[syzbot] KASAN: slab-use-after-free Read in vhci_send_cmd_submit

[syzbot] KASAN: slab-use-after-free Read in vhci_send_cmd_submit

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    3eb40771c00a Merge tag 'soc-fixes-7.2-3' of git://git.kern..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=16e07a79580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=1d67342c314f228d
dashboard link: https://syzkaller.appspot.com/bug?extid=ecbb1750082f7528b507
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=12849949580000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+ecbb1750082f7528b507@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: slab-use-after-free in vhci_send_cmd_submit+0xed2/0x10c0 drivers/usb/usbip/vhci_tx.c:91
Read of size 4 at addr ffff888022a66584 by task vhci_tx/6044

CPU: 0 UID: 0 PID: 6044 Comm: vhci_tx 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
 vhci_send_cmd_submit+0xed2/0x10c0 drivers/usb/usbip/vhci_tx.c:91
 vhci_tx_loop+0xff/0x460 drivers/usb/usbip/vhci_tx.c:241
 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
 </TASK>

Allocated by task 6031:
 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]
 usb_alloc_urb+0x66/0xa0 drivers/usb/core/urb.c:75
 alloc_async drivers/usb/core/devio.c:408 [inline]
 proc_do_submiturb+0x741/0x3820 drivers/usb/core/devio.c:1780
 proc_submiturb drivers/usb/core/devio.c:2002 [inline]
 usbdev_do_ioctl drivers/usb/core/devio.c:2702 [inline]
 usbdev_ioctl+0x2adb/0x3aa0 drivers/usb/core/devio.c:2826
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl fs/ioctl.c:583 [inline]
 __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583
 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

Freed by task 6031:
 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
 urb_destroy drivers/usb/core/urb.c:27 [inline]
 kref_put include/linux/kref.h:65 [inline]
 usb_free_urb.part.0+0xa5/0x110 drivers/usb/core/urb.c:96
 usb_free_urb+0x1f/0x30 drivers/usb/core/urb.c:95
 free_async+0x358/0x530 drivers/usb/core/devio.c:435
 proc_reapurbnonblock drivers/usb/core/devio.c:2129 [inline]
 usbdev_do_ioctl drivers/usb/core/devio.c:2621 [inline]
 usbdev_ioctl+0x2e7/0x3aa0 drivers/usb/core/devio.c:2826
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl fs/ioctl.c:583 [inline]
 __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583
 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

The buggy address belongs to the object at ffff888022a66500
 which belongs to the cache kmalloc-192 of size 192
The buggy address is located 132 bytes inside of
 freed 192-byte region [ffff888022a66500, ffff888022a665c0)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x22a66
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000000 ffff88801c0423c0 dead000000000100 dead000000000122
raw: 0000000000000000 0000000800100010 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 1, tgid 1 (swapper/0), ts 5964583883, free_ts 0
 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]
 __kmalloc_cache_noprof+0x479/0x6c0 mm/slub.c:5485
 _kmalloc_noprof include/linux/slab.h:988 [inline]
 _kzalloc_noprof include/linux/slab.h:1309 [inline]
 acpi_os_map_iomem+0x138/0x5e0 drivers/acpi/osl.c:353
 acpi_ex_system_memory_space_handler+0x4e8/0xbb0 drivers/acpi/acpica/exregion.c:145
 acpi_ev_address_space_dispatch+0x4d2/0xf00 drivers/acpi/acpica/evregion.c:295
 acpi_ex_access_region+0x6e1/0xe00 drivers/acpi/acpica/exfldio.c:246
 acpi_ex_field_datum_io+0x168/0xe40 drivers/acpi/acpica/exfldio.c:445
 acpi_ex_write_with_update_rule+0x2b1/0x4b0 drivers/acpi/acpica/exfldio.c:627
 acpi_ex_insert_into_field+0x672/0x870 drivers/acpi/acpica/exfldio.c:957
 acpi_ex_write_data_to_field+0x23a/0xb20 drivers/acpi/acpica/exfield.c:401
 acpi_ex_store_object_to_node+0x3f0/0x790 drivers/acpi/acpica/exstore.c:523
page_owner free stack trace missing

Memory state around the buggy address:
 ffff888022a66480: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
 ffff888022a66500: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888022a66580: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
                   ^
 ffff888022a66600: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888022a66680: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
==================================================================


---
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] KASAN: slab-use-after-free Read in vhci_send_cmd_submit

[Edward Adam Davis]

#syz test

diff --git a/drivers/usb/usbip/vhci_tx.c b/drivers/usb/usbip/vhci_tx.c
index 32e6fabccf72..c3aacbb6939f 100644
--- a/drivers/usb/usbip/vhci_tx.c
+++ b/drivers/usb/usbip/vhci_tx.c
@@ -13,7 +13,12 @@
 static void setup_cmd_submit_pdu(struct usbip_header *pdup,  struct urb *urb)
 {
 	struct vhci_priv *priv = ((struct vhci_priv *)urb->hcpriv);
-	struct vhci_device *vdev = priv->vdev;
+	struct vhci_device *vdev;
+
+	if (!priv)
+		return;
+
+	vdev = priv->vdev;
 
 	usbip_dbg_vhci_tx("URB, local devnum %u, remote devid %u\n",
 			  usb_pipedevice(urb->pipe), vdev->devid);
@@ -68,7 +73,9 @@ static int vhci_send_cmd_submit(struct vhci_device *vdev)
 		int ret;
 		struct urb *urb = priv->urb;
 		struct usbip_header pdu_header;
+		unsigned long flags;
 
+		usb_get_urb(urb);
 		txsize = 0;
 		memset(&pdu_header, 0, sizeof(pdu_header));
 		memset(&msg, 0, sizeof(msg));
@@ -85,6 +92,7 @@ static int vhci_send_cmd_submit(struct vhci_device *vdev)
 		iov = kzalloc_objs(*iov, iovnum);
 		if (!iov) {
 			usbip_event_add(&vdev->ud, SDEV_EVENT_ERROR_MALLOC);
+			usb_put_urb(urb);
 			return -ENOMEM;
 		}
 
@@ -92,7 +100,14 @@ static int vhci_send_cmd_submit(struct vhci_device *vdev)
 			urb->transfer_flags |= URB_DMA_MAP_SG;
 
 		/* 1. setup usbip_header */
+		spin_lock_irqsave(&vdev->priv_lock, flags);
+		if (!urb->hcpriv) {
+			usb_put_urb(urb);
+			spin_unlock_irqrestore(&vdev->priv_lock, flags);
+			return -EIO;
+		}
 		setup_cmd_submit_pdu(&pdu_header, urb);
+		spin_unlock_irqrestore(&vdev->priv_lock, flags);
 		usbip_header_correct_endian(&pdu_header, 1);
 		iovnum = 0;
 
@@ -127,6 +142,7 @@ static int vhci_send_cmd_submit(struct vhci_device *vdev)
 			if (!iso_buffer) {
 				usbip_event_add(&vdev->ud,
 						SDEV_EVENT_ERROR_MALLOC);
+				usb_put_urb(urb);
 				goto err_iso_buffer;
 			}
 
@@ -143,6 +159,7 @@ static int vhci_send_cmd_submit(struct vhci_device *vdev)
 			       txsize);
 			usbip_event_add(&vdev->ud, VDEV_EVENT_ERROR_TCP);
 			err = -EPIPE;
+			usb_put_urb(urb);
 			goto err_tx;
 		}
 
@@ -154,6 +171,7 @@ static int vhci_send_cmd_submit(struct vhci_device *vdev)
 		usbip_dbg_vhci_tx("send txdata\n");
 
 		total_size += txsize;
+		usb_put_urb(urb);
 	}
 
 	return total_size;

Re: [syzbot] KASAN: slab-use-after-free Read in vhci_send_cmd_submit

[syzbot]

Hello,

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

Reported-by: syzbot+ecbb1750082f7528b507@syzkaller.appspotmail.com
Tested-by: syzbot+ecbb1750082f7528b507@syzkaller.appspotmail.com

Tested on:

commit:         8dbbc7e1 Merge tag 'mm-hotfixes-stable-2026-08-19-21-3..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=17f6de79580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=ccca94d2c01b9e78
dashboard link: https://syzkaller.appspot.com/bug?extid=ecbb1750082f7528b507
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=16450415580000

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

Re: [syzbot] KASAN: slab-use-after-free Read in vhci_send_cmd_submit

[Hillf Danton]

> Date: Thu, 20 Aug 2026 07:58:25 -0700	[thread overview]
> Hello,
> 
> syzbot found the following issue on:
> 
> HEAD commit:    3eb40771c00a Merge tag 'soc-fixes-7.2-3' of git://git.kern..
> git tree:       upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=16e07a79580000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=1d67342c314f228d
> dashboard link: https://syzkaller.appspot.com/bug?extid=ecbb1750082f7528b507
> 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=12849949580000

#syz test

--- x/drivers/usb/core/devio.c
+++ y/drivers/usb/core/devio.c
@@ -417,6 +417,7 @@ static void free_async(struct async *as)
 {
 	int i;
 
+	usb_kill_urb(as->urb);
 	put_pid(as->pid);
 	if (as->cred)
 		put_cred(as->cred);
--

Re: [syzbot] KASAN: slab-use-after-free Read in vhci_send_cmd_submit

[syzbot]

Hello,

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

==================================================================
BUG: KASAN: slab-use-after-free in vhci_send_cmd_submit+0xed2/0x10c0 drivers/usb/usbip/vhci_tx.c:91
Read of size 4 at addr ffff88802ae62784 by task vhci_tx/6047

CPU: 0 UID: 0 PID: 6047 Comm: vhci_tx 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
 vhci_send_cmd_submit+0xed2/0x10c0 drivers/usb/usbip/vhci_tx.c:91
 vhci_tx_loop+0xff/0x460 drivers/usb/usbip/vhci_tx.c:241
 kthread+0x373/0x450 kernel/kthread.c:436
 ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Allocated by task 6032:
 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:5337 [inline]
 __kmalloc_noprof+0x324/0x820 mm/slub.c:5362
 _kmalloc_noprof include/linux/slab.h:992 [inline]
 usb_alloc_urb+0x66/0xa0 drivers/usb/core/urb.c:75
 alloc_async drivers/usb/core/devio.c:408 [inline]
 proc_do_submiturb+0x741/0x3820 drivers/usb/core/devio.c:1781
 proc_submiturb drivers/usb/core/devio.c:2003 [inline]
 usbdev_do_ioctl drivers/usb/core/devio.c:2703 [inline]
 usbdev_ioctl+0x2ae7/0x3a90 drivers/usb/core/devio.c:2827
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl fs/ioctl.c:583 [inline]
 __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 6032:
 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:2678 [inline]
 slab_free mm/slub.c:6372 [inline]
 kfree+0x22b/0x6c0 mm/slub.c:6687
 urb_destroy drivers/usb/core/urb.c:27 [inline]
 kref_put include/linux/kref.h:65 [inline]
 usb_free_urb.part.0+0xa5/0x110 drivers/usb/core/urb.c:96
 usb_free_urb+0x1f/0x30 drivers/usb/core/urb.c:95
 free_async+0x37d/0x570 drivers/usb/core/devio.c:436
 proc_reapurbnonblock drivers/usb/core/devio.c:2130 [inline]
 usbdev_do_ioctl drivers/usb/core/devio.c:2622 [inline]
 usbdev_ioctl+0x2e7/0x3a90 drivers/usb/core/devio.c:2827
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl fs/ioctl.c:583 [inline]
 __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88802ae62700
 which belongs to the cache kmalloc-192 of size 192
The buggy address is located 132 bytes inside of
 freed 192-byte region [ffff88802ae62700, ffff88802ae627c0)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2ae62
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000000 ffff88801c0423c0 dead000000000100 dead000000000122
raw: 0000000000000000 0000000800100010 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 1, tgid 1 (swapper/0), ts 9072505480
 set_page_owner include/linux/page_owner.h:33 [inline]
 post_alloc_hook+0xfd/0x120 mm/page_alloc.c:1871
 prep_new_page mm/page_alloc.c:1879 [inline]
 get_page_from_freelist+0x110d/0x35b0 mm/page_alloc.c:3943
 __alloc_frozen_pages_noprof+0x2eb/0x3300 mm/page_alloc.c:5436
 alloc_slab_page mm/slub.c:3267 [inline]
 allocate_slab mm/slub.c:3382 [inline]
 new_slab+0xa5/0x640 mm/slub.c:3428
 refill_objects+0xe3/0x410 mm/slub.c:7305
 refill_sheaf mm/slub.c:2805 [inline]
 __pcs_replace_empty_main+0x372/0x680 mm/slub.c:4677
 alloc_from_pcs mm/slub.c:4775 [inline]
 slab_alloc_node mm/slub.c:4907 [inline]
 __do_kmalloc_node mm/slub.c:5336 [inline]
 __kmalloc_noprof+0x66b/0x820 mm/slub.c:5362
 _kmalloc_noprof include/linux/slab.h:992 [inline]
 _kzalloc_noprof include/linux/slab.h:1309 [inline]
 new_dir fs/proc/proc_sysctl.c:965 [inline]
 get_subdir fs/proc/proc_sysctl.c:1009 [inline]
 sysctl_mkdir_p fs/proc/proc_sysctl.c:1319 [inline]
 __register_sysctl_table+0xbe4/0x1650 fs/proc/proc_sysctl.c:1394
 register_net_sysctl_sz+0x325/0x420 net/sysctl_net.c:172
 neigh_sysctl_register+0x326/0x660 net/core/neighbour.c:3915
 devinet_sysctl_register+0xb6/0x210 net/ipv4/devinet.c:2781
 inetdev_init+0x2b8/0x570 net/ipv4/devinet.c:291
 inetdev_event+0x827/0x17f0 net/ipv4/devinet.c:1590
 notifier_call_chain+0x99/0x3f0 kernel/notifier.c:85
 call_netdevice_notifiers_info+0xbe/0x110 net/core/dev.c:2275
 call_netdevice_notifiers_extack net/core/dev.c:2313 [inline]
 call_netdevice_notifiers net/core/dev.c:2327 [inline]
 register_netdevice+0x1998/0x25a0 net/core/dev.c:11541
page_owner free stack trace missing

Memory state around the buggy address:
 ffff88802ae62680: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
 ffff88802ae62700: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88802ae62780: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
                   ^
 ffff88802ae62800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88802ae62880: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
==================================================================


Tested on:

commit:         818bebeb drm/xe: Don't hand out the flat CCS storage a..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=148c0179580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=ccca94d2c01b9e78
dashboard link: https://syzkaller.appspot.com/bug?extid=ecbb1750082f7528b507
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=16c30415580000

[PATCH] usbip: prevent the use of unavailable urb and hcpriv in tx

[Edward Adam Davis]

A race condition between TX and RX causes the URB to enter an unstable
state, triggering [1].

Similarly, a race condition exists between TX and URB reaping, leading
to [2].

In vhci_send_cmd_submit(), the URB refer count is temporarily incremented
to prevent RX or the reaping process from prematurely freeing a URB that
has not yet finished transmitting.

The priv_lock is used to protect access to hcpriv, preventing it from being
prematurely freed by RX while TX is unaware.

[1]
BUG: KASAN: slab-use-after-free in vhci_send_cmd_submit+0xed2/0x10c0 drivers/usb/usbip/vhci_tx.c:91
Read of size 4 at addr ffff888022a66584 by task vhci_tx/6044
Call Trace:
 vhci_send_cmd_submit+0xed2/0x10c0 drivers/usb/usbip/vhci_tx.c:91
 vhci_tx_loop+0xff/0x460 drivers/usb/usbip/vhci_tx.c:241
 
Allocated by task 6031:
 usb_alloc_urb+0x66/0xa0 drivers/usb/core/urb.c:75
 alloc_async drivers/usb/core/devio.c:408 [inline]
 proc_do_submiturb+0x741/0x3820 drivers/usb/core/devio.c:1780
 proc_submiturb drivers/usb/core/devio.c:2002 [inline]
 usbdev_do_ioctl drivers/usb/core/devio.c:2702 [inline]
 usbdev_ioctl+0x2adb/0x3aa0 drivers/usb/core/devio.c:2826

Freed by task 6031:
 urb_destroy drivers/usb/core/urb.c:27 [inline]
 kref_put include/linux/kref.h:65 [inline]
 usb_free_urb.part.0+0xa5/0x110 drivers/usb/core/urb.c:96
 usb_free_urb+0x1f/0x30 drivers/usb/core/urb.c:95
 free_async+0x358/0x530 drivers/usb/core/devio.c:435
 proc_reapurbnonblock drivers/usb/core/devio.c:2129 [inline]
 usbdev_do_ioctl drivers/usb/core/devio.c:2621 [inline]
 usbdev_ioctl+0x2e7/0x3aa0 drivers/usb/core/devio.c:2826

[2]
BUG: KASAN: slab-use-after-free in vhci_send_cmd_submit+0xe87/0x1110
Read of size 8 at addr ffff888020de4820 by task vhci_tx/9324
Call Trace:
vhci_send_cmd_submit drivers/usb/usbip/vhci_tx.c:158
vhci_tx_loop drivers/usb/usbip/vhci_tx.c:256

Allocated by task 9322:
vhci_urb_enqueue drivers/usb/usbip/vhci_hcd.c:674
usb_hcd_submit_urb drivers/usb/core/hcd.c:1542
usb_submit_urb drivers/usb/core/urb.c:586
proc_do_submiturb drivers/usb/core/devio.c:1968
usbdev_ioctl drivers/usb/core/devio.c:2003

Freed by task 9323:
pickup_urb_and_free_priv drivers/usb/usbip/vhci_rx.c:46
vhci_rx_loop drivers/usb/usbip/vhci_rx.c:66

Fixes: ddeee0b2eec2 ("USB: usbfs: properly clean up the as structure on error paths")
Fixes: 04679b3489e0 ("Staging: USB/IP: add client driver")
Reported-by: syzbot+ecbb1750082f7528b507@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=ecbb1750082f7528b507
Tested-by: syzbot+ecbb1750082f7528b507@syzkaller.appspotmail.com
Signed-off-by: Edward Adam Davis <eadavis@qq.com>
---
 drivers/usb/usbip/vhci_tx.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/drivers/usb/usbip/vhci_tx.c b/drivers/usb/usbip/vhci_tx.c
index 32e6fabccf72..03fc070d5825 100644
--- a/drivers/usb/usbip/vhci_tx.c
+++ b/drivers/usb/usbip/vhci_tx.c
@@ -68,7 +68,9 @@ static int vhci_send_cmd_submit(struct vhci_device *vdev)
 		int ret;
 		struct urb *urb = priv->urb;
 		struct usbip_header pdu_header;
+		unsigned long flags;
 
+		usb_get_urb(urb);
 		txsize = 0;
 		memset(&pdu_header, 0, sizeof(pdu_header));
 		memset(&msg, 0, sizeof(msg));
@@ -85,6 +87,7 @@ static int vhci_send_cmd_submit(struct vhci_device *vdev)
 		iov = kzalloc_objs(*iov, iovnum);
 		if (!iov) {
 			usbip_event_add(&vdev->ud, SDEV_EVENT_ERROR_MALLOC);
+			usb_put_urb(urb);
 			return -ENOMEM;
 		}
 
@@ -92,7 +95,15 @@ static int vhci_send_cmd_submit(struct vhci_device *vdev)
 			urb->transfer_flags |= URB_DMA_MAP_SG;
 
 		/* 1. setup usbip_header */
+		spin_lock_irqsave(&vdev->priv_lock, flags);
+		if (!urb->hcpriv) {
+			err = -EIO;
+			spin_unlock_irqrestore(&vdev->priv_lock, flags);
+			usb_put_urb(urb);
+			goto err_iso_buffer;
+		}
 		setup_cmd_submit_pdu(&pdu_header, urb);
+		spin_unlock_irqrestore(&vdev->priv_lock, flags);
 		usbip_header_correct_endian(&pdu_header, 1);
 		iovnum = 0;
 
@@ -127,6 +138,7 @@ static int vhci_send_cmd_submit(struct vhci_device *vdev)
 			if (!iso_buffer) {
 				usbip_event_add(&vdev->ud,
 						SDEV_EVENT_ERROR_MALLOC);
+				usb_put_urb(urb);
 				goto err_iso_buffer;
 			}
 
@@ -143,8 +155,10 @@ static int vhci_send_cmd_submit(struct vhci_device *vdev)
 			       txsize);
 			usbip_event_add(&vdev->ud, VDEV_EVENT_ERROR_TCP);
 			err = -EPIPE;
+			usb_put_urb(urb);
 			goto err_tx;
 		}
+		usb_put_urb(urb);
 
 		kfree(iov);
 		/* This is only for isochronous case */
-- 
2.43.0

Re: [syzbot] KASAN: slab-use-after-free Read in vhci_send_cmd_submit

[Hillf Danton]

> Date: Thu, 20 Aug 2026 07:58:25 -0700	[thread overview]
> Hello,
> 
> syzbot found the following issue on:
> 
> HEAD commit:    3eb40771c00a Merge tag 'soc-fixes-7.2-3' of git://git.kern..
> git tree:       upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=16e07a79580000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=1d67342c314f228d
> dashboard link: https://syzkaller.appspot.com/bug?extid=ecbb1750082f7528b507
> 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=12849949580000

#syz test

--- x/drivers/usb/core/devio.c
+++ y/drivers/usb/core/devio.c
@@ -612,7 +612,7 @@ __acquires(ps->lock)
 			urb = as->urb;
 			usb_get_urb(urb);
 			spin_unlock(&ps->lock);		/* Allow completions */
-			usb_unlink_urb(urb);
+			usb_kill_urb(urb);
 			usb_put_urb(urb);
 			spin_lock(&ps->lock);
 			goto rescan;
--

Re: [syzbot] KASAN: slab-use-after-free Read in vhci_send_cmd_submit

[syzbot]

Hello,

syzbot tried to test the proposed patch but the build/boot failed:

 max_idle_ns: 440795210424 ns
[    5.995352][    T1] clocksource: Switched to clocksource tsc
[    6.007879][   T81] kworker/u33:1 (81) used greatest stack depth: 26904 bytes left
[    6.062555][    T1] Initialise system trusted keyrings
[    6.068264][    T1] workingset: timestamp_bits=40 (anon: 35) max_order=20 bucket_order=0 (anon: 0)
[    6.084373][    T1] DLM installed
[    6.093346][    T1] squashfs: version 4.0 (2009/01/31) Phillip Lougher
[    6.107861][    T1] NFS: Registering the id_resolver key type
[    6.111646][    T1] Key type id_resolver registered
[    6.114786][    T1] Key type id_legacy registered
[    6.119374][    T1] nfs4filelayout_init: NFSv4 File Layout Driver Registering...
[    6.125128][    T1] nfs4flexfilelayout_init: NFSv4 Flexfile Layout Driver Registering...
[    6.134956][    T1] smbdirect: subsystem loading...
[    6.142804][    T1] smbdirect: subsystem loaded
[    6.170761][    T1] Key type cifs.spnego registered
[    6.174632][    T1] Key type cifs.idmap registered
[    6.182165][    T1] ntfs3: Enabled Linux POSIX ACLs support
[    6.186222][    T1] ntfs3: Read-only LZX/Xpress compression included
[    6.190956][    T1] jffs2: version 2.2. (NAND) (SUMMARY)  © 2001-2006 Red Hat, Inc.
[    6.199740][    T1] romfs: ROMFS MTD (C) 2007 Red Hat, Inc.
[    6.204013][    T1] QNX4 filesystem 0.2.3 registered.
[    6.207716][    T1] qnx6: QNX6 filesystem 1.0.0 registered.
[    6.213095][    T1] fuse: init (API version 7.45)
[    6.219370][    T1] orangefs_debugfs_init: called with debug mask: :none: :0:
[    6.226020][    T1] orangefs_init: module version upstream loaded
[    6.230617][    T1] JFS: nTxBlock = 8192, nTxLock = 65536
[    6.246493][    T1] SGI XFS with ACLs, security attributes, realtime, scrub, repair, quota, no debug enabled
[    6.258932][    T1] 9p: Installing v9fs 9p2000 file system support
[    6.263234][    T1] NILFS version 2 loaded
[    6.265499][    T1] befs: version: 0.9.3
[    6.268610][    T1] ocfs2: Registered cluster interface o2cb
[    6.273749][    T1] ocfs2: Registered cluster interface user
[    6.278040][    T1] OCFS2 User DLM kernel interface loaded
[    6.293970][    T1] gfs2: GFS2 installed
[    6.308103][    T1] ceph: loaded (mds proto 32)
[    6.323721][    T1] NET: Registered PF_ALG protocol family
[    6.327858][    T1] async_tx: api initialized (async)
[    6.331276][    T1] Key type asymmetric registered
[    6.334605][    T1] Asymmetric key parser 'x509' registered
[    6.338691][    T1] Asymmetric key parser 'pkcs8' registered
[    6.342508][    T1] Key type pkcs7_test registered
[    6.346832][    T1] Block layer SCSI generic (bsg) driver version 0.4 loaded (major 239)
[    6.354523][    T1] io scheduler mq-deadline registered
[    6.358129][    T1] io scheduler kyber registered
[    6.361302][    T1] io scheduler bfq registered
[    6.402053][    T1] ACPI: \_SB_.GSIE: Enabled at IRQ 20
[    6.413790][    T1] pcieport 0000:00:04.0: PME: Signaling with IRQ 25
[    6.421868][    T1] pcieport 0000:00:04.0: AER: enabled with IRQ 26
[    6.437647][    T1] input: Power Button as /devices/platform/LNXPWRBN:00/input/input0
[    6.445066][    T1] ACPI: button: Power Button [PWRF]
[    6.840917][    T1] ioatdma: Intel(R) QuickData Technology Driver 5.00
[    6.842379][  T235] kworker/u33:7 (235) used greatest stack depth: 26728 bytes left
[    6.874382][    T1] ACPI: \_SB_.GSIF: Enabled at IRQ 21
[    6.924408][    T1] ACPI: \_SB_.GSIH: Enabled at IRQ 23
[    7.089820][  T387] kworker/u33:5 (387) used greatest stack depth: 26688 bytes left
[    7.223811][  T534] kworker/u33:5 (534) used greatest stack depth: 25576 bytes left
[    7.428304][    T1] N_HDLC line discipline registered with maxframe=4096
[    7.437551][    T1] Serial: 8250/16550 driver, 4 ports, IRQ sharing enabled
[    7.448472][    T1] 00:04: ttyS0 at I/O 0x3f8 (irq = 4, base_baud = 115200) is a 16550A
[    7.496195][    T1] Non-volatile memory driver v1.3
[    7.514250][    T1] usbcore: registered new interface driver xillyusb
[    7.527635][    T1] ACPI: bus type drm_connector registered
[    7.539604][    T1] [drm] Initialized vgem 1.0.0 for vgem on minor 0
[    7.544386][    T1] usbcore: registered new interface driver udl
[    7.549606][    T1] [drm] pci: virtio-vga detected at 0000:00:01.0
[    7.553602][    T1] virtio-pci 0000:00:01.0: vgaarb: deactivate vga console
[    7.582344][    T1] Console: switching to colour dummy device 80x25
[    7.591585][    T1] [drm] features: -virgl +edid -resource_blob -host_visible
[    7.591604][    T1] [drm] features: -context_init -blob_alignment
[    7.606984][    T1] [drm] number of scanouts: 1
[    7.609434][    T1] [drm] number of cap sets: 0
[    7.615497][    T1] ------------[ cut here ]------------
[    7.618695][    T1] [PLANE:36:plane-1] pixel format with alpha exposed but blend mode not setup
[    7.618711][    T1] WARNING: drivers/gpu/drm/drm_mode_config.c:872 at drm_mode_config_validate+0xfb4/0x1be0, CPU#3: swapper/0/1
[    7.631767][    T1] Modules linked in:
[    7.634235][    T1] CPU: 3 UID: 0 PID: 1 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT(full) 
[    7.639231][    T1] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
[    7.644605][    T1] RIP: 0010:drm_mode_config_validate+0xfbb/0x1be0
[    7.648817][    T1] Code: 00 49 8b 57 18 48 89 f8 48 c1 e8 03 0f b6 04 28 84 c0 74 08 3c 03 0f 8e 00 0b 00 00 48 8d 3d 3c 18 81 0b 41 8b b7 c8 00 00 00 <67> 48 0f b9 3a e9 fa fd ff ff 48 8b 5c 24 20 e8 41 aa 3c fc 48 8d
[    7.660004][    T1] RSP: 0000:ffffc90000047908 EFLAGS: 00010246
[    7.663325][    T1] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
[    7.667419][    T1] RDX: ffff8880283767c0 RSI: 0000000000000024 RDI: ffffffff914f8190
[    7.672329][    T1] RBP: dffffc0000000000 R08: 0000000000000001 R09: 0000000000000000
[    7.677054][    T1] R10: 0000000000000001 R11: 0000000000000000 R12: ffffed1005094423
[    7.681820][    T1] R13: ffffed1005094424 R14: 0000000000000001 R15: ffff8880284a2028
[    7.686388][    T1] FS:  0000000000000000(0000) GS:ffff8880d5e88000(0000) knlGS:0000000000000000
[    7.691716][    T1] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    7.695512][    T1] CR2: 0000000000000000 CR3: 000000000eb94000 CR4: 0000000000352ef0
[    7.700076][    T1] Call Trace:
[    7.702162][    T1]  <TASK>
[    7.704132][    T1]  ? queue_work_on+0x137/0x1e0
[    7.707046][    T1]  drm_dev_register+0x56e/0x7b0
[    7.709670][    T1]  ? aperture_remove_conflicting_pci_devices+0x138/0x1e0
[    7.713695][    T1]  virtio_gpu_probe+0x271/0x360
[    7.716494][    T1]  virtio_dev_probe+0x6a2/0xbe0
[    7.719075][    T1]  ? __pfx_virtio_dev_probe+0x10/0x10
[    7.721871][    T1]  ? kernfs_create_link+0x1bd/0x240
[    7.724888][    T1]  ? kernfs_put+0x3f/0x60
[    7.727455][    T1]  ? sysfs_do_create_link_sd+0xbb/0x140
[    7.730461][    T1]  ? sysfs_create_link+0x68/0xc0
[    7.733024][    T1]  ? __pfx_virtio_dev_probe+0x10/0x10
[    7.736642][    T1]  really_probe+0x241/0xa60
[    7.739518][    T1]  __driver_probe_device+0x210/0x460
[    7.743005][    T1]  ? _raw_spin_unlock_irqrestore+0x52/0x80
[    7.746855][    T1]  driver_probe_device+0x4a/0x140
[    7.750272][    T1]  __driver_attach+0x21f/0x5b0
[    7.753271][    T1]  ? __pfx___driver_attach+0x10/0x10
[    7.756432][    T1]  bus_for_each_dev+0x13e/0x1d0
[    7.759384][    T1]  ? __pfx_bus_for_each_dev+0x10/0x10
[    7.763028][    T1]  ? bus_add_driver+0x2b5/0x5b0
[    7.765807][    T1]  bus_add_driver+0x305/0x5b0
[    7.768636][    T1]  driver_register+0x1e2/0x360
[    7.771737][    T1]  ? __pfx_virtio_gpu_driver_init+0x10/0x10
[    7.775777][    T1]  virtio_gpu_driver_init+0xc9/0x170
[    7.779251][    T1]  do_one_initcall+0x11c/0x6f0
[    7.781839][    T1]  ? __pfx_do_one_initcall+0x10/0x10
[    7.785228][    T1]  ? kasan_unpoison+0x22/0x60
[    7.788554][    T1]  ? kernel_init_freeable+0x4ca/0x7b0
[    7.792220][    T1]  kernel_init_freeable+0x6ea/0x7b0
[    7.795726][    T1]  ? __pfx_kernel_init+0x10/0x10
[    7.799065][    T1]  kernel_init+0x21/0x1e0
[    7.802141][    T1]  ? __pfx_kernel_init+0x10/0x10
[    7.805542][    T1]  ret_from_fork+0x730/0xd60
[    7.808865][    T1]  ? __pfx_ret_from_fork+0x10/0x10
[    7.812255][    T1]  ? __switch_to+0x800/0x10f0
[    7.815334][    T1]  ? __pfx_kernel_init+0x10/0x10
[    7.818677][    T1]  ret_from_fork_asm+0x1a/0x30
[    7.821765][    T1]  </TASK>
[    7.823834][    T1] Kernel panic - not syncing: kernel: panic_on_warn set ...
[    7.828642][    T1] CPU: 3 UID: 0 PID: 1 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT(full) 
[    7.828642][    T1] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
[    7.828642][    T1] Call Trace:
[    7.828642][    T1]  <TASK>
[    7.828642][    T1]  dump_stack_lvl+0x100/0x190
[    7.828642][    T1]  vpanic+0x553/0x970
[    7.828642][    T1]  ? __pfx_vpanic+0x10/0x10
[    7.828642][    T1]  panic+0xd1/0xe0
[    7.828642][    T1]  ? __pfx_panic+0x10/0x10
[    7.828642][    T1]  check_panic_on_warn.cold+0x19/0x34
[    7.828642][    T1]  ? drm_mode_config_validate+0xfb4/0x1be0
[    7.828642][    T1]  __warn.cold+0x191/0x318
[    7.828642][    T1]  __report_bug+0x30f/0x440
[    7.828642][    T1]  ? drm_mode_config_validate+0xfb4/0x1be0
[    7.828642][    T1]  ? __pfx___report_bug+0x10/0x10
[    7.828642][    T1]  ? __pfx___might_resched+0x10/0x10
[    7.828642][    T1]  ? schedule_timeout+0x161/0x280
[    7.828642][    T1]  report_bug_entry+0xe2/0x290
[    7.828642][    T1]  ? drm_mode_config_validate+0xfbb/0x1be0
[    7.828642][    T1]  handle_bug+0x1cd/0x2a0
[    7.828642][    T1]  exc_invalid_op+0x17/0x50
[    7.828642][    T1]  asm_exc_invalid_op+0x1a/0x20
[    7.828642][    T1] RIP: 0010:drm_mode_config_validate+0xfbb/0x1be0
[    7.828642][    T1] Code: 00 49 8b 57 18 48 89 f8 48 c1 e8 03 0f b6 04 28 84 c0 74 08 3c 03 0f 8e 00 0b 00 00 48 8d 3d 3c 18 81 0b 41 8b b7 c8 00 00 00 <67> 48 0f b9 3a e9 fa fd ff ff 48 8b 5c 24 20 e8 41 aa 3c fc 48 8d
[    7.828642][    T1] RSP: 0000:ffffc90000047908 EFLAGS: 00010246
[    7.828642][    T1] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
[    7.828642][    T1] RDX: ffff8880283767c0 RSI: 0000000000000024 RDI: ffffffff914f8190
[    7.828642][    T1] RBP: dffffc0000000000 R08: 0000000000000001 R09: 0000000000000000
[    7.828642][    T1] R10: 0000000000000001 R11: 0000000000000000 R12: ffffed1005094423
[    7.828642][    T1] R13: ffffed1005094424 R14: 0000000000000001 R15: ffff8880284a2028
[    7.828642][    T1]  ? drm_mode_config_validate+0xf76/0x1be0
[    7.828642][    T1]  ? queue_work_on+0x137/0x1e0
[    7.828642][    T1]  drm_dev_register+0x56e/0x7b0
[    7.828642][    T1]  ? aperture_remove_conflicting_pci_devices+0x138/0x1e0
[    7.828642][    T1]  virtio_gpu_probe+0x271/0x360
[    7.828642][    T1]  virtio_dev_probe+0x6a2/0xbe0
[    7.828642][    T1]  ? __pfx_virtio_dev_probe+0x10/0x10
[    7.828642][    T1]  ? kernfs_create_link+0x1bd/0x240
[    7.828642][    T1]  ? kernfs_put+0x3f/0x60
[    7.828642][    T1]  ? sysfs_do_create_link_sd+0xbb/0x140
[    7.828642][    T1]  ? sysfs_create_link+0x68/0xc0
[    7.828642][    T1]  ? __pfx_virtio_dev_probe+0x10/0x10
[    7.828642][    T1]  really_probe+0x241/0xa60
[    7.828642][    T1]  __driver_probe_device+0x210/0x460
[    7.828642][    T1]  ? _raw_spin_unlock_irqrestore+0x52/0x80
[    7.828642][    T1]  driver_probe_device+0x4a/0x140
[    7.828642][    T1]  __driver_attach+0x21f/0x5b0
[    7.828642][    T1]  ? __pfx___driver_attach+0x10/0x10
[    7.828642][    T1]  bus_for_each_dev+0x13e/0x1d0
[    7.828642][    T1]  ? __pfx_bus_for_each_dev+0x10/0x10
[    7.828642][    T1]  ? bus_add_driver+0x2b5/0x5b0
[    7.828642][    T1]  bus_add_driver+0x305/0x5b0
[    7.828642][    T1]  driver_register+0x1e2/0x360
[    7.828642][    T1]  ? __pfx_virtio_gpu_driver_init+0x10/0x10
[    7.828642][    T1]  virtio_gpu_driver_init+0xc9/0x170
[    7.828642][    T1]  do_one_initcall+0x11c/0x6f0
[    7.828642][    T1]  ? __pfx_do_one_initcall+0x10/0x10
[    7.828642][    T1]  ? kasan_unpoison+0x22/0x60
[    7.828642][    T1]  ? kernel_init_freeable+0x4ca/0x7b0
[    7.828642][    T1]  kernel_init_freeable+0x6ea/0x7b0
[    7.828642][    T1]  ? __pfx_kernel_init+0x10/0x10
[    7.828642][    T1]  kernel_init+0x21/0x1e0
[    7.828642][    T1]  ? __pfx_kernel_init+0x10/0x10
[    7.828642][    T1]  ret_from_fork+0x730/0xd60
[    7.828642][    T1]  ? __pfx_ret_from_fork+0x10/0x10
[    7.828642][    T1]  ? __switch_to+0x800/0x10f0
[    7.828642][    T1]  ? __pfx_kernel_init+0x10/0x10
[    7.828642][    T1]  ret_from_fork_asm+0x1a/0x30
[    7.828642][    T1]  </TASK>
[    7.828642][    T1] Kernel Offset: disabled
[    7.828642][    T1] Rebooting in 86400 seconds..


syzkaller build log:
go env (err=<nil>)
AR='ar'
CC='gcc'
CGO_CFLAGS='-O2 -g'
CGO_CPPFLAGS=''
CGO_CXXFLAGS='-O2 -g'
CGO_ENABLED='1'
CGO_FFLAGS='-O2 -g'
CGO_LDFLAGS='-O2 -g'
CXX='g++'
GCCGO='gccgo'
GO111MODULE='auto'
GOAMD64='v1'
GOARCH='amd64'
GOAUTH='netrc'
GOBIN=''
GOCACHE='/syzkaller/.cache/go-build'
GOCACHEPROG=''
GODEBUG=''
GOENV='/syzkaller/.config/go/env'
GOEXE=''
GOEXPERIMENT=''
GOFIPS140='off'
GOFLAGS=''
GOGCCFLAGS='-fPIC -m64 -pthread -Wl,--no-gc-sections -fmessage-length=0 -ffile-prefix-map=/tmp/go-build3835240120=/tmp/go-build -gno-record-gcc-switches'
GOHOSTARCH='amd64'
GOHOSTOS='linux'
GOINSECURE=''
GOMOD='/syzkaller/jobs/linux/gopath/src/github.com/google/syzkaller/go.mod'
GOMODCACHE='/syzkaller/jobs/linux/gopath/pkg/mod'
GONOPROXY=''
GONOSUMDB=''
GOOS='linux'
GOPATH='/syzkaller/jobs/linux/gopath'
GOPRIVATE=''
GOPROXY='https://proxy.golang.org,direct'
GOROOT='/usr/local/go'
GOSUMDB='sum.golang.org'
GOTELEMETRY='local'
GOTELEMETRYDIR='/syzkaller/.config/go/telemetry'
GOTMPDIR=''
GOTOOLCHAIN='auto'
GOTOOLDIR='/usr/local/go/pkg/tool/linux_amd64'
GOVCS=''
GOVERSION='go1.26.0'
GOWORK=''
PKG_CONFIG='pkg-config'

git status (err=<nil>)
HEAD detached at a9ede23c6b9
nothing to commit, working tree clean


tput: No value for $TERM and no -T specified
tput: No value for $TERM and no -T specified
Makefile:31: run command via tools/syz-env for best compatibility, see:
Makefile:32: https://github.com/google/syzkaller/blob/master/docs/contributing.md#using-syz-env
go list -f '{{.Stale}}' -ldflags="-s -w -X github.com/google/syzkaller/prog.GitRevision=a9ede23c6b9721e9bd95dcb2343c1d6c68e4f0ac -X github.com/google/syzkaller/prog.gitRevisionDate=20260813-125026"  ./sys/syz-sysgen | grep -q false || go install -ldflags="-s -w -X github.com/google/syzkaller/prog.GitRevision=a9ede23c6b9721e9bd95dcb2343c1d6c68e4f0ac -X github.com/google/syzkaller/prog.gitRevisionDate=20260813-125026"  ./sys/syz-sysgen
make .descriptions
tput: No value for $TERM and no -T specified
tput: No value for $TERM and no -T specified
Makefile:31: run command via tools/syz-env for best compatibility, see:
Makefile:32: https://github.com/google/syzkaller/blob/master/docs/contributing.md#using-syz-env
bin/syz-sysgen
touch .descriptions
GOOS=linux GOARCH=amd64 go build -ldflags="-s -w -X github.com/google/syzkaller/prog.GitRevision=a9ede23c6b9721e9bd95dcb2343c1d6c68e4f0ac -X github.com/google/syzkaller/prog.gitRevisionDate=20260813-125026"  -o ./bin/linux_amd64/syz-execprog github.com/google/syzkaller/tools/syz-execprog
mkdir -p ./bin/linux_amd64
g++ -o ./bin/linux_amd64/syz-executor executor/executor.cc \
	-m64 -O2 -pthread -Wall -Werror -Wparentheses -Wunused-const-variable -Wframe-larger-than=16384 -Wno-stringop-overflow -Wno-array-bounds -Wno-format-overflow -Wno-unused-but-set-variable -Wno-unused-command-line-argument -static-pie -std=c++17 -I. -Iexecutor/_include   -DGOOS_linux=1 -DGOARCH_amd64=1 \
	-DHOSTGOOS_linux=1 -DGIT_REVISION=\"a9ede23c6b9721e9bd95dcb2343c1d6c68e4f0ac\"
/usr/bin/ld: /tmp/ccGWcbwL.o: in function `Connection::Connect(char const*, char const*)':
executor.cc:(.text._ZN10Connection7ConnectEPKcS1_[_ZN10Connection7ConnectEPKcS1_]+0x386): warning: Using 'gethostbyname' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking
./tools/check-syzos.sh 2>/dev/null


Error text is too large and was truncated, full error text is at:
https://syzkaller.appspot.com/x/error.txt?x=1548be79580000


Tested on:

commit:         26260251 Merge tag 'livepatching-for-7.3' of git://git..
git tree:       upstream
kernel config:  https://syzkaller.appspot.com/x/.config?x=b0978f5ed2905b98
dashboard link: https://syzkaller.appspot.com/bug?extid=ecbb1750082f7528b507
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=16bc0625580000