| Message ID | 20221012152514.2060384-1-glider@google.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 777ecaabd614d47c482a5c9031579e66da13989a |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | tipc: fix an information leak in tipc_topsrv_kern_subscr | expand |
Hello: This patch was applied to netdev/net.git (master) by David S. Miller <davem@davemloft.net>: On Wed, 12 Oct 2022 17:25:14 +0200 you wrote: > Use a 8-byte write to initialize sub.usr_handle in > tipc_topsrv_kern_subscr(), otherwise four bytes remain uninitialized > when issuing setsockopt(..., SOL_TIPC, ...). > This resulted in an infoleak reported by KMSAN when the packet was > received: > > ===================================================== > BUG: KMSAN: kernel-infoleak in copyout+0xbc/0x100 lib/iov_iter.c:169 > instrument_copy_to_user ./include/linux/instrumented.h:121 > copyout+0xbc/0x100 lib/iov_iter.c:169 > _copy_to_iter+0x5c0/0x20a0 lib/iov_iter.c:527 > copy_to_iter ./include/linux/uio.h:176 > simple_copy_to_iter+0x64/0xa0 net/core/datagram.c:513 > __skb_datagram_iter+0x123/0xdc0 net/core/datagram.c:419 > skb_copy_datagram_iter+0x58/0x200 net/core/datagram.c:527 > skb_copy_datagram_msg ./include/linux/skbuff.h:3903 > packet_recvmsg+0x521/0x1e70 net/packet/af_packet.c:3469 > ____sys_recvmsg+0x2c4/0x810 net/socket.c:? > ___sys_recvmsg+0x217/0x840 net/socket.c:2743 > __sys_recvmsg net/socket.c:2773 > __do_sys_recvmsg net/socket.c:2783 > __se_sys_recvmsg net/socket.c:2780 > __x64_sys_recvmsg+0x364/0x540 net/socket.c:2780 > do_syscall_x64 arch/x86/entry/common.c:50 > do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 > entry_SYSCALL_64_after_hwframe+0x63/0xcd arch/x86/entry/entry_64.S:120 > > [...] Here is the summary with links: - tipc: fix an information leak in tipc_topsrv_kern_subscr https://git.kernel.org/netdev/net/c/777ecaabd614 You are awesome, thank you!
diff --git a/net/tipc/topsrv.c b/net/tipc/topsrv.c index 5522865deae95..14fd05fd6107d 100644 --- a/net/tipc/topsrv.c +++ b/net/tipc/topsrv.c @@ -568,7 +568,7 @@ bool tipc_topsrv_kern_subscr(struct net *net, u32 port, u32 type, u32 lower, sub.seq.upper = upper; sub.timeout = TIPC_WAIT_FOREVER; sub.filter = filter; - *(u32 *)&sub.usr_handle = port; + *(u64 *)&sub.usr_handle = (u64)port; con = tipc_conn_alloc(tipc_topsrv(net)); if (IS_ERR(con))
Use a 8-byte write to initialize sub.usr_handle in tipc_topsrv_kern_subscr(), otherwise four bytes remain uninitialized when issuing setsockopt(..., SOL_TIPC, ...). This resulted in an infoleak reported by KMSAN when the packet was received: ===================================================== BUG: KMSAN: kernel-infoleak in copyout+0xbc/0x100 lib/iov_iter.c:169 instrument_copy_to_user ./include/linux/instrumented.h:121 copyout+0xbc/0x100 lib/iov_iter.c:169 _copy_to_iter+0x5c0/0x20a0 lib/iov_iter.c:527 copy_to_iter ./include/linux/uio.h:176 simple_copy_to_iter+0x64/0xa0 net/core/datagram.c:513 __skb_datagram_iter+0x123/0xdc0 net/core/datagram.c:419 skb_copy_datagram_iter+0x58/0x200 net/core/datagram.c:527 skb_copy_datagram_msg ./include/linux/skbuff.h:3903 packet_recvmsg+0x521/0x1e70 net/packet/af_packet.c:3469 ____sys_recvmsg+0x2c4/0x810 net/socket.c:? ___sys_recvmsg+0x217/0x840 net/socket.c:2743 __sys_recvmsg net/socket.c:2773 __do_sys_recvmsg net/socket.c:2783 __se_sys_recvmsg net/socket.c:2780 __x64_sys_recvmsg+0x364/0x540 net/socket.c:2780 do_syscall_x64 arch/x86/entry/common.c:50 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd arch/x86/entry/entry_64.S:120 ... Uninit was stored to memory at: tipc_sub_subscribe+0x42d/0xb50 net/tipc/subscr.c:156 tipc_conn_rcv_sub+0x246/0x620 net/tipc/topsrv.c:375 tipc_topsrv_kern_subscr+0x2e8/0x400 net/tipc/topsrv.c:579 tipc_group_create+0x4e7/0x7d0 net/tipc/group.c:190 tipc_sk_join+0x2a8/0x770 net/tipc/socket.c:3084 tipc_setsockopt+0xae5/0xe40 net/tipc/socket.c:3201 __sys_setsockopt+0x87f/0xdc0 net/socket.c:2252 __do_sys_setsockopt net/socket.c:2263 __se_sys_setsockopt net/socket.c:2260 __x64_sys_setsockopt+0xe0/0x160 net/socket.c:2260 do_syscall_x64 arch/x86/entry/common.c:50 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd arch/x86/entry/entry_64.S:120 Local variable sub created at: tipc_topsrv_kern_subscr+0x57/0x400 net/tipc/topsrv.c:562 tipc_group_create+0x4e7/0x7d0 net/tipc/group.c:190 Bytes 84-87 of 88 are uninitialized Memory access of size 88 starts at ffff88801ed57cd0 Data copied to user address 0000000020000400 ... ===================================================== Signed-off-by: Alexander Potapenko <glider@google.com> Fixes: 026321c6d056a5 ("tipc: rename tipc_server to tipc_topsrv") --- net/tipc/topsrv.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)