bisecting fixing commit since 210e04ff768142b96452030c4c2627512b30ad95
building syzkaller on 744a39e220cece33e207035facce6c5ae161b775
testing commit 210e04ff768142b96452030c4c2627512b30ad95
compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2
kernel signature: 29741244d9082148594acb0c523434d5074e3922a6f151e54cd9628f035be3b2
all runs: crashed: BUG: "hc->tx_t_ipi == NUM" holds (exception!) at net/dccp/ccids/ccid3.c:LINE/ccid3_update_send_interval()
testing current HEAD 941e3e7912696b9fbe3586083a7c2e102cee7a87
testing commit 941e3e7912696b9fbe3586083a7c2e102cee7a87
compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2
kernel signature: 08107229831efd7e5a33dabb7fb59285a2826368fd90bc3b26094cd73adc3931
run #0: basic kernel testing failed: BUG: program execution failed: executor NUM: EOF
run #1: basic kernel testing failed: BUG: program execution failed: executor NUM: EOF
run #2: crashed: BUG: "hc->tx_t_ipi == NUM" holds (exception!) at net/dccp/ccids/ccid3.c:LINE/ccid3_update_send_interval()
run #3: crashed: BUG: "hc->tx_t_ipi == NUM" holds (exception!) at net/dccp/ccids/ccid3.c:LINE/ccid3_update_send_interval()
run #4: crashed: BUG: "hc->tx_t_ipi == NUM" holds (exception!) at net/dccp/ccids/ccid3.c:LINE/ccid3_update_send_interval()
run #5: crashed: BUG: "hc->tx_t_ipi == NUM" holds (exception!) at net/dccp/ccids/ccid3.c:LINE/ccid3_update_send_interval()
run #6: crashed: BUG: "hc->tx_t_ipi == NUM" holds (exception!) at net/dccp/ccids/ccid3.c:LINE/ccid3_update_send_interval()
run #7: crashed: BUG: "hc->tx_t_ipi == NUM" holds (exception!) at net/dccp/ccids/ccid3.c:LINE/ccid3_update_send_interval()
run #8: crashed: BUG: "hc->tx_t_ipi == NUM" holds (exception!) at net/dccp/ccids/ccid3.c:LINE/ccid3_update_send_interval()
run #9: crashed: BUG: "hc->tx_t_ipi == NUM" holds (exception!) at net/dccp/ccids/ccid3.c:LINE/ccid3_update_send_interval()
revisions tested: 2, total time: 20m23.483191551s (build: 13m28.627157269s, test: 6m19.661892236s)
the crash still happens on HEAD
commit msg: Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost
crash: BUG: "hc->tx_t_ipi == NUM" holds (exception!) at net/dccp/ccids/ccid3.c:LINE/ccid3_update_send_interval()
BUG: "hc->tx_t_ipi == 0" holds (exception!) at net/dccp/ccids/ccid3.c:90/ccid3_update_send_interval()
CPU: 0 PID: 4121 Comm: syz-executor.0 Not tainted 5.19.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x57/0x7d lib/dump_stack.c:106
 ccid3_hc_tx_update_s net/dccp/ccids/ccid3.c:169 [inline]
 ccid3_hc_tx_packet_sent+0xda/0x110 net/dccp/ccids/ccid3.c:353
 ccid_hc_tx_packet_sent net/dccp/ccid.h:175 [inline]
 dccp_xmit_packet+0x28a/0x660 net/dccp/output.c:289
 dccp_write_xmit+0x10e/0x180 net/dccp/output.c:366
 dccp_sendmsg+0x6fd/0xa70 net/dccp/proto.c:783
 sock_sendmsg_nosec net/socket.c:714 [inline]
 sock_sendmsg+0xab/0xe0 net/socket.c:734
 ____sys_sendmsg+0x395/0x7a0 net/socket.c:2492
 ___sys_sendmsg+0xd3/0x150 net/socket.c:2546
 __sys_sendmmsg+0x141/0x310 net/socket.c:2632
 __do_sys_sendmmsg net/socket.c:2661 [inline]
 __se_sys_sendmmsg net/socket.c:2658 [inline]
 __x64_sys_sendmmsg+0x94/0x100 net/socket.c:2658
 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: 0033:0x7fc00ac890e9
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:00007fc00bdb9168 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00007fc00ad9c030 RCX: 00007fc00ac890e9
RDX: 0000000000000503 RSI: 0000000020000ac0 RDI: 0000000000000004
RBP: 00007fc00ace308d R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffd6f8c551f R14: 00007fc00bdb9300 R15: 0000000000022000
 </TASK>