CVE-2023-53798

*** Pendiente de traducción *** In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> ethtool: Fix uninitialized number of lanes<br /> <br /> It is not possible to set the number of lanes when setting link modes<br /> using the legacy IOCTL ethtool interface. Since &amp;#39;struct<br /> ethtool_link_ksettings&amp;#39; is not initialized in this path, drivers receive<br /> an uninitialized number of lanes in &amp;#39;struct<br /> ethtool_link_ksettings::lanes&amp;#39;.<br /> <br /> When this information is later queried from drivers, it results in the<br /> ethtool code making decisions based on uninitialized memory, leading to<br /> the following KMSAN splat [1]. In practice, this most likely only<br /> happens with the tun driver that simply returns whatever it got in the<br /> set operation.<br /> <br /> As far as I can tell, this uninitialized memory is not leaked to user<br /> space thanks to the &amp;#39;ethtool_ops-&gt;cap_link_lanes_supported&amp;#39; check in<br /> linkmodes_prepare_data().<br /> <br /> Fix by initializing the structure in the IOCTL path. Did not find any<br /> more call sites that pass an uninitialized structure when calling<br /> &amp;#39;ethtool_ops::set_link_ksettings()&amp;#39;.<br /> <br /> [1]<br /> BUG: KMSAN: uninit-value in ethnl_update_linkmodes net/ethtool/linkmodes.c:273 [inline]<br /> BUG: KMSAN: uninit-value in ethnl_set_linkmodes+0x190b/0x19d0 net/ethtool/linkmodes.c:333<br /> ethnl_update_linkmodes net/ethtool/linkmodes.c:273 [inline]<br /> ethnl_set_linkmodes+0x190b/0x19d0 net/ethtool/linkmodes.c:333<br /> ethnl_default_set_doit+0x88d/0xde0 net/ethtool/netlink.c:640<br /> genl_family_rcv_msg_doit net/netlink/genetlink.c:968 [inline]<br /> genl_family_rcv_msg net/netlink/genetlink.c:1048 [inline]<br /> genl_rcv_msg+0x141a/0x14c0 net/netlink/genetlink.c:1065<br /> netlink_rcv_skb+0x3f8/0x750 net/netlink/af_netlink.c:2577<br /> genl_rcv+0x40/0x60 net/netlink/genetlink.c:1076<br /> netlink_unicast_kernel net/netlink/af_netlink.c:1339 [inline]<br /> netlink_unicast+0xf41/0x1270 net/netlink/af_netlink.c:1365<br /> netlink_sendmsg+0x127d/0x1430 net/netlink/af_netlink.c:1942<br /> sock_sendmsg_nosec net/socket.c:724 [inline]<br /> sock_sendmsg net/socket.c:747 [inline]<br /> ____sys_sendmsg+0xa24/0xe40 net/socket.c:2501<br /> ___sys_sendmsg+0x2a1/0x3f0 net/socket.c:2555<br /> __sys_sendmsg net/socket.c:2584 [inline]<br /> __do_sys_sendmsg net/socket.c:2593 [inline]<br /> __se_sys_sendmsg net/socket.c:2591 [inline]<br /> __x64_sys_sendmsg+0x36b/0x540 net/socket.c:2591<br /> do_syscall_x64 arch/x86/entry/common.c:50 [inline]<br /> do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80<br /> entry_SYSCALL_64_after_hwframe+0x63/0xcd<br /> <br /> Uninit was stored to memory at:<br /> tun_get_link_ksettings+0x37/0x60 drivers/net/tun.c:3544<br /> __ethtool_get_link_ksettings+0x17b/0x260 net/ethtool/ioctl.c:441<br /> ethnl_set_linkmodes+0xee/0x19d0 net/ethtool/linkmodes.c:327<br /> ethnl_default_set_doit+0x88d/0xde0 net/ethtool/netlink.c:640<br /> genl_family_rcv_msg_doit net/netlink/genetlink.c:968 [inline]<br /> genl_family_rcv_msg net/netlink/genetlink.c:1048 [inline]<br /> genl_rcv_msg+0x141a/0x14c0 net/netlink/genetlink.c:1065<br /> netlink_rcv_skb+0x3f8/0x750 net/netlink/af_netlink.c:2577<br /> genl_rcv+0x40/0x60 net/netlink/genetlink.c:1076<br /> netlink_unicast_kernel net/netlink/af_netlink.c:1339 [inline]<br /> netlink_unicast+0xf41/0x1270 net/netlink/af_netlink.c:1365<br /> netlink_sendmsg+0x127d/0x1430 net/netlink/af_netlink.c:1942<br /> sock_sendmsg_nosec net/socket.c:724 [inline]<br /> sock_sendmsg net/socket.c:747 [inline]<br /> ____sys_sendmsg+0xa24/0xe40 net/socket.c:2501<br /> ___sys_sendmsg+0x2a1/0x3f0 net/socket.c:2555<br /> __sys_sendmsg net/socket.c:2584 [inline]<br /> __do_sys_sendmsg net/socket.c:2593 [inline]<br /> __se_sys_sendmsg net/socket.c:2591 [inline]<br /> __x64_sys_sendmsg+0x36b/0x540 net/socket.c:2591<br /> do_syscall_x64 arch/x86/entry/common.c:50 [inline]<br /> do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80<br /> entry_SYSCALL_64_after_hwframe+0x63/0xcd<br /> <br /> Uninit was stored to memory at:<br /> tun_set_link_ksettings+0x37/0x60 drivers/net/tun.c:3553<br /> ethtool_set_link_ksettings+0x600/0x690 net/ethtool/ioctl.c:609<br /> __dev_ethtool net/ethtool/ioctl.c:3024 [inline]<br /> dev_ethtool+0x1db9/0x2a70 net/ethtool/ioctl.c:3078<br /> dev_ioctl+0xb07/0x1270 net/core/dev_ioctl.c:524<br /> sock_do_ioctl+0x295/0x540 net/socket.c:1213<br /> sock_i<br /> ---truncated---