From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-io1-f77.google.com (mail-io1-f77.google.com [209.85.166.77]) (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 B4EF334D3A9 for ; Sat, 8 Nov 2025 13:32:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.166.77 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762608750; cv=none; b=diBmb5nSupewb8ZYeZpTCTvDeqepSmgOA9873UsGwzasuhHlO8tnIZlFXO39a+FLylrRlAGtW0hdylFe90zNf+8moiJS8WFTn+Ch0SBGRyDUns+RQaLZ5MWYtAOiDy4aSkJoXW/6py/t/oCd1kZ5rpqzgiiwgBANsBCtSTOMyKE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762608750; c=relaxed/simple; bh=tvyPpx2oKJCgMZ0OCvlfNSNK2yNzIZpotW4gFJ2ZgAA=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=kKU7ko/EQzelp0HIy+frqMsNV7qB3gjE6FB2MXb9NPBat8O9/V8enC8SEKPzYIT+wlwLtIbmUPd+T13mJXA2ahFaQmL3jZO4YB03i4bUyF6phGXG5ySEzQGLd+TnsyZXli7d9dAu24Ht5Mk26vsknKhaig1zMtqU4Ag27TdBjZM= 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=209.85.166.77 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-io1-f77.google.com with SMTP id ca18e2360f4ac-937e5f9ea74so189436639f.1 for ; Sat, 08 Nov 2025 05:32:28 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1762608748; x=1763213548; h=to:from:subject:message-id:date:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=hrV43ErWe+VCsj3PED4WP6R1zksVrZQcOrd5/ODDNBY=; b=E0C4KEIwCGIPx2cQITt7FcKdG0t8UrfN6D+nPs9wWr3I/caWy1MzPs47uOwfkdxfq9 SOb+nQh1eg7Mtrgc3gLMlqCYQA2NbVqNc5F0rQ5Ew7yiZk0o4dCVZdnMCmlz1X39wMU6 Gn1N+9kaux1FgSRoBGEUeiG5ZBo9O0WFrUuB6QwU/rRHdRc9tqlDoglCEu3jKQEv3Zve t2F9Yx+t2YTjA/w/o49YZ+7rdquaH6DSCNrWqt7BuYSrmBt5KXqnxLIva5nFWYWb1MK7 vsIoDhHkkw000KqhwqoeN1XwITGjlYPOI7AErr3zWLYyNubSFrwTg1/Op36Cve12Sc+K LI8A== X-Forwarded-Encrypted: i=1; AJvYcCWCXcQ29rKCviWjGQv9FYOIBj1jVpBaFQNQ9z9crksUCJ4B1WMK65cdD/S4oJo7wlvbZOxVGhpS91Gmh0I=@vger.kernel.org X-Gm-Message-State: AOJu0YxLtFEe7QIcSm9GTgS9e36HW5tXZoFEGmthT2CGPaTgBdqFqi1a o4BHH1JhUuQE/y7brRm6lBBfpAZZXhaKth/aVqkWk03grZYSPwfsverUzu+9g7pq8EMXPscTeF5 KtapQMMHwetPUtdYdV+weVKPeEz2uChjotefb463KkPe89ecmFnvutV4d7+0= X-Google-Smtp-Source: AGHT+IFb7G/aUo9IE5T/xFX1bwdFxBnGo66gqhmbGtcL2NZyA5TwvSnqsfDL6uv1af+6Sfc2/0Pnd97OgqL+feEqGu8y5oEPyo4z Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a92:ce85:0:b0:433:68ab:e2a with SMTP id e9e14a558f8ab-43368ab0ee1mr25840965ab.23.1762608747790; Sat, 08 Nov 2025 05:32:27 -0800 (PST) Date: Sat, 08 Nov 2025 05:32:27 -0800 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <690f466b.a70a0220.22f260.0081.GAE@google.com> Subject: [syzbot] [ext4?] possible deadlock in ext4_xattr_get (2) From: syzbot To: adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com, tytso@mit.edu Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: 8bb886cb8f3a Merge tag 'edac_urgent_for_v6.18_rc5' of git:.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=11ea2532580000 kernel config: https://syzkaller.appspot.com/x/.config?x=e46b8a1c645465a9 dashboard link: https://syzkaller.appspot.com/bug?extid=5b61c1d24f8022b26f7d compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/addfade563b0/disk-8bb886cb.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/1254c89ad16b/vmlinux-8bb886cb.xz kernel image: https://storage.googleapis.com/syzbot-assets/3123c5319b7e/bzImage-8bb886cb.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+5b61c1d24f8022b26f7d@syzkaller.appspotmail.com ext4 filesystem being mounted at /86/bus supports timestamps until 2038-01-19 (0x7fffffff) ====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.5.1778/13399 is trying to acquire lock: ffff888047d9ba28 (&ei->xattr_sem){++++}-{4:4}, at: ext4_xattr_get+0x10a/0x6a0 fs/ext4/xattr.c:708 but task is already holding lock: ffff88807a168b98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages_down_write fs/ext4/ext4.h:1808 [inline] ffff88807a168b98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_ext_migrate+0x2f3/0x1010 fs/ext4/migrate.c:438 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&sbi->s_writepages_rwsem){++++}-{0:0}: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 percpu_down_read_internal+0x48/0x1c0 include/linux/percpu-rwsem.h:53 percpu_down_read include/linux/percpu-rwsem.h:77 [inline] ext4_writepages_down_read fs/ext4/ext4.h:1796 [inline] ext4_writepages+0x1cc/0x350 fs/ext4/inode.c:3024 do_writepages+0x32e/0x550 mm/page-writeback.c:2604 __writeback_single_inode+0x145/0xff0 fs/fs-writeback.c:1719 writeback_single_inode+0x1f9/0x6a0 fs/fs-writeback.c:1840 write_inode_now+0x160/0x1d0 fs/fs-writeback.c:2903 iput_final fs/inode.c:1901 [inline] iput+0x830/0xc50 fs/inode.c:1966 ext4_xattr_block_set+0x1fce/0x2ac0 fs/ext4/xattr.c:2199 ext4_xattr_move_to_block fs/ext4/xattr.c:2664 [inline] ext4_xattr_make_inode_space fs/ext4/xattr.c:2739 [inline] ext4_expand_extra_isize_ea+0x12da/0x1ea0 fs/ext4/xattr.c:2827 __ext4_expand_extra_isize+0x30d/0x400 fs/ext4/inode.c:6364 ext4_try_to_expand_extra_isize fs/ext4/inode.c:6407 [inline] __ext4_mark_inode_dirty+0x46c/0x700 fs/ext4/inode.c:6485 ext4_evict_inode+0x80d/0xee0 fs/ext4/inode.c:254 evict+0x504/0x9c0 fs/inode.c:810 ext4_orphan_cleanup+0xc20/0x1460 fs/ext4/orphan.c:470 __ext4_fill_super fs/ext4/super.c:5617 [inline] ext4_fill_super+0x5920/0x61e0 fs/ext4/super.c:5736 get_tree_bdev_flags+0x40e/0x4d0 fs/super.c:1691 vfs_get_tree+0x92/0x2b0 fs/super.c:1751 fc_mount fs/namespace.c:1208 [inline] do_new_mount_fc fs/namespace.c:3651 [inline] do_new_mount+0x302/0xa10 fs/namespace.c:3727 do_mount fs/namespace.c:4050 [inline] __do_sys_mount fs/namespace.c:4238 [inline] __se_sys_mount+0x313/0x410 fs/namespace.c:4215 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (&ei->xattr_sem){++++}-{4:4}: check_prev_add kernel/locking/lockdep.c:3165 [inline] check_prevs_add kernel/locking/lockdep.c:3284 [inline] validate_chain+0xb9b/0x2140 kernel/locking/lockdep.c:3908 __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5237 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 down_read+0x46/0x2e0 kernel/locking/rwsem.c:1537 ext4_xattr_get+0x10a/0x6a0 fs/ext4/xattr.c:708 ext4_get_acl+0x84/0x930 fs/ext4/acl.c:165 __get_acl+0x279/0x400 fs/posix_acl.c:159 get_inode_acl fs/posix_acl.c:184 [inline] posix_acl_create+0x131/0x440 fs/posix_acl.c:646 ext4_init_acl+0xb3/0x320 fs/ext4/acl.c:284 __ext4_new_inode+0x3218/0x3cb0 fs/ext4/ialloc.c:1321 ext4_ext_migrate+0x69f/0x1010 fs/ext4/migrate.c:456 __ext4_ioctl fs/ext4/ioctl.c:1694 [inline] ext4_ioctl+0x204b/0x48e0 fs/ext4/ioctl.c:1923 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+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&sbi->s_writepages_rwsem); lock(&ei->xattr_sem); lock(&sbi->s_writepages_rwsem); rlock(&ei->xattr_sem); *** DEADLOCK *** 3 locks held by syz.5.1778/13399: #0: ffff88807a16a420 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write_file+0x60/0x200 fs/namespace.c:552 #1: ffff888047d9c6d0 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: inode_lock include/linux/fs.h:980 [inline] #1: ffff888047d9c6d0 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: __ext4_ioctl fs/ext4/ioctl.c:1693 [inline] #1: ffff888047d9c6d0 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: ext4_ioctl+0x2043/0x48e0 fs/ext4/ioctl.c:1923 #2: ffff88807a168b98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages_down_write fs/ext4/ext4.h:1808 [inline] #2: ffff88807a168b98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_ext_migrate+0x2f3/0x1010 fs/ext4/migrate.c:438 stack backtrace: CPU: 0 UID: 0 PID: 13399 Comm: syz.5.1778 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_circular_bug+0x2ee/0x310 kernel/locking/lockdep.c:2043 check_noncircular+0x134/0x160 kernel/locking/lockdep.c:2175 check_prev_add kernel/locking/lockdep.c:3165 [inline] check_prevs_add kernel/locking/lockdep.c:3284 [inline] validate_chain+0xb9b/0x2140 kernel/locking/lockdep.c:3908 __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5237 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 down_read+0x46/0x2e0 kernel/locking/rwsem.c:1537 ext4_xattr_get+0x10a/0x6a0 fs/ext4/xattr.c:708 ext4_get_acl+0x84/0x930 fs/ext4/acl.c:165 __get_acl+0x279/0x400 fs/posix_acl.c:159 get_inode_acl fs/posix_acl.c:184 [inline] posix_acl_create+0x131/0x440 fs/posix_acl.c:646 ext4_init_acl+0xb3/0x320 fs/ext4/acl.c:284 __ext4_new_inode+0x3218/0x3cb0 fs/ext4/ialloc.c:1321 ext4_ext_migrate+0x69f/0x1010 fs/ext4/migrate.c:456 __ext4_ioctl fs/ext4/ioctl.c:1694 [inline] ext4_ioctl+0x204b/0x48e0 fs/ext4/ioctl.c:1923 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+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f33aa18f6c9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f33ab026038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f33aa3e5fa0 RCX: 00007f33aa18f6c9 RDX: 0000000000000000 RSI: 0000000000006609 RDI: 0000000000000006 RBP: 00007f33aa211f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f33aa3e6038 R14: 00007f33aa3e5fa0 R15: 00007ffcf65b20e8 EXT4-fs error (device loop5): ext4_lookup:1787: inode #12: comm syz.5.1778: iget: bad i_size value: 2533274857506816 EXT4-fs error (device loop5): ext4_lookup:1787: inode #12: comm syz.5.1778: iget: bad i_size value: 2533274857506816 --- This report is generated by a bot. 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