In the Linux kernel, the following vulnerability has been resolved: ppp: fix ppp_async_encode() illegal access syzbot reported an issue in ppp_async_encode() [1] In this case, pppoe_sendmsg() is called with a zero size. Then ppp_async_encode() is called with an empty skb. BUG: KMSAN: uninit-value in ppp_async_encode drivers/net/ppp/ppp_async.c:545 [inline] BUG: KMSAN: uninit-value in ppp_async_push+0xb4f/0x2660 drivers/net/ppp/ppp_async.c:675 ppp_async_encode drivers/net/ppp/ppp_async.c:545 [inline] ppp_async_push+0xb4f/0x2660 drivers/net/ppp/ppp_async.c:675 ppp_async_send+0x130/0x1b0 drivers/net/ppp/ppp_async.c:634 ppp_channel_bridge_input drivers/net/ppp/ppp_generic.c:2280 [inline] ppp_input+0x1f1/0xe60 drivers/net/ppp/ppp_generic.c:2304 pppoe_rcv_core+0x1d3/0x720 drivers/net/ppp/pppoe.c:379 sk_backlog_rcv+0x13b/0x420 include/net/sock.h:1113 __release_sock+0x1da/0x330 net/core/sock.c:3072 release_sock+0x6b/0x250 net/core/sock.c:3626 pppoe_sendmsg+0x2b8/0xb90…