769a807d0b
syzbot reported a splat: xfrm_policy_inexact_list_reinsert+0x625/0x6e0 net/xfrm/xfrm_policy.c:877 CPU: 1 PID: 6756 Comm: syz-executor.1 Not tainted 5.3.0-rc2+ #57 Call Trace: xfrm_policy_inexact_node_reinsert net/xfrm/xfrm_policy.c:922 [inline] xfrm_policy_inexact_node_merge net/xfrm/xfrm_policy.c:958 [inline] xfrm_policy_inexact_insert_node+0x537/0xb50 net/xfrm/xfrm_policy.c:1023 xfrm_policy_inexact_alloc_chain+0x62b/0xbd0 net/xfrm/xfrm_policy.c:1139 xfrm_policy_inexact_insert+0xe8/0x1540 net/xfrm/xfrm_policy.c:1182 xfrm_policy_insert+0xdf/0xce0 net/xfrm/xfrm_policy.c:1574 xfrm_add_policy+0x4cf/0x9b0 net/xfrm/xfrm_user.c:1670 xfrm_user_rcv_msg+0x46b/0x720 net/xfrm/xfrm_user.c:2676 netlink_rcv_skb+0x1f0/0x460 net/netlink/af_netlink.c:2477 xfrm_netlink_rcv+0x74/0x90 net/xfrm/xfrm_user.c:2684 netlink_unicast_kernel net/netlink/af_netlink.c:1302 [inline] netlink_unicast+0x809/0x9a0 net/netlink/af_netlink.c:1328 netlink_sendmsg+0xa70/0xd30 net/netlink/af_netlink.c:1917 sock_sendmsg_nosec net/socket.c:637 [inline] sock_sendmsg net/socket.c:657 [inline] There is no reproducer, however, the warning can be reproduced by adding rules with ever smaller prefixes. The sanity check ("does the policy match the node") uses the prefix value of the node before its updated to the smaller value. To fix this, update the prefix earlier. The bug has no impact on tree correctness, this is only to prevent a false warning. Reported-by: syzbot+8cc27ace5f6972910b31@syzkaller.appspotmail.com Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
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.