From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ot1-f77.google.com (mail-ot1-f77.google.com [209.85.210.77]) (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 897D72F60CC for ; Thu, 25 Jun 2026 19:01:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.77 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782414091; cv=none; b=YzSzt1RUT0VbJWSwvrfTYcx5iZv6aDNRALQO6VwrX2zQYSwNh/2+zLHJBAWcQbURSEJfxb8CxZhvTFGg6jiNGeUFchXtw+rdWynzX32h8exopW9luJmzf5fE65YpkZHYKS5Ebx/9rJEy50btfwbHczsbqXKl9xMYhg023bj1rUs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782414091; c=relaxed/simple; bh=U+9Pg7LZTteB7bGAXe7Wca5uqE0ep9Fab2bsiHj5h6s=; h=MIME-Version:Date:In-Reply-To:Message-ID:Subject:From:To: Content-Type; b=k7R6GqVYAQ3SzbS60h3Y4o6rgaq5N2icF/IBEYY0UmgKP/aos+jdPLsufNFPcKtqz+4TRGChkCfqkM8l3ZBpGhBx/owiLtE42Rahos+VVOZOJfisODQy6CcKMRVV/MwtG8sNjhzenLnYlWPB7MfYWTKweGeOpX2ZQBTgsSbPq9E= 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=209.85.210.77 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-ot1-f77.google.com with SMTP id 46e09a7af769-7e93b1cc222so166264a34.0 for ; Thu, 25 Jun 2026 12:01:29 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1782414088; x=1783018888; h=to:from:subject:message-id:in-reply-to:date:mime-version :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=bPE8wXGKOmWU+LCJGWedkcoAB0MXjj0b/x0uvz98G7M=; b=K22/JAUTBUI9FKw93axXZb8B7QenfNGtvSDT5B79XFA/18T72V0OCzzvLtudXqitg5 BSDfcnpja3FRnj+dJvmiHTe0VCPkPV9ZiknmK+rbODJ5NMBaYXNFXVsc6C3zFdsLyljy 76z6HkZ1W70mogF9ezd8RqJDiNrnbYuFW7oPwb6+yYs2ujw7VqZG6fiKVaqysFVxMxCQ fRwAVGqhkDGV6ElZ67xhV9k1X1UMhvtvUXyqLKVTj1wIljoGyva+uUjKwksMiZpmLL0R zragxIQ1q4M3AWmT7BoemZoPP6Abn82T2zIZYEe4jznSMOWDT7BfIIv05Tb+3jrIyCtU Stiw== X-Forwarded-Encrypted: i=1; AFNElJ//dSDRSVDxFWoaYxKlW81Ze8RdtTGsnDfKT0FnnvIVizXAZ0ub8VEW+o17+mGyMdFHMb7qRdfjdENOTSU=@vger.kernel.org X-Gm-Message-State: AOJu0YwgIJYUf3KX3Yqg4905lnyv7ktCsY1zHaM+jTeP8aDDbD/VLiXB XM8FD7GUt7q0oDLjx3HbionqTDDps+ONhUdsJfRJnfWnppGmhVOj7tyYyPJ9vmtzEI2UFHo42Eu YkRCNYT8xZxPlkMtywbyKrbJLBLMl/G0fV2Xaz2Up+Wknod0auSk1DKZU4rk= Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6820:2222:b0:69e:df26:ad45 with SMTP id 006d021491bc7-6a13525d216mr3047171eaf.43.1782414088306; Thu, 25 Jun 2026 12:01:28 -0700 (PDT) Date: Thu, 25 Jun 2026 12:01:28 -0700 In-Reply-To: <6a1eb319.c1435f33.112120.0156.GAE@google.com> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6a3d7b08.80e5668d.5d0ef.0006.GAE@google.com> Subject: Re: [syzbot] [jfs?] KASAN: slab-use-after-free Write in lmLogSync From: syzbot To: jfs-discussion@lists.sourceforge.net, jie.wang@intel.com, linux-kernel@vger.kernel.org, shaggy@kernel.org, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" syzbot has found a reproducer for the following issue on: HEAD commit: ab9de95c9cf9 Merge tag 'rust-7.2-2' of git://git.kernel.or.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=11e27046580000 kernel config: https://syzkaller.appspot.com/x/.config?x=86ba763b42fa66a dashboard link: https://syzkaller.appspot.com/bug?extid=ea7ed3bb2f444cb4dfeb compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=109b430e580000 Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/c16df342a923/disk-ab9de95c.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/ddf00a828178/vmlinux-ab9de95c.xz kernel image: https://storage.googleapis.com/syzbot-assets/f468c716a7be/bzImage-ab9de95c.xz mounted in repro: https://storage.googleapis.com/syzbot-assets/410234fc5bd7/mount_0.gz fsck result: failed (log: https://syzkaller.appspot.com/x/fsck.log?x=13bc540a580000) IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+ea7ed3bb2f444cb4dfeb@syzkaller.appspotmail.com ... Log Wrap ... Log Wrap ... Log Wrap ... ================================================================== BUG: KASAN: slab-use-after-free in lmLogSync+0x9a5/0xa40 fs/jfs/jfs_logmgr.c:1003 Write of size 4 at addr ffff888078b39a18 by task jfsCommit/119 CPU: 1 UID: 0 PID: 119 Comm: jfsCommit Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 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 lmLogSync+0x9a5/0xa40 fs/jfs/jfs_logmgr.c:1003 jfs_syncpt+0x7b/0x90 fs/jfs/jfs_logmgr.c:1039 txEnd+0x2e5/0x530 fs/jfs/jfs_txnmgr.c:551 txLazyCommit fs/jfs/jfs_txnmgr.c:2686 [inline] jfs_lazycommit+0x5d6/0xac0 fs/jfs/jfs_txnmgr.c:2735 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 6176: 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:398 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __kmalloc_cache_noprof+0x32d/0x660 mm/slub.c:5515 _kmalloc_noprof include/linux/slab.h:969 [inline] _kzalloc_noprof include/linux/slab.h:1290 [inline] open_inline_log fs/jfs/jfs_logmgr.c:1157 [inline] lmLogOpen+0x2d1/0xf90 fs/jfs/jfs_logmgr.c:1067 jfs_mount_rw+0xf3/0x670 fs/jfs/jfs_mount.c:257 jfs_fill_super+0x769/0xda0 fs/jfs/super.c:533 get_tree_bdev_flags+0x430/0x4f0 fs/super.c:1634 vfs_get_tree+0x92/0x2a0 fs/super.c:1694 fc_mount fs/namespace.c:1198 [inline] do_new_mount_fc fs/namespace.c:3765 [inline] do_new_mount+0x319/0xdc0 fs/namespace.c:3841 do_mount fs/namespace.c:4174 [inline] __do_sys_mount fs/namespace.c:4390 [inline] __se_sys_mount+0x31d/0x420 fs/namespace.c:4367 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 5770: 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] kfree+0x1c5/0x640 mm/slub.c:6720 lmLogClose+0x296/0x530 fs/jfs/jfs_logmgr.c:-1 jfs_umount+0x2da/0x3b0 fs/jfs/jfs_umount.c:124 jfs_put_super+0x8c/0x190 fs/jfs/super.c:194 generic_shutdown_super+0x13d/0x2d0 fs/super.c:647 kill_block_super+0x44/0x90 fs/super.c:1665 deactivate_locked_super+0xbc/0x130 fs/super.c:477 cleanup_mnt+0x3d3/0x460 fs/namespace.c:1317 task_work_run+0x1d9/0x270 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:70 [inline] exit_to_user_mode_loop+0x1fa/0x730 kernel/entry/common.c:101 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline] do_syscall_64+0x353/0x580 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff888078b39800 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 536 bytes inside of freed 1024-byte region [ffff888078b39800, ffff888078b39c00) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x78b38 head: order:3 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 ffff88813fe25dc0 dead000000000100 dead000000000122 raw: 0000000000000000 0000000800100010 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88813fe25dc0 dead000000000100 dead000000000122 head: 0000000000000000 0000000800100010 00000000f5000000 0000000000000000 head: 00fff00000000003 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 Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 6055, tgid 6055 (kworker/u8:2), ts 107606662230, free_ts 107579789139 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] __do_kmalloc_node mm/slub.c:5361 [inline] __kmalloc_noprof+0x485/0x720 mm/slub.c:5387 _kmalloc_noprof include/linux/slab.h:973 [inline] load_elf_phdrs fs/binfmt_elf.c:540 [inline] load_elf_binary+0x2c3/0x2950 fs/binfmt_elf.c:869 search_binary_handler fs/exec.c:1694 [inline] exec_binprm fs/exec.c:1726 [inline] bprm_execve+0x9c7/0x1630 fs/exec.c:1778 kernel_execve+0x8c3/0x9c0 fs/exec.c:1922 call_usermodehelper_exec_async+0x20f/0x360 kernel/umh.c:109 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 page last free pid 4986 tgid 4986 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1406 [inline] __free_frozen_pages+0xc1e/0xd10 mm/page_alloc.c:2950 __slab_free+0x274/0x2c0 mm/slub.c:5767 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x99/0x100 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350 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_noprof+0x2a0/0x5f0 mm/slub.c:4959 alloc_filename fs/namei.c:147 [inline] do_getname+0x2e/0x250 fs/namei.c:187 class_filename_flags_constructor include/linux/fs.h:2561 [inline] do_readlinkat+0xc8/0x510 fs/stat.c:569 __do_sys_readlink fs/stat.c:605 [inline] __se_sys_readlink fs/stat.c:602 [inline] __x64_sys_readlink+0x7f/0x90 fs/stat.c:602 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 Memory state around the buggy address: ffff888078b39900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888078b39980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888078b39a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888078b39a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888078b39b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== --- 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.