From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oi2-f11.google.com (mail-oi2-f11.google.com [74.125.231.203]) (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 83FA4125A0 for ; Sun, 20 Sep 2026 00:28:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=74.125.231.203 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789864119; cv=none; b=TTjJ2T8oQ2ykyxXxE/Izf9CzHFBb9vGpg5XGFZYnHnJDCiO64sppAApEPCr/zNNp5GDijk6jgJgmypVbwLYQ2V11eIYn21jqX4RNWJm7ZKZikn1pMN0t5G4N068Awie9tsEKMxFmZSMaSlg+AZDDFK70g7FHtchDIWfpST5B4x4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789864119; c=relaxed/simple; bh=J85FaY8hAWBjhygK/XgUN89yhwVad/Lz+KB4pdXzSjY=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=Gqx+uADag7r8yaOseHrP4DE1cSwv2kbt3F4Yy21rKcrYDgZeC1Jv/VhZEPkKQk+PMbQkFRy5fjdECcKPz+0W4s0W7d8OipxyaxSQffZ3/AsiGnLkDSVL9ryGqQW2aQNJKjKXLNnf9iUp3bI/UUsJtTcFyScC5OE/VYVVmYZvn88= 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=74.125.231.203 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-oi2-f11.google.com with SMTP id 5614622812f47-4bfec71901fso955616b6e.1 for ; Sat, 19 Sep 2026 17:28:37 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1789864116; x=1790468916; 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=2ReM82aEcRwh1FAqo17hhPk/qhH0GNuuHIChn6NhnZg=; b=LBtb82Zw+oG4rtmQ5iCa9Mpy0xeTsLZYI1yc3UFCTHkOuNbHBmQpCDfuFrznQAXxRQ z+fx8Jr1hN+DA0fjszjj4fcLvRdkm1/oC07XYLY7bDkKvj9CKnotGGAj33KezC9GHjaA OAb6Ta2UExQsbayC9/0DrK64NtDyrkQKx6GzT99GgnT5P4sNGPYg4YxINvOTBzdoJIVr 8jpV3rO3NIXQFqOisf8Vbx5FdrDO/7h1rpyFUFmhVidsaj4+WJauqWAEg73FTTOd5Qw6 hHF7/Ilk0PpkJxJ0lcRQc+51HwqYEmyC55U2M6VSlfjWpxvgA6isnjhGJxCQ4TLERe5a pmQw== X-Forwarded-Encrypted: i=1; AKwUvByA6GzFXPLYFXRhTM9hSvm+xbHCiAlz0wsIy2IuTQO4tCi2YoQ+1orXV55kKIpzAJo4zT8G6Pchq2CAPpA=@vger.kernel.org X-Gm-Message-State: AFuF++myp7/u6+rYd2HU7QGJxyL/yZAlxivByLMNsqJ1LHsWw8CprXy/ dqhBTdMicPAh18GMoMZHdKBDzNeyBTWpCTevCCc5mFqbkwDkFO4evaAIqxnPx1CNh3aPFevTHAT y5X9pb1pLxLo754pIWdPIErMqmMoyUGddZCiCxRuQNZzhXzMWo+U21SwAeP8= Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6820:1f11:b0:6b7:83d6:2935 with SMTP id 006d021491bc7-6ca9d14501dmr6425675eaf.56.1789864116376; Sat, 19 Sep 2026 17:28:36 -0700 (PDT) Date: Sat, 19 Sep 2026 17:28:36 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6aaf28b4.71f81b7d.15fa6d.000e.GAE@google.com> Subject: [syzbot] [nvme?] KASAN: slab-use-after-free Read in fcloop_t2h_xmt_ls_rsp From: syzbot To: hch@lst.de, justin.tee@broadcom.com, kch@nvidia.com, linux-kernel@vger.kernel.org, linux-nvme@lists.infradead.org, nareshgottumukkala83@gmail.com, paul.ely@broadcom.com, sagi@grimberg.me, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: 50d05c7c76c9 Merge tag 'landlock-7.3-rc3' of git://git.ker.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=16386115580000 kernel config: https://syzkaller.appspot.com/x/.config?x=85bc5cc2fc7394d9 dashboard link: https://syzkaller.appspot.com/bug?extid=2a31ef5d37a9d722e987 compiler: gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44 userspace arch: i386 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-50d05c7c.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/303a0ade8f9e/vmlinux-50d05c7c.xz kernel image: https://storage.googleapis.com/syzbot-assets/70b8ca71442b/bzImage-50d05c7c.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+2a31ef5d37a9d722e987@syzkaller.appspotmail.com (NULL device *): Disconnect LS failed: No Association ================================================================== BUG: KASAN: slab-use-after-free in fcloop_t2h_xmt_ls_rsp+0x393/0x460 drivers/nvme/target/fcloop.c:518 Read of size 4 at addr ffff8880237d2228 by task kworker/1:4/5844 CPU: 1 UID: 0 PID: 5844 Comm: kworker/1:4 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 Workqueue: events nvme_fc_handle_ls_rqst_work Call Trace: __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 fcloop_t2h_xmt_ls_rsp+0x393/0x460 drivers/nvme/target/fcloop.c:518 nvme_fc_xmt_ls_rsp+0x1bd/0x270 drivers/nvme/host/fc.c:1456 nvme_fc_handle_ls_rqst_work+0x43c/0x2100 drivers/nvme/host/fc.c:1660 process_one_work+0xac7/0x1b10 kernel/workqueue.c:3396 process_scheduled_works kernel/workqueue.c:3479 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3560 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 Allocated by task 8325: 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] _kzalloc_noprof include/linux/slab.h:1312 [inline] nvmet_fc_xmt_disconnect_assoc drivers/nvme/target/fc.c:489 [inline] nvmet_fc_target_assoc_free+0xbd5/0x2220 drivers/nvme/target/fc.c:1177 kref_put include/linux/kref.h:65 [inline] nvmet_fc_tgt_a_put drivers/nvme/target/fc.c:1195 [inline] nvmet_fc_delete_assoc_work.cold+0x118/0x144 drivers/nvme/target/fc.c:1068 process_one_work+0xac7/0x1b10 kernel/workqueue.c:3396 process_scheduled_works kernel/workqueue.c:3479 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3560 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 17245: 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 nvmet_fc_free_pending_reqs drivers/nvme/target/fc.c:1619 [inline] nvmet_fc_unregister_targetport+0x351/0x760 drivers/nvme/target/fc.c:1651 __targetport_unreg drivers/nvme/target/fcloop.c:1600 [inline] fcloop_delete_target_port+0x185/0x1f0 drivers/nvme/target/fcloop.c:1630 dev_attr_store+0x58/0x80 drivers/base/core.c:2509 sysfs_kf_write+0xf2/0x150 fs/sysfs/file.c:145 kernfs_fop_write_iter+0x3e0/0x5f0 fs/kernfs/file.c:345 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x6af/0x1050 fs/read_write.c:687 ksys_write+0x12a/0x250 fs/read_write.c:739 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:79 [inline] __do_fast_syscall_32+0x13a/0x8b0 arch/x86/entry/syscall_32.c:291 do_fast_syscall_32+0x32/0x70 arch/x86/entry/syscall_32.c:316 entry_SYSENTER_compat_after_hwframe+0x84/0x8e The buggy address belongs to the object at ffff8880237d2200 which belongs to the cache kmalloc-256 of size 256 The buggy address is located 40 bytes inside of freed 256-byte region [ffff8880237d2200, ffff8880237d2300) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x237d2 head: order:1 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88801c042b40 dead000000000100 dead000000000122 raw: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88801c042b40 dead000000000100 dead000000000122 head: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 00fff00000000001 ffffffffffffff81 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000002 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 1, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5746, tgid 5746 (syz-executor), ts 39099710655 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/0x35d0 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] ____ip_mc_inc_group+0x40b/0x10d0 net/ipv4/igmp.c:1601 __ip_mc_inc_group net/ipv4/igmp.c:1639 [inline] ip_mc_inc_group net/ipv4/igmp.c:1645 [inline] ip_mc_up+0x154/0x390 net/ipv4/igmp.c:1950 inetdev_event+0x6f0/0x17f0 net/ipv4/devinet.c:1630 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] __dev_notify_flags+0x22c/0x4b0 net/core/dev.c:9853 netif_change_flags+0x108/0x160 net/core/dev.c:9882 do_setlink.isra.0+0x1ac4/0x3e60 net/core/rtnetlink.c:3266 rtnl_changelink net/core/rtnetlink.c:3905 [inline] __rtnl_newlink net/core/rtnetlink.c:4076 [inline] rtnl_newlink+0x13c1/0x2620 net/core/rtnetlink.c:4215 page last free pid 5151 tgid 5151 ts 10778201277 stack trace: reset_page_owner include/linux/page_owner.h:26 [inline] __free_pages_prepare mm/page_alloc.c:1418 [inline] __free_frozen_pages+0x79f/0x10f0 mm/page_alloc.c:2962 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x47/0xf0 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x1a0/0x1f0 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:350 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4683 [inline] slab_alloc_node mm/slub.c:4996 [inline] kmem_cache_alloc_noprof+0x269/0x6a0 mm/slub.c:5010 alloc_filename fs/namei.c:147 [inline] do_getname+0x35/0x390 fs/namei.c:187 class_filename_flags_constructor include/linux/fs.h:2586 [inline] do_readlinkat+0xa9/0x370 fs/stat.c:569 __do_sys_readlink fs/stat.c:605 [inline] __se_sys_readlink fs/stat.c:602 [inline] __x64_sys_readlink+0x78/0xc0 fs/stat.c:602 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x121/0x770 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff8880237d2100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880237d2180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8880237d2200: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880237d2280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880237d2300: fc fc fc fc fc fc fc fc 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 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