From: Haimin Zhang <tcs_kernel@xxxxxxxxxxx> commit d6d86830705f173fca6087a3e67ceaf68db80523 upstream. struct tipc_socket_addr.ref has a 4-byte hole,and __tipc_getname() currently copying it to user space,causing kernel-infoleak. BUG: KMSAN: kernel-infoleak in instrument_copy_to_user include/linux/instrumented.h:121 [inline] BUG: KMSAN: kernel-infoleak in instrument_copy_to_user include/linux/instrumented.h:121 [inline] lib/usercopy.c:33 BUG: KMSAN: kernel-infoleak in _copy_to_user+0x1c9/0x270 lib/usercopy.c:33 lib/usercopy.c:33 instrument_copy_to_user include/linux/instrumented.h:121 [inline] instrument_copy_to_user include/linux/instrumented.h:121 [inline] lib/usercopy.c:33 _copy_to_user+0x1c9/0x270 lib/usercopy.c:33 lib/usercopy.c:33 copy_to_user include/linux/uaccess.h:209 [inline] copy_to_user include/linux/uaccess.h:209 [inline] net/socket.c:287 move_addr_to_user+0x3f6/0x600 net/socket.c:287 net/socket.c:287 __sys_getpeername+0x470/0x6b0 net/socket.c:1987 net/socket.c:1987 __do_sys_getpeername net/socket.c:1997 [inline] __se_sys_getpeername net/socket.c:1994 [inline] __do_sys_getpeername net/socket.c:1997 [inline] net/socket.c:1994 __se_sys_getpeername net/socket.c:1994 [inline] net/socket.c:1994 __x64_sys_getpeername+0xda/0x120 net/socket.c:1994 net/socket.c:1994 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_x64 arch/x86/entry/common.c:51 [inline] arch/x86/entry/common.c:82 do_syscall_64+0x54/0xd0 arch/x86/entry/common.c:82 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x44/0xae Uninit was stored to memory at: tipc_getname+0x575/0x5e0 net/tipc/socket.c:757 net/tipc/socket.c:757 __sys_getpeername+0x3b3/0x6b0 net/socket.c:1984 net/socket.c:1984 __do_sys_getpeername net/socket.c:1997 [inline] __se_sys_getpeername net/socket.c:1994 [inline] __do_sys_getpeername net/socket.c:1997 [inline] net/socket.c:1994 __se_sys_getpeername net/socket.c:1994 [inline] net/socket.c:1994 __x64_sys_getpeername+0xda/0x120 net/socket.c:1994 net/socket.c:1994 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_x64 arch/x86/entry/common.c:51 [inline] arch/x86/entry/common.c:82 do_syscall_64+0x54/0xd0 arch/x86/entry/common.c:82 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x44/0xae Uninit was stored to memory at: msg_set_word net/tipc/msg.h:212 [inline] msg_set_destport net/tipc/msg.h:619 [inline] msg_set_word net/tipc/msg.h:212 [inline] net/tipc/socket.c:1486 msg_set_destport net/tipc/msg.h:619 [inline] net/tipc/socket.c:1486 __tipc_sendmsg+0x44fa/0x5890 net/tipc/socket.c:1486 net/tipc/socket.c:1486 tipc_sendmsg+0xeb/0x140 net/tipc/socket.c:1402 net/tipc/socket.c:1402 sock_sendmsg_nosec net/socket.c:704 [inline] sock_sendmsg net/socket.c:724 [inline] sock_sendmsg_nosec net/socket.c:704 [inline] net/socket.c:2409 sock_sendmsg net/socket.c:724 [inline] net/socket.c:2409 ____sys_sendmsg+0xe11/0x12c0 net/socket.c:2409 net/socket.c:2409 ___sys_sendmsg net/socket.c:2463 [inline] ___sys_sendmsg net/socket.c:2463 [inline] net/socket.c:2492 __sys_sendmsg+0x704/0x840 net/socket.c:2492 net/socket.c:2492 __do_sys_sendmsg net/socket.c:2501 [inline] __se_sys_sendmsg net/socket.c:2499 [inline] __do_sys_sendmsg net/socket.c:2501 [inline] net/socket.c:2499 __se_sys_sendmsg net/socket.c:2499 [inline] net/socket.c:2499 __x64_sys_sendmsg+0xe2/0x120 net/socket.c:2499 net/socket.c:2499 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_x64 arch/x86/entry/common.c:51 [inline] arch/x86/entry/common.c:82 do_syscall_64+0x54/0xd0 arch/x86/entry/common.c:82 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x44/0xae Local variable skaddr created at: __tipc_sendmsg+0x2d0/0x5890 net/tipc/socket.c:1419 net/tipc/socket.c:1419 tipc_sendmsg+0xeb/0x140 net/tipc/socket.c:1402 net/tipc/socket.c:1402 Bytes 4-7 of 16 are uninitialized Memory access of size 16 starts at ffff888113753e00 Data copied to user address 0000000020000280 Reported-by: syzbot+cdbd40e0c3ca02cae3b7@xxxxxxxxxxxxxxxxxxxxxxxxx Signed-off-by: Haimin Zhang <tcs_kernel@xxxxxxxxxxx> Acked-by: Jon Maloy <jmaloy@xxxxxxxxxx> Link: https://lore.kernel.org/r/1640918123-14547-1-git-send-email-tcs.kernel@xxxxxxxxx Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/tipc/socket.c | 2 ++ 1 file changed, 2 insertions(+) --- a/net/tipc/socket.c +++ b/net/tipc/socket.c @@ -1461,6 +1461,8 @@ static int __tipc_sendmsg(struct socket msg_set_syn(hdr, 1); } + memset(&skaddr, 0, sizeof(skaddr)); + /* Determine destination */ if (atype == TIPC_SERVICE_RANGE) { return tipc_sendmcast(sock, ua, m, dlen, timeout);
