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author | Xie He <xie.he.0141@gmail.com> | 2021-02-01 06:57:06 +0100 |
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committer | Jakub Kicinski <kuba@kernel.org> | 2021-02-02 17:40:48 +0100 |
commit | 88c7a9fd9bdd3e453f04018920964c6f848a591a (patch) | |
tree | c23e141783bf91569d06000f5c3c26153b9ecbb5 /net/lapb/lapb_timer.c | |
parent | Merge tag 'mac80211-for-net-2021-02-02' of git://git.kernel.org/pub/scm/linux... (diff) | |
download | linux-88c7a9fd9bdd3e453f04018920964c6f848a591a.tar.xz linux-88c7a9fd9bdd3e453f04018920964c6f848a591a.zip |
net: lapb: Copy the skb before sending a packet
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>
Diffstat (limited to 'net/lapb/lapb_timer.c')
0 files changed, 0 insertions, 0 deletions