bisecting fixing commit since 22da5264abf497a10a4ed629f07f4ba28a7ed5eb building syzkaller on 131df97d431404458e805009bda794abfb00f45f testing commit 22da5264abf497a10a4ed629f07f4ba28a7ed5eb compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: 471f863c1d8e6be3e776ca327bd851a1d7628ead8f8ac2c93f8faa1337d95da3 all runs: crashed: WARNING: suspicious RCU usage in hsr_node_get_first testing current HEAD 0840a7914caa14315a3191178a9f72c742477860 testing commit 0840a7914caa14315a3191178a9f72c742477860 compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: 31074b6827d8f2d16cb16039b273bb07683ca5cf5ca2871f22078873333fd279 all runs: crashed: WARNING: suspicious RCU usage in hsr_node_get_first revisions tested: 2, total time: 19m52.018335322s (build: 12m49.342348672s, test: 6m31.708287236s) the crash still happens on HEAD commit msg: Merge tag 'char-misc-5.19-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc crash: WARNING: suspicious RCU usage in hsr_node_get_first netlink: 'syz-executor.0': attribute type 2 has an invalid length. netlink: 194488 bytes leftover after parsing attributes in process `syz-executor.0'. ============================= WARNING: suspicious RCU usage 5.19.0-rc3-syzkaller #0 Not tainted ----------------------------- net/hsr/hsr_framereg.c:41 suspicious rcu_dereference_check() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 3 locks held by syz-executor.0/4086: #0: ffffffff8c9554d0 (cb_lock){++++}-{3:3}, at: genl_rcv+0x10/0x30 net/netlink/genetlink.c:802 #1: ffffffff8c955588 (genl_mutex){+.+.}-{3:3}, at: genl_lock net/netlink/genetlink.c:33 [inline] #1: ffffffff8c955588 (genl_mutex){+.+.}-{3:3}, at: genl_rcv_msg+0x315/0x4a0 net/netlink/genetlink.c:790 #2: ffffffff8b17c7a0 (rcu_read_lock){....}-{1:2}, at: hsr_get_node_list+0xc1/0x900 net/hsr/hsr_netlink.c:425 stack backtrace: CPU: 0 PID: 4086 Comm: syz-executor.0 Not tainted 5.19.0-rc3-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x57/0x7d lib/dump_stack.c:106 hsr_node_get_first+0x76/0xa0 net/hsr/hsr_framereg.c:41 hsr_get_next_node+0x1b3/0x330 net/hsr/hsr_framereg.c:608 hsr_get_node_list+0x2c2/0x900 net/hsr/hsr_netlink.c:461 genl_family_rcv_msg_doit+0x1e4/0x2f0 net/netlink/genetlink.c:731 genl_family_rcv_msg net/netlink/genetlink.c:775 [inline] genl_rcv_msg+0x27a/0x4a0 net/netlink/genetlink.c:792 netlink_rcv_skb+0x118/0x370 net/netlink/af_netlink.c:2501 genl_rcv+0x1f/0x30 net/netlink/genetlink.c:803 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0x433/0x710 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x782/0xc30 net/netlink/af_netlink.c:1921 sock_sendmsg_nosec net/socket.c:714 [inline] sock_sendmsg+0xab/0xe0 net/socket.c:734 ____sys_sendmsg+0x5c2/0x7a0 net/socket.c:2492 ___sys_sendmsg+0xd3/0x150 net/socket.c:2546 __sys_sendmsg+0xb9/0x150 net/socket.c:2575 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 RIP: 0033:0x7fbabf0890e9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fbac0105168 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007fbabf19bf60 RCX: 00007fbabf0890e9 RDX: 0000000000000000 RSI: 0000000020000000 RDI: 0000000000000003 RBP: 00007fbabf0e308d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffc2b5a806f R14: 00007fbac0105300 R15: 0000000000022000