. Because the LAPB drivers first remove a 1-byte
pseudo-header before handing over the skb to us, if we don't copy the
skb before prepending the LAPB header, the first byte of the packets
received on AF_PACKET sockets can be corrupted.
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Xie He <xie.he.0141@gmail.com>
Acked-by: Martin Schiller <ms@dev.tdt.de>
Link: https://lore.kernel.org/r/20210201055706.415842-1-xie.he.0141@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'tools')
0 files changed, 0 insertions, 0 deletions