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

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

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    933069701c1b Merge tag '6.11-rc-smb3-server-fixes' of git:..
git tree:       https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing
console output: https://syzkaller.appspot.com/x/log.txt?x=10ad0075980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=f828342678294017
dashboard link: https://syzkaller.appspot.com/bug?extid=916742d5d24f6c254761
compiler:       gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1467b055980000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=16849cbd980000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/22dd51445d03/disk-93306970.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/f85f111961d5/vmlinux-93306970.xz
kernel image: https://storage.googleapis.com/syzbot-assets/7971b4814e87/bzImage-93306970.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+916742d5d24f6c254761@syzkaller.appspotmail.com

usb 1-1: New USB device found, idVendor=0424, idProduct=c001, bcdDevice=1c.8f
usb 1-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
usb 1-1: config 0 descriptor??
usb 1-1: USB disconnect, device number 2
==================================================================
BUG: KASAN: slab-use-after-free in hdm_disconnect+0x227/0x250 drivers/most/most_usb.c:1125
Read of size 8 at addr ffff88811314d898 by task kworker/0:1/9

CPU: 0 UID: 0 PID: 9 Comm: kworker/0:1 Not tainted 6.10.0-syzkaller-g933069701c1b #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024
Workqueue: usb_hub_wq hub_event
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:93 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:119
 print_address_description mm/kasan/report.c:377 [inline]
 print_report+0xc3/0x620 mm/kasan/report.c:488
 kasan_report+0xd9/0x110 mm/kasan/report.c:601
 hdm_disconnect+0x227/0x250 drivers/most/most_usb.c:1125
 usb_unbind_interface+0x1e8/0x970 drivers/usb/core/driver.c:461
 device_remove drivers/base/dd.c:568 [inline]
 device_remove+0x122/0x170 drivers/base/dd.c:560
 __device_release_driver drivers/base/dd.c:1270 [inline]
 device_release_driver_internal+0x44a/0x610 drivers/base/dd.c:1293
 bus_remove_device+0x22f/0x420 drivers/base/bus.c:574
 device_del+0x396/0x9f0 drivers/base/core.c:3868
 usb_disable_device+0x36c/0x7f0 drivers/usb/core/message.c:1418
 usb_disconnect+0x2e1/0x920 drivers/usb/core/hub.c:2304
 hub_port_connect drivers/usb/core/hub.c:5361 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5661 [inline]
 port_event drivers/usb/core/hub.c:5821 [inline]
 hub_event+0x1be4/0x4f50 drivers/usb/core/hub.c:5903
 process_one_work+0x9c5/0x1b40 kernel/workqueue.c:3231
 process_scheduled_works kernel/workqueue.c:3312 [inline]
 worker_thread+0x6c8/0xf20 kernel/workqueue.c:3390
 kthread+0x2c1/0x3a0 kernel/kthread.c:389
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>

Allocated by task 9:
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
 kasan_save_track+0x14/0x30 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:370 [inline]
 __kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:387
 kmalloc_noprof include/linux/slab.h:681 [inline]
 kzalloc_noprof include/linux/slab.h:807 [inline]
 hdm_probe+0xb3/0x1880 drivers/most/most_usb.c:959
 usb_probe_interface+0x309/0x9d0 drivers/usb/core/driver.c:399
 call_driver_probe drivers/base/dd.c:578 [inline]
 really_probe+0x23e/0xa90 drivers/base/dd.c:656
 __driver_probe_device+0x1de/0x440 drivers/base/dd.c:798
 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:828
 __device_attach_driver+0x1df/0x310 drivers/base/dd.c:956
 bus_for_each_drv+0x157/0x1e0 drivers/base/bus.c:457
 __device_attach+0x1e8/0x4b0 drivers/base/dd.c:1028
 bus_probe_device+0x17f/0x1c0 drivers/base/bus.c:532
 device_add+0x114b/0x1a70 drivers/base/core.c:3679
 usb_set_configuration+0x10cb/0x1c50 drivers/usb/core/message.c:2210
 usb_generic_driver_probe+0xb1/0x110 drivers/usb/core/generic.c:254
 usb_probe_device+0xec/0x3e0 drivers/usb/core/driver.c:294
 call_driver_probe drivers/base/dd.c:578 [inline]
 really_probe+0x23e/0xa90 drivers/base/dd.c:656
 __driver_probe_device+0x1de/0x440 drivers/base/dd.c:798
 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:828
 __device_attach_driver+0x1df/0x310 drivers/base/dd.c:956
 bus_for_each_drv+0x157/0x1e0 drivers/base/bus.c:457
 __device_attach+0x1e8/0x4b0 drivers/base/dd.c:1028
 bus_probe_device+0x17f/0x1c0 drivers/base/bus.c:532
 device_add+0x114b/0x1a70 drivers/base/core.c:3679
 usb_new_device+0xd90/0x1a10 drivers/usb/core/hub.c:2651
 hub_port_connect drivers/usb/core/hub.c:5521 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5661 [inline]
 port_event drivers/usb/core/hub.c:5821 [inline]
 hub_event+0x2e66/0x4f50 drivers/usb/core/hub.c:5903
 process_one_work+0x9c5/0x1b40 kernel/workqueue.c:3231
 process_scheduled_works kernel/workqueue.c:3312 [inline]
 worker_thread+0x6c8/0xf20 kernel/workqueue.c:3390
 kthread+0x2c1/0x3a0 kernel/kthread.c:389
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Freed by task 9:
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
 kasan_save_track+0x14/0x30 mm/kasan/common.c:68
 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:579
 poison_slab_object+0xf7/0x160 mm/kasan/common.c:240
 __kasan_slab_free+0x14/0x30 mm/kasan/common.c:256
 kasan_slab_free include/linux/kasan.h:184 [inline]
 slab_free_hook mm/slub.c:2252 [inline]
 slab_free mm/slub.c:4473 [inline]
 kfree+0x10b/0x380 mm/slub.c:4594
 device_release+0xa1/0x240 drivers/base/core.c:2581
 kobject_cleanup lib/kobject.c:689 [inline]
 kobject_release lib/kobject.c:720 [inline]
 kref_put include/linux/kref.h:65 [inline]
 kobject_put+0x1fa/0x5b0 lib/kobject.c:737
 put_device drivers/base/core.c:3787 [inline]
 device_unregister+0x2f/0xc0 drivers/base/core.c:3910
 hdm_disconnect+0x10b/0x250 drivers/most/most_usb.c:1123
 usb_unbind_interface+0x1e8/0x970 drivers/usb/core/driver.c:461
 device_remove drivers/base/dd.c:568 [inline]
 device_remove+0x122/0x170 drivers/base/dd.c:560
 __device_release_driver drivers/base/dd.c:1270 [inline]
 device_release_driver_internal+0x44a/0x610 drivers/base/dd.c:1293
 bus_remove_device+0x22f/0x420 drivers/base/bus.c:574
 device_del+0x396/0x9f0 drivers/base/core.c:3868
 usb_disable_device+0x36c/0x7f0 drivers/usb/core/message.c:1418
 usb_disconnect+0x2e1/0x920 drivers/usb/core/hub.c:2304
 hub_port_connect drivers/usb/core/hub.c:5361 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5661 [inline]
 port_event drivers/usb/core/hub.c:5821 [inline]
 hub_event+0x1be4/0x4f50 drivers/usb/core/hub.c:5903
 process_one_work+0x9c5/0x1b40 kernel/workqueue.c:3231
 process_scheduled_works kernel/workqueue.c:3312 [inline]
 worker_thread+0x6c8/0xf20 kernel/workqueue.c:3390
 kthread+0x2c1/0x3a0 kernel/kthread.c:389
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

The buggy address belongs to the object at ffff88811314c000
 which belongs to the cache kmalloc-8k of size 8192
The buggy address is located 6296 bytes inside of
 freed 8192-byte region [ffff88811314c000, ffff88811314e000)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x113148
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x200000000000040(head|node=0|zone=2)
page_type: 0xfdffffff(slab)
raw: 0200000000000040 ffff888100042280 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000020002 00000001fdffffff 0000000000000000
head: 0200000000000040 ffff888100042280 dead000000000122 0000000000000000
head: 0000000000000000 0000000000020002 00000001fdffffff 0000000000000000
head: 0200000000000003 ffffea00044c5201 ffffffffffffffff 0000000000000000
head: 0000000000000008 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0x52820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 2644, tgid 2644 (syz-executor274), ts 44471884834, free_ts 39926477070
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x2d1/0x350 mm/page_alloc.c:1493
 prep_new_page mm/page_alloc.c:1501 [inline]
 get_page_from_freelist+0x1311/0x25f0 mm/page_alloc.c:3438
 __alloc_pages_noprof+0x21e/0x2290 mm/page_alloc.c:4696
 __alloc_pages_node_noprof include/linux/gfp.h:269 [inline]
 alloc_pages_node_noprof include/linux/gfp.h:296 [inline]
 alloc_slab_page+0x4e/0xf0 mm/slub.c:2321
 allocate_slab mm/slub.c:2484 [inline]
 new_slab+0x84/0x260 mm/slub.c:2537
 ___slab_alloc+0xdac/0x1870 mm/slub.c:3723
 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3813
 __slab_alloc_node mm/slub.c:3866 [inline]
 slab_alloc_node mm/slub.c:4025 [inline]
 __kmalloc_cache_noprof+0x27a/0x2c0 mm/slub.c:4184
 kmalloc_noprof include/linux/slab.h:681 [inline]
 audit_log_d_path+0xce/0x1e0 kernel/audit.c:2148
 dump_common_audit_data security/lsm_audit.c:250 [inline]
 common_lsm_audit+0x7bf/0x2220 security/lsm_audit.c:458
 slow_avc_audit+0x17d/0x210 security/selinux/avc.c:781
 avc_xperms_audit security/selinux/avc.c:427 [inline]
 avc_has_extended_perms+0x9c6/0xf90 security/selinux/avc.c:1087
 ioctl_has_perm.constprop.0.isra.0+0x2f0/0x470 security/selinux/hooks.c:3692
 selinux_file_ioctl+0x180/0x270 security/selinux/hooks.c:3740
 security_file_ioctl+0x75/0xc0 security/security.c:2791
 __do_sys_ioctl fs/ioctl.c:901 [inline]
 __se_sys_ioctl fs/ioctl.c:893 [inline]
 __x64_sys_ioctl+0xbb/0x220 fs/ioctl.c:893
page last free pid 2505 tgid 2505 stack trace:
 create_dummy_stack mm/page_owner.c:94 [inline]
 register_dummy_stack+0x8a/0xd0 mm/page_owner.c:100
 init_page_owner+0x48/0xbe0 mm/page_owner.c:118
 invoke_init_callbacks mm/page_ext.c:148 [inline]
 page_ext_init+0x730/0xc40 mm/page_ext.c:507
 mm_core_init+0x202/0x240 mm/mm_init.c:2680

Memory state around the buggy address:
 ffff88811314d780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88811314d800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88811314d880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                            ^
 ffff88811314d900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88811314d980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.

If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)

If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report

If you want to undo deduplication, reply with:
#syz undup

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

[syzbot]

Hello,

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

Reported-by: syzbot+916742d5d24f6c254761@syzkaller.appspotmail.com
Tested-by: syzbot+916742d5d24f6c254761@syzkaller.appspotmail.com

Tested on:

commit:         1722389b Merge tag 'net-6.11-rc1' of git://git.kernel...
git tree:       https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing
console output: https://syzkaller.appspot.com/x/log.txt?x=163ffdb1980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=e3044dca4d5f6dbe
dashboard link: https://syzkaller.appspot.com/bug?extid=916742d5d24f6c254761
compiler:       gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
patch:          https://syzkaller.appspot.com/x/patch.diff?x=1057af03980000

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

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

[Edward Adam Davis]

move the relase dev to the end

#syz test: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git 933069701c1b

diff --git a/drivers/most/most_usb.c b/drivers/most/most_usb.c
index 485d5ca39951..ed3fcba00cae 100644
--- a/drivers/most/most_usb.c
+++ b/drivers/most/most_usb.c
@@ -1118,15 +1118,14 @@ static void hdm_disconnect(struct usb_interface *interface)
 	del_timer_sync(&mdev->link_stat_timer);
 	cancel_work_sync(&mdev->poll_work_obj);
 
-	if (mdev->dci)
-		device_unregister(&mdev->dci->dev);
 	most_deregister_interface(&mdev->iface);
 
 	kfree(mdev->busy_urbs);
 	kfree(mdev->cap);
 	kfree(mdev->conf);
 	kfree(mdev->ep_address);
-	put_device(&mdev->dci->dev);
+	if (mdev->dci)
+		device_unregister(&mdev->dci->dev);
 	put_device(&mdev->dev);
 }
 

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

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
KASAN: slab-use-after-free Read in hdm_disconnect

usb 1-1: USB disconnect, device number 2
==================================================================
BUG: KASAN: slab-use-after-free in hdm_disconnect+0x1fd/0x220 drivers/most/most_usb.c:1123
Read of size 8 at addr ffff88812b88d898 by task kworker/0:1/9

CPU: 0 UID: 0 PID: 9 Comm: kworker/0:1 Not tainted 6.10.0-syzkaller-11840-g933069701c1b-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024
Workqueue: usb_hub_wq hub_event
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:93 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:119
 print_address_description mm/kasan/report.c:377 [inline]
 print_report+0xc3/0x620 mm/kasan/report.c:488
 kasan_report+0xd9/0x110 mm/kasan/report.c:601
 hdm_disconnect+0x1fd/0x220 drivers/most/most_usb.c:1123
 usb_unbind_interface+0x1e8/0x970 drivers/usb/core/driver.c:461
 device_remove drivers/base/dd.c:568 [inline]
 device_remove+0x122/0x170 drivers/base/dd.c:560
 __device_release_driver drivers/base/dd.c:1270 [inline]
 device_release_driver_internal+0x44a/0x610 drivers/base/dd.c:1293
 bus_remove_device+0x22f/0x420 drivers/base/bus.c:574
 device_del+0x396/0x9f0 drivers/base/core.c:3868
 usb_disable_device+0x36c/0x7f0 drivers/usb/core/message.c:1418
 usb_disconnect+0x2e1/0x920 drivers/usb/core/hub.c:2304
 hub_port_connect drivers/usb/core/hub.c:5361 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5661 [inline]
 port_event drivers/usb/core/hub.c:5821 [inline]
 hub_event+0x1be4/0x4f50 drivers/usb/core/hub.c:5903
 process_one_work+0x9c5/0x1b40 kernel/workqueue.c:3231
 process_scheduled_works kernel/workqueue.c:3312 [inline]
 worker_thread+0x6c8/0xf20 kernel/workqueue.c:3390
 kthread+0x2c1/0x3a0 kernel/kthread.c:389
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>

Allocated by task 24:
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
 kasan_save_track+0x14/0x30 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:370 [inline]
 __kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:387
 kmalloc_noprof include/linux/slab.h:681 [inline]
 kzalloc_noprof include/linux/slab.h:807 [inline]
 hdm_probe+0xb3/0x1880 drivers/most/most_usb.c:959
 usb_probe_interface+0x309/0x9d0 drivers/usb/core/driver.c:399
 call_driver_probe drivers/base/dd.c:578 [inline]
 really_probe+0x23e/0xa90 drivers/base/dd.c:656
 __driver_probe_device+0x1de/0x440 drivers/base/dd.c:798
 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:828
 __device_attach_driver+0x1df/0x310 drivers/base/dd.c:956
 bus_for_each_drv+0x157/0x1e0 drivers/base/bus.c:457
 __device_attach+0x1e8/0x4b0 drivers/base/dd.c:1028
 bus_probe_device+0x17f/0x1c0 drivers/base/bus.c:532
 device_add+0x114b/0x1a70 drivers/base/core.c:3679
 usb_set_configuration+0x10cb/0x1c50 drivers/usb/core/message.c:2210
 usb_generic_driver_probe+0xb1/0x110 drivers/usb/core/generic.c:254
 usb_probe_device+0xec/0x3e0 drivers/usb/core/driver.c:294
 call_driver_probe drivers/base/dd.c:578 [inline]
 really_probe+0x23e/0xa90 drivers/base/dd.c:656
 __driver_probe_device+0x1de/0x440 drivers/base/dd.c:798
 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:828
 __device_attach_driver+0x1df/0x310 drivers/base/dd.c:956
 bus_for_each_drv+0x157/0x1e0 drivers/base/bus.c:457
 __device_attach+0x1e8/0x4b0 drivers/base/dd.c:1028
 bus_probe_device+0x17f/0x1c0 drivers/base/bus.c:532
 device_add+0x114b/0x1a70 drivers/base/core.c:3679
 usb_new_device+0xd90/0x1a10 drivers/usb/core/hub.c:2651
 hub_port_connect drivers/usb/core/hub.c:5521 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5661 [inline]
 port_event drivers/usb/core/hub.c:5821 [inline]
 hub_event+0x2e66/0x4f50 drivers/usb/core/hub.c:5903
 process_one_work+0x9c5/0x1b40 kernel/workqueue.c:3231
 process_scheduled_works kernel/workqueue.c:3312 [inline]
 worker_thread+0x6c8/0xf20 kernel/workqueue.c:3390
 kthread+0x2c1/0x3a0 kernel/kthread.c:389
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Freed by task 9:
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
 kasan_save_track+0x14/0x30 mm/kasan/common.c:68
 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:579
 poison_slab_object+0xf7/0x160 mm/kasan/common.c:240
 __kasan_slab_free+0x14/0x30 mm/kasan/common.c:256
 kasan_slab_free include/linux/kasan.h:184 [inline]
 slab_free_hook mm/slub.c:2252 [inline]
 slab_free mm/slub.c:4473 [inline]
 kfree+0x10b/0x380 mm/slub.c:4594
 device_release+0xa1/0x240 drivers/base/core.c:2581
 kobject_cleanup lib/kobject.c:689 [inline]
 kobject_release lib/kobject.c:720 [inline]
 kref_put include/linux/kref.h:65 [inline]
 kobject_put+0x1fa/0x5b0 lib/kobject.c:737
 put_device drivers/base/core.c:3787 [inline]
 device_unregister+0x2f/0xc0 drivers/base/core.c:3910
 hdm_disconnect+0xcb/0x220 drivers/most/most_usb.c:1121
 usb_unbind_interface+0x1e8/0x970 drivers/usb/core/driver.c:461
 device_remove drivers/base/dd.c:568 [inline]
 device_remove+0x122/0x170 drivers/base/dd.c:560
 __device_release_driver drivers/base/dd.c:1270 [inline]
 device_release_driver_internal+0x44a/0x610 drivers/base/dd.c:1293
 bus_remove_device+0x22f/0x420 drivers/base/bus.c:574
 device_del+0x396/0x9f0 drivers/base/core.c:3868
 usb_disable_device+0x36c/0x7f0 drivers/usb/core/message.c:1418
 usb_disconnect+0x2e1/0x920 drivers/usb/core/hub.c:2304
 hub_port_connect drivers/usb/core/hub.c:5361 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5661 [inline]
 port_event drivers/usb/core/hub.c:5821 [inline]
 hub_event+0x1be4/0x4f50 drivers/usb/core/hub.c:5903
 process_one_work+0x9c5/0x1b40 kernel/workqueue.c:3231
 process_scheduled_works kernel/workqueue.c:3312 [inline]
 worker_thread+0x6c8/0xf20 kernel/workqueue.c:3390
 kthread+0x2c1/0x3a0 kernel/kthread.c:389
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

The buggy address belongs to the object at ffff88812b88c000
 which belongs to the cache kmalloc-8k of size 8192
The buggy address is located 6296 bytes inside of
 freed 8192-byte region [ffff88812b88c000, ffff88812b88e000)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x12b888
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
anon flags: 0x200000000000040(head|node=0|zone=2)
page_type: 0xfdffffff(slab)
raw: 0200000000000040 ffff888100042280 0000000000000000 0000000000000001
raw: 0000000000000000 0000000000020002 00000001fdffffff 0000000000000000
head: 0200000000000040 ffff888100042280 0000000000000000 0000000000000001
head: 0000000000000000 0000000000020002 00000001fdffffff 0000000000000000
head: 0200000000000003 ffffea0004ae2201 ffffffffffffffff 0000000000000000
head: 0000000000000008 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 3760, tgid 3760 (syz-executor), ts 94461081420, free_ts 94383274108
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x2d1/0x350 mm/page_alloc.c:1493
 prep_new_page mm/page_alloc.c:1501 [inline]
 get_page_from_freelist+0x1311/0x25f0 mm/page_alloc.c:3438
 __alloc_pages_noprof+0x21e/0x2290 mm/page_alloc.c:4696
 __alloc_pages_node_noprof include/linux/gfp.h:269 [inline]
 alloc_pages_node_noprof include/linux/gfp.h:296 [inline]
 alloc_slab_page+0x4e/0xf0 mm/slub.c:2321
 allocate_slab mm/slub.c:2484 [inline]
 new_slab+0x84/0x260 mm/slub.c:2537
 ___slab_alloc+0xdac/0x1870 mm/slub.c:3723
 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3813
 __slab_alloc_node mm/slub.c:3866 [inline]
 slab_alloc_node mm/slub.c:4025 [inline]
 __do_kmalloc_node mm/slub.c:4157 [inline]
 __kmalloc_node_track_caller_noprof+0x14e/0x3e0 mm/slub.c:4177
 kmemdup_noprof+0x29/0x60 mm/util.c:133
 kmemdup_noprof include/linux/fortify-string.h:753 [inline]
 ipv4_sysctl_init_net+0x3e/0x350 net/ipv4/sysctl_net_ipv4.c:1587
 ops_init+0xb9/0x650 net/core/net_namespace.c:139
 setup_net+0x435/0xb40 net/core/net_namespace.c:343
 copy_net_ns+0x2f0/0x670 net/core/net_namespace.c:508
 create_new_namespaces+0x3ea/0xb10 kernel/nsproxy.c:110
 unshare_nsproxy_namespaces+0xc0/0x1f0 kernel/nsproxy.c:228
 ksys_unshare+0x419/0x970 kernel/fork.c:3309
page last free pid 37 tgid 37 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1094 [inline]
 free_unref_page+0x698/0xce0 mm/page_alloc.c:2608
 __put_partials+0x14c/0x170 mm/slub.c:3051
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x4e/0x140 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x192/0x1e0 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x4e/0x70 mm/kasan/common.c:322
 kasan_slab_alloc include/linux/kasan.h:201 [inline]
 slab_post_alloc_hook mm/slub.c:3988 [inline]
 slab_alloc_node mm/slub.c:4037 [inline]
 kmem_cache_alloc_node_noprof+0x13e/0x2e0 mm/slub.c:4080
 __alloc_skb+0x2b1/0x380 net/core/skbuff.c:664
 alloc_skb include/linux/skbuff.h:1320 [inline]
 nlmsg_new include/net/netlink.h:1015 [inline]
 inet6_netconf_notify_devconf+0x84/0x180 net/ipv6/addrconf.c:589
 __addrconf_sysctl_unregister net/ipv6/addrconf.c:7250 [inline]
 addrconf_exit_net+0xe9/0x3f0 net/ipv6/addrconf.c:7367
 ops_exit_list+0xb0/0x180 net/core/net_namespace.c:173
 cleanup_net+0x5b7/0xbf0 net/core/net_namespace.c:640
 process_one_work+0x9c5/0x1b40 kernel/workqueue.c:3231
 process_scheduled_works kernel/workqueue.c:3312 [inline]
 worker_thread+0x6c8/0xf20 kernel/workqueue.c:3390
 kthread+0x2c1/0x3a0 kernel/kthread.c:389
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Memory state around the buggy address:
 ffff88812b88d780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88812b88d800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88812b88d880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                            ^
 ffff88812b88d900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88812b88d980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================


Tested on:

commit:         93306970 Merge tag '6.11-rc-smb3-server-fixes' of git:..
git tree:       https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
console output: https://syzkaller.appspot.com/x/log.txt?x=173e7345980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=f828342678294017
dashboard link: https://syzkaller.appspot.com/bug?extid=916742d5d24f6c254761
compiler:       gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
patch:          https://syzkaller.appspot.com/x/patch.diff?x=1532a965980000

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

[Edward Adam Davis]

move the relase dev to the end

#syz test: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git 933069701c1b

diff --git a/drivers/most/most_usb.c b/drivers/most/most_usb.c
index 485d5ca39951..3f3abb6efb3e 100644
--- a/drivers/most/most_usb.c
+++ b/drivers/most/most_usb.c
@@ -1118,15 +1118,13 @@ static void hdm_disconnect(struct usb_interface *interface)
 	del_timer_sync(&mdev->link_stat_timer);
 	cancel_work_sync(&mdev->poll_work_obj);
 
-	if (mdev->dci)
-		device_unregister(&mdev->dci->dev);
-	most_deregister_interface(&mdev->iface);
-
 	kfree(mdev->busy_urbs);
 	kfree(mdev->cap);
 	kfree(mdev->conf);
 	kfree(mdev->ep_address);
-	put_device(&mdev->dci->dev);
+	if (mdev->dci)
+		device_unregister(&mdev->dci->dev);
+	most_deregister_interface(&mdev->iface);
 	put_device(&mdev->dev);
 }
 

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

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
KASAN: slab-use-after-free Read in put_device

usb 1-1: USB disconnect, device number 2
==================================================================
BUG: KASAN: slab-use-after-free in kobject_put+0x503/0x5b0 lib/kobject.c:733
Read of size 1 at addr ffff88811374003c by task kworker/0:2/43

CPU: 0 UID: 0 PID: 43 Comm: kworker/0:2 Not tainted 6.10.0-syzkaller-11840-g933069701c1b-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024
Workqueue: usb_hub_wq hub_event
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:93 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:119
 print_address_description mm/kasan/report.c:377 [inline]
 print_report+0xc3/0x620 mm/kasan/report.c:488
 kasan_report+0xd9/0x110 mm/kasan/report.c:601
 kobject_put+0x503/0x5b0 lib/kobject.c:733
 put_device+0x1f/0x30 drivers/base/core.c:3787
 usb_unbind_interface+0x1e8/0x970 drivers/usb/core/driver.c:461
 device_remove drivers/base/dd.c:568 [inline]
 device_remove+0x122/0x170 drivers/base/dd.c:560
 __device_release_driver drivers/base/dd.c:1270 [inline]
 device_release_driver_internal+0x44a/0x610 drivers/base/dd.c:1293
 bus_remove_device+0x22f/0x420 drivers/base/bus.c:574
 device_del+0x396/0x9f0 drivers/base/core.c:3868
 usb_disable_device+0x36c/0x7f0 drivers/usb/core/message.c:1418
 usb_disconnect+0x2e1/0x920 drivers/usb/core/hub.c:2304
 hub_port_connect drivers/usb/core/hub.c:5361 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5661 [inline]
 port_event drivers/usb/core/hub.c:5821 [inline]
 hub_event+0x1be4/0x4f50 drivers/usb/core/hub.c:5903
 process_one_work+0x9c5/0x1b40 kernel/workqueue.c:3231
 process_scheduled_works kernel/workqueue.c:3312 [inline]
 worker_thread+0x6c8/0xf20 kernel/workqueue.c:3390
 kthread+0x2c1/0x3a0 kernel/kthread.c:389
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>

Allocated by task 41:
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
 kasan_save_track+0x14/0x30 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:370 [inline]
 __kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:387
 kmalloc_noprof include/linux/slab.h:681 [inline]
 kzalloc_noprof include/linux/slab.h:807 [inline]
 hdm_probe+0xb3/0x1880 drivers/most/most_usb.c:959
 usb_probe_interface+0x309/0x9d0 drivers/usb/core/driver.c:399
 call_driver_probe drivers/base/dd.c:578 [inline]
 really_probe+0x23e/0xa90 drivers/base/dd.c:656
 __driver_probe_device+0x1de/0x440 drivers/base/dd.c:798
 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:828
 __device_attach_driver+0x1df/0x310 drivers/base/dd.c:956
 bus_for_each_drv+0x157/0x1e0 drivers/base/bus.c:457
 __device_attach+0x1e8/0x4b0 drivers/base/dd.c:1028
 bus_probe_device+0x17f/0x1c0 drivers/base/bus.c:532
 device_add+0x114b/0x1a70 drivers/base/core.c:3679
 usb_set_configuration+0x10cb/0x1c50 drivers/usb/core/message.c:2210
 usb_generic_driver_probe+0xb1/0x110 drivers/usb/core/generic.c:254
 usb_probe_device+0xec/0x3e0 drivers/usb/core/driver.c:294
 call_driver_probe drivers/base/dd.c:578 [inline]
 really_probe+0x23e/0xa90 drivers/base/dd.c:656
 __driver_probe_device+0x1de/0x440 drivers/base/dd.c:798
 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:828
 __device_attach_driver+0x1df/0x310 drivers/base/dd.c:956
 bus_for_each_drv+0x157/0x1e0 drivers/base/bus.c:457
 __device_attach+0x1e8/0x4b0 drivers/base/dd.c:1028
 bus_probe_device+0x17f/0x1c0 drivers/base/bus.c:532
 device_add+0x114b/0x1a70 drivers/base/core.c:3679
 usb_new_device+0xd90/0x1a10 drivers/usb/core/hub.c:2651
 hub_port_connect drivers/usb/core/hub.c:5521 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5661 [inline]
 port_event drivers/usb/core/hub.c:5821 [inline]
 hub_event+0x2e66/0x4f50 drivers/usb/core/hub.c:5903
 process_one_work+0x9c5/0x1b40 kernel/workqueue.c:3231
 process_scheduled_works kernel/workqueue.c:3312 [inline]
 worker_thread+0x6c8/0xf20 kernel/workqueue.c:3390
 kthread+0x2c1/0x3a0 kernel/kthread.c:389
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Freed by task 43:
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
 kasan_save_track+0x14/0x30 mm/kasan/common.c:68
 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:579
 poison_slab_object+0xf7/0x160 mm/kasan/common.c:240
 __kasan_slab_free+0x14/0x30 mm/kasan/common.c:256
 kasan_slab_free include/linux/kasan.h:184 [inline]
 slab_free_hook mm/slub.c:2252 [inline]
 slab_free mm/slub.c:4473 [inline]
 kfree+0x10b/0x380 mm/slub.c:4594
 device_release+0xa1/0x240 drivers/base/core.c:2581
 kobject_cleanup lib/kobject.c:689 [inline]
 kobject_release lib/kobject.c:720 [inline]
 kref_put include/linux/kref.h:65 [inline]
 kobject_put+0x1fa/0x5b0 lib/kobject.c:737
 put_device drivers/base/core.c:3787 [inline]
 device_unregister+0x2f/0xc0 drivers/base/core.c:3910
 hdm_disconnect+0x1bb/0x220 drivers/most/most_usb.c:1127
 usb_unbind_interface+0x1e8/0x970 drivers/usb/core/driver.c:461
 device_remove drivers/base/dd.c:568 [inline]
 device_remove+0x122/0x170 drivers/base/dd.c:560
 __device_release_driver drivers/base/dd.c:1270 [inline]
 device_release_driver_internal+0x44a/0x610 drivers/base/dd.c:1293
 bus_remove_device+0x22f/0x420 drivers/base/bus.c:574
 device_del+0x396/0x9f0 drivers/base/core.c:3868
 usb_disable_device+0x36c/0x7f0 drivers/usb/core/message.c:1418
 usb_disconnect+0x2e1/0x920 drivers/usb/core/hub.c:2304
 hub_port_connect drivers/usb/core/hub.c:5361 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5661 [inline]
 port_event drivers/usb/core/hub.c:5821 [inline]
 hub_event+0x1be4/0x4f50 drivers/usb/core/hub.c:5903
 process_one_work+0x9c5/0x1b40 kernel/workqueue.c:3231
 process_scheduled_works kernel/workqueue.c:3312 [inline]
 worker_thread+0x6c8/0xf20 kernel/workqueue.c:3390
 kthread+0x2c1/0x3a0 kernel/kthread.c:389
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

The buggy address belongs to the object at ffff888113740000
 which belongs to the cache kmalloc-8k of size 8192
The buggy address is located 60 bytes inside of
 freed 8192-byte region [ffff888113740000, ffff888113742000)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x113740
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
anon flags: 0x200000000000040(head|node=0|zone=2)
page_type: 0xfdffffff(slab)
raw: 0200000000000040 ffff888100042280 ffffea000425be00 dead000000000003
raw: 0000000000000000 0000000000020002 00000001fdffffff 0000000000000000
head: 0200000000000040 ffff888100042280 ffffea000425be00 dead000000000003
head: 0000000000000000 0000000000020002 00000001fdffffff 0000000000000000
head: 0200000000000003 ffffea00044dd001 ffffffffffffffff 0000000000000000
head: 0000000000000008 0000000000000000 00000000ffffffff 0000000000000000
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 2651, tgid 2651 (syz-executor), ts 42037680054, free_ts 41938721681
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x2d1/0x350 mm/page_alloc.c:1493
 prep_new_page mm/page_alloc.c:1501 [inline]
 get_page_from_freelist+0x1311/0x25f0 mm/page_alloc.c:3438
 __alloc_pages_noprof+0x21e/0x2290 mm/page_alloc.c:4696
 __alloc_pages_node_noprof include/linux/gfp.h:269 [inline]
 alloc_pages_node_noprof include/linux/gfp.h:296 [inline]
 alloc_slab_page+0x4e/0xf0 mm/slub.c:2321
 allocate_slab mm/slub.c:2484 [inline]
 new_slab+0x84/0x260 mm/slub.c:2537
 ___slab_alloc+0xdac/0x1870 mm/slub.c:3723
 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3813
 __slab_alloc_node mm/slub.c:3866 [inline]
 slab_alloc_node mm/slub.c:4025 [inline]
 __kmalloc_cache_noprof+0x27a/0x2c0 mm/slub.c:4184
 kmalloc_noprof include/linux/slab.h:681 [inline]
 kzalloc_noprof include/linux/slab.h:807 [inline]
 cgroup1_root_to_use kernel/cgroup/cgroup-v1.c:1217 [inline]
 cgroup1_get_tree+0x936/0xed0 kernel/cgroup/cgroup-v1.c:1244
 vfs_get_tree+0x8f/0x380 fs/super.c:1789
 do_new_mount fs/namespace.c:3472 [inline]
 path_mount+0x14e6/0x1f20 fs/namespace.c:3799
 do_mount fs/namespace.c:3812 [inline]
 __do_sys_mount fs/namespace.c:4020 [inline]
 __se_sys_mount fs/namespace.c:3997 [inline]
 __x64_sys_mount+0x294/0x320 fs/namespace.c:3997
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
page last free pid 2651 tgid 2651 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1094 [inline]
 free_unref_page+0x698/0xce0 mm/page_alloc.c:2608
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x4e/0x140 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x192/0x1e0 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x4e/0x70 mm/kasan/common.c:322
 kasan_slab_alloc include/linux/kasan.h:201 [inline]
 slab_post_alloc_hook mm/slub.c:3988 [inline]
 slab_alloc_node mm/slub.c:4037 [inline]
 kmem_cache_alloc_noprof+0x11c/0x2b0 mm/slub.c:4044
 getname_flags.part.0+0x4c/0x550 fs/namei.c:139
 getname_flags+0x93/0xf0 include/linux/audit.h:322
 vfs_fstatat+0x86/0x160 fs/stat.c:340
 __do_sys_newfstatat+0xa2/0x130 fs/stat.c:505
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff88811373ff00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88811373ff80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888113740000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                        ^
 ffff888113740080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888113740100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================


Tested on:

commit:         93306970 Merge tag '6.11-rc-smb3-server-fixes' of git:..
git tree:       https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
console output: https://syzkaller.appspot.com/x/log.txt?x=14d2e79d980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=f828342678294017
dashboard link: https://syzkaller.appspot.com/bug?extid=916742d5d24f6c254761
compiler:       gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
patch:          https://syzkaller.appspot.com/x/patch.diff?x=160b42f9980000

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

[Edward Adam Davis]

move the relase dev to the end

#syz test: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git 933069701c1b


diff --git a/drivers/base/dd.c b/drivers/base/dd.c
index 83d352394fdf..02f5aeadd8fd 100644
--- a/drivers/base/dd.c
+++ b/drivers/base/dd.c
@@ -1027,6 +1027,8 @@ static int __device_attach(struct device *dev, bool allow_async)
 
 		ret = bus_for_each_drv(dev->bus, NULL, &data,
 					__device_attach_driver);
+		if (!ret)
+			get_device(dev);
 		if (!ret && allow_async && data.have_async) {
 			/*
 			 * If we could not find appropriate driver
@@ -1036,7 +1038,6 @@ static int __device_attach(struct device *dev, bool allow_async)
 			 * try them.
 			 */
 			dev_dbg(dev, "scheduling asynchronous probe\n");
-			get_device(dev);
 			async = true;
 		} else {
 			pm_request_idle(dev);

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

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
KASAN: slab-use-after-free Read in hdm_disconnect

usb 1-1: New USB device found, idVendor=0424, idProduct=c001, bcdDevice=1c.8f
usb 1-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
usb 1-1: config 0 descriptor??
usb 1-1: USB disconnect, device number 2
==================================================================
BUG: KASAN: slab-use-after-free in hdm_disconnect+0x227/0x250 drivers/most/most_usb.c:1125
Read of size 8 at addr ffff8881131c1898 by task kworker/0:1/9

CPU: 0 UID: 0 PID: 9 Comm: kworker/0:1 Not tainted 6.10.0-syzkaller-11840-g933069701c1b-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024
Workqueue: usb_hub_wq hub_event
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:93 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:119
 print_address_description mm/kasan/report.c:377 [inline]
 print_report+0xc3/0x620 mm/kasan/report.c:488
 kasan_report+0xd9/0x110 mm/kasan/report.c:601
 hdm_disconnect+0x227/0x250 drivers/most/most_usb.c:1125
 usb_unbind_interface+0x1e8/0x970 drivers/usb/core/driver.c:461
 device_remove drivers/base/dd.c:568 [inline]
 device_remove+0x122/0x170 drivers/base/dd.c:560
 __device_release_driver drivers/base/dd.c:1271 [inline]
 device_release_driver_internal+0x44a/0x610 drivers/base/dd.c:1294
 bus_remove_device+0x22f/0x420 drivers/base/bus.c:574
 device_del+0x396/0x9f0 drivers/base/core.c:3868
 usb_disable_device+0x36c/0x7f0 drivers/usb/core/message.c:1418
 usb_disconnect+0x2e1/0x920 drivers/usb/core/hub.c:2304
 hub_port_connect drivers/usb/core/hub.c:5361 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5661 [inline]
 port_event drivers/usb/core/hub.c:5821 [inline]
 hub_event+0x1be4/0x4f50 drivers/usb/core/hub.c:5903
 process_one_work+0x9c5/0x1b40 kernel/workqueue.c:3231
 process_scheduled_works kernel/workqueue.c:3312 [inline]
 worker_thread+0x6c8/0xf20 kernel/workqueue.c:3390
 kthread+0x2c1/0x3a0 kernel/kthread.c:389
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>

Allocated by task 9:
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
 kasan_save_track+0x14/0x30 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:370 [inline]
 __kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:387
 kmalloc_noprof include/linux/slab.h:681 [inline]
 kzalloc_noprof include/linux/slab.h:807 [inline]
 hdm_probe+0xb3/0x1880 drivers/most/most_usb.c:959
 usb_probe_interface+0x309/0x9d0 drivers/usb/core/driver.c:399
 call_driver_probe drivers/base/dd.c:578 [inline]
 really_probe+0x23e/0xa90 drivers/base/dd.c:656
 __driver_probe_device+0x1de/0x440 drivers/base/dd.c:798
 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:828
 __device_attach_driver+0x1df/0x310 drivers/base/dd.c:956
 bus_for_each_drv+0x157/0x1e0 drivers/base/bus.c:457
 __device_attach+0x1e8/0x4e0 drivers/base/dd.c:1028
 bus_probe_device+0x17f/0x1c0 drivers/base/bus.c:532
 device_add+0x114b/0x1a70 drivers/base/core.c:3679
 usb_set_configuration+0x10cb/0x1c50 drivers/usb/core/message.c:2210
 usb_generic_driver_probe+0xb1/0x110 drivers/usb/core/generic.c:254
 usb_probe_device+0xec/0x3e0 drivers/usb/core/driver.c:294
 call_driver_probe drivers/base/dd.c:578 [inline]
 really_probe+0x23e/0xa90 drivers/base/dd.c:656
 __driver_probe_device+0x1de/0x440 drivers/base/dd.c:798
 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:828
 __device_attach_driver+0x1df/0x310 drivers/base/dd.c:956
 bus_for_each_drv+0x157/0x1e0 drivers/base/bus.c:457
 __device_attach+0x1e8/0x4e0 drivers/base/dd.c:1028
 bus_probe_device+0x17f/0x1c0 drivers/base/bus.c:532
 device_add+0x114b/0x1a70 drivers/base/core.c:3679
 usb_new_device+0xd90/0x1a10 drivers/usb/core/hub.c:2651
 hub_port_connect drivers/usb/core/hub.c:5521 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5661 [inline]
 port_event drivers/usb/core/hub.c:5821 [inline]
 hub_event+0x2e66/0x4f50 drivers/usb/core/hub.c:5903
 process_one_work+0x9c5/0x1b40 kernel/workqueue.c:3231
 process_scheduled_works kernel/workqueue.c:3312 [inline]
 worker_thread+0x6c8/0xf20 kernel/workqueue.c:3390
 kthread+0x2c1/0x3a0 kernel/kthread.c:389
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Freed by task 9:
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
 kasan_save_track+0x14/0x30 mm/kasan/common.c:68
 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:579
 poison_slab_object+0xf7/0x160 mm/kasan/common.c:240
 __kasan_slab_free+0x14/0x30 mm/kasan/common.c:256
 kasan_slab_free include/linux/kasan.h:184 [inline]
 slab_free_hook mm/slub.c:2252 [inline]
 slab_free mm/slub.c:4473 [inline]
 kfree+0x10b/0x380 mm/slub.c:4594
 device_release+0xa1/0x240 drivers/base/core.c:2581
 kobject_cleanup lib/kobject.c:689 [inline]
 kobject_release lib/kobject.c:720 [inline]
 kref_put include/linux/kref.h:65 [inline]
 kobject_put+0x1fa/0x5b0 lib/kobject.c:737
 put_device drivers/base/core.c:3787 [inline]
 device_unregister+0x2f/0xc0 drivers/base/core.c:3910
 hdm_disconnect+0x10b/0x250 drivers/most/most_usb.c:1123
 usb_unbind_interface+0x1e8/0x970 drivers/usb/core/driver.c:461
 device_remove drivers/base/dd.c:568 [inline]
 device_remove+0x122/0x170 drivers/base/dd.c:560
 __device_release_driver drivers/base/dd.c:1271 [inline]
 device_release_driver_internal+0x44a/0x610 drivers/base/dd.c:1294
 bus_remove_device+0x22f/0x420 drivers/base/bus.c:574
 device_del+0x396/0x9f0 drivers/base/core.c:3868
 usb_disable_device+0x36c/0x7f0 drivers/usb/core/message.c:1418
 usb_disconnect+0x2e1/0x920 drivers/usb/core/hub.c:2304
 hub_port_connect drivers/usb/core/hub.c:5361 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5661 [inline]
 port_event drivers/usb/core/hub.c:5821 [inline]
 hub_event+0x1be4/0x4f50 drivers/usb/core/hub.c:5903
 process_one_work+0x9c5/0x1b40 kernel/workqueue.c:3231
 process_scheduled_works kernel/workqueue.c:3312 [inline]
 worker_thread+0x6c8/0xf20 kernel/workqueue.c:3390
 kthread+0x2c1/0x3a0 kernel/kthread.c:389
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

The buggy address belongs to the object at ffff8881131c0000
 which belongs to the cache kmalloc-8k of size 8192
The buggy address is located 6296 bytes inside of
 freed 8192-byte region [ffff8881131c0000, ffff8881131c2000)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1131c0
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x200000000000040(head|node=0|zone=2)
page_type: 0xfdffffff(slab)
raw: 0200000000000040 ffff888100042280 ffffea00040ff000 dead000000000002
raw: 0000000000000000 0000000000020002 00000001fdffffff 0000000000000000
head: 0200000000000040 ffff888100042280 ffffea00040ff000 dead000000000002
head: 0000000000000000 0000000000020002 00000001fdffffff 0000000000000000
head: 0200000000000003 ffffea00044c7001 ffffffffffffffff 0000000000000000
head: 0000000000000008 0000000000000000 00000000ffffffff 0000000000000000
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 2651, tgid 2651 (syz-executor), ts 39969872238, free_ts 37861985419
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x2d1/0x350 mm/page_alloc.c:1493
 prep_new_page mm/page_alloc.c:1501 [inline]
 get_page_from_freelist+0x1311/0x25f0 mm/page_alloc.c:3438
 __alloc_pages_noprof+0x21e/0x2290 mm/page_alloc.c:4696
 __alloc_pages_node_noprof include/linux/gfp.h:269 [inline]
 alloc_pages_node_noprof include/linux/gfp.h:296 [inline]
 alloc_slab_page+0x4e/0xf0 mm/slub.c:2321
 allocate_slab mm/slub.c:2484 [inline]
 new_slab+0x84/0x260 mm/slub.c:2537
 ___slab_alloc+0xdac/0x1870 mm/slub.c:3723
 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3813
 __slab_alloc_node mm/slub.c:3866 [inline]
 slab_alloc_node mm/slub.c:4025 [inline]
 __kmalloc_cache_noprof+0x27a/0x2c0 mm/slub.c:4184
 kmalloc_noprof include/linux/slab.h:681 [inline]
 kzalloc_noprof include/linux/slab.h:807 [inline]
 cgroup1_root_to_use kernel/cgroup/cgroup-v1.c:1217 [inline]
 cgroup1_get_tree+0x936/0xed0 kernel/cgroup/cgroup-v1.c:1244
 vfs_get_tree+0x8f/0x380 fs/super.c:1789
 do_new_mount fs/namespace.c:3472 [inline]
 path_mount+0x14e6/0x1f20 fs/namespace.c:3799
 do_mount fs/namespace.c:3812 [inline]
 __do_sys_mount fs/namespace.c:4020 [inline]
 __se_sys_mount fs/namespace.c:3997 [inline]
 __x64_sys_mount+0x294/0x320 fs/namespace.c:3997
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
page last free pid 2646 tgid 2646 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1094 [inline]
 free_unref_page+0x698/0xce0 mm/page_alloc.c:2608
 rcu_do_batch kernel/rcu/tree.c:2569 [inline]
 rcu_core+0x828/0x16b0 kernel/rcu/tree.c:2843
 handle_softirqs+0x209/0x8e0 kernel/softirq.c:554
 __do_softirq kernel/softirq.c:588 [inline]
 invoke_softirq kernel/softirq.c:428 [inline]
 __irq_exit_rcu kernel/softirq.c:637 [inline]
 irq_exit_rcu+0xac/0x110 kernel/softirq.c:649
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline]
 sysvec_apic_timer_interrupt+0x43/0xb0 arch/x86/kernel/apic/apic.c:1043
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702

Memory state around the buggy address:
 ffff8881131c1780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8881131c1800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8881131c1880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                            ^
 ffff8881131c1900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8881131c1980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================


Tested on:

commit:         93306970 Merge tag '6.11-rc-smb3-server-fixes' of git:..
git tree:       https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
console output: https://syzkaller.appspot.com/x/log.txt?x=1402a373980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=f828342678294017
dashboard link: https://syzkaller.appspot.com/bug?extid=916742d5d24f6c254761
compiler:       gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
patch:          https://syzkaller.appspot.com/x/patch.diff?x=1022d19d980000

Re: [syzbot] #syz test https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git e04c78d86a9699d136910cfc0bdcf01087e3267e

[syzbot]

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

***

Subject: #syz test https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git e04c78d86a9699d136910cfc0bdcf01087e3267e
Author: dmantipov@yandex.ru

#syz test https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git e04c78d86a9699d136910cfc0bdcf01087e3267e

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

[syzbot]

Hello,

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

Reported-by: syzbot+916742d5d24f6c254761@syzkaller.appspotmail.com
Tested-by: syzbot+916742d5d24f6c254761@syzkaller.appspotmail.com

Tested on:

commit:         e04c78d8 Linux 6.16-rc2
git tree:       https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
console output: https://syzkaller.appspot.com/x/log.txt?x=12c915d4580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=8f72e140c622500d
dashboard link: https://syzkaller.appspot.com/bug?extid=916742d5d24f6c254761
compiler:       Debian clang version 20.1.6 (++20250514063057+1e4d39e07757-1~exp1~20250514183223.118), Debian LLD 20.1.6
patch:          https://syzkaller.appspot.com/x/patch.diff?x=12d70370580000

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