Subject: Re: [syzbot] [kasan?] [mm?] INFO: rcu detected stall in __run_timer_base

From: syzbot <[email-masked]>
Date: Fri, 03 May 2024 05:03:02 -0700

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
UBSAN: array-index-out-of-bounds in ktime_mono_to_any

------------[ cut here ]------------
UBSAN: array-index-out-of-bounds in kernel/time/timekeeping.c:927:20
index 3 is out of range for type 'ktime_t *[3]' (aka 'long long *[3]')
CPU: 0 PID: 5514 Comm: syz-executor.0 Not tainted 6.9.0-rc6-syzkaller-00131-gf03359bca01b-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
 ubsan_epilogue lib/ubsan.c:231 [inline]
 __ubsan_handle_out_of_bounds+0x121/0x150 lib/ubsan.c:429
 ktime_mono_to_any+0xf7/0x100 kernel/time/timekeeping.c:927
 taprio_get_offset net/sched/sch_taprio.c:178 [inline]
 taprio_get_start_time+0xf6/0x2a0 net/sched/sch_taprio.c:1232
 taprio_change+0x30c5/0x42d0 net/sched/sch_taprio.c:1963
 taprio_init+0x9da/0xc80 net/sched/sch_taprio.c:2135
 qdisc_create+0x9d6/0x1190 net/sched/sch_api.c:1355
 tc_modify_qdisc+0xa26/0x1e40 net/sched/sch_api.c:1776
 rtnetlink_rcv_msg+0x89d/0x10d0 net/core/rtnetlink.c:6595
 netlink_rcv_skb+0x1e5/0x430 net/netlink/af_netlink.c:2559
 netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline]
 netlink_unicast+0x7ec/0x980 net/netlink/af_netlink.c:1361
 netlink_sendmsg+0x8e1/0xcb0 net/netlink/af_netlink.c:1905
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg+0x223/0x270 net/socket.c:745
 ____sys_sendmsg+0x525/0x7d0 net/socket.c:2584
 ___sys_sendmsg net/socket.c:2638 [inline]
 __sys_sendmsg+0x2b0/0x3a0 net/socket.c:2667
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fca4dc7de69
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fca4e9720c8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fca4ddabf80 RCX: 00007fca4dc7de69
RDX: 0000000000000000 RSI: 00000000200007c0 RDI: 0000000000000004
RBP: 00007fca4dcca47a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007fca4ddabf80 R15: 00007fffc66d5928
 </TASK>
---[ end trace ]---

Tested on:

commit:         f03359bc Merge tag 'for-6.9-rc6-tag' of git://git.kern..
git tree:       https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
console output: https://syzkaller.appspot.com/x/log.txt?x=17aef62f180000
kernel config:  https://syzkaller.appspot.com/x/.config?x=38cdad974684e704
dashboard link: https://syzkaller.appspot.com/bug?extid=1acbadd9f48eeeacda29
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
patch:          https://syzkaller.appspot.com/x/patch.diff?x=1665ecc0980000