c1833c3964
The "__ip6_tnl_parm" struct was left uninitialized causing an invalid load of random data when the "__ip6_tnl_parm" struct was used elsewhere. As an example, in the function "ip6_tnl_xmit_ctl()", it tries to access the "collect_md" member. With "__ip6_tnl_parm" being uninitialized and containing random data, the UBSAN detected that "collect_md" held a non-boolean value. The UBSAN issue is as follows: =============================================================== UBSAN: invalid-load in net/ipv6/ip6_tunnel.c:1025:14 load of value 30 is not a valid value for type '_Bool' CPU: 1 PID: 228 Comm: kworker/1:3 Not tainted 5.16.0-rc4+ #8 Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011 Workqueue: ipv6_addrconf addrconf_dad_work Call Trace: <TASK> dump_stack_lvl+0x44/0x57 ubsan_epilogue+0x5/0x40 __ubsan_handle_load_invalid_value+0x66/0x70 ? __cpuhp_setup_state+0x1d3/0x210 ip6_tnl_xmit_ctl.cold.52+0x2c/0x6f [ip6_tunnel] vti6_tnl_xmit+0x79c/0x1e96 [ip6_vti] ? lock_is_held_type+0xd9/0x130 ? vti6_rcv+0x100/0x100 [ip6_vti] ? lock_is_held_type+0xd9/0x130 ? rcu_read_lock_bh_held+0xc0/0xc0 ? lock_acquired+0x262/0xb10 dev_hard_start_xmit+0x1e6/0x820 __dev_queue_xmit+0x2079/0x3340 ? mark_lock.part.52+0xf7/0x1050 ? netdev_core_pick_tx+0x290/0x290 ? kvm_clock_read+0x14/0x30 ? kvm_sched_clock_read+0x5/0x10 ? sched_clock_cpu+0x15/0x200 ? find_held_lock+0x3a/0x1c0 ? lock_release+0x42f/0xc90 ? lock_downgrade+0x6b0/0x6b0 ? mark_held_locks+0xb7/0x120 ? neigh_connected_output+0x31f/0x470 ? lockdep_hardirqs_on+0x79/0x100 ? neigh_connected_output+0x31f/0x470 ? ip6_finish_output2+0x9b0/0x1d90 ? rcu_read_lock_bh_held+0x62/0xc0 ? ip6_finish_output2+0x9b0/0x1d90 ip6_finish_output2+0x9b0/0x1d90 ? ip6_append_data+0x330/0x330 ? ip6_mtu+0x166/0x370 ? __ip6_finish_output+0x1ad/0xfb0 ? nf_hook_slow+0xa6/0x170 ip6_output+0x1fb/0x710 ? nf_hook.constprop.32+0x317/0x430 ? ip6_finish_output+0x180/0x180 ? __ip6_finish_output+0xfb0/0xfb0 ? lock_is_held_type+0xd9/0x130 ndisc_send_skb+0xb33/0x1590 ? __sk_mem_raise_allocated+0x11cf/0x1560 ? dst_output+0x4a0/0x4a0 ? ndisc_send_rs+0x432/0x610 addrconf_dad_completed+0x30c/0xbb0 ? addrconf_rs_timer+0x650/0x650 ? addrconf_dad_work+0x73c/0x10e0 addrconf_dad_work+0x73c/0x10e0 ? addrconf_dad_completed+0xbb0/0xbb0 ? rcu_read_lock_sched_held+0xaf/0xe0 ? rcu_read_lock_bh_held+0xc0/0xc0 process_one_work+0x97b/0x1740 ? pwq_dec_nr_in_flight+0x270/0x270 worker_thread+0x87/0xbf0 ? process_one_work+0x1740/0x1740 kthread+0x3ac/0x490 ? set_kthread_struct+0x100/0x100 ret_from_fork+0x22/0x30 </TASK> =============================================================== The solution is to initialize "__ip6_tnl_parm" struct to zeros in the "vti6_siocdevprivate()" function. Signed-off-by: William Zhao <wizhao@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.