CVE-2022-50531

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> tipc: fix an information leak in tipc_topsrv_kern_subscr<br /> <br /> Use a 8-byte write to initialize sub.usr_handle in<br /> tipc_topsrv_kern_subscr(), otherwise four bytes remain uninitialized<br /> when issuing setsockopt(..., SOL_TIPC, ...).<br /> This resulted in an infoleak reported by KMSAN when the packet was<br /> received:<br /> <br /> =====================================================<br /> BUG: KMSAN: kernel-infoleak in copyout+0xbc/0x100 lib/iov_iter.c:169<br /> instrument_copy_to_user ./include/linux/instrumented.h:121<br /> copyout+0xbc/0x100 lib/iov_iter.c:169<br /> _copy_to_iter+0x5c0/0x20a0 lib/iov_iter.c:527<br /> copy_to_iter ./include/linux/uio.h:176<br /> simple_copy_to_iter+0x64/0xa0 net/core/datagram.c:513<br /> __skb_datagram_iter+0x123/0xdc0 net/core/datagram.c:419<br /> skb_copy_datagram_iter+0x58/0x200 net/core/datagram.c:527<br /> skb_copy_datagram_msg ./include/linux/skbuff.h:3903<br /> packet_recvmsg+0x521/0x1e70 net/packet/af_packet.c:3469<br /> ____sys_recvmsg+0x2c4/0x810 net/socket.c:?<br /> ___sys_recvmsg+0x217/0x840 net/socket.c:2743<br /> __sys_recvmsg net/socket.c:2773<br /> __do_sys_recvmsg net/socket.c:2783<br /> __se_sys_recvmsg net/socket.c:2780<br /> __x64_sys_recvmsg+0x364/0x540 net/socket.c:2780<br /> do_syscall_x64 arch/x86/entry/common.c:50<br /> do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80<br /> entry_SYSCALL_64_after_hwframe+0x63/0xcd arch/x86/entry/entry_64.S:120<br /> <br /> ...<br /> <br /> Uninit was stored to memory at:<br /> tipc_sub_subscribe+0x42d/0xb50 net/tipc/subscr.c:156<br /> tipc_conn_rcv_sub+0x246/0x620 net/tipc/topsrv.c:375<br /> tipc_topsrv_kern_subscr+0x2e8/0x400 net/tipc/topsrv.c:579<br /> tipc_group_create+0x4e7/0x7d0 net/tipc/group.c:190<br /> tipc_sk_join+0x2a8/0x770 net/tipc/socket.c:3084<br /> tipc_setsockopt+0xae5/0xe40 net/tipc/socket.c:3201<br /> __sys_setsockopt+0x87f/0xdc0 net/socket.c:2252<br /> __do_sys_setsockopt net/socket.c:2263<br /> __se_sys_setsockopt net/socket.c:2260<br /> __x64_sys_setsockopt+0xe0/0x160 net/socket.c:2260<br /> do_syscall_x64 arch/x86/entry/common.c:50<br /> do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80<br /> entry_SYSCALL_64_after_hwframe+0x63/0xcd arch/x86/entry/entry_64.S:120<br /> <br /> Local variable sub created at:<br /> tipc_topsrv_kern_subscr+0x57/0x400 net/tipc/topsrv.c:562<br /> tipc_group_create+0x4e7/0x7d0 net/tipc/group.c:190<br /> <br /> Bytes 84-87 of 88 are uninitialized<br /> Memory access of size 88 starts at ffff88801ed57cd0<br /> Data copied to user address 0000000020000400<br /> ...<br /> =====================================================