From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oi1-f197.google.com (mail-oi1-f197.google.com [209.85.167.197]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5613922E3F0 for ; Fri, 9 Oct 2026 02:07:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.167.197 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791511660; cv=none; b=C41kntcfH3dXCRb0ZkGBakg/1gdIe9H+J++wSsqlqw7hfdNh0hIJBYfXRbCnvmPbgxUk9vYptxjFAE1rIax1f9JL8Ws3F1B+6xWWkgXUnaEX+040Il0l15KxPH2NXi2s5dyo71d9vYf2BAyHv3KxAyLeeKh8uR4oVulhn2NgEWo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791511660; c=relaxed/simple; bh=ZAOqnswg2rkuR0i1i2W4xenzfuTSHt3eTCoR93DscBE=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=Yo8WY721w0T6gIhINQRNoMbA0cvaQ7RpmS7MPAhikkQfY6EJtdvudzsfyhdNFp5rQNUYgCePGdvmO50Rk7AMwebu9qfbOd7V65p6WcSkg26nkZdCOKLKLilf1/v8fhpS7ifdMi3cUeomt1dBIl4elTrawSqWAIs3z6BNlDJvG5Y= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com; arc=none smtp.client-ip=209.85.167.197 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com Received: by mail-oi1-f197.google.com with SMTP id 5614622812f47-4b597558c4cso9620042b6e.1 for ; Thu, 08 Oct 2026 19:07:38 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1791511657; x=1792116457; h=content-type:to:from:subject:message-id:date:mime-version :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to :content-type; bh=1qYt+vG48IlGBzSCcHqzAFgeG84ds5Yd6CbKOVQRobY=; b=MMzFnmAOMG/OYwRLAL7bIht48XakAL05Mfl/D2oNcPfhtcLWDyjrRjAYdxmzLfYepX iS4+hl5u82TYwMuQPkLC/NzxHCJlc9GJQd1CHyvXF1uj42GweXEnlGN1zeN4hJBZeC2b Ge+wAFX0IJSI2bTUNFlmp5EcH0QNBvqWqyo/QqQQ17FxLibRmm0pBDXCm0J2TEqqrQSj kwdY1ETMvTscOtqTQUk71D1uCwBPVe45AKCKPIg7NS4/ECLLlCEs2zoG3uZQMRN1iDU/ bOm+5tvX1dbOFxrxMLtPN+3zpGme4kRKe2/0Ejda9WwKrA5Uea82Jk9tGaKLRPPMzdp1 ifxw== X-Forwarded-Encrypted: i=1; AKwUvBwP8DfNp96sk2FIQxjCTZj0rJNUYcS/tlKKh/JjeCgLybxZBck3RYiJmSwvOkrLtpLlDyaxGaf9doo=@vger.kernel.org X-Gm-Message-State: AFuF++mBsRd+3K571u0NNK7+63bySeLTHN7vOHYlLY3g3f9OEBw0/66/ L6k8fFvjTE92/QkdN30xbK13OaVUS0p6+SG6WO41budPpSkSfQY+xxz52vTOly8GigE1YzFY0iE wrpw/33C5E+V4N7h2oRMSQ6qKVffn7+KPczDtpOJlzyK5hWnUwZTOAFMyC28= Precedence: bulk X-Mailing-List: linux-usb@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6808:30a8:b0:4f5:d3bf:edf3 with SMTP id 5614622812f47-50c563489c1mr342565b6e.59.1791511657364; Thu, 08 Oct 2026 19:07:37 -0700 (PDT) Date: Thu, 08 Oct 2026 19:07:37 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6ac84c69.70ed5d86.2ac85.0025.GAE@google.com> Subject: [syzbot] [usb?] KASAN: slab-use-after-free Read in printer_func_unbind From: syzbot To: gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: f0406245cb98 Add linux-next specific files for 20261002 git tree: linux-next console output: https://syzkaller.appspot.com/x/log.txt?x=1142b7f5580000 kernel config: https://syzkaller.appspot.com/x/.config?x=dfd189b706ddeebe dashboard link: https://syzkaller.appspot.com/bug?extid=ffc483dc87891d3c107b compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/3727ac4f2c2d/disk-f0406245.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/fb9b2c85f6d9/vmlinux-f0406245.xz kernel image: https://storage.googleapis.com/syzbot-assets/738723ef945a/bzImage-f0406245.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+ffc483dc87891d3c107b@syzkaller.appspotmail.com ================================================================== BUG: KASAN: slab-use-after-free in printer_req_free drivers/usb/gadget/function/f_printer.c:258 [inline] BUG: KASAN: slab-use-after-free in printer_func_unbind+0x2e6/0x6d0 drivers/usb/gadget/function/f_printer.c:1466 Read of size 8 at addr ffff8880742abb18 by task syz.1.167/6184 CPU: 1 UID: 0 PID: 6184 Comm: syz.1.167 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_address_description+0x55/0x1e0 mm/kasan/report.c:378 print_report+0x58/0x70 mm/kasan/report.c:482 kasan_report+0x117/0x150 mm/kasan/report.c:595 printer_req_free drivers/usb/gadget/function/f_printer.c:258 [inline] printer_func_unbind+0x2e6/0x6d0 drivers/usb/gadget/function/f_printer.c:1466 purge_configs_funcs+0x248/0x3d0 drivers/usb/gadget/configfs.c:1600 configfs_composite_unbind+0xa4/0x1c0 drivers/usb/gadget/configfs.c:1846 gadget_unbind_driver+0x1cb/0x410 drivers/usb/gadget/udc/core.c:1725 device_remove drivers/base/dd.c:616 [inline] __device_release_driver drivers/base/dd.c:1349 [inline] device_release_driver_internal+0x48b/0x880 drivers/base/dd.c:1372 driver_detach+0x1f3/0x2d0 drivers/base/dd.c:1435 bus_remove_driver+0x226/0x320 drivers/base/bus.c:840 usb_gadget_unregister_driver+0x4e/0x70 drivers/usb/gadget/udc/core.c:1785 unregister_gadget drivers/usb/gadget/configfs.c:263 [inline] config_usb_cfg_unlink+0x84/0x260 drivers/usb/gadget/configfs.c:502 configfs_unlink+0x44f/0x6b0 fs/configfs/symlink.c:258 vfs_unlink+0x27b/0x6d0 fs/namei.c:5662 filename_unlinkat+0x3cd/0x610 fs/namei.c:5732 __do_sys_unlinkat fs/namei.c:5761 [inline] __se_sys_unlinkat+0x83/0x1a0 fs/namei.c:5753 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f796539e159 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:00007f79635b4028 EFLAGS: 00000246 ORIG_RAX: 0000000000000107 RAX: ffffffffffffffda RBX: 00007f7965626180 RCX: 00007f796539e159 RDX: 0000000000000000 RSI: 0000200000000440 RDI: ffffffffffffff9c RBP: 00007f796543506b R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f7965626218 R14: 00007f7965626180 R15: 00007ffc6fa5e9f8 Allocated by task 5932: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:409 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:426 kasan_kmalloc include/linux/kasan.h:263 [inline] __kmalloc_cache_noprof+0x31c/0x600 mm/slub.c:5680 _kmalloc_noprof include/linux/slab.h:991 [inline] _kzalloc_noprof include/linux/slab.h:1312 [inline] dummy_alloc_request+0x7f/0x130 drivers/usb/gadget/udc/dummy_hcd.c:695 usb_ep_alloc_request+0x67/0x280 drivers/usb/gadget/udc/core.c:198 printer_req_alloc drivers/usb/gadget/function/f_printer.c:240 [inline] printer_func_bind+0x55c/0xbc0 drivers/usb/gadget/function/f_printer.c:1150 usb_add_function+0x2e1/0x9f0 drivers/usb/gadget/composite.c:333 configfs_composite_bind+0xde0/0x1410 drivers/usb/gadget/configfs.c:1802 gadget_bind_driver+0x2ca/0x9e0 drivers/usb/gadget/udc/core.c:1663 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x254/0xae0 drivers/base/dd.c:706 __driver_probe_device+0x1e8/0x360 drivers/base/dd.c:868 driver_probe_device+0x4f/0x240 drivers/base/dd.c:898 __driver_attach+0x339/0x600 drivers/base/dd.c:1292 bus_for_each_dev+0x23b/0x2c0 drivers/base/bus.c:386 bus_add_driver+0x38f/0x6e0 drivers/base/bus.c:771 driver_register+0x23a/0x320 drivers/base/driver.c:174 usb_gadget_register_driver_owner+0xf9/0x270 drivers/usb/gadget/udc/core.c:1753 gadget_dev_desc_UDC_store+0x1c9/0x2f0 drivers/usb/gadget/configfs.c:300 flush_write_buffer fs/configfs/file.c:207 [inline] configfs_write_iter+0x337/0x430 fs/configfs/file.c:229 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x612/0xba0 fs/read_write.c:687 ksys_write+0x150/0x270 fs/read_write.c:739 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 6168: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:264 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:296 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2780 [inline] slab_free mm/slub.c:6630 [inline] kfree+0x1c5/0x650 mm/slub.c:6923 printer_req_free drivers/usb/gadget/function/f_printer.c:259 [inline] printer_func_unbind+0x2fa/0x6d0 drivers/usb/gadget/function/f_printer.c:1466 purge_configs_funcs+0x248/0x3d0 drivers/usb/gadget/configfs.c:1600 configfs_composite_unbind+0xa4/0x1c0 drivers/usb/gadget/configfs.c:1846 gadget_unbind_driver+0x1cb/0x410 drivers/usb/gadget/udc/core.c:1725 device_remove drivers/base/dd.c:616 [inline] __device_release_driver drivers/base/dd.c:1349 [inline] device_release_driver_internal+0x48b/0x880 drivers/base/dd.c:1372 driver_detach+0x1f3/0x2d0 drivers/base/dd.c:1435 bus_remove_driver+0x226/0x320 drivers/base/bus.c:840 usb_gadget_unregister_driver+0x4e/0x70 drivers/usb/gadget/udc/core.c:1785 unregister_gadget drivers/usb/gadget/configfs.c:263 [inline] gadget_dev_desc_UDC_store+0x17a/0x2f0 drivers/usb/gadget/configfs.c:290 flush_write_buffer fs/configfs/file.c:207 [inline] configfs_write_iter+0x337/0x430 fs/configfs/file.c:229 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x612/0xba0 fs/read_write.c:687 ksys_write+0x150/0x270 fs/read_write.c:739 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff8880742abb00 which belongs to the cache kmalloc-128 of size 128 The buggy address is located 24 bytes inside of freed 128-byte region [ffff8880742abb00, ffff8880742abb80) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x742ab flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000000 ffff88813ff24a00 dead000000000122 0000000000000000 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 5932, tgid 5931 (syz.0.63), ts 80748630940 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0x1f9/0x250 mm/page_alloc.c:1854 prep_new_page mm/page_alloc.c:1862 [inline] get_page_from_freelist+0x220f/0x2280 mm/page_alloc.c:3933 __alloc_frozen_pages_noprof+0x1fc/0x400 mm/page_alloc.c:5471 alloc_slab_page mm/slub.c:3384 [inline] allocate_slab+0x7d/0x5e0 mm/slub.c:3499 new_slab mm/slub.c:3550 [inline] refill_objects+0x2d5/0x350 mm/slub.c:7539 refill_sheaf mm/slub.c:2917 [inline] __pcs_replace_empty_main+0x2c8/0x6c0 mm/slub.c:4811 alloc_from_pcs mm/slub.c:4887 [inline] slab_alloc_node mm/slub.c:5021 [inline] __kmalloc_cache_noprof+0x396/0x600 mm/slub.c:5676 _kmalloc_noprof include/linux/slab.h:991 [inline] _kzalloc_noprof include/linux/slab.h:1312 [inline] dummy_alloc_request+0x7f/0x130 drivers/usb/gadget/udc/dummy_hcd.c:695 usb_ep_alloc_request+0x67/0x280 drivers/usb/gadget/udc/core.c:198 printer_req_alloc drivers/usb/gadget/function/f_printer.c:240 [inline] printer_func_bind+0x265/0xbc0 drivers/usb/gadget/function/f_printer.c:1143 usb_add_function+0x2e1/0x9f0 drivers/usb/gadget/composite.c:333 configfs_composite_bind+0xde0/0x1410 drivers/usb/gadget/configfs.c:1802 gadget_bind_driver+0x2ca/0x9e0 drivers/usb/gadget/udc/core.c:1663 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x254/0xae0 drivers/base/dd.c:706 __driver_probe_device+0x1e8/0x360 drivers/base/dd.c:868 driver_probe_device+0x4f/0x240 drivers/base/dd.c:898 page last free pid 16 tgid 16 ts 80343580851 stack trace: reset_page_owner include/linux/page_owner.h:26 [inline] __free_pages_prepare mm/page_alloc.c:1401 [inline] __free_frozen_pages+0xc97/0xd90 mm/page_alloc.c:2952 rcu_do_batch kernel/rcu/tree.c:2650 [inline] rcu_core+0x926/0x1260 kernel/rcu/tree.c:2919 handle_softirqs+0x223/0x840 kernel/softirq.c:645 __do_softirq kernel/softirq.c:679 [inline] invoke_softirq kernel/softirq.c:519 [inline] __irq_exit_rcu+0xcb/0x220 kernel/softirq.c:758 irq_exit_rcu+0x9/0x30 kernel/softirq.c:775 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1062 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 Memory state around the buggy address: ffff8880742aba00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880742aba80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8880742abb00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880742abb80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880742abc00: fa 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 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