Hello, Syzkaller has triggered a GPF when fuzzing a 4.4 kernel with the following stacktrace. Call Trace: [<ffffffff823936f9>] nfnetlink_rcv_msg+0xa59/0xbc0 net/netfilter/nfnetlink.c:215 [<ffffffff82382be9>] netlink_rcv_skb+0x149/0x380 net/netlink/af_netlink.c:2296 [<ffffffff82391b6c>] nfnetlink_rcv+0x2ac/0x1190 net/netfilter/nfnetlink.c:479 [<ffffffff8238178e>] netlink_unicast_kernel net/netlink/af_netlink.c:1223 [inline] [<ffffffff8238178e>] netlink_unicast+0x51e/0x760 net/netlink/af_netlink.c:1249 [<ffffffff82382295>] netlink_sendmsg+0x8c5/0xc20 net/netlink/af_netlink.c:1803 [<ffffffff821f45ff>] sock_sendmsg_nosec net/socket.c:625 [inline] [<ffffffff821f45ff>] sock_sendmsg+0xcf/0x110 net/socket.c:635 [<ffffffff821f4862>] sock_write_iter+0x222/0x3a0 net/socket.c:834 [<ffffffff8150b3fe>] new_sync_write fs/read_write.c:478 [inline] [<ffffffff8150b3fe>] __vfs_write+0x32e/0x440 fs/read_write.c:491 [<ffffffff8150cf2c>] vfs_write+0x16c/0x4a0 fs/read_write.c:538 [<ffffffff8150f599>] SYSC_write fs/read_write.c:585 [inline] [<ffffffff8150f599>] SyS_write+0xd9/0x1b0 fs/read_write.c:577 [<ffffffff82a0b3b2>] entry_SYSCALL_64_fastpath+0x12/0x72 Code: c0 49 89 c4 0f 84 64 04 00 00 e8 ea b7 f6 fe 49 8b 95 68 ff ff ff 48 b8 00 00 00 00 00 fc ff df 48 8d 7a 04 48 89 f9 48 c1 e9 03 <0f> b6 0c 01 48 89 f8 83 e0 07 83 c0 03 38 c8 7c 17 84 c9 74 13 RIP [<ffffffff823956f2>] nla_get_be32 include/net/netlink.h:1003 [inline] RIP [<ffffffff823956f2>] nfacct_filter_alloc net/netfilter/nfnetlink_acct.c:250 [inline] RIP [<ffffffff823956f2>] nfnl_acct_get+0x1f2/0x6d0 net/netfilter/nfnetlink_acct.c:274 RSP <ffff8801d7def6a8> ---[ end trace a8de975a65b4d2ea ]--- Could the following patch be applied to v4.4.y? The patch is present in v4.9.y. * 017b1b6d28c4 ("netfilter: nfnetlink_acct: validate NFACCT_FILTER parameters") Tests run: * Chrome OS tryjobs * Syzkaller reproducer Thanks, - Zubin