KASAN: invalid-free in dev_free (4)

Status: upstream: reported on 2026/07/26 16:18
Subsystems: usb
Labels: prio:normal
[Documentation on labels]
Reported-by: syzbot+95b9b8670fa88368360e@syzkaller.appspotmail.com
First crash: 97d, last: 8d09h
▶ ▼ ✨ AI Jobs (2)
ID Workflow Result Correct Bug Created Started Finished Revision
0ba1546b repro-c Reproduced: ✅ ❓ KASAN: invalid-free in dev_free (4) 2026/10/20 05:11 2026/10/20 05:11 2026/10/20 07:23 21286ae2
4797eb3a assessment-security DenialOfService: ✅ Exploitable: ✅ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ❌ VMGuestTrigger: ❌ VMHostTrigger: ❌ ❓ KASAN: invalid-free in dev_free (4) 2026/07/24 00:02 2026/07/24 00:02 2026/07/24 00:39 71a13572
▶ ▼ Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [usb?] KASAN: invalid-free in dev_free (4) 0 (1) 2026/07/26 16:18
▶ ▼ Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KASAN: invalid-free in dev_free (2) usb 24 3 458d 500d 0/29 auto-obsoleted due to no activity on 2025/11/03 02:30
upstream KASAN: invalid-free in dev_free usb 24 syz, C 1163 655d 802d 0/29 auto-obsoleted due to no activity on 2025/03/21 11:28
upstream KASAN: invalid-free in dev_free (3) usb 24 1 220d 216d 0/29 auto-obsoleted due to no activity on 2026/05/20 15:37
▶ ▼ Last patch testing requests (1)
Created Duration User Patch Repo Result
2026/10/20 14:06 26m retest repro git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git f47d223627f80cb7a1eb14c585fe6cb35de5e984 report job log log

Sample crash report:
==================================================================
BUG: KASAN: double-free in dev_free+0x43f/0x750 drivers/usb/gadget/legacy/raw_gadget.c:226
Free of addr ffff88803706c020 by task syz.5.4224/22979

CPU: 0 UID: 0 PID: 22979 Comm: syz.5.4224 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/25/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_address_description+0x55/0x1e0 mm/kasan/report.c:378
 print_report+0x58/0x70 mm/kasan/report.c:482
 kasan_report_invalid_free+0xea/0x110 mm/kasan/report.c:557
 check_slab_allocation mm/kasan/common.c:-1 [inline]
 __kasan_slab_pre_free+0x104/0x120 mm/kasan/common.c:261
 kasan_slab_pre_free include/linux/kasan.h:199 [inline]
 slab_free_hook mm/slub.c:2650 [inline]
 slab_free mm/slub.c:6405 [inline]
 kfree+0x173/0x640 mm/slub.c:6720
 dev_free+0x43f/0x750 drivers/usb/gadget/legacy/raw_gadget.c:226
 kref_put include/linux/kref.h:65 [inline]
 raw_release+0x199/0x260 drivers/usb/gadget/legacy/raw_gadget.c:474
 __fput+0x418/0xa50 fs/file_table.c:512
 task_work_run+0x1d9/0x270 kernel/task_work.c:233
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0x73a/0x2360 kernel/exit.c:1009
 do_group_exit+0x22d/0x2f0 kernel/exit.c:1152
 get_signal+0x121b/0x12c0 kernel/signal.c:3046
 arch_do_signal_or_restart+0xbb/0x860 arch/x86/kernel/signal.c:337
 __exit_to_user_mode_loop kernel/entry/common.c:66 [inline]
 exit_to_user_mode_loop+0x104/0x730 kernel/entry/common.c:101
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
 do_syscall_64+0x353/0x580 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc8b1f5e6ce
Code: Unable to access opcode bytes at 0x7fc8b1f5e6a4.
RSP: 002b:00007fc8b2ea5f98 EFLAGS: 00000246 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 00007fc8b2ea66c0 RCX: 00007fc8b1f5e6ce
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00007fc8b2033eaf R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc8b2226038 R14: 00007fc8b2225fa0 R15: 00007fc8b234fa48
 </TASK>

Allocated by task 22980:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
 __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415
 kasan_kmalloc include/linux/kasan.h:263 [inline]
 __do_kmalloc_node mm/slub.c:5362 [inline]
 __kmalloc_node_track_caller_noprof+0x4c3/0x730 mm/slub.c:5497
 memdup_user+0x2b/0xd0 mm/util.c:221
 raw_ioctl_ep_enable drivers/usb/gadget/legacy/raw_gadget.c:848 [inline]
 raw_ioctl+0xdbc/0x41c0 drivers/usb/gadget/legacy/raw_gadget.c:1319
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 22979:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2705 [inline]
 slab_free mm/slub.c:6405 [inline]
 kfree+0x1c5/0x640 mm/slub.c:6720
 dev_free+0x43f/0x750 drivers/usb/gadget/legacy/raw_gadget.c:226
 kref_put include/linux/kref.h:65 [inline]
 raw_release+0x199/0x260 drivers/usb/gadget/legacy/raw_gadget.c:474
 __fput+0x418/0xa50 fs/file_table.c:512
 fput_close_sync+0x11f/0x240 fs/file_table.c:617
 __do_sys_close fs/open.c:1511 [inline]
 __se_sys_close fs/open.c:1496 [inline]
 __x64_sys_close+0x7e/0x110 fs/open.c:1496
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88803706c020
 which belongs to the cache kmalloc-16 of size 16
The buggy address is located 0 bytes inside of
 16-byte region [ffff88803706c020, ffff88803706c030)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88803706c300 pfn:0x3706c
flags: 0xfff00000000200(workingset|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000200 ffff88801b004640 ffffea0000d32790 ffffea0001db5950
raw: ffff88803706c300 0000000800800050 00000000f5000000 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0xd2cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5768, tgid 5768 (kworker/0:9), ts 885089792261, free_ts 885088005196
 create_dummy_stack mm/page_owner.c:103 [inline]
 register_dummy_stack+0x98/0x100 mm/page_owner.c:109
 init_page_owner+0x2e/0x5f0 mm/page_owner.c:127
 invoke_init_callbacks mm/page_ext.c:152 [inline]
 page_ext_init+0x509/0x550 mm/page_ext.c:490
 mm_core_init+0x97/0xb0 mm/mm_init.c:2741
page last free pid 5768 tgid 5768 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 __free_pages_prepare mm/page_alloc.c:1406 [inline]
 __free_frozen_pages+0xc1e/0xd10 mm/page_alloc.c:2950
 rcu_do_batch kernel/rcu/tree.c:2645 [inline]
 rcu_core+0x78b/0x10a0 kernel/rcu/tree.c:2897
 handle_softirqs+0x225/0x840 kernel/softirq.c:622
 do_softirq+0x76/0xd0 kernel/softirq.c:523
 __local_bh_enable_ip+0xf8/0x130 kernel/softirq.c:450
 local_bh_enable include/linux/bottom_half.h:33 [inline]
 __alloc_skb+0x1ad/0x7a0 net/core/skbuff.c:699
 alloc_skb include/linux/skbuff.h:1384 [inline]
 alloc_uevent_skb+0x7d/0x230 lib/kobject_uevent.c:289
 uevent_net_broadcast_untagged lib/kobject_uevent.c:326 [inline]
 kobject_uevent_net_broadcast+0x2fa/0x560 lib/kobject_uevent.c:410
 kobject_uevent_env+0x566/0x9e0 lib/kobject_uevent.c:611
 device_add+0x544/0xb80 drivers/base/core.c:3738
 device_create_groups_vargs drivers/base/core.c:4454 [inline]
 device_create+0x269/0x300 drivers/base/core.c:4493
 dvb_register_device+0x116d/0x1dd0 drivers/media/dvb-core/dvbdev.c:567
 dvb_dmxdev_init+0x2d4/0x430 drivers/media/dvb-core/dmxdev.c:1427
 dvb_usb_adapter_dvb_init+0x905/0xdb0 drivers/media/usb/dvb-usb/dvb-usb-dvb.c:192
 dvb_usb_adapter_init drivers/media/usb/dvb-usb/dvb-usb-init.c:86 [inline]
 dvb_usb_init drivers/media/usb/dvb-usb/dvb-usb-init.c:186 [inline]
 dvb_usb_device_init+0x1c05/0x2570 drivers/media/usb/dvb-usb/dvb-usb-init.c:310
 usb_probe_interface+0x653/0xc60 drivers/usb/core/driver.c:396

Memory state around the buggy address:
 ffff88803706bf00: 00 00 00 00 fc fc fc fc 00 00 00 00 fc fc fc fc
 ffff88803706bf80: fa fb fb fb fc fc fc fc 00 00 00 00 fc fc fc fc
>ffff88803706c000: 00 03 fc fc fa fb fc fc fa fb fc fc 00 05 fc fc
                               ^
 ffff88803706c080: 00 05 fc fc 00 04 fc fc fa fb fc fc fa fb fc fc
 ffff88803706c100: 00 03 fc fc 00 00 fc fc fa fb fc fc 00 05 fc fc
==================================================================

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/07/22 16:08 upstream 248951ddc14d b561ce9c .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce KASAN: invalid-free in dev_free
2026/10/19 16:01 upstream c03c1a14507d 432c0077 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 KASAN: invalid-free in dev_free
* Struck through repros no longer work on HEAD.