linux_dsm_epyc7002/drivers/net/wan
Xie He 8754e1379e drivers/net/wan: lapb: Corrected the usage of skb_cow
This patch fixed 2 issues with the usage of skb_cow in LAPB drivers
"lapbether" and "hdlc_x25":

1) After skb_cow fails, kfree_skb should be called to drop a reference
to the skb. But in both drivers, kfree_skb is not called.

2) skb_cow should be called before skb_push so that is can ensure the
safety of skb_push. But in "lapbether", it is incorrectly called after
skb_push.

More details about these 2 issues:

1) The behavior of calling kfree_skb on failure is also the behavior of
netif_rx, which is called by this function with "return netif_rx(skb);".
So this function should follow this behavior, too.

2) In "lapbether", skb_cow is called after skb_push. This results in 2
logical issues:
   a) skb_push is not protected by skb_cow;
   b) An extra headroom of 1 byte is ensured after skb_push. This extra
      headroom has no use in this function. It also has no use in the
      upper-layer function that this function passes the skb to
      (x25_lapb_receive_frame in net/x25/x25_dev.c).
So logically skb_cow should instead be called before skb_push.

Cc: Eric Dumazet <edumazet@google.com>
Cc: Martin Schiller <ms@dev.tdt.de>
Signed-off-by: Xie He <xie.he.0141@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-24 20:17:42 -07:00
..
lmc
.gitignore
c101.c
cosa.c
cosa.h
dlci.c
farsync.c
farsync.h
fsl_ucc_hdlc.c
fsl_ucc_hdlc.h
hd64570.c
hd64570.h
hd64572.c
hd64572.h
hdlc_cisco.c
hdlc_fr.c
hdlc_ppp.c
hdlc_raw_eth.c
hdlc_raw.c
hdlc_x25.c drivers/net/wan: lapb: Corrected the usage of skb_cow 2020-07-24 20:17:42 -07:00
hdlc.c
hostess_sv11.c
ixp4xx_hss.c
Kconfig treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
lapbether.c drivers/net/wan: lapb: Corrected the usage of skb_cow 2020-07-24 20:17:42 -07:00
Makefile net: wan: wanxl: refactor the firmware rebuild rule 2020-03-29 22:37:53 +09:00
n2.c
pc300too.c
pci200syn.c
sbni.c
sbni.h
sdla.c
sealevel.c
slic_ds26522.c
slic_ds26522.h
wanxl.c
wanxl.h
wanxlfw.inc_shipped
wanxlfw.S
x25_asy.c drivers/net/wan/x25_asy: Fix to make it work 2020-07-21 18:28:36 -07:00
x25_asy.h
z85230.c
z85230.h