[syzbot] [usb?] KASAN: slab-use-after-free Read in attach_store

[syzbot] [usb?] KASAN: slab-use-after-free Read in attach_store

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    2f1baf1fc892 Merge tag 'trace-v7.2-rc7' of git://git.kerne..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=13a98a25580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=c44651ea7dd2f307
dashboard link: https://syzkaller.appspot.com/bug?extid=8753715f05759f1a10de
compiler:       gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=12de5279580000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+8753715f05759f1a10de@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: slab-use-after-free in __mutex_lock_common kernel/locking/mutex.c:728 [inline]
BUG: KASAN: slab-use-after-free in __mutex_lock+0x18bb/0x1bd0 kernel/locking/mutex.c:821
Read of size 8 at addr ffff8880265c84f0 by task syz-executor396/6022

CPU: 0 UID: 0 PID: 6022 Comm: syz-executor396 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0x13d/0x4b0 mm/kasan/report.c:482
 kasan_report+0xdf/0x1c0 mm/kasan/report.c:595
 __mutex_lock_common kernel/locking/mutex.c:728 [inline]
 __mutex_lock+0x18bb/0x1bd0 kernel/locking/mutex.c:821
 attach_store+0x333/0x8f0 drivers/usb/usbip/vhci_sysfs.c:364
 dev_attr_store+0x58/0x80 drivers/base/core.c:2505
 sysfs_kf_write+0xf2/0x150 fs/sysfs/file.c:145
 kernfs_fop_write_iter+0x3e0/0x5f0 fs/kernfs/file.c:345
 new_sync_write fs/read_write.c:595 [inline]
 vfs_write+0x6ac/0x1050 fs/read_write.c:687
 ksys_write+0x12a/0x250 fs/read_write.c:739
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5f9e9f6bde
Code: 08 0f 85 f5 e2 ff ff 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 <c3> 90 41 57 41 56 4d 89 c6 41 55 4d 89 cd 41 54 55 53 48 83 ec 08
RSP: 002b:00007f5f9e1a0098 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f5f9e1a06c0 RCX: 00007f5f9e9f6bde
RDX: 0000000000000009 RSI: 00007f5f9e1a0100 RDI: 0000000000000008
RBP: 00007f5f9ea420b0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: ffffffffffffffd0
R13: 0000000000000009 R14: 00007ffc89c49e90 R15: 00007ffc89c49f78
 </TASK>

Allocated by task 1:
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
 __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:415
 kasan_kmalloc include/linux/kasan.h:263 [inline]
 __do_kmalloc_node mm/slub.c:5334 [inline]
 __kmalloc_noprof+0x322/0x820 mm/slub.c:5359
 _kmalloc_noprof include/linux/slab.h:992 [inline]
 _kzalloc_noprof include/linux/slab.h:1309 [inline]
 __usb_create_hcd+0x5e/0xac0 drivers/usb/core/hcd.c:2566
 vhci_hcd_probe+0x1a5/0x4e0 drivers/usb/usbip/vhci_hcd.c:1394
 platform_probe+0x106/0x1d0 drivers/base/platform.c:1439
 call_driver_probe drivers/base/dd.c:628 [inline]
 really_probe+0x241/0xa60 drivers/base/dd.c:706
 __driver_probe_device+0x20e/0x450 drivers/base/dd.c:868
 driver_probe_device+0x4a/0x140 drivers/base/dd.c:898
 __device_attach_driver+0x1df/0x320 drivers/base/dd.c:1026
 bus_for_each_drv+0x159/0x1e0 drivers/base/bus.c:500
 __device_attach+0x1e4/0x4d0 drivers/base/dd.c:1098
 device_initial_probe+0xaf/0xd0 drivers/base/dd.c:1153
 bus_probe_device+0x64/0x160 drivers/base/bus.c:620
 device_add+0x121d/0x1970 drivers/base/core.c:3772
 platform_device_add+0x35a/0x800 drivers/base/platform.c:762
 platform_device_register_full+0x5cf/0x830 drivers/base/platform.c:902
 vhci_hcd_init+0x1a1/0x2f0 drivers/usb/usbip/vhci_hcd.c:1557
 do_one_initcall+0x11d/0x700 init/main.c:1347
 do_initcall_level init/main.c:1409 [inline]
 do_initcalls init/main.c:1425 [inline]
 do_basic_setup init/main.c:1445 [inline]
 kernel_init_freeable+0x6ea/0x7b0 init/main.c:1658
 kernel_init+0x1f/0x1e0 init/main.c:1548
 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Freed by task 6021:
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2677 [inline]
 slab_free mm/slub.c:6377 [inline]
 kfree+0x22b/0x6c0 mm/slub.c:6692
 hcd_release drivers/usb/core/hcd.c:2690 [inline]
 kref_put include/linux/kref.h:65 [inline]
 usb_put_hcd drivers/usb/core/hcd.c:2704 [inline]
 usb_put_hcd+0x149/0x1f0 drivers/usb/core/hcd.c:2701
 vhci_hcd_remove+0xb5/0x1b0 drivers/usb/usbip/vhci_hcd.c:1431
 platform_remove+0x5f/0x80 drivers/base/platform.c:1456
 device_remove+0xcb/0x180 drivers/base/dd.c:616
 __device_release_driver drivers/base/dd.c:1349 [inline]
 device_release_driver_internal+0x44e/0x620 drivers/base/dd.c:1372
 unbind_store+0xf8/0x110 drivers/base/bus.c:244
 drv_attr_store+0x74/0xb0 drivers/base/bus.c:125
 sysfs_kf_write+0xf2/0x150 fs/sysfs/file.c:145
 kernfs_fop_write_iter+0x3e0/0x5f0 fs/kernfs/file.c:345
 new_sync_write fs/read_write.c:595 [inline]
 vfs_write+0x6ac/0x1050 fs/read_write.c:687
 ksys_write+0x12a/0x250 fs/read_write.c:739
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Last potentially related work creation:
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_record_aux_stack+0xa7/0xc0 mm/kasan/generic.c:556
 insert_work+0x36/0x230 kernel/workqueue.c:2226
 __queue_work+0x9bc/0x12b0 kernel/workqueue.c:2401
 queue_work_on+0x1a9/0x1e0 kernel/workqueue.c:2452
 queue_work include/linux/workqueue.h:699 [inline]
 usb_hcd_giveback_urb+0x330/0x4a0 drivers/usb/core/hcd.c:1758
 usb_rh_urb_dequeue drivers/usb/core/hcd.c:845 [inline]
 unlink1+0x418/0x510 drivers/usb/core/hcd.c:1580
 usb_hcd_unlink_urb+0x131/0x210 drivers/usb/core/hcd.c:1617
 usb_kill_urb drivers/usb/core/urb.c:716 [inline]
 usb_kill_urb+0x121/0x320 drivers/usb/core/urb.c:703
 hub_quiesce+0x1e9/0x320 drivers/usb/core/hub.c:1412
 hub_suspend+0x4ab/0x9e0 drivers/usb/core/hub.c:4016
 usb_suspend_interface drivers/usb/core/driver.c:1323 [inline]
 usb_suspend_both+0x288/0x950 drivers/usb/core/driver.c:1446
 usb_runtime_suspend+0x49/0x120 drivers/usb/core/driver.c:2000
 __rpm_callback+0xc8/0x620 drivers/base/power/runtime.c:406
 rpm_callback+0x16a/0x1b0 drivers/base/power/runtime.c:460
 rpm_suspend+0x2f4/0x11a0 drivers/base/power/runtime.c:698
 __pm_runtime_suspend+0xba/0x1a0 drivers/base/power/runtime.c:1167
 pm_runtime_put_sync_autosuspend include/linux/pm_runtime.h:740 [inline]
 usb_new_device.part.0+0x1653/0x1686 drivers/usb/core/hub.c:2735
 register_root_hub+0x4e6/0x639 drivers/usb/core/hcd.c:990
 usb_add_hcd.cold+0xccd/0x1158 drivers/usb/core/hcd.c:2987
 vhci_hcd_probe+0x1c2/0x4e0 drivers/usb/usbip/vhci_hcd.c:1401
 platform_probe+0x106/0x1d0 drivers/base/platform.c:1439
 call_driver_probe drivers/base/dd.c:628 [inline]
 really_probe+0x241/0xa60 drivers/base/dd.c:706
 __driver_probe_device+0x20e/0x450 drivers/base/dd.c:868
 driver_probe_device+0x4a/0x140 drivers/base/dd.c:898
 __device_attach_driver+0x1df/0x320 drivers/base/dd.c:1026
 bus_for_each_drv+0x159/0x1e0 drivers/base/bus.c:500
 __device_attach+0x1e4/0x4d0 drivers/base/dd.c:1098
 device_initial_probe+0xaf/0xd0 drivers/base/dd.c:1153
 bus_probe_device+0x64/0x160 drivers/base/bus.c:620
 device_add+0x121d/0x1970 drivers/base/core.c:3772
 platform_device_add+0x35a/0x800 drivers/base/platform.c:762
 platform_device_register_full+0x5cf/0x830 drivers/base/platform.c:902
 vhci_hcd_init+0x1a1/0x2f0 drivers/usb/usbip/vhci_hcd.c:1557
 do_one_initcall+0x11d/0x700 init/main.c:1347
 do_initcall_level init/main.c:1409 [inline]
 do_initcalls init/main.c:1425 [inline]
 do_basic_setup init/main.c:1445 [inline]
 kernel_init_freeable+0x6ea/0x7b0 init/main.c:1658
 kernel_init+0x1f/0x1e0 init/main.c:1548
 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Second to last potentially related work creation:
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_record_aux_stack+0xa7/0xc0 mm/kasan/generic.c:556
 insert_work+0x36/0x230 kernel/workqueue.c:2226
 __queue_work+0x9bc/0x12b0 kernel/workqueue.c:2401
 queue_work_on+0x1a9/0x1e0 kernel/workqueue.c:2452
 queue_work include/linux/workqueue.h:699 [inline]
 usb_hcd_giveback_urb+0x3b8/0x4a0 drivers/usb/core/hcd.c:1760
 rh_call_control drivers/usb/core/hcd.c:706 [inline]
 rh_urb_enqueue drivers/usb/core/hcd.c:817 [inline]
 usb_hcd_submit_urb+0xab7/0x2150 drivers/usb/core/hcd.c:1538
 usb_submit_urb+0x827/0x19b0 drivers/usb/core/urb.c:586
 usb_start_wait_urb+0x10e/0x580 drivers/usb/core/message.c:62
 usb_internal_control_msg drivers/usb/core/message.c:117 [inline]
 usb_control_msg+0x328/0x4b0 drivers/usb/core/message.c:167
 set_port_feature drivers/usb/core/hub.c:466 [inline]
 hub_suspend+0x826/0x9e0 drivers/usb/core/hub.c:4004
 usb_suspend_interface drivers/usb/core/driver.c:1323 [inline]
 usb_suspend_both+0x288/0x950 drivers/usb/core/driver.c:1446
 usb_runtime_suspend+0x49/0x120 drivers/usb/core/driver.c:2000
 __rpm_callback+0xc8/0x620 drivers/base/power/runtime.c:406
 rpm_callback+0x16a/0x1b0 drivers/base/power/runtime.c:460
 rpm_suspend+0x2f4/0x11a0 drivers/base/power/runtime.c:698
 __pm_runtime_suspend+0xba/0x1a0 drivers/base/power/runtime.c:1167
 pm_runtime_put_sync_autosuspend include/linux/pm_runtime.h:740 [inline]
 usb_new_device.part.0+0x1653/0x1686 drivers/usb/core/hub.c:2735
 register_root_hub+0x4e6/0x639 drivers/usb/core/hcd.c:990
 usb_add_hcd.cold+0xccd/0x1158 drivers/usb/core/hcd.c:2987
 vhci_hcd_probe+0x1c2/0x4e0 drivers/usb/usbip/vhci_hcd.c:1401
 platform_probe+0x106/0x1d0 drivers/base/platform.c:1439
 call_driver_probe drivers/base/dd.c:628 [inline]
 really_probe+0x241/0xa60 drivers/base/dd.c:706
 __driver_probe_device+0x20e/0x450 drivers/base/dd.c:868
 driver_probe_device+0x4a/0x140 drivers/base/dd.c:898
 __device_attach_driver+0x1df/0x320 drivers/base/dd.c:1026
 bus_for_each_drv+0x159/0x1e0 drivers/base/bus.c:500
 __device_attach+0x1e4/0x4d0 drivers/base/dd.c:1098
 device_initial_probe+0xaf/0xd0 drivers/base/dd.c:1153
 bus_probe_device+0x64/0x160 drivers/base/bus.c:620
 device_add+0x121d/0x1970 drivers/base/core.c:3772
 platform_device_add+0x35a/0x800 drivers/base/platform.c:762
 platform_device_register_full+0x5cf/0x830 drivers/base/platform.c:902
 vhci_hcd_init+0x1a1/0x2f0 drivers/usb/usbip/vhci_hcd.c:1557
 do_one_initcall+0x11d/0x700 init/main.c:1347
 do_initcall_level init/main.c:1409 [inline]
 do_initcalls init/main.c:1425 [inline]
 do_basic_setup init/main.c:1445 [inline]
 kernel_init_freeable+0x6ea/0x7b0 init/main.c:1658
 kernel_init+0x1f/0x1e0 init/main.c:1548
 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

The buggy address belongs to the object at ffff8880265c8000
 which belongs to the cache kmalloc-8k of size 8192
The buggy address is located 1264 bytes inside of
 freed 8192-byte region [ffff8880265c8000, ffff8880265ca000)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x265c8
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff88801bc43180 dead000000000122 0000000000000000
raw: 0000000000000000 0000000800020002 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88801bc43180 dead000000000122 0000000000000000
head: 0000000000000000 0000000800020002 00000000f5000000 0000000000000000
head: 00fff00000000003 fffffffffffffe01 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1, tgid 1 (swapper/0), ts 11610115084, free_ts 6038226833
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0xfd/0x120 mm/page_alloc.c:1859
 prep_new_page mm/page_alloc.c:1867 [inline]
 get_page_from_freelist+0xf48/0x3530 mm/page_alloc.c:3946
 __alloc_frozen_pages_noprof+0x299/0x2dc0 mm/page_alloc.c:5304
 alloc_slab_page mm/slub.c:3266 [inline]
 allocate_slab mm/slub.c:3380 [inline]
 new_slab+0xa2/0x640 mm/slub.c:3426
 refill_objects+0xe3/0x410 mm/slub.c:7310
 refill_sheaf mm/slub.c:2804 [inline]
 __pcs_replace_empty_main+0x376/0x680 mm/slub.c:4675
 alloc_from_pcs mm/slub.c:4773 [inline]
 slab_alloc_node mm/slub.c:4905 [inline]
 __do_kmalloc_node mm/slub.c:5333 [inline]
 __kmalloc_noprof+0x66d/0x820 mm/slub.c:5359
 _kmalloc_noprof include/linux/slab.h:992 [inline]
 _kzalloc_noprof include/linux/slab.h:1309 [inline]
 __usb_create_hcd+0x5e/0xac0 drivers/usb/core/hcd.c:2566
 vhci_hcd_probe+0xf3/0x4e0 drivers/usb/usbip/vhci_hcd.c:1378
 platform_probe+0x106/0x1d0 drivers/base/platform.c:1439
 call_driver_probe drivers/base/dd.c:628 [inline]
 really_probe+0x241/0xa60 drivers/base/dd.c:706
 __driver_probe_device+0x20e/0x450 drivers/base/dd.c:868
 driver_probe_device+0x4a/0x140 drivers/base/dd.c:898
 __device_attach_driver+0x1df/0x320 drivers/base/dd.c:1026
 bus_for_each_drv+0x159/0x1e0 drivers/base/bus.c:500
 __device_attach+0x1e4/0x4d0 drivers/base/dd.c:1098
page last free pid 34 tgid 34 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 __free_pages_prepare mm/page_alloc.c:1406 [inline]
 free_pages_prepare+0x586/0xd80 mm/page_alloc.c:1451
 __free_contig_range_common+0x14f/0x250 mm/page_alloc.c:6897
 __free_contig_range mm/page_alloc.c:6942 [inline]
 free_pages_bulk+0x12a/0x200 mm/page_alloc.c:5257
 vm_area_free_pages+0xad/0x2b0 mm/vmalloc.c:3461
 vfree mm/vmalloc.c:3510 [inline]
 vfree+0x107/0x750 mm/vmalloc.c:3484
 delayed_vfree_work+0x56/0x80 mm/vmalloc.c:3414
 process_one_work+0xa23/0x1940 kernel/workqueue.c:3322
 process_scheduled_works kernel/workqueue.c:3405 [inline]
 worker_thread+0x5ef/0xe50 kernel/workqueue.c:3486
 kthread+0x370/0x450 kernel/kthread.c:436
 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Memory state around the buggy address:
 ffff8880265c8380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880265c8400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8880265c8480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                             ^
 ffff8880265c8500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880265c8580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================


---
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Forwarded: [PATCH] usbip: vhci_hcd: fix UAF in attach_store() during unbind

[syzbot]

For archival purposes, forwarding an incoming command email to
linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com.

***

Subject: [PATCH] usbip: vhci_hcd: fix UAF in attach_store() during unbind
Author: kartikey406@gmail.com

#syz test: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master


vhci_hcd_remove() frees the SS hcd via usb_put_hcd() before the HS hcd's
vhci_stop() removes the sysfs attribute group, since the group removal is
guarded by usb_hcd_is_primary_hcd(). A concurrent write to the attach
attribute can therefore reach vhci->vhci_hcd_ss after it has been freed.

Remove the attribute group at the start of vhci_hcd_remove(), before
either hcd reference is dropped. sysfs_remove_group() drains in-flight
store callbacks, so no writer can be inside attach_store() once it
returns.

Reported-by: syzbot+8753715f05759f1a10de@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=8753715f05759f1a10de
Signed-off-by: Deepanshu Kartikey <kartikey406@gmail.com>
---
 drivers/usb/usbip/vhci_hcd.c | 39 +++++++++++++++++++++---------------
 1 file changed, 23 insertions(+), 16 deletions(-)

diff --git a/drivers/usb/usbip/vhci_hcd.c b/drivers/usb/usbip/vhci_hcd.c
index 39e8faf4c18c..3ce8893729b1 100644
--- a/drivers/usb/usbip/vhci_hcd.c
+++ b/drivers/usb/usbip/vhci_hcd.c
@@ -1252,18 +1252,11 @@ static int vhci_start(struct usb_hcd *hcd)
 static void vhci_stop(struct usb_hcd *hcd)
 {
 	struct vhci_hcd *vhci_hcd = hcd_to_vhci_hcd(hcd);
-	int id, rhport;
+	int rhport;
 
 	usbip_dbg_vhci_hc("stop VHCI controller\n");
 
-	/* 1. remove the userland interface of vhci_hcd */
-	id = hcd_name_to_id(hcd_name(hcd));
-	if (id == 0 && usb_hcd_is_primary_hcd(hcd)) {
-		sysfs_remove_group(&hcd_dev(hcd)->kobj, &vhci_attr_group);
-		vhci_finish_attr_group();
-	}
-
-	/* 2. shutdown all the ports of vhci_hcd */
+	/* shutdown all the ports of vhci_hcd */
 	for (rhport = 0; rhport < VHCI_HC_PORTS; rhport++) {
 		struct vhci_device *vdev = &vhci_hcd->vdev[rhport];
 
@@ -1421,20 +1414,34 @@ static int vhci_hcd_probe(struct platform_device *pdev)
 static void vhci_hcd_remove(struct platform_device *pdev)
 {
 	struct vhci *vhci = *((void **)dev_get_platdata(&pdev->dev));
+	struct usb_hcd *hcd_hs = vhci_hcd_to_hcd(vhci->vhci_hcd_hs);
+	struct usb_hcd *hcd_ss = vhci_hcd_to_hcd(vhci->vhci_hcd_ss);
+
+	/*
+	 * Remove the userland interface before dropping the hcd references.
+	 * sysfs_remove_group() waits for in-flight attach_store()/detach_store()
+	 * callers to return and rejects new ones, so neither hcd can be reached
+	 * from sysfs by the time it is freed below.
+	 */
+	if (pdev->id == 0) {
+		sysfs_remove_group(&pdev->dev.kobj, &vhci_attr_group);
+		vhci_finish_attr_group();
+	}
+
+	vhci->vhci_hcd_hs = NULL;
+	vhci->vhci_hcd_ss = NULL;
+
 
 	/*
 	 * Disconnects the root hub,
 	 * then reverses the effects of usb_add_hcd(),
 	 * invoking the HCD's stop() methods.
 	 */
-	usb_remove_hcd(vhci_hcd_to_hcd(vhci->vhci_hcd_ss));
-	usb_put_hcd(vhci_hcd_to_hcd(vhci->vhci_hcd_ss));
-
-	usb_remove_hcd(vhci_hcd_to_hcd(vhci->vhci_hcd_hs));
-	usb_put_hcd(vhci_hcd_to_hcd(vhci->vhci_hcd_hs));
+	usb_remove_hcd(hcd_ss);
+	usb_put_hcd(hcd_ss);
 
-	vhci->vhci_hcd_hs = NULL;
-	vhci->vhci_hcd_ss = NULL;
+	usb_remove_hcd(hcd_hs);
+	usb_put_hcd(hcd_hs);
 }
 
 #ifdef CONFIG_PM
-- 
2.43.0

Forwarded: [PATCH] usbip: vhci_hcd: move sysfs attribute setup into probe/remove

[syzbot]

For archival purposes, forwarding an incoming command email to
linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com.

***

Subject: [PATCH] usbip: vhci_hcd: move sysfs attribute setup into probe/remove
Author: kartikey406@gmail.com

#syz test: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master


The vhci sysfs attribute group is created in vhci_start() and removed in
vhci_stop(), guarded by usb_hcd_is_primary_hcd(). Since vhci_start() and
vhci_stop() run from usb_add_hcd()/usb_remove_hcd(), which are each called
twice, the attach attribute is live while only one of the two hcds exists:
it is created during the first usb_add_hcd() before vhci_hcd_ss is set,
and it survives the first usb_put_hcd() during removal. A concurrent write
to attach can therefore reach a NULL or freed vhci_hcd_ss.

Create the group at the end of vhci_hcd_probe(), after both hcds are
added, and remove it at the start of vhci_hcd_remove(), before either
reference is dropped. sysfs_remove_group() drains in-flight store
callbacks, so no writer can be inside attach_store() once it returns.

Reported-by: syzbot+8753715f05759f1a10de@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=8753715f05759f1a10de
Signed-off-by: Deepanshu Kartikey <kartikey406@gmail.com>
---
 drivers/usb/usbip/vhci_hcd.c | 66 ++++++++++++++++++++----------------
 1 file changed, 36 insertions(+), 30 deletions(-)

diff --git a/drivers/usb/usbip/vhci_hcd.c b/drivers/usb/usbip/vhci_hcd.c
index 39e8faf4c18c..90f166f3ae96 100644
--- a/drivers/usb/usbip/vhci_hcd.c
+++ b/drivers/usb/usbip/vhci_hcd.c
@@ -1199,7 +1199,6 @@ static int vhci_start(struct usb_hcd *hcd)
 {
 	struct vhci_hcd *vhci_hcd = hcd_to_vhci_hcd(hcd);
 	int id, rhport;
-	int err;
 
 	usbip_dbg_vhci_hc("enter vhci_start\n");
 
@@ -1230,40 +1229,17 @@ static int vhci_start(struct usb_hcd *hcd)
 		return -EINVAL;
 	}
 
-	/* vhci_hcd is now ready to be controlled through sysfs */
-	if (id == 0 && usb_hcd_is_primary_hcd(hcd)) {
-		err = vhci_init_attr_group();
-		if (err) {
-			dev_err(hcd_dev(hcd), "init attr group failed, err = %d\n", err);
-			return err;
-		}
-		err = sysfs_create_group(&hcd_dev(hcd)->kobj, &vhci_attr_group);
-		if (err) {
-			dev_err(hcd_dev(hcd), "create sysfs files failed, err = %d\n", err);
-			vhci_finish_attr_group();
-			return err;
-		}
-		dev_info(hcd_dev(hcd), "created sysfs %s\n", hcd_name(hcd));
-	}
-
 	return 0;
 }
 
 static void vhci_stop(struct usb_hcd *hcd)
 {
 	struct vhci_hcd *vhci_hcd = hcd_to_vhci_hcd(hcd);
-	int id, rhport;
+	int rhport;
 
 	usbip_dbg_vhci_hc("stop VHCI controller\n");
 
-	/* 1. remove the userland interface of vhci_hcd */
-	id = hcd_name_to_id(hcd_name(hcd));
-	if (id == 0 && usb_hcd_is_primary_hcd(hcd)) {
-		sysfs_remove_group(&hcd_dev(hcd)->kobj, &vhci_attr_group);
-		vhci_finish_attr_group();
-	}
-
-	/* 2. shutdown all the ports of vhci_hcd */
+	/* shutdown all the ports of vhci_hcd */
 	for (rhport = 0; rhport < VHCI_HC_PORTS; rhport++) {
 		struct vhci_device *vdev = &vhci_hcd->vdev[rhport];
 
@@ -1405,8 +1381,25 @@ static int vhci_hcd_probe(struct platform_device *pdev)
 	}
 
 	usbip_dbg_vhci_hc("bye\n");
+
+	if (pdev->id == 0) {
+		ret = vhci_init_attr_group();
+		if (ret) {
+			dev_err_probe(&pdev->dev, ret, "init attr group failed\n");
+			goto remove_usb3_hcd;
+		}
+		ret = sysfs_create_group(&pdev->dev.kobj, &vhci_attr_group);
+		if (ret) {
+			dev_err_probe(&pdev->dev, ret, "create sysfs files failed\n");
+			vhci_finish_attr_group();
+			goto remove_usb3_hcd;
+		}
+	}
+
 	return 0;
 
+remove_usb3_hcd:
+	usb_remove_hcd(hcd_ss);
 put_usb3_hcd:
 	usb_put_hcd(hcd_ss);
 remove_usb2_hcd:
@@ -1421,17 +1414,30 @@ static int vhci_hcd_probe(struct platform_device *pdev)
 static void vhci_hcd_remove(struct platform_device *pdev)
 {
 	struct vhci *vhci = *((void **)dev_get_platdata(&pdev->dev));
+	struct usb_hcd *hcd_hs = vhci_hcd_to_hcd(vhci->vhci_hcd_hs);
+	struct usb_hcd *hcd_ss = vhci_hcd_to_hcd(vhci->vhci_hcd_ss);
+
+	/*
+	 * Remove the userland interface before dropping the hcd references.
+	 * sysfs_remove_group() waits for in-flight attach_store()/detach_store()
+	 * callers to return and rejects new ones, so neither hcd can be reached
+	 * from sysfs by the time it is freed below.
+	 */
+	if (pdev->id == 0) {
+		sysfs_remove_group(&pdev->dev.kobj, &vhci_attr_group);
+		vhci_finish_attr_group();
+	}
 
 	/*
 	 * Disconnects the root hub,
 	 * then reverses the effects of usb_add_hcd(),
 	 * invoking the HCD's stop() methods.
 	 */
-	usb_remove_hcd(vhci_hcd_to_hcd(vhci->vhci_hcd_ss));
-	usb_put_hcd(vhci_hcd_to_hcd(vhci->vhci_hcd_ss));
+	usb_remove_hcd(hcd_ss);
+	usb_put_hcd(hcd_ss);
 
-	usb_remove_hcd(vhci_hcd_to_hcd(vhci->vhci_hcd_hs));
-	usb_put_hcd(vhci_hcd_to_hcd(vhci->vhci_hcd_hs));
+	usb_remove_hcd(hcd_hs);
+	usb_put_hcd(hcd_hs);
 
 	vhci->vhci_hcd_hs = NULL;
 	vhci->vhci_hcd_ss = NULL;
-- 
2.43.0

Forwarded: [PATCH] usbip: vhci_hcd: let the driver core manage the sysfs attributes

[syzbot]

For archival purposes, forwarding an incoming command email to
linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com.

***

Subject: [PATCH] usbip: vhci_hcd: let the driver core manage the sysfs attributes
Author: kartikey406@gmail.com

#syz test: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master


The vhci attribute group is created in vhci_start() and removed in
vhci_stop(), guarded by usb_hcd_is_primary_hcd(). Both run from
usb_add_hcd()/usb_remove_hcd(), which are called once per hcd, so the
attach attribute is live while only one of the two hcds exists: it is
created during the first usb_add_hcd() before vhci_hcd_ss is set, and it
survives the first usb_put_hcd() on removal. A concurrent write to attach
can therefore reach a NULL or freed vhci_hcd_ss.

Register the group as dev_groups on the platform driver instead, so the
driver core creates the files before probe and removes them after remove
returns, and drop the sysfs_create_group()/sysfs_remove_group() calls from
the driver. The attributes have always been created only on vhci_hcd.0;
an is_visible() callback keeps them there.

vhci_init_attr_group() is moved into vhci_hcd_init() ahead of
platform_driver_register() so the group is populated before the core
reads it. The attribute array is still built at runtime because the
number of status attributes comes from CONFIG_USBIP_VHCI_NR_HCS and the
preprocessor cannot emit a variable number of __ATTR() declarations. If
statically declaring all 32 and hiding the unused ones with is_visible()
is preferred, I can respin that way.

Reported-by: syzbot+8753715f05759f1a10de@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=8753715f05759f1a10de
Signed-off-by: Deepanshu Kartikey <kartikey406@gmail.com>
---
v2:
 - use dev_groups instead of moving sysfs_create_group() into probe (Greg)
 - add is_visible() to keep the attributes on vhci_hcd.0 only
 - move vhci_init_attr_group() into vhci_hcd_init()
---
 drivers/usb/usbip/vhci.h       |  1 +
 drivers/usb/usbip/vhci_hcd.c   | 37 ++++++++++------------------------
 drivers/usb/usbip/vhci_sysfs.c | 19 +++++++++++++++++
 3 files changed, 31 insertions(+), 26 deletions(-)

diff --git a/drivers/usb/usbip/vhci.h b/drivers/usb/usbip/vhci.h
index 5659dce1526e..844500e3b0ea 100644
--- a/drivers/usb/usbip/vhci.h
+++ b/drivers/usb/usbip/vhci.h
@@ -121,6 +121,7 @@ struct vhci_hcd {
 extern int vhci_num_controllers;
 extern struct vhci *vhcis;
 extern struct attribute_group vhci_attr_group;
+extern const struct attribute_group *vhci_groups[];
 
 /* vhci_hcd.c */
 void rh_port_connect(struct vhci_device *vdev, enum usb_device_speed speed);
diff --git a/drivers/usb/usbip/vhci_hcd.c b/drivers/usb/usbip/vhci_hcd.c
index 39e8faf4c18c..4bace5b8b879 100644
--- a/drivers/usb/usbip/vhci_hcd.c
+++ b/drivers/usb/usbip/vhci_hcd.c
@@ -1199,7 +1199,6 @@ static int vhci_start(struct usb_hcd *hcd)
 {
 	struct vhci_hcd *vhci_hcd = hcd_to_vhci_hcd(hcd);
 	int id, rhport;
-	int err;
 
 	usbip_dbg_vhci_hc("enter vhci_start\n");
 
@@ -1230,40 +1229,17 @@ static int vhci_start(struct usb_hcd *hcd)
 		return -EINVAL;
 	}
 
-	/* vhci_hcd is now ready to be controlled through sysfs */
-	if (id == 0 && usb_hcd_is_primary_hcd(hcd)) {
-		err = vhci_init_attr_group();
-		if (err) {
-			dev_err(hcd_dev(hcd), "init attr group failed, err = %d\n", err);
-			return err;
-		}
-		err = sysfs_create_group(&hcd_dev(hcd)->kobj, &vhci_attr_group);
-		if (err) {
-			dev_err(hcd_dev(hcd), "create sysfs files failed, err = %d\n", err);
-			vhci_finish_attr_group();
-			return err;
-		}
-		dev_info(hcd_dev(hcd), "created sysfs %s\n", hcd_name(hcd));
-	}
-
 	return 0;
 }
 
 static void vhci_stop(struct usb_hcd *hcd)
 {
 	struct vhci_hcd *vhci_hcd = hcd_to_vhci_hcd(hcd);
-	int id, rhport;
+	int rhport;
 
 	usbip_dbg_vhci_hc("stop VHCI controller\n");
 
-	/* 1. remove the userland interface of vhci_hcd */
-	id = hcd_name_to_id(hcd_name(hcd));
-	if (id == 0 && usb_hcd_is_primary_hcd(hcd)) {
-		sysfs_remove_group(&hcd_dev(hcd)->kobj, &vhci_attr_group);
-		vhci_finish_attr_group();
-	}
-
-	/* 2. shutdown all the ports of vhci_hcd */
+	/* shutdown all the ports of vhci_hcd */
 	for (rhport = 0; rhport < VHCI_HC_PORTS; rhport++) {
 		struct vhci_device *vdev = &vhci_hcd->vdev[rhport];
 
@@ -1513,6 +1489,7 @@ static struct platform_driver vhci_driver = {
 	.resume	= vhci_hcd_resume,
 	.driver	= {
 		.name = driver_name,
+		.dev_groups = vhci_groups,
 	},
 };
 
@@ -1541,6 +1518,10 @@ static int __init vhci_hcd_init(void)
 	if (vhcis == NULL)
 		return -ENOMEM;
 
+	ret = vhci_init_attr_group();
+	if (ret)
+		goto err_init_attr_group;
+
 	ret = platform_driver_register(&vhci_driver);
 	if (ret)
 		goto err_driver_register;
@@ -1565,9 +1546,12 @@ static int __init vhci_hcd_init(void)
 
 	return 0;
 
+
 err_add_hcd:
 	platform_driver_unregister(&vhci_driver);
 err_driver_register:
+	vhci_finish_attr_group();
+err_init_attr_group:
 	kfree(vhcis);
 	return ret;
 }
@@ -1576,6 +1560,7 @@ static void __exit vhci_hcd_exit(void)
 {
 	del_platform_devices();
 	platform_driver_unregister(&vhci_driver);
+	vhci_finish_attr_group();
 	kfree(vhcis);
 }
 
diff --git a/drivers/usb/usbip/vhci_sysfs.c b/drivers/usb/usbip/vhci_sysfs.c
index a7ede6fb3da9..8c0bff2ddabb 100644
--- a/drivers/usb/usbip/vhci_sysfs.c
+++ b/drivers/usb/usbip/vhci_sysfs.c
@@ -497,8 +497,27 @@ static void finish_status_attrs(void)
 	kfree(status_attrs);
 }
 
+static umode_t vhci_attr_is_visible(struct kobject *kobj,
+				    struct attribute *attr, int n)
+{
+	struct platform_device *pdev = to_platform_device(kobj_to_dev(kobj));
+	/*
+	 * The attributes control every controller and have always lived on
+	 * vhci_hcd.0 only.  Keep them there now that the driver core creates
+	 * the group for each device.
+	 */
+	return pdev->id == 0 ? attr->mode : 0;
+}
+
+
 struct attribute_group vhci_attr_group = {
 	.attrs = NULL,
+	.is_visible = vhci_attr_is_visible,
+};
+
+const struct attribute_group *vhci_groups[] = {
+	&vhci_attr_group,
+	NULL,
 };
 
 int vhci_init_attr_group(void)
-- 
2.43.0

Re: [syzbot] [usb?] KASAN: slab-use-after-free Read in attach_store

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-by: syzbot+8753715f05759f1a10de@syzkaller.appspotmail.com
Tested-by: syzbot+8753715f05759f1a10de@syzkaller.appspotmail.com

Tested on:

commit:         3eb40771 Merge tag 'soc-fixes-7.2-3' of git://git.kern..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=135b1a79580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=c44651ea7dd2f307
dashboard link: https://syzkaller.appspot.com/bug?extid=8753715f05759f1a10de
compiler:       gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44
patch:          https://syzkaller.appspot.com/x/patch.diff?x=146b1a79580000

Note: testing is done by a robot and is best-effort only.

Re: [syzbot] [usb?] KASAN: slab-use-after-free Read in attach_store

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-by: syzbot+8753715f05759f1a10de@syzkaller.appspotmail.com
Tested-by: syzbot+8753715f05759f1a10de@syzkaller.appspotmail.com

Tested on:

commit:         15ef2f78 Merge tag 'input-for-v7.2-rc7' of git://git.k..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=16bb3279580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=c44651ea7dd2f307
dashboard link: https://syzkaller.appspot.com/bug?extid=8753715f05759f1a10de
compiler:       gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44
patch:          https://syzkaller.appspot.com/x/patch.diff?x=15dc6949580000

Note: testing is done by a robot and is best-effort only.

Re: [syzbot] [usb?] KASAN: slab-use-after-free Read in attach_store

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-by: syzbot+8753715f05759f1a10de@syzkaller.appspotmail.com
Tested-by: syzbot+8753715f05759f1a10de@syzkaller.appspotmail.com

Tested on:

commit:         15ef2f78 Merge tag 'input-for-v7.2-rc7' of git://git.k..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=164fca25580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=c44651ea7dd2f307
dashboard link: https://syzkaller.appspot.com/bug?extid=8753715f05759f1a10de
compiler:       gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44
patch:          https://syzkaller.appspot.com/x/patch.diff?x=14c81279580000

Note: testing is done by a robot and is best-effort only.

Re: [syzbot] [usb?] KASAN: slab-use-after-free Read in attach_store

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
general protection fault in attach_store

Oops: general protection fault, probably for non-canonical address 0xdffffc000000001f: 0000 [#1] SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x00000000000000f8-0x00000000000000ff]
CPU: 3 UID: 0 PID: 5994 Comm: syz-executor227 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:__mutex_lock_common kernel/locking/mutex.c:625 [inline]
RIP: 0010:__mutex_lock+0x15d/0x1bd0 kernel/locking/mutex.c:821
Code: 08 84 d2 0f 85 67 14 00 00 44 8b 3d bd 29 b6 0f 45 85 ff 75 29 48 b8 00 00 00 00 00 fc ff df 48 8d 7b 58 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 5e 14 00 00 48 3b 5b 58 0f 85 8b 07 00 00 bf 01
RSP: 0018:ffffc900034a79c0 EFLAGS: 00010202

RAX: dffffc0000000000 RBX: 00000000000000a0 RCX: 0000000000000001
RDX: 000000000000001f RSI: ffffffff8e183b4b RDI: 00000000000000f8
RBP: ffffc900034a7b30 R08: ffffffff87ea8263 R09: 0000000000000004
R10: ffffc900034a7b48 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: dffffc0000000000 R15: 0000000000000000
FS:  00007fa40066f6c0(0000) GS:ffff8880d60e9000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555b3ccb5258 CR3: 000000002e664000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 attach_store+0x333/0x8f0 drivers/usb/usbip/vhci_sysfs.c:364
 dev_attr_store+0x58/0x80 drivers/base/core.c:2505
 sysfs_kf_write+0xf2/0x150 fs/sysfs/file.c:145
 kernfs_fop_write_iter+0x3e0/0x5f0 fs/kernfs/file.c:345
 new_sync_write fs/read_write.c:595 [inline]
 vfs_write+0x6ac/0x1050 fs/read_write.c:687
 ksys_write+0x12a/0x250 fs/read_write.c:739
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa401ec7bde
Code: 08 0f 85 f5 e2 ff ff 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 <c3> 90 41 57 41 56 4d 89 c6 41 55 4d 89 cd 41 54 55 53 48 83 ec 08
RSP: 002b:00007fa40066f098 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fa40066f6c0 RCX: 00007fa401ec7bde
RDX: 0000000000000009 RSI: 00007fa40066f100 RDI: 0000000000000007
RBP: 00007fa401f130b0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: ffffffffffffffd0
R13: 0000000000000009 R14: 00007ffc9812f530 R15: 00007ffc9812f618
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__mutex_lock_common kernel/locking/mutex.c:625 [inline]
RIP: 0010:__mutex_lock+0x15d/0x1bd0 kernel/locking/mutex.c:821
Code: 08 84 d2 0f 85 67 14 00 00 44 8b 3d bd 29 b6 0f 45 85 ff 75 29 48 b8 00 00 00 00 00 fc ff df 48 8d 7b 58 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 5e 14 00 00 48 3b 5b 58 0f 85 8b 07 00 00 bf 01
RSP: 0018:ffffc900034a79c0 EFLAGS: 00010202

RAX: dffffc0000000000 RBX: 00000000000000a0 RCX: 0000000000000001
RDX: 000000000000001f RSI: ffffffff8e183b4b RDI: 00000000000000f8
RBP: ffffc900034a7b30 R08: ffffffff87ea8263 R09: 0000000000000004
R10: ffffc900034a7b48 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: dffffc0000000000 R15: 0000000000000000
FS:  00007fa40066f6c0(0000) GS:ffff8880d60e9000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555b3cb6c620 CR3: 000000002e664000 CR4: 0000000000352ef0
----------------
Code disassembly (best guess):
   0:	08 84 d2 0f 85 67 14 	or     %al,0x1467850f(%rdx,%rdx,8)
   7:	00 00                	add    %al,(%rax)
   9:	44 8b 3d bd 29 b6 0f 	mov    0xfb629bd(%rip),%r15d        # 0xfb629cd
  10:	45 85 ff             	test   %r15d,%r15d
  13:	75 29                	jne    0x3e
  15:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  1c:	fc ff df
  1f:	48 8d 7b 58          	lea    0x58(%rbx),%rdi
  23:	48 89 fa             	mov    %rdi,%rdx
  26:	48 c1 ea 03          	shr    $0x3,%rdx
* 2a:	80 3c 02 00          	cmpb   $0x0,(%rdx,%rax,1) <-- trapping instruction
  2e:	0f 85 5e 14 00 00    	jne    0x1492
  34:	48 3b 5b 58          	cmp    0x58(%rbx),%rbx
  38:	0f 85 8b 07 00 00    	jne    0x7c9
  3e:	bf                   	.byte 0xbf
  3f:	01                   	.byte 0x1


Tested on:

commit:         15ef2f78 Merge tag 'input-for-v7.2-rc7' of git://git.k..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=158bca25580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=c44651ea7dd2f307
dashboard link: https://syzkaller.appspot.com/bug?extid=8753715f05759f1a10de
compiler:       gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44
patch:          https://syzkaller.appspot.com/x/patch.diff?x=17f74279580000