From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-io1-f70.google.com (mail-io1-f70.google.com [209.85.166.70]) (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 3F514199FB2 for ; Thu, 20 Nov 2025 01:27:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.166.70 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763602025; cv=none; b=oAoyCf/Uq1pio4LpbVZAuKIgjT+c9L5nYtlqaht8eSpLbCMLJY7ssdlUo6qEdQSIZ3FJE+yWSU0r9FqyeJWMUpbjy66fv5zNQ7/gA21VoSTBwGxkueNA0VV7CT8jHY/IITun2oGZj3Fifte3yaX9StMjxWF9ljA/G1gF7Jpi2RU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763602025; c=relaxed/simple; bh=YdauHc7NQ3WqhBALQ0DsMhcMQWnShiYMvZWhOuuEVYM=; h=MIME-Version:Date:In-Reply-To:Message-ID:Subject:From:To: Content-Type; b=TAG8/QyOsEAqf/6cFAf3HlRCwpvqAm8ZkWM5tNjwrBRmv7GvkjRn3pC/nFdsCrcveSASzD563Yo83Z2/HQVUolJ8uqYjQaOgcKZU3O3u5FJRQHhpadMcvyOsppkNTn2Ek8rT9HTyu8MNhZZ7OMDslPdEaRC4qed0bJYjE2BJNt0= 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=209.85.166.70 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-io1-f70.google.com with SMTP id ca18e2360f4ac-948f6c90813so30023939f.3 for ; Wed, 19 Nov 2025 17:27:04 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1763602023; x=1764206823; 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=kXnO9go1Tx3VdlP7bqKZreQoI1FCcYo2DJc1QYWpjGY=; b=QAuo+6qRdDAPC7T8qBo0pDPXZa/SO/alTg9rXBIUDWgVO1gpauzGtbKeVz0Lg31oYS nnaIa5gJMjFPrS/um8f+KBLI113sYHttqgHcwVOpy7IX4C7z1sFSHpNk7Q1BQSeRqKZq zjmRL1wGg+8e3zZQewj1CFx3/7cDHWXN9mEjafpLloKU72mfhl8jYSvrzYj8bOyHqBt5 A3xrDRYqd66WKzGujCtsl2HgatCyEVFUqTnyqyi3ZW1qyIkgr5xz/TBiVgwWWgYUlQjC 78v6wATC3w64Hfzt4cZno9m6V4S1Pjc/+XOY6Mr24jfpiYSGI9qSo9NQ8aKiMpmxByCs gjEg== X-Forwarded-Encrypted: i=1; AJvYcCVkdzsJtCMzMoipyI6chzG3qfONIH7whJwA7WNr2r6Gk1rJYALkvJC90C9z4EllcRg1LgHRwXOH/LkuWus=@vger.kernel.org X-Gm-Message-State: AOJu0Yz3A43mE5IWzanSxBiB5pp76WbaOhG2utHcEllt8CqIUIFrrjoS +V9PHOxAHfTLl4CW6O2M+n1Y6NmJej8mf5DrbGoyFaWsrYUehdmIM/qYwCu2cgvRdkOutef3+th s3RvGoOHYbkgVrJX5Ttnk1/5j8gyHpFealLcVOo4mAkeQ5Bh/edUkvbVrGao= X-Google-Smtp-Source: AGHT+IFb2eNj2HB6lWYNZo8U9CtFznoeJCc5PmDrTHy3GotiQ/cOlfWj7GhMi6ekgTD9njaSPrNuI5H7HzqczCW3XFg11esOJGe8 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6e02:164d:b0:433:7d37:38ea with SMTP id e9e14a558f8ab-435a9e077ccmr8726315ab.24.1763602023398; Wed, 19 Nov 2025 17:27:03 -0800 (PST) Date: Wed, 19 Nov 2025 17:27:03 -0800 In-Reply-To: X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <691e6e67.a70a0220.d98e3.0023.GAE@google.com> Subject: Re: [syzbot] [ext4?] KASAN: use-after-free Read in ext4_find_extent (4) From: syzbot To: eraykrdg1@gmail.com, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" Hello, syzbot has tested the proposed patch but the reproducer is still triggering an issue: KASAN: use-after-free Read in ext4_find_extent ================================================================== BUG: KASAN: use-after-free in ext4_ext_binsearch fs/ext4/extents.c:841 [inline] BUG: KASAN: use-after-free in ext4_find_extent+0xae6/0xcc0 fs/ext4/extents.c:956 Read of size 4 at addr ffff888060ccb018 by task kworker/u8:0/12 CPU: 0 UID: 0 PID: 12 Comm: kworker/u8:0 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: ext4-rsv-conversion ext4_end_io_rsv_work Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xca/0x240 mm/kasan/report.c:482 kasan_report+0x118/0x150 mm/kasan/report.c:595 ext4_ext_binsearch fs/ext4/extents.c:841 [inline] ext4_find_extent+0xae6/0xcc0 fs/ext4/extents.c:956 ext4_ext_map_blocks+0x288/0x6ac0 fs/ext4/extents.c:4208 ext4_map_create_blocks fs/ext4/inode.c:609 [inline] ext4_map_blocks+0x860/0x1740 fs/ext4/inode.c:811 ext4_convert_unwritten_extents+0x2ae/0x5d0 fs/ext4/extents.c:4976 ext4_convert_unwritten_io_end_vec+0xff/0x170 fs/ext4/extents.c:5016 ext4_end_io_end+0xc7/0x410 fs/ext4/page-io.c:199 ext4_do_flush_completed_IO fs/ext4/page-io.c:290 [inline] ext4_end_io_rsv_work+0x262/0x330 fs/ext4/page-io.c:305 process_one_work kernel/workqueue.c:3263 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 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 physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x60ccb flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000000 dead000000000100 dead000000000122 0000000000000000 raw: 0000000000000001 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as freed page last allocated via order 0, migratetype Movable, gfp_mask 0x148c48(GFP_NOFS|__GFP_MOVABLE|__GFP_NOFAIL|__GFP_COMP|__GFP_HARDWALL), pid 10925, tgid 10924 (syz.0.1091), ts 292203567761, free_ts 292265476069 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x234/0x290 mm/page_alloc.c:1845 prep_new_page mm/page_alloc.c:1853 [inline] get_page_from_freelist+0x2356/0x2430 mm/page_alloc.c:3879 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5178 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2416 alloc_frozen_pages_noprof mm/mempolicy.c:2487 [inline] alloc_pages_noprof+0xa9/0x190 mm/mempolicy.c:2507 folio_alloc_noprof+0x1e/0x30 mm/mempolicy.c:2517 filemap_alloc_folio_noprof+0xdf/0x470 mm/filemap.c:1020 __filemap_get_folio+0x3f2/0xaf0 mm/filemap.c:2012 grow_dev_folio fs/buffer.c:1050 [inline] grow_buffers fs/buffer.c:1116 [inline] __getblk_slow fs/buffer.c:1134 [inline] bdev_getblk+0x1ad/0x660 fs/buffer.c:1461 __getblk include/linux/buffer_head.h:380 [inline] sb_getblk include/linux/buffer_head.h:386 [inline] __ext4_get_inode_loc+0x561/0x1040 fs/ext4/inode.c:4837 __ext4_get_inode_loc_noinmem fs/ext4/inode.c:4950 [inline] __ext4_iget+0x451/0x4220 fs/ext4/inode.c:5225 __ext4_fill_super fs/ext4/super.c:5512 [inline] ext4_fill_super+0x4637/0x61e0 fs/ext4/super.c:5736 get_tree_bdev_flags+0x40e/0x4d0 fs/super.c:1698 vfs_get_tree+0x92/0x2b0 fs/super.c:1758 fc_mount fs/namespace.c:1199 [inline] do_new_mount_fc fs/namespace.c:3642 [inline] do_new_mount+0x302/0xa10 fs/namespace.c:3718 do_mount fs/namespace.c:4041 [inline] __do_sys_mount fs/namespace.c:4229 [inline] __se_sys_mount+0x313/0x410 fs/namespace.c:4206 page last free pid 8941 tgid 8941 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1394 [inline] free_unref_folios+0xe5d/0x15f0 mm/page_alloc.c:2958 folios_put_refs+0x584/0x670 mm/swap.c:1002 folio_batch_release include/linux/pagevec.h:101 [inline] mapping_try_invalidate+0x324/0x410 mm/truncate.c:579 ext4_put_super+0x813/0xc40 fs/ext4/super.c:1348 generic_shutdown_super+0x135/0x2c0 fs/super.c:642 kill_block_super+0x44/0x90 fs/super.c:1729 ext4_kill_sb+0x68/0xb0 fs/ext4/super.c:7403 deactivate_locked_super+0xbc/0x130 fs/super.c:473 cleanup_mnt+0x425/0x4c0 fs/namespace.c:1318 task_work_run+0x1d4/0x260 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop+0xe9/0x130 kernel/entry/common.c:43 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x2bd/0xfa0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff888060ccaf00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff888060ccaf80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff888060ccb000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff888060ccb080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff888060ccb100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ================================================================== Tested on: commit: 23cb64fb Merge tag 'soc-fixes-6.18-3' of git://git.ker.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=128cba12580000 kernel config: https://syzkaller.appspot.com/x/.config?x=6e611fe59206f39f dashboard link: https://syzkaller.appspot.com/bug?extid=ee60e584b5c6bb229126 compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8 patch: https://syzkaller.appspot.com/x/patch.diff?x=14657692580000