linux/net/ax25
Eric Dumazet 8156210d36 ax25: properly unshare skbs in ax25_kiss_rcv()
Bernard Pidoux reported a regression apparently caused by commit
c353e8983e ("net: introduce per netns packet chains").

skb->dev becomes NULL and we crash in __netif_receive_skb_core().

Before above commit, different kind of bugs or corruptions could happen
without a major crash.

But the root cause is that ax25_kiss_rcv() can queue/mangle input skb
without checking if this skb is shared or not.

Many thanks to Bernard Pidoux for his help, diagnosis and tests.

We had a similar issue years ago fixed with commit 7aaed57c5c
("phonet: properly unshare skbs in phonet_rcv()").

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Reported-by: Bernard Pidoux <f6bvp@free.fr>
Closes: https://lore.kernel.org/netdev/1713f383-c538-4918-bc64-13b3288cd542@free.fr/
Tested-by: Bernard Pidoux <f6bvp@free.fr>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Joerg Reuter <jreuter@yaina.de>
Cc: David Ranch <dranch@trinnet.net>
Cc: Folkert van Heusden <folkert@vanheusden.com>
Reviewed-by: Dan Cross <crossd@gmail.com>
Link: https://patch.msgid.link/20250902124642.212705-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-03 17:06:30 -07:00
..
af_ax25.c treewide, timers: Rename from_timer() to timer_container_of() 2025-06-08 09:07:37 +02:00
ax25_addr.c
ax25_dev.c
ax25_ds_in.c
ax25_ds_subr.c
ax25_ds_timer.c treewide, timers: Rename from_timer() to timer_container_of() 2025-06-08 09:07:37 +02:00
ax25_iface.c
ax25_in.c ax25: properly unshare skbs in ax25_kiss_rcv() 2025-09-03 17:06:30 -07:00
ax25_ip.c
ax25_out.c
ax25_route.c ax25: Remove broken autobind 2025-03-24 10:26:53 +00:00
ax25_std_in.c
ax25_std_subr.c
ax25_std_timer.c
ax25_subr.c treewide: Switch/rename to timer_delete[_sync]() 2025-04-05 10:30:12 +02:00
ax25_timer.c treewide, timers: Rename from_timer() to timer_container_of() 2025-06-08 09:07:37 +02:00
ax25_uid.c
Kconfig
Makefile
sysctl_net_ax25.c