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CVE-2022-48865

Description

In the Linux kernel, the following vulnerability has been resolved:tipc: fix kernel panic when enabling bearerWhen enabling a bearer on a node, a kernel panic is observed:[ 4.498085] RIP: 0010:tipc_mon_prep+0x4e/0x130 [tipc]...[ 4.520030] Call Trace:[ 4.520689] [ 4.521236] tipc_link_build_proto_msg+0x375/0x750 [tipc][ 4.522654] tipc_link_build_state_msg+0x48/0xc0 [tipc][ 4.524034] __tipc_node_link_up+0xd7/0x290 [tipc][ 4.525292] tipc_rcv+0x5da/0x730 [tipc][ 4.526346] ? __netif_receive_skb_core+0xb7/0xfc0[ 4.527601] tipc_l2_rcv_msg+0x5e/0x90 [tipc][ 4.528737] __netif_receive_skb_list_core+0x20b/0x260[ 4.530068] netif_receive_skb_list_internal+0x1bf/0x2e0[ 4.531450] ? dev_gro_receive+0x4c2/0x680[ 4.532512] napi_complete_done+0x6f/0x180[ 4.533570] virtnet_poll+0x29c/0x42e [virtio_net]...The node in question is receiving activate messages in anotherthread after changing bearer status to allow message sending/receiving in current thread: thread 1 | thread 2 -------- | -------- |tipc_enable_bearer() | test_and_set_bit_lock() | tipc_bearer_xmit_skb() | | tipc_l2_rcv_msg() | tipc_rcv() | __tipc_node_link_up() | tipc_link_build_state_msg() | tipc_link_build_proto_msg() | tipc_mon_prep() | { | ... | // null-pointer dereference | u16 gen = mon->dom_gen; | ... | } // Not being executed yet | tipc_mon_create() | { | ... | // allocate | mon = kzalloc(); | ... | } |Monitoring pointer in thread 2 is dereferenced before monitoring datais allocated in thread 1. This causes kernel panic.This commit fixes it by allocating the monitoring data before enablingthe bearer to receive messages.

CVE-2022-48865

Description

POC

Reference

Github