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* Re: [syzbot] [usb?] KASAN: slab-use-after-free Write in keyspan_close
       [not found] <20260831001012.8665-1-kartikey406@gmail.com>
@ 2026-08-31  0:37 ` syzbot
  0 siblings, 0 replies; 6+ messages in thread
From: syzbot @ 2026-08-31  0:37 UTC (permalink / raw)
  To: kartikey406, linux-kernel, syzkaller-bugs

Hello,

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

Reported-by: syzbot+5fabc1ae99ff40690d84@syzkaller.appspotmail.com
Tested-by: syzbot+5fabc1ae99ff40690d84@syzkaller.appspotmail.com

Tested on:

commit:         cee9395a Linux 7.3-rc1
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=13a68349580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=8c5c3949d762a91f
dashboard link: https://syzkaller.appspot.com/bug?extid=5fabc1ae99ff40690d84
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=155a8349580000

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

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [syzbot] [usb?] KASAN: slab-use-after-free Write in keyspan_close
  2026-08-31  0:38 ` Edward Adam Davis
@ 2026-08-31  1:02   ` syzbot
  0 siblings, 0 replies; 6+ messages in thread
From: syzbot @ 2026-08-31  1:02 UTC (permalink / raw)
  To: eadavis, linux-kernel, syzkaller-bugs

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
BUG: corrupted list in usb_hcd_link_urb_to_ep

list_add double add: new=ffff88803dbb4e18, prev=ffff88803dbb4e18, next=ffff888054867878.
------------[ cut here ]------------
kernel BUG at lib/list_debug.c:35!
Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI
CPU: 2 UID: 0 PID: 8045 Comm: syz.3.731 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:__list_add_valid_or_report.cold+0x34/0x36 lib/list_debug.c:35
Code: eb ff 90 0f 0b 48 c7 c7 00 0d 62 8c e8 7a be eb ff 90 0f 0b 48 89 d9 4c 89 ea 48 89 ee 48 c7 c7 40 0f 62 8c e8 62 be eb ff 90 <0f> 0b 48 89 de 48 c7 c7 00 10 62 8c e8 50 be eb ff 90 0f 0b 48 89
RSP: 0018:ffffc900006588b8 EFLAGS: 00010086
RAX: 0000000000000058 RBX: ffff888054867878 RCX: 0000000000000000
RDX: 0000000000000058 RSI: ffffffff81e9e1d9 RDI: fffff520000cb108
RBP: ffff88803dbb4e18 R08: 0000000000000007 R09: 0000000000000000
R10: 8000000000000103 R11: 0000000000000001 R12: ffff888054867880
R13: ffff88803dbb4e18 R14: 0000000000000000 R15: ffff88803dbb4e18
FS:  00007ff211c5e6c0(0000) GS:ffff8880d5d64000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f348dc70050 CR3: 000000002dba6000 CR4: 0000000000352ef0
Call Trace:
 <IRQ>
 __list_add_valid include/linux/list.h:104 [inline]
 __list_add include/linux/list.h:169 [inline]
 list_add_tail include/linux/list.h:206 [inline]
 usb_hcd_link_urb_to_ep+0x220/0x3a0 drivers/usb/core/hcd.c:1154
 dummy_urb_enqueue+0x2b5/0x880 drivers/usb/gadget/udc/dummy_hcd.c:1310
 usb_hcd_submit_urb+0x268/0x2150 drivers/usb/core/hcd.c:1542
 usb_submit_urb+0x827/0x19b0 drivers/usb/core/urb.c:586
 keyspan_usa67_send_setup.isra.0+0x641/0x950 drivers/usb/serial/keyspan.c:2740
 usa67_glocont_callback+0x1bb/0x2a0 drivers/usb/serial/keyspan.c:1454
 __usb_hcd_giveback_urb+0x38e/0x610 drivers/usb/core/hcd.c:1657
 usb_hcd_giveback_urb+0x3ca/0x4a0 drivers/usb/core/hcd.c:1741
 dummy_timer+0xdb2/0x3700 drivers/usb/gadget/udc/dummy_hcd.c:2019
 __run_hrtimer kernel/time/hrtimer.c:2067 [inline]
 __hrtimer_run_queues+0x462/0x9c0 kernel/time/hrtimer.c:2124
 hrtimer_run_softirq+0x1ca/0x360 kernel/time/hrtimer.c:2141
 handle_softirqs+0x1e6/0x9d0 kernel/softirq.c:645
 __do_softirq kernel/softirq.c:679 [inline]
 invoke_softirq kernel/softirq.c:519 [inline]
 __irq_exit_rcu+0x194/0x210 kernel/softirq.c:767
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:784
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
 sysvec_apic_timer_interrupt+0xa3/0xc0 arch/x86/kernel/apic/apic.c:1062
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:owner_on_cpu include/linux/sched.h:2338 [inline]
RIP: 0010:mutex_spin_on_owner+0xbb/0x2b0 kernel/locking/mutex.c:406
Code: 48 89 df e8 d7 f0 98 00 48 89 d8 48 c1 e8 03 42 80 3c 38 00 0f 85 c0 01 00 00 48 8b 03 48 83 e0 f8 48 39 c5 0f 85 24 01 00 00 <48> 8d 7d 34 48 89 f8 48 89 f9 48 c1 e8 03 83 e1 07 42 0f b6 04 38
RSP: 0018:ffffc90023b476b0 EFLAGS: 00000246
RAX: ffff888027e88000 RBX: ffff88802db3a150 RCX: ffffffff81e60db9
RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffff88802db3a150
RBP: ffff888027e88000 R08: 0000000000000000 R09: ffffed1005b6742a
R10: ffff88802db3a157 R11: 0000000000000000 R12: ffffed10056b84b0
R13: ffff88802b5c2580 R14: 0000000000000000 R15: dffffc0000000000
 mutex_optimistic_spin kernel/locking/mutex.c:509 [inline]
 __mutex_lock_common kernel/locking/mutex.c:761 [inline]
 __mutex_lock+0x12c3/0x1bc0 kernel/locking/mutex.c:821
 tty_lock_interruptible+0x75/0xe0 drivers/tty/tty_mutex.c:27
 tty_open_by_driver drivers/tty/tty_io.c:2032 [inline]
 tty_open+0x5e7/0xe20 drivers/tty/tty_io.c:2093
 chrdev_open+0x234/0x6a0 fs/char_dev.c:411
 do_dentry_open+0x6ab/0x14d0 fs/open.c:996
 vfs_open+0x82/0x3f0 fs/open.c:1101
 do_open fs/namei.c:4837 [inline]
 path_openat+0x19fa/0x2440 fs/namei.c:5000
 do_file_open+0x20e/0x430 fs/namei.c:5029
 do_sys_openat2+0x10f/0x1e0 fs/open.c:1417
 do_sys_open fs/open.c:1423 [inline]
 __do_sys_openat fs/open.c:1439 [inline]
 __se_sys_openat fs/open.c:1434 [inline]
 __x64_sys_openat+0x12d/0x210 fs/open.c:1434
 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
RIP: 0033:0x7ff210d9e159
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ff211c5e028 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007ff211025fa0 RCX: 00007ff210d9e159
RDX: 0000000000000002 RSI: 0000200000000400 RDI: ffffffffffffff9c
RBP: 00007ff210e35024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff211026038 R14: 00007ff211025fa0 R15: 00007ffc38d9dfd8
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__list_add_valid_or_report.cold+0x34/0x36 lib/list_debug.c:35
Code: eb ff 90 0f 0b 48 c7 c7 00 0d 62 8c e8 7a be eb ff 90 0f 0b 48 89 d9 4c 89 ea 48 89 ee 48 c7 c7 40 0f 62 8c e8 62 be eb ff 90 <0f> 0b 48 89 de 48 c7 c7 00 10 62 8c e8 50 be eb ff 90 0f 0b 48 89
RSP: 0018:ffffc900006588b8 EFLAGS: 00010086
RAX: 0000000000000058 RBX: ffff888054867878 RCX: 0000000000000000
RDX: 0000000000000058 RSI: ffffffff81e9e1d9 RDI: fffff520000cb108
RBP: ffff88803dbb4e18 R08: 0000000000000007 R09: 0000000000000000
R10: 8000000000000103 R11: 0000000000000001 R12: ffff888054867880
R13: ffff88803dbb4e18 R14: 0000000000000000 R15: ffff88803dbb4e18
FS:  00007ff211c5e6c0(0000) GS:ffff8880d5d64000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f348dc70050 CR3: 000000002dba6000 CR4: 0000000000352ef0
----------------
Code disassembly (best guess):
   0:	48 89 df             	mov    %rbx,%rdi
   3:	e8 d7 f0 98 00       	call   0x98f0df
   8:	48 89 d8             	mov    %rbx,%rax
   b:	48 c1 e8 03          	shr    $0x3,%rax
   f:	42 80 3c 38 00       	cmpb   $0x0,(%rax,%r15,1)
  14:	0f 85 c0 01 00 00    	jne    0x1da
  1a:	48 8b 03             	mov    (%rbx),%rax
  1d:	48 83 e0 f8          	and    $0xfffffffffffffff8,%rax
  21:	48 39 c5             	cmp    %rax,%rbp
  24:	0f 85 24 01 00 00    	jne    0x14e
* 2a:	48 8d 7d 34          	lea    0x34(%rbp),%rdi <-- trapping instruction
  2e:	48 89 f8             	mov    %rdi,%rax
  31:	48 89 f9             	mov    %rdi,%rcx
  34:	48 c1 e8 03          	shr    $0x3,%rax
  38:	83 e1 07             	and    $0x7,%ecx
  3b:	42 0f b6 04 38       	movzbl (%rax,%r15,1),%eax


Tested on:

commit:         08dbfad3 Merge tag 'for-linus' of git://git.kernel.org..
git tree:       git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
console output: https://syzkaller.appspot.com/x/log.txt?x=17f68349580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=8c5c3949d762a91f
dashboard link: https://syzkaller.appspot.com/bug?extid=5fabc1ae99ff40690d84
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=10fd7379580000


^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [syzbot] [usb?] KASAN: slab-use-after-free Write in keyspan_close
  2026-08-30 15:03 syzbot
  2026-08-30 23:50 ` Edward Adam Davis
@ 2026-08-31  0:38 ` Edward Adam Davis
  2026-08-31  1:02   ` syzbot
  1 sibling, 1 reply; 6+ messages in thread
From: Edward Adam Davis @ 2026-08-31  0:38 UTC (permalink / raw)
  To: syzbot+5fabc1ae99ff40690d84; +Cc: linux-kernel, syzkaller-bugs

From: Edward Aadm Davis <eadavis@sina.com>

#syz test: upstream 08dbfad3f504

diff --git a/drivers/usb/serial/usb-serial.c b/drivers/usb/serial/usb-serial.c
index 17edc057a311..0464dbab17c1 100644
--- a/drivers/usb/serial/usb-serial.c
+++ b/drivers/usb/serial/usb-serial.c
@@ -301,10 +301,19 @@ static void serial_port_shutdown(struct tty_port *tport)
 	struct usb_serial_port *port =
 		container_of(tport, struct usb_serial_port, port);
 	struct usb_serial_driver *drv = port->serial->type;
+	struct usb_serial *serial = port->serial;
+
+	mutex_lock(&serial->disc_mutex);
+	if (serial->disconnected) {
+		mutex_unlock(&serial->disc_mutex);
+		goto out;
+	}
 
 	if (drv->close)
 		drv->close(port);
 
+	mutex_unlock(&serial->disc_mutex);
+out:
 	usb_autopm_put_interface(port->serial->interface);
 }
 

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [syzbot] [usb?] KASAN: slab-use-after-free Write in keyspan_close
  2026-08-30 23:50 ` Edward Adam Davis
@ 2026-08-31  0:14   ` syzbot
  0 siblings, 0 replies; 6+ messages in thread
From: syzbot @ 2026-08-31  0:14 UTC (permalink / raw)
  To: eadavis, linux-kernel, syzkaller-bugs

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
BUG: corrupted list in usb_hcd_link_urb_to_ep

list_add double add: new=ffff888024daf118, prev=ffff888024daf118, next=ffff88802b357078.
------------[ cut here ]------------
kernel BUG at lib/list_debug.c:35!
Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI
CPU: 0 UID: 0 PID: 7594 Comm: syz.3.536 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:__list_add_valid_or_report.cold+0x34/0x36 lib/list_debug.c:35
Code: eb ff 90 0f 0b 48 c7 c7 00 0d 62 8c e8 7a be eb ff 90 0f 0b 48 89 d9 4c 89 ea 48 89 ee 48 c7 c7 40 0f 62 8c e8 62 be eb ff 90 <0f> 0b 48 89 de 48 c7 c7 00 10 62 8c e8 50 be eb ff 90 0f 0b 48 89
RSP: 0018:ffffc900000078b8 EFLAGS: 00010086
RAX: 0000000000000058 RBX: ffff88802b357078 RCX: 0000000000000000
RDX: 0000000000000058 RSI: ffffffff81e9e1d9 RDI: fffff52000000f08
RBP: ffff888024daf118 R08: 0000000000000007 R09: 0000000000000000
R10: 8000000000000102 R11: 0000000000000001 R12: ffff88802b357080
R13: ffff888024daf118 R14: 0000000000000000 R15: ffff888024daf118
FS:  00007f9d428ff6c0(0000) GS:ffff8880d5b64000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fbabb227dac CR3: 000000003d2aa000 CR4: 0000000000352ef0
Call Trace:
 <IRQ>
 __list_add_valid include/linux/list.h:104 [inline]
 __list_add include/linux/list.h:169 [inline]
 list_add_tail include/linux/list.h:206 [inline]
 usb_hcd_link_urb_to_ep+0x220/0x3a0 drivers/usb/core/hcd.c:1154
 dummy_urb_enqueue+0x2b5/0x880 drivers/usb/gadget/udc/dummy_hcd.c:1310
 usb_hcd_submit_urb+0x268/0x2150 drivers/usb/core/hcd.c:1542
 usb_submit_urb+0x827/0x19b0 drivers/usb/core/urb.c:586
 keyspan_usa67_send_setup.isra.0+0x641/0x950 drivers/usb/serial/keyspan.c:2740
 usa67_glocont_callback+0x1bb/0x2a0 drivers/usb/serial/keyspan.c:1454
 __usb_hcd_giveback_urb+0x38e/0x610 drivers/usb/core/hcd.c:1657
 usb_hcd_giveback_urb+0x3ca/0x4a0 drivers/usb/core/hcd.c:1741
 dummy_timer+0xdb2/0x3700 drivers/usb/gadget/udc/dummy_hcd.c:2019
 __run_hrtimer kernel/time/hrtimer.c:2067 [inline]
 __hrtimer_run_queues+0x462/0x9c0 kernel/time/hrtimer.c:2124
 hrtimer_run_softirq+0x1ca/0x360 kernel/time/hrtimer.c:2141
 handle_softirqs+0x1e6/0x9d0 kernel/softirq.c:645
 __do_softirq kernel/softirq.c:679 [inline]
 invoke_softirq kernel/softirq.c:519 [inline]
 __irq_exit_rcu+0x194/0x210 kernel/softirq.c:767
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:784
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
 sysvec_apic_timer_interrupt+0xa3/0xc0 arch/x86/kernel/apic/apic.c:1062
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:lock_acquire+0x5e/0x380 kernel/locking/lockdep.c:5913
Code: 05 4f a1 a4 12 83 f8 07 0f 87 da 00 00 00 48 0f a3 05 5e d7 5d 0f 0f 82 c9 02 00 00 8b 35 fe 08 5e 0f 85 f6 0f 85 c7 00 00 00 <48> 8b 44 24 30 65 48 2b 05 ed a0 a4 12 0f 85 09 03 00 00 48 83 c4
RSP: 0018:ffffc9000dfbf6f0 EFLAGS: 00000206
RAX: 0000000000000046 RBX: 0000000000000000 RCX: 0000000000000200
RDX: 0000000000000000 RSI: ffffffff8e3c46cc RDI: ffffffff8c620c80
RBP: ffffffff8edec060 R08: 00000000c68d1768 R09: 0000000000000007
R10: 0000000000000200 R11: 0000000000000001 R12: 0000000000000002
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 rcu_read_lock include/linux/rcupdate.h:849 [inline]
 class_rcu_constructor include/linux/rcupdate.h:1216 [inline]
 unwind_next_frame+0xd1/0x2090 arch/x86/kernel/unwind_orc.c:495
 arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
 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:5414 [inline]
 __kmalloc_noprof+0x32f/0x840 mm/slub.c:5439
 _kmalloc_noprof include/linux/slab.h:995 [inline]
 tomoyo_realpath_from_path+0xb6/0x690 security/tomoyo/realpath.c:251
 tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
 tomoyo_path_number_perm+0x23c/0x580 security/tomoyo/file.c:728
 security_file_ioctl+0xd3/0x230 security/security.c:2512
 __do_sys_ioctl fs/ioctl.c:591 [inline]
 __se_sys_ioctl fs/ioctl.c:583 [inline]
 __x64_sys_ioctl+0xb7/0x210 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
RIP: 0033:0x7f9d4199e159
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f9d428ff028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f9d41c25fa0 RCX: 00007f9d4199e159
RDX: 0000000000000000 RSI: 0000000000005437 RDI: 0000000000000004
RBP: 00007f9d41a35024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f9d41c26038 R14: 00007f9d41c25fa0 R15: 00007ffc0da26608
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__list_add_valid_or_report.cold+0x34/0x36 lib/list_debug.c:35
Code: eb ff 90 0f 0b 48 c7 c7 00 0d 62 8c e8 7a be eb ff 90 0f 0b 48 89 d9 4c 89 ea 48 89 ee 48 c7 c7 40 0f 62 8c e8 62 be eb ff 90 <0f> 0b 48 89 de 48 c7 c7 00 10 62 8c e8 50 be eb ff 90 0f 0b 48 89
RSP: 0018:ffffc900000078b8 EFLAGS: 00010086
RAX: 0000000000000058 RBX: ffff88802b357078 RCX: 0000000000000000
RDX: 0000000000000058 RSI: ffffffff81e9e1d9 RDI: fffff52000000f08
RBP: ffff888024daf118 R08: 0000000000000007 R09: 0000000000000000
R10: 8000000000000102 R11: 0000000000000001 R12: ffff88802b357080
R13: ffff888024daf118 R14: 0000000000000000 R15: ffff888024daf118
FS:  00007f9d428ff6c0(0000) GS:ffff8880d5b64000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fbabb227dac CR3: 000000003d2aa000 CR4: 0000000000352ef0
----------------
Code disassembly (best guess):
   0:	05 4f a1 a4 12       	add    $0x12a4a14f,%eax
   5:	83 f8 07             	cmp    $0x7,%eax
   8:	0f 87 da 00 00 00    	ja     0xe8
   e:	48 0f a3 05 5e d7 5d 	bt     %rax,0xf5dd75e(%rip)        # 0xf5dd774
  15:	0f
  16:	0f 82 c9 02 00 00    	jb     0x2e5
  1c:	8b 35 fe 08 5e 0f    	mov    0xf5e08fe(%rip),%esi        # 0xf5e0920
  22:	85 f6                	test   %esi,%esi
  24:	0f 85 c7 00 00 00    	jne    0xf1
* 2a:	48 8b 44 24 30       	mov    0x30(%rsp),%rax <-- trapping instruction
  2f:	65 48 2b 05 ed a0 a4 	sub    %gs:0x12a4a0ed(%rip),%rax        # 0x12a4a124
  36:	12
  37:	0f 85 09 03 00 00    	jne    0x346
  3d:	48                   	rex.W
  3e:	83                   	.byte 0x83
  3f:	c4                   	.byte 0xc4


Tested on:

commit:         08dbfad3 Merge tag 'for-linus' of git://git.kernel.org..
git tree:       git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
console output: https://syzkaller.appspot.com/x/log.txt?x=113a8349580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=8c5c3949d762a91f
dashboard link: https://syzkaller.appspot.com/bug?extid=5fabc1ae99ff40690d84
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=14357379580000


^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [syzbot] [usb?] KASAN: slab-use-after-free Write in keyspan_close
  2026-08-30 15:03 syzbot
@ 2026-08-30 23:50 ` Edward Adam Davis
  2026-08-31  0:14   ` syzbot
  2026-08-31  0:38 ` Edward Adam Davis
  1 sibling, 1 reply; 6+ messages in thread
From: Edward Adam Davis @ 2026-08-30 23:50 UTC (permalink / raw)
  To: syzbot+5fabc1ae99ff40690d84; +Cc: linux-kernel, syzkaller-bugs

From: Edward Aadm Davis <eadavis@sina.com>

#syz test: upstream 08dbfad3f504

diff --git a/drivers/usb/serial/usb-serial.c b/drivers/usb/serial/usb-serial.c
index 17edc057a311..51359815432a 100644
--- a/drivers/usb/serial/usb-serial.c
+++ b/drivers/usb/serial/usb-serial.c
@@ -301,11 +301,19 @@ static void serial_port_shutdown(struct tty_port *tport)
 	struct usb_serial_port *port =
 		container_of(tport, struct usb_serial_port, port);
 	struct usb_serial_driver *drv = port->serial->type;
+	struct usb_serial *serial = port->serial;
+
+	mutex_lock(&serial->disc_mutex);
+	if (serial->disconnected) {
+		mutex_unlock(&serial->disc_mutex);
+		return;
+	}
 
 	if (drv->close)
 		drv->close(port);
 
 	usb_autopm_put_interface(port->serial->interface);
+	mutex_unlock(&serial->disc_mutex);
 }
 
 static void serial_hangup(struct tty_struct *tty)

^ permalink raw reply	[flat|nested] 6+ messages in thread

* [syzbot] [usb?] KASAN: slab-use-after-free Write in keyspan_close
@ 2026-08-30 15:03 syzbot
  2026-08-30 23:50 ` Edward Adam Davis
  2026-08-31  0:38 ` Edward Adam Davis
  0 siblings, 2 replies; 6+ messages in thread
From: syzbot @ 2026-08-30 15:03 UTC (permalink / raw)
  To: gregkh, johan, linux-kernel, linux-usb, syzkaller-bugs

Hello,

syzbot found the following issue on:

HEAD commit:    08dbfad3f504 Merge tag 'for-linus' of git://git.kernel.org..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1731ac15580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=8c5c3949d762a91f
dashboard link: https://syzkaller.appspot.com/bug?extid=5fabc1ae99ff40690d84
compiler:       gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=15677d79580000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=108ffd49580000

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-08dbfad3.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/1b5cf3bd2698/vmlinux-08dbfad3.xz
kernel image: https://storage.googleapis.com/syzbot-assets/05ad56c0b8bc/bzImage-08dbfad3.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+5fabc1ae99ff40690d84@syzkaller.appspotmail.com

==================================================================
BU
BUG: KASAN: slab-use-after-free in keyspan_close+0x23e/0x260 drivers/usb/serial/keyspan.c:1594
Write of size 4 at addr ffff888028051104 by task syz.2.29/6038

CPU: 1 UID: 0 PID: 6038 Comm: syz.2.29 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
 keyspan_close+0x23e/0x260 drivers/usb/serial/keyspan.c:1594
 serial_port_shutdown+0x92/0x110 drivers/usb/serial/usb-serial.c:306
 tty_port_shutdown+0x1fa/0x250 drivers/tty/tty_port.c:372
 tty_port_hangup+0xfb/0x160 drivers/tty/tty_port.c:397
 __tty_hangup.part.0+0x696/0x7c0 drivers/tty/tty_io.c:644
 __tty_hangup drivers/tty/tty_io.c:688 [inline]
 tty_vhangup drivers/tty/tty_io.c:691 [inline]
 tty_vhangup drivers/tty/tty_io.c:688 [inline]
 tty_ioctl+0x112e/0x1640 drivers/tty/tty_io.c:2705
 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
RIP: 0033:0x7f32c159e159
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffd7a0b3f98 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f32c1825fa0 RCX: 00007f32c159e159
RDX: 0000000000000000 RSI: 0000000000005437 RDI: 0000000000000004
RBP: 00007f32c1635024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f32c1825fac R14: 00007f32c1825fa0 R15: 00007f32c1825fa0
 </TASK>

Allocated by task 991:
 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]
 __kmalloc_cache_noprof+0x2f8/0x6d0 mm/slub.c:5563
 _kmalloc_noprof include/linux/slab.h:991 [inline]
 _kzalloc_noprof include/linux/slab.h:1312 [inline]
 keyspan_port_probe+0xbc/0xdd0 drivers/usb/serial/keyspan.c:2891
 usb_serial_device_probe+0x106/0x3e0 drivers/usb/serial/bus.c:47
 call_driver_probe drivers/base/dd.c:628 [inline]
 really_probe+0x241/0xa60 drivers/base/dd.c:706
 __driver_probe_device+0x210/0x460 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:3776
 usb_serial_probe.cold+0x257e/0x29f8 drivers/usb/serial/usb-serial.c:1147
 usb_probe_interface+0x386/0x9b0 drivers/usb/core/driver.c:399
 call_driver_probe drivers/base/dd.c:628 [inline]
 really_probe+0x241/0xa60 drivers/base/dd.c:706
 __driver_probe_device+0x210/0x460 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:3776
 usb_set_configuration+0xd97/0x1c60 drivers/usb/core/message.c:2268
 usb_generic_driver_probe+0xa1/0xe0 drivers/usb/core/generic.c:250
 usb_probe_device+0xef/0x400 drivers/usb/core/driver.c:293
 call_driver_probe drivers/base/dd.c:628 [inline]
 really_probe+0x241/0xa60 drivers/base/dd.c:706
 __driver_probe_device+0x210/0x460 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:3776
 usb_new_device.part.0+0xcc2/0x1686 drivers/usb/core/hub.c:2708
 usb_new_device include/linux/workqueue.h:715 [inline]
 hub_port_connect drivers/usb/core/hub.c:5580 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5720 [inline]
 port_event drivers/usb/core/hub.c:5884 [inline]
 hub_event.cold+0x1e3/0xe90 drivers/usb/core/hub.c:5966
 process_one_work+0xac7/0x1b10 kernel/workqueue.c:3387
 process_scheduled_works kernel/workqueue.c:3470 [inline]
 worker_thread+0x5ef/0xe50 kernel/workqueue.c:3551
 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

Freed by task 58:
 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:2748 [inline]
 slab_free mm/slub.c:6499 [inline]
 kfree+0x22b/0x6d0 mm/slub.c:6792
 usb_serial_device_remove+0x146/0x1a0 drivers/usb/serial/bus.c:97
 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
 bus_remove_device+0x2bc/0x560 drivers/base/bus.c:664
 device_del+0x376/0x9b0 drivers/base/core.c:3965
 usb_serial_disconnect+0x21e/0x490 drivers/usb/serial/usb-serial.c:1195
 usb_unbind_interface+0x1dd/0x9e0 drivers/usb/core/driver.c:461
 device_remove drivers/base/dd.c:618 [inline]
 device_remove+0x12a/0x180 drivers/base/dd.c:610
 __device_release_driver drivers/base/dd.c:1349 [inline]
 device_release_driver_internal+0x44e/0x620 drivers/base/dd.c:1372
 bus_remove_device+0x2bc/0x560 drivers/base/bus.c:664
 device_del+0x376/0x9b0 drivers/base/core.c:3965
 usb_disable_device+0x367/0x810 drivers/usb/core/message.c:1478
 usb_disconnect+0x2e2/0x9a0 drivers/usb/core/hub.c:2350
 hub_port_connect drivers/usb/core/hub.c:5420 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5720 [inline]
 port_event drivers/usb/core/hub.c:5884 [inline]
 hub_event+0x1bb1/0x4420 drivers/usb/core/hub.c:5966
 process_one_work+0xac7/0x1b10 kernel/workqueue.c:3387
 process_scheduled_works kernel/workqueue.c:3470 [inline]
 worker_thread+0x5ef/0xe50 kernel/workqueue.c:3551
 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

The buggy address belongs to the object at ffff888028051100
 which belongs to the cache kmalloc-192 of size 192
The buggy address is located 4 bytes inside of
 freed 192-byte region [ffff888028051100, ffff8880280511c0)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x28051
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000000 ffff88801c0423c0 dead000000000100 dead000000000122
raw: 0000000000000000 0000000000100010 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 5549223145
 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:3347 [inline]
 allocate_slab mm/slub.c:3462 [inline]
 new_slab+0xa9/0x6e0 mm/slub.c:3513
 refill_objects+0xe3/0x410 mm/slub.c:7410
 refill_sheaf mm/slub.c:2885 [inline]
 __pcs_replace_empty_main+0x35e/0x650 mm/slub.c:4774
 alloc_from_pcs mm/slub.c:4850 [inline]
 slab_alloc_node mm/slub.c:4984 [inline]
 __kmalloc_cache_noprof+0x4f4/0x6d0 mm/slub.c:5559
 _kmalloc_noprof include/linux/slab.h:991 [inline]
 _kzalloc_noprof include/linux/slab.h:1312 [inline]
 call_usermodehelper_setup+0xaf/0x360 kernel/umh.c:360
 kobject_uevent_env+0x17c1/0x18b0 lib/kobject_uevent.c:631
 __kobject_del+0x168/0x220 lib/kobject.c:601
 kobject_cleanup lib/kobject.c:680 [inline]
 kobject_release lib/kobject.c:720 [inline]
 kref_put include/linux/kref.h:65 [inline]
 kobject_put+0x348/0x640 lib/kobject.c:737
 bus_remove_driver+0x16e/0x2e0 drivers/base/bus.c:834
 driver_unregister+0x76/0xb0 drivers/base/driver.c:202
 pci_unregister_driver+0x2a/0x220 drivers/pci/pci-driver.c:1519
 agp_amd64_init+0x174/0x2c0 drivers/char/agp/amd64-agp.c:761
 do_one_initcall+0x11c/0x6f0 init/main.c:1357
page_owner free stack trace missing

Memory state around the buggy address:
 ffff888028051000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff888028051080: 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888028051100: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                   ^
 ffff888028051180: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
 ffff888028051200: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================


---
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

^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2026-08-31  1:02 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
     [not found] <20260831001012.8665-1-kartikey406@gmail.com>
2026-08-31  0:37 ` [syzbot] [usb?] KASAN: slab-use-after-free Write in keyspan_close syzbot
2026-08-30 15:03 syzbot
2026-08-30 23:50 ` Edward Adam Davis
2026-08-31  0:14   ` syzbot
2026-08-31  0:38 ` Edward Adam Davis
2026-08-31  1:02   ` syzbot

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