e195e9b5de
Commit2c611ad97a("net, neigh: Extend neigh->flags to 32 bit to allow for extensions") enables a new KMSAM warning [1] I think the bug is actually older, because the following intruction only occurred if ndm->ndm_flags had NTF_PROXY set. pn->flags = ndm->ndm_flags; Let's clear all pneigh_entry fields at alloc time. [1] BUG: KMSAN: uninit-value in pneigh_fill_info+0x986/0xb30 net/core/neighbour.c:2593 pneigh_fill_info+0x986/0xb30 net/core/neighbour.c:2593 pneigh_dump_table net/core/neighbour.c:2715 [inline] neigh_dump_info+0x1e3f/0x2c60 net/core/neighbour.c:2832 netlink_dump+0xaca/0x16a0 net/netlink/af_netlink.c:2265 __netlink_dump_start+0xd1c/0xee0 net/netlink/af_netlink.c:2370 netlink_dump_start include/linux/netlink.h:254 [inline] rtnetlink_rcv_msg+0x181b/0x18c0 net/core/rtnetlink.c:5534 netlink_rcv_skb+0x447/0x800 net/netlink/af_netlink.c:2491 rtnetlink_rcv+0x50/0x60 net/core/rtnetlink.c:5589 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0x1095/0x1360 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x16f3/0x1870 net/netlink/af_netlink.c:1916 sock_sendmsg_nosec net/socket.c:704 [inline] sock_sendmsg net/socket.c:724 [inline] sock_write_iter+0x594/0x690 net/socket.c:1057 call_write_iter include/linux/fs.h:2162 [inline] new_sync_write fs/read_write.c:503 [inline] vfs_write+0x1318/0x2030 fs/read_write.c:590 ksys_write+0x28c/0x520 fs/read_write.c:643 __do_sys_write fs/read_write.c:655 [inline] __se_sys_write fs/read_write.c:652 [inline] __x64_sys_write+0xdb/0x120 fs/read_write.c:652 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x54/0xd0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x44/0xae Uninit was created at: slab_post_alloc_hook mm/slab.h:524 [inline] slab_alloc_node mm/slub.c:3251 [inline] slab_alloc mm/slub.c:3259 [inline] __kmalloc+0xc3c/0x12d0 mm/slub.c:4437 kmalloc include/linux/slab.h:595 [inline] pneigh_lookup+0x60f/0xd70 net/core/neighbour.c:766 arp_req_set_public net/ipv4/arp.c:1016 [inline] arp_req_set+0x430/0x10a0 net/ipv4/arp.c:1032 arp_ioctl+0x8d4/0xb60 net/ipv4/arp.c:1232 inet_ioctl+0x4ef/0x820 net/ipv4/af_inet.c:947 sock_do_ioctl net/socket.c:1118 [inline] sock_ioctl+0xa3f/0x13e0 net/socket.c:1235 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:874 [inline] __se_sys_ioctl+0x2df/0x4a0 fs/ioctl.c:860 __x64_sys_ioctl+0xd8/0x110 fs/ioctl.c:860 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x54/0xd0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x44/0xae CPU: 1 PID: 20001 Comm: syz-executor.0 Not tainted 5.16.0-rc3-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Fixes:62dd93181a("[IPV6] NDISC: Set per-entry is_router flag in Proxy NA.") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Roopa Prabhu <roopa@nvidia.com> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://lore.kernel.org/r/20211206165329.1049835-1-eric.dumazet@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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.