From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oi1-f205.google.com (mail-oi1-f205.google.com [209.85.167.205]) (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 4AE573ACA58 for ; Tue, 4 Aug 2026 01:22:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.167.205 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785806551; cv=none; b=NlUeZ/yyorehtFDCcQyBLRAYow6ejyUJVOA4nybz87JW8CEQB/VtpjRw3EIuVP6J+Ej1evawu2QkUHsMpAUQuYvXOVLQksp3CCozskMc6nDJQTgWYs/DUNEkU0DzMTOergv5FcsPBIsFMDMdpA34D/3lNrorcSLc2SuOrEdeLhU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785806551; c=relaxed/simple; bh=qRqnXLyfzoi6U819BVmQMD9BvtRbcz9twZE+6VW4Arg=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=rfYJtsg/957dGQLxjVKUoxYhpr12UkUq8FCwH9d5m/vyDmZ6bYvw1vMdBxCKg4Eu5XxJ8TkR2FWr+mg47qOZLvgeq/u14eoYUDFUWDeTFREZYLCvzw60lHQ1EhTBilJDZc82zo4aKxwI3Fs7lCMHBIsFR5bTS2JO50JdnAC06P8= 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=209.85.167.205 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-oi1-f205.google.com with SMTP id 5614622812f47-4ab7bb257bbso3491591b6e.0 for ; Mon, 03 Aug 2026 18:22:29 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1785806548; x=1786411348; 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=qtCjnm/puTsZsa/2CwFjtGJb+lx6edEGVd7fXIrsF7U=; b=T1Vc/QN6nUMoSqZufH1AJj98qt9Ym4o671kkkVV1Z06ULSqggPIKmqBAXT1y42lQAe Xg8vbOeRS1PWsiLIs9DD5mirAUlG6XY0B1lDof8M4XBzVtIsqpmK3/1ELFa7vn+Fqx2E Oa6nlRdgJyosJoInTGhM8zcO9+FOa6mXTcSYzQge948Datr+W2NOkb/iKeAeJuSGi5Q5 puZeKsLPN7mLcy5jIQwvC+PCFYICuDwmqZj9Ifvo/tS+cUaxg2aPvt8rgaq1UCCfsDfw BZ2Z1erUpLBSotxce6O+K+cVSFy5sDt48pploitPvJxwnPkS3791bc5cEHxImpuXSYFc 7fjw== X-Forwarded-Encrypted: i=1; AHgh+RqB3P2G5Y0SshZ5XTNVkaxGpDbZXXA2BXWbUXgEoT+DMy5oh9N8xngC3uEXo78X9FS7Uce1QLXffwFOZzU=@vger.kernel.org X-Gm-Message-State: AOJu0Yz06+H3RcqQqq1g0O1/r9aBTIBgFZt7+VClVIVa7DZcMTvBWasu NxtHFXCyCYL3fWRhbT2mXJ4t0m2ABZUiM5aKrE08bjbCLVg5RsEGO2HHuZaGbq7C2JQsNmsLliC iN7m+BNqOaz24/jNhtAeKhDOfyKOJyDzmh4dUCyzA3yF8ypA47zCvH2BWMqU= Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6808:14c6:b0:4a3:4598:f390 with SMTP id 5614622812f47-4af5e3d7eabmr18997623b6e.17.1785806548189; Mon, 03 Aug 2026 18:22:28 -0700 (PDT) Date: Mon, 03 Aug 2026 18:22:28 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6a713ed4.d35e88fd.de8b.0007.GAE@google.com> Subject: [syzbot] [fuse?] KASAN: slab-use-after-free Read in fuse_copy_do From: syzbot To: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, miklos@szeredi.hu, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: 92e3f6ef4ffb Merge branch 'for-next/core' into for-kernelci git tree: git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci console output: https://syzkaller.appspot.com/x/log.txt?x=117200d6580000 kernel config: https://syzkaller.appspot.com/x/.config?x=a4a42e870a0b0ae0 dashboard link: https://syzkaller.appspot.com/bug?extid=a036bdf7d7bad319e404 compiler: Debian clang version 22.1.6 (++20260514074242+fc4aad7b5db3-1~exp1~20260514074407.73), Debian LLD 22.1.6 userspace arch: arm64 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/75ce25b4a6ef/disk-92e3f6ef.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/14bda28d7d38/vmlinux-92e3f6ef.xz kernel image: https://storage.googleapis.com/syzbot-assets/247283a18992/Image-92e3f6ef.gz.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+a036bdf7d7bad319e404@syzkaller.appspotmail.com ================================================================== BUG: KASAN: slab-use-after-free in fuse_copy_do+0x1a0/0x38c fs/fuse/dev.c:-1 Read of size 64 at addr ffff0000cbe00888 by task syz.7.1148/9889 CPU: 1 UID: 0 PID: 9889 Comm: syz.7.1148 Tainted: G L syzkaller #0 PREEMPT Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/02/2026 Call trace: show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:499 (C) __dump_stack+0x30/0x40 lib/dump_stack.c:94 dump_stack_lvl+0xd8/0x12c lib/dump_stack.c:120 print_address_description+0xb0/0x238 mm/kasan/report.c:378 print_report+0x68/0x84 mm/kasan/report.c:482 kasan_report+0x8c/0xc4 mm/kasan/report.c:595 check_region_inline mm/kasan/generic.c:-1 [inline] kasan_check_range+0x17c/0x1ac mm/kasan/generic.c:200 __asan_memcpy+0x3c/0x84 mm/kasan/shadow.c:105 fuse_copy_do+0x1a0/0x38c fs/fuse/dev.c:-1 fuse_copy_one+0xc4/0x130 fs/fuse/dev.c:1215 fuse_copy_args+0x2a8/0x398 fs/fuse/dev.c:1233 fuse_dev_do_read+0xac8/0xfe8 fs/fuse/dev.c:1507 fuse_dev_read+0x140/0x1c8 fs/fuse/dev.c:1586 new_sync_read fs/read_write.c:493 [inline] vfs_read+0x498/0x8c8 fs/read_write.c:574 ksys_read+0x12c/0x228 fs/read_write.c:717 __do_sys_read fs/read_write.c:726 [inline] __se_sys_read fs/read_write.c:724 [inline] __arm64_sys_read+0x7c/0x90 fs/read_write.c:724 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x244 arch/arm64/kernel/syscall.c:49 el0_svc_common+0xec/0x23c arch/arm64/kernel/syscall.c:121 do_el0_svc+0x4c/0x5c arch/arm64/kernel/syscall.c:140 el0_svc+0x64/0x260 arch/arm64/kernel/entry-common.c:736 el0t_64_sync_handler+0x48/0x148 arch/arm64/kernel/entry-common.c:755 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:594 Allocated by task 9885: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x40/0x78 mm/kasan/common.c:78 kasan_save_alloc_info+0x44/0x54 mm/kasan/generic.c:570 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0x9c/0xb4 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __kmalloc_cache_noprof+0x2d4/0x624 mm/slub.c:5420 kmalloc_noprof include/linux/slab.h:950 [inline] kzalloc_noprof include/linux/slab.h:1188 [inline] fuse_new_init fs/fuse/inode.c:1519 [inline] fuse_send_init+0x64/0x630 fs/fuse/inode.c:1579 fuse_fill_super+0x100/0x124 fs/fuse/inode.c:1990 vfs_get_super+0xb8/0x148 fs/super.c:1327 get_tree_nodev+0x2c/0x3c fs/super.c:1346 fuse_get_tree+0x240/0x324 fs/fuse/inode.c:2055 vfs_get_tree+0x90/0x28c fs/super.c:1754 fc_mount+0x24/0xac fs/namespace.c:1193 do_new_mount_fc fs/namespace.c:3758 [inline] do_new_mount+0x2a4/0x538 fs/namespace.c:3834 path_mount+0x5f0/0xa88 fs/namespace.c:4154 do_mount+0xe8/0x148 fs/namespace.c:4167 __do_sys_mount fs/namespace.c:4383 [inline] __se_sys_mount fs/namespace.c:4360 [inline] __arm64_sys_mount+0x334/0x380 fs/namespace.c:4360 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x244 arch/arm64/kernel/syscall.c:49 el0_svc_common+0xec/0x23c arch/arm64/kernel/syscall.c:121 do_el0_svc+0x4c/0x5c arch/arm64/kernel/syscall.c:140 el0_svc+0x64/0x260 arch/arm64/kernel/entry-common.c:736 el0t_64_sync_handler+0x48/0x148 arch/arm64/kernel/entry-common.c:755 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:594 Freed by task 9885: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x40/0x78 mm/kasan/common.c:78 kasan_save_free_info+0x58/0x70 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x74/0xa4 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2689 [inline] slab_free mm/slub.c:6251 [inline] kfree+0x188/0x690 mm/slub.c:6566 process_init_reply+0xdc/0x1b30 fs/fuse/inode.c:1503 fuse_send_init+0x378/0x630 fs/fuse/inode.c:1594 fuse_fill_super+0x100/0x124 fs/fuse/inode.c:1990 vfs_get_super+0xb8/0x148 fs/super.c:1327 get_tree_nodev+0x2c/0x3c fs/super.c:1346 fuse_get_tree+0x240/0x324 fs/fuse/inode.c:2055 vfs_get_tree+0x90/0x28c fs/super.c:1754 fc_mount+0x24/0xac fs/namespace.c:1193 do_new_mount_fc fs/namespace.c:3758 [inline] do_new_mount+0x2a4/0x538 fs/namespace.c:3834 path_mount+0x5f0/0xa88 fs/namespace.c:4154 do_mount+0xe8/0x148 fs/namespace.c:4167 __do_sys_mount fs/namespace.c:4383 [inline] __se_sys_mount fs/namespace.c:4360 [inline] __arm64_sys_mount+0x334/0x380 fs/namespace.c:4360 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x244 arch/arm64/kernel/syscall.c:49 el0_svc_common+0xec/0x23c arch/arm64/kernel/syscall.c:121 do_el0_svc+0x4c/0x5c arch/arm64/kernel/syscall.c:140 el0_svc+0x64/0x260 arch/arm64/kernel/entry-common.c:736 el0t_64_sync_handler+0x48/0x148 arch/arm64/kernel/entry-common.c:755 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:594 The buggy address belongs to the object at ffff0000cbe00800 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 136 bytes inside of freed 512-byte region [ffff0000cbe00800, ffff0000cbe00a00) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x10be00 head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0x5ffc00000000040(head|node=0|zone=2|lastcpupid=0x7ff) page_type: f5(slab) raw: 05ffc00000000040 ffff0000c0001c80 dead000000000100 dead000000000122 raw: 0000000000000000 0000000800100010 00000000f5000000 0000000000000000 head: 05ffc00000000040 ffff0000c0001c80 dead000000000100 dead000000000122 head: 0000000000000000 0000000800100010 00000000f5000000 0000000000000000 head: 05ffc00000000002 fffffdffc32f8001 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000004 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff0000cbe00780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff0000cbe00800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff0000cbe00880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff0000cbe00900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff0000cbe00980: 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