From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oa1-f79.google.com (mail-oa1-f79.google.com [209.85.160.79]) (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 97829175A9D for ; Mon, 13 Jul 2026 01:04:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.160.79 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783904674; cv=none; b=oDQzfmKSdzel+Q4cyIXYSb+46bRs7eYaw9v0msQzFwX6zkSdxaxgUcJlVRH25p1cLxlCV3WvS4eAhPF+oUQmWSDrA6ptiSXUMqLpfLa3AOjWYuuHisiXnEYDQAUDW/kHob2qplDU0CbxfOw2j4/AO0TWyGvt/6xerknm6OHXw4I= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783904674; c=relaxed/simple; bh=YbEmnHMtVlQ2AY06n1jytrK/bLvHqW1Oe9+OanWghx8=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=CxaMAokj4O050AP+8KmXAL+HMZkHKTyzFDcTqZPKD0NGuK9ZMJDWGW4zyF/bsxievE0vRgj/35t8qenElC6DL27MIvSIMPIbwIa52aULDKnfW69ZxKtnsvEYXqPkXfaV3NGqHWYakTt7EbnDiD7+h7FDN/pc6xXCv1+Qhf+nGpI= 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=209.85.160.79 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-oa1-f79.google.com with SMTP id 586e51a60fabf-451acf33124so1497065fac.0 for ; Sun, 12 Jul 2026 18:04:32 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1783904671; x=1784509471; 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=6+U7PyFX1Kqit0bR8s7WERf65H1Kv5zCzUrqfobcgqc=; b=WO8Ge5JJYzTLHoZ/qcuTDLBfbGW4j9pnSlV7sIXzZUC2DAg9Eip1B3Za3Ipu4aukyg Sq5KZ8DPqo29TNh/Koo8suzD9dkgJMoeHK2UDoDBCknICNTewJ9Oq6a/J1FNXv2cKoYQ 0o6hG5P4YWsVwuXii9PexpitIl9o7fvai/aFmqr6MYMzcTb9f585x7PK6HuMskRZ8cM1 0L7lCJz2L/JQ4uzaF+GHGKykvpwS+3PuKVabmTI4j8Z7HHO+jv7hG2Kc4F1oLv74hWyV JKEPP7y2wkx/939/wdIB5M3iKDiN0fRH0Z5T7PXlMj0ta9Pw2gp2NXRmnqDhYFPtyL9r YPJA== X-Forwarded-Encrypted: i=1; AFNElJ9QaOlR8XeDYofBCx7JYI2FGpF+AvQV0UJ2Ngt1yug7OenENXeeJwhS0ISe0FcAWEPHxnZu8Kknz2KwBw==@vger.kernel.org X-Gm-Message-State: AOJu0YyjeGP6Dv1VbvVY14xdY/HZtB3pxJxOcLGtg8ZlFma0+E4hIPLt O7LZOH9pE0am3NVsHnTG4UJmR/9B1s98iATcpmEO57mQ9ukGk4At0hBpdBjwAAWPD8/LNAg8fRw Fg3EGwiqqlOmFto1P7X1nHnz3fy2uctqENtWuKYzTep4MJQ3acPSTurSCMnc= Precedence: bulk X-Mailing-List: linux-block@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6808:1b2c:b0:495:f79d:b08e with SMTP id 5614622812f47-4a42ae80d43mr4664082b6e.21.1783904671685; Sun, 12 Jul 2026 18:04:31 -0700 (PDT) Date: Sun, 12 Jul 2026 18:04:31 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6a54399f.278cdcd2.e885.0023.GAE@google.com> Subject: [syzbot] [block?] KASAN: slab-use-after-free Read in update_io_ticks (5) From: syzbot To: axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: 0e35b9b6ec0f Merge tag 'mm-hotfixes-stable-2026-07-06-17-4.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=17ba0f39580000 kernel config: https://syzkaller.appspot.com/x/.config?x=20c9876b0f77b546 dashboard link: https://syzkaller.appspot.com/bug?extid=8be85719817f5c3d8a9d 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 (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-0e35b9b6.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/2a17ca6db8f5/vmlinux-0e35b9b6.xz kernel image: https://storage.googleapis.com/syzbot-assets/c885024dccba/bzImage-0e35b9b6.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+8be85719817f5c3d8a9d@syzkaller.appspotmail.com ================================================================== BUG: KASAN: slab-use-after-free in update_io_ticks+0xa9/0x280 block/blk-core.c:1064 Read of size 8 at addr ffff88803236b9a8 by task kworker/u4:6/176 CPU: 0 UID: 0 PID: 176 Comm: kworker/u4:6 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 Workqueue: loop0 loop_rootcg_workfn 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 update_io_ticks+0xa9/0x280 block/blk-core.c:1064 blk_account_io_done+0x188/0x870 block/blk-mq.c:1082 __blk_mq_end_request_acct block/blk-mq.c:1125 [inline] __blk_mq_end_request+0x2cf/0x6c0 block/blk-mq.c:1131 lo_rw_aio_complete drivers/block/loop.c:337 [inline] lo_rw_aio+0xcd4/0xf20 drivers/block/loop.c:405 do_req_filebacked drivers/block/loop.c:431 [inline] loop_handle_cmd drivers/block/loop.c:1921 [inline] loop_process_work+0x95e/0x11c0 drivers/block/loop.c:1956 process_one_work kernel/workqueue.c:3322 [inline] process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 5324: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 unpoison_slab_object mm/kasan/common.c:340 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4612 [inline] slab_alloc_node mm/slub.c:4945 [inline] kmem_cache_alloc_lru_noprof+0x2aa/0x5f0 mm/slub.c:4978 bdev_alloc_inode+0x29/0x90 block/bdev.c:380 alloc_inode+0x6a/0x1b0 fs/inode.c:338 new_inode+0x1f/0x170 fs/inode.c:1174 bdev_alloc+0x24/0x370 block/bdev.c:464 add_partition+0x1c3/0x8e0 block/partitions/core.c:328 blk_add_partition block/partitions/core.c:566 [inline] blk_add_partitions block/partitions/core.c:635 [inline] bdev_disk_changed+0xc3e/0x17a0 block/partitions/core.c:695 loop_reread_partitions drivers/block/loop.c:443 [inline] loop_set_status+0x9f7/0xd50 drivers/block/loop.c:1272 loop_set_status64 drivers/block/loop.c:1368 [inline] lo_ioctl+0xc14/0x1fc0 drivers/block/loop.c:1554 blkdev_ioctl+0x5e3/0x740 block/ioctl.c:797 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 5287: 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:253 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2705 [inline] slab_free mm/slub.c:6405 [inline] kmem_cache_free+0x182/0x650 mm/slub.c:6532 rcu_do_batch kernel/rcu/tree.c:2645 [inline] rcu_core+0x78b/0x10a0 kernel/rcu/tree.c:2897 handle_softirqs+0x225/0x840 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0xca/0x220 kernel/softirq.c:735 irq_exit_rcu+0x9/0x30 kernel/softirq.c:752 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 Last potentially related work creation: kasan_save_stack+0x3e/0x60 mm/kasan/common.c:57 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556 __call_rcu_common kernel/rcu/tree.c:3159 [inline] call_rcu+0xee/0x8b0 kernel/rcu/tree.c:3279 destroy_inode fs/inode.c:392 [inline] evict+0x987/0xb50 fs/inode.c:849 device_release+0xc4/0x1f0 drivers/base/core.c:-1 kobject_cleanup lib/kobject.c:689 [inline] kobject_release lib/kobject.c:720 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x222/0x550 lib/kobject.c:737 blkdev_release+0x15/0x20 block/fops.c:680 __fput+0x418/0xa50 fs/file_table.c:512 fput_close_sync+0x11f/0x240 fs/file_table.c:617 __do_sys_close fs/open.c:1511 [inline] __se_sys_close fs/open.c:1496 [inline] __x64_sys_close+0x7e/0x110 fs/open.c:1496 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88803236b980 which belongs to the cache bdev_cache of size 2792 The buggy address is located 40 bytes inside of freed 2792-byte region [ffff88803236b980, ffff88803236c468) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x32368 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 memcg:ffff888040428e81 flags: 0x4fff00000000040(head|node=1|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 04fff00000000040 ffff88801ca81140 dead000000000122 0000000000000000 raw: 0000000000000000 00000008000b000b 00000000f5000000 ffff888040428e81 head: 04fff00000000040 ffff88801ca81140 dead000000000122 0000000000000000 head: 0000000000000000 00000008000b000b 00000000f5000000 ffff888040428e81 head: 04fff00000000003 fffffffffffffe01 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Reclaimable, gfp_mask 0xd20d0(__GFP_RECLAIMABLE|__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1, tgid 1 (swapper/0), ts 19037798701, free_ts 0 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f9/0x250 mm/page_alloc.c:1859 prep_new_page mm/page_alloc.c:1867 [inline] get_page_from_freelist+0x21fa/0x2270 mm/page_alloc.c:3946 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5304 alloc_slab_page mm/slub.c:3294 [inline] allocate_slab+0x79/0x5e0 mm/slub.c:3408 new_slab mm/slub.c:3454 [inline] refill_objects+0x2d5/0x350 mm/slub.c:7338 refill_sheaf mm/slub.c:2832 [inline] __pcs_replace_empty_main+0x2bf/0x6b0 mm/slub.c:4703 alloc_from_pcs mm/slub.c:4801 [inline] slab_alloc_node mm/slub.c:4933 [inline] kmem_cache_alloc_lru_noprof+0x389/0x5f0 mm/slub.c:4978 bdev_alloc_inode+0x29/0x90 block/bdev.c:380 alloc_inode+0x6a/0x1b0 fs/inode.c:338 new_inode+0x1f/0x170 fs/inode.c:1174 bdev_alloc+0x24/0x370 block/bdev.c:464 __alloc_disk_node+0x11f/0x600 block/genhd.c:1465 __blk_alloc_disk+0x105/0x1d0 block/genhd.c:1523 pmem_attach_disk+0x4d9/0xe10 drivers/nvdimm/pmem.c:509 nvdimm_bus_probe+0x332/0x6c0 drivers/nvdimm/bus.c:91 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x254/0xae0 drivers/base/dd.c:706 page_owner free stack trace missing Memory state around the buggy address: ffff88803236b880: 00 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc ffff88803236b900: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88803236b980: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88803236ba00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88803236ba80: 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 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