syzbot


KASAN: vmalloc-out-of-bounds Read in kcov_remote_start

Status: upstream: reported on 2025/10/05 04:26
Subsystems: usb bluetooth
[Documentation on labels]
Reported-by: syzbot+8a173e13208949931dc7@syzkaller.appspotmail.com
First crash: 100d, last: 1h59m
Discussions (2)
Title Replies (including bot) Last reply
[syzbot] Monthly bluetooth report (Dec 2025) 0 (1) 2025/12/29 08:12
[syzbot] [usb?] KASAN: vmalloc-out-of-bounds Read in kcov_remote_start 0 (1) 2025/10/05 04:26

Sample crash report:
==================================================================
BUG: KASAN: vmalloc-out-of-bounds in __list_del_entry_valid_or_report+0xb5/0x190 lib/list_debug.c:65
Read of size 8 at addr ffffc900056c2008 by task kworker/u9:5/5808

CPU: 1 UID: 0 PID: 5808 Comm: kworker/u9:5 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: hci3 hci_rx_work
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0xca/0x240 mm/kasan/report.c:482
 kasan_report+0x118/0x150 mm/kasan/report.c:595
 __list_del_entry_valid_or_report+0xb5/0x190 lib/list_debug.c:65
 __list_del_entry_valid include/linux/list.h:132 [inline]
 __list_del_entry include/linux/list.h:223 [inline]
 list_del include/linux/list.h:237 [inline]
 kcov_remote_area_get kernel/kcov.c:143 [inline]
 kcov_remote_start+0x2b0/0x710 kernel/kcov.c:906
 kcov_remote_start_common include/linux/kcov.h:50 [inline]
 hci_rx_work+0x10f/0x1060 net/bluetooth/hci_core.c:4039
 process_one_work kernel/workqueue.c:3257 [inline]
 process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>

The buggy address belongs to a vmalloc virtual mapping
Memory state around the buggy address:
 ffffc900056c1f00: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
 ffffc900056c1f80: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
>ffffc900056c2000: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
                      ^
 ffffc900056c2080: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
 ffffc900056c2100: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
==================================================================

Crashes (694):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/01/09 23:11 upstream 372800cb95a3 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root KASAN: vmalloc-out-of-bounds Read in kcov_remote_start
2026/01/09 21:54 upstream 372800cb95a3 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root KASAN: vmalloc-out-of-bounds Read in kcov_remote_start
2026/01/09 06:48 upstream 79b95d74470d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root KASAN: vmalloc-out-of-bounds Read in kcov_remote_start
2026/01/09 05:09 upstream 79b95d74470d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root KASAN: vmalloc-out-of-bounds Read in kcov_remote_start
2026/01/09 03:05 upstream 79b95d74470d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root KASAN: vmalloc-out-of-bounds Read in kcov_remote_start
2026/01/08 19:35 upstream 79b95d74470d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root KASAN: vmalloc-out-of-bounds Read in kcov_remote_start
2026/01/08 13:59 upstream f0b9d8eb98df d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root KASAN: vmalloc-out-of-bounds Read in kcov_remote_start
2026/01/08 12:02 upstream f0b9d8eb98df d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root KASAN: vmalloc-out-of-bounds Read in kcov_remote_start
2026/01/08 03:25 upstream f0b9d8eb98df d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root KASAN: vmalloc-out-of-bounds Read in kcov_remote_start
2026/01/07 17:07 upstream f0b9d8eb98df d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root KASAN: vmalloc-out-of-bounds Read in kcov_remote_start
2026/01/07 03:42 upstream f0b9d8eb98df d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root KASAN: vmalloc-out-of-bounds Read in kcov_remote_start
2026/01/06 22:51 upstream f0b9d8eb98df d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root KASAN: vmalloc-out-of-bounds Read in kcov_remote_start
2026/01/06 16:31 upstream 7f98ab9da046 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root KASAN: vmalloc-out-of-bounds Read in kcov_remote_start
2026/01/06 12:31 upstream 7f98ab9da046 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root KASAN: vmalloc-out-of-bounds Read in kcov_remote_start
2026/01/06 09:09 upstream 7f98ab9da046 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root KASAN: vmalloc-out-of-bounds Read in kcov_remote_start
2026/01/06 06:21 upstream 7f98ab9da046 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root KASAN: vmalloc-out-of-bounds Read in kcov_remote_start
2026/01/06 02:07 upstream 7f98ab9da046 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root KASAN: vmalloc-out-of-bounds Read in kcov_remote_start
2026/01/05 14:14 upstream 3609fa95fb0f d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root KASAN: vmalloc-out-of-bounds Read in kcov_remote_start
2026/01/05 13:02 upstream 3609fa95fb0f d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root KASAN: vmalloc-out-of-bounds Read in kcov_remote_start
2026/01/05 05:42 upstream 54e82e93ca93 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root KASAN: vmalloc-out-of-bounds Read in kcov_remote_start
2026/01/04 20:08 upstream 54e82e93ca93 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root KASAN: vmalloc-out-of-bounds Read in kcov_remote_start
2026/01/04 13:15 upstream aacb0a6d604a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root KASAN: vmalloc-out-of-bounds Read in kcov_remote_start
2026/01/03 01:10 upstream 9b0436804460 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root KASAN: vmalloc-out-of-bounds Read in kcov_remote_start
2025/10/05 02:43 upstream d104e3d17f7b 49379ee0 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root KASAN: vmalloc-out-of-bounds Read in kcov_remote_start
2025/10/01 04:17 upstream 50c19e20ed2e 65a0eece .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root KASAN: vmalloc-out-of-bounds Read in kcov_remote_start
2026/01/09 14:18 upstream 623fb9912f6a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root BUG: unable to handle kernel NULL pointer dereference in kcov_remote_start
2026/01/09 01:41 upstream 79b95d74470d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root BUG: unable to handle kernel NULL pointer dereference in kcov_remote_start
2026/01/08 18:12 upstream 79b95d74470d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root BUG: unable to handle kernel NULL pointer dereference in kcov_remote_start
2026/01/08 17:09 upstream f0b9d8eb98df d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root BUG: unable to handle kernel NULL pointer dereference in kcov_remote_start
2026/01/08 15:11 upstream f0b9d8eb98df d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root BUG: unable to handle kernel NULL pointer dereference in kcov_remote_start
2026/01/08 07:51 upstream f0b9d8eb98df d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root BUG: unable to handle kernel NULL pointer dereference in kcov_remote_start
2026/01/08 01:53 upstream f0b9d8eb98df d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root BUG: corrupted list in kcov_remote_start
2026/01/07 19:53 upstream f0b9d8eb98df d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root BUG: corrupted list in kcov_remote_start
2026/01/07 02:22 upstream f0b9d8eb98df d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root BUG: unable to handle kernel NULL pointer dereference in kcov_remote_start
2026/01/06 10:10 upstream 7f98ab9da046 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root BUG: corrupted list in kcov_remote_start
2026/01/06 07:27 upstream 7f98ab9da046 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root BUG: unable to handle kernel NULL pointer dereference in kcov_remote_start
2026/01/06 05:20 upstream 7f98ab9da046 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root BUG: unable to handle kernel NULL pointer dereference in kcov_remote_start
2026/01/05 23:28 upstream 3609fa95fb0f d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root BUG: corrupted list in kcov_remote_start
2026/01/05 22:25 upstream 3609fa95fb0f d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root BUG: unable to handle kernel NULL pointer dereference in kcov_remote_start
2026/01/05 10:21 upstream 3609fa95fb0f d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root BUG: unable to handle kernel NULL pointer dereference in kcov_remote_start
2026/01/05 02:01 upstream 54e82e93ca93 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root BUG: unable to handle kernel NULL pointer dereference in kcov_remote_start
2026/01/04 03:51 upstream aacb0a6d604a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root BUG: unable to handle kernel NULL pointer dereference in kcov_remote_start
2026/01/03 20:04 upstream 805f9a061372 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root BUG: corrupted list in kcov_remote_start
2026/01/03 17:45 upstream 805f9a061372 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root BUG: unable to handle kernel NULL pointer dereference in kcov_remote_start
2026/01/03 07:24 upstream 9b0436804460 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root BUG: unable to handle kernel NULL pointer dereference in kcov_remote_start
2026/01/03 03:05 upstream 9b0436804460 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root BUG: unable to handle kernel NULL pointer dereference in kcov_remote_start
2026/01/02 22:34 upstream 9b0436804460 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root BUG: unable to handle kernel NULL pointer dereference in kcov_remote_start
2025/12/30 23:04 upstream dbf8fe85a16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root BUG: unable to handle kernel paging request in kcov_remote_start
* Struck through repros no longer work on HEAD.