From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oo2-f4.google.com (mail-oo2-f4.google.com [74.125.231.132]) (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 892B91C84DC for ; Sat, 12 Sep 2026 00:47:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=74.125.231.132 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789174066; cv=none; b=CcqRsrFRt13j/cJu7D7abzfvirV0p2NlRBTVhZaC+kxDkD0+Sm9zFggFNXDfNyIXJ1TQRQxpgDbg1MRF9+tVz0aZnebNBccv0G+Ffv/hIatxzULa/ATXvk/S37+axxCUzdRAvLBjjF8ckVLf6elDDf5GYlxX8FijzHm15PSikI8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789174066; c=relaxed/simple; bh=gMuliW5QjP2cRZymyy5ef4oU1RFUpLf2LDkUinKWE8Y=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=Lwhj+mN+EPrGe2kTTmdIcmC3+gGpOS15tHNaoXec2s9BGgiGuxGbCczK4E6Fe0Pp6OJjmq46n8RKqM0u5VknwHR4SVzNXfAn3FcpL9xbW2YFhPwCNtMUZy6h5zu+9RhjP8norNY3DlErZCCcKD3a+WIFsbmS4zxeCvOorN5cNFc= 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=74.125.231.132 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-oo2-f4.google.com with SMTP id 46e09a7af769-7f4e2118db8so528151a34.1 for ; Fri, 11 Sep 2026 17:47:43 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1789174061; x=1789778861; 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=seRlCS++4FDyl1r7S13VogHo/qZgqTrgoFbcFWoWHnI=; b=A97DN/3/SvHxsP3vabDcWguEaKkhZwECXNe3D9QfYweXIU36n4Rf/7jVWOVh8bk9yu 5XjyMMHcKuOKcqss24jE+h31mBUitUSjmZbHFKtqnlAYF8vEl9So7yrtKculUjIuqWmi DbjKB8nTAsNp4aG36otfjVjN28BZIbBwkI4OTkJah/ePwC2F6WbAoQ3UhS/gTqUMCzj+ LtoL4QoQwy3JCqI2cxMBNS0CZ0+l7yHDgsjwyEFXtxqQRkkh+IbSmC2L8DaF23iR2i10 Y7GUkBrIV1njjA5Ftg/+dfJi4QsDpqD4utGp5FTcSoIHs98EiJ84pWvRPx9YTUqgDIO8 lQog== X-Forwarded-Encrypted: i=1; AKwUvBw2wpv7QHD+FcwIv6fIMoMhK3TYJOFAyNGITXRoL/f/lTUP4TD4GDQljeyZbdm7KM+eID9MtBFNrMDpECk=@vger.kernel.org X-Gm-Message-State: AFuF++nwFytB+CBg5IomSUm5xvApbAsAG+b9GwwuP2RApRG8nQ7F8SNv kggW+SY4R1dNB8zi9PVweITCTVGhOeJ9l9fg6DE52pQqrzLm7t4vctJEOmZ6hiPEmS0L72VGd8O zAhq1Hb0f9TFdgEUMmpMKs82fTnKqOw7+q7McgFZ8er1HRE3LRUTrcYGeHU8= Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6820:5605:b0:6b1:b33a:db69 with SMTP id 006d021491bc7-6c0bb3f863cmr6673662eaf.15.1789174061360; Fri, 11 Sep 2026 17:47:41 -0700 (PDT) Date: Fri, 11 Sep 2026 17:47:41 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6aa4a12d.f81106d8.2ab401.0023.GAE@google.com> Subject: [syzbot] [cifs?] KASAN: slab-use-after-free Read in smb2_reconnect_server From: syzbot To: bharathsm@microsoft.com, linkinjeon@kernel.org, linux-cifs@vger.kernel.org, linux-kernel@vger.kernel.org, pc@manguebit.org, ronniesahlberg@gmail.com, samba-technical@lists.samba.org, sprasad@microsoft.com, syzkaller-bugs@googlegroups.com, tom@talpey.com Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: df2908090cda Linux 7.3-rc2 git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=172f6af9580000 kernel config: https://syzkaller.appspot.com/x/.config?x=19560cab9a915237 dashboard link: https://syzkaller.appspot.com/bug?extid=5003556314abc915a71f compiler: gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/16e15edbf5cd/disk-df290809.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/7ccece7686f7/vmlinux-df290809.xz kernel image: https://storage.googleapis.com/syzbot-assets/d0faf024d724/bzImage-df290809.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+5003556314abc915a71f@syzkaller.appspotmail.com ================================================================== BUG: KASAN: slab-use-after-free in smb2_reconnect_server+0x1a9a/0x1b80 fs/smb/client/smb2pdu.c:4257 Read of size 4 at addr ffff888021aca078 by task kworker/1:1/30 CPU: 1 UID: 0 PID: 30 Comm: kworker/1:1 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/05/2026 Workqueue: cifsiod smb2_reconnect_server 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 smb2_reconnect_server+0x1a9a/0x1b80 fs/smb/client/smb2pdu.c:4257 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 9709: 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] __kmalloc_cache_noprof+0x2f8/0x6d0 mm/slub.c:5563 _kmalloc_noprof include/linux/slab.h:991 [inline] _kzalloc_noprof include/linux/slab.h:1312 [inline] cifs_get_tcp_session+0x144/0x1f20 fs/smb/client/connect.c:1758 cifs_mount_get_session+0xc9/0x460 fs/smb/client/connect.c:3570 get_session fs/smb/client/dfs.c:65 [inline] dfs_mount_share+0x200/0x1e20 fs/smb/client/dfs.c:275 cifs_mount+0xc4/0xdb0 fs/smb/client/connect.c:3860 cifs_smb3_do_mount+0x2c0/0x1b10 fs/smb/client/cifsfs.c:1026 smb3_get_tree_common fs/smb/client/fs_context.c:897 [inline] smb3_get_tree fs/smb/client/fs_context.c:917 [inline] smb3_get_tree+0x1fd/0x440 fs/smb/client/fs_context.c:909 vfs_get_tree+0x92/0x320 fs/super.c:1947 fc_mount fs/namespace.c:1198 [inline] do_new_mount_fc fs/namespace.c:3772 [inline] do_new_mount fs/namespace.c:3848 [inline] path_mount+0x7d0/0x24c0 fs/namespace.c:4168 do_mount fs/namespace.c:4181 [inline] __do_sys_mount fs/namespace.c:4397 [inline] __se_sys_mount fs/namespace.c:4374 [inline] __x64_sys_mount+0x293/0x310 fs/namespace.c:4374 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 9713: 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 clean_demultiplex_info+0x98a/0xe90 fs/smb/client/connect.c:1146 cifs_demultiplex_thread+0x5b5/0x2ea0 fs/smb/client/connect.c:1439 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 Last potentially related work creation: kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_record_aux_stack+0xa7/0xc0 mm/kasan/generic.c:556 insert_work+0x36/0x230 kernel/workqueue.c:2272 __queue_work+0xa60/0x1370 kernel/workqueue.c:2448 __queue_delayed_work+0x357/0x450 kernel/workqueue.c:2617 mod_delayed_work_on+0x195/0x1c0 kernel/workqueue.c:2705 mod_delayed_work include/linux/workqueue.h:730 [inline] cifs_queue_server_reconn fs/smb/client/cifsglob.h:2340 [inline] cifs_queue_server_reconn fs/smb/client/cifsglob.h:2336 [inline] __cifs_reconnect+0x51d/0xa80 fs/smb/client/connect.c:431 _cifs_reconnect fs/smb/client/connect.c:590 [inline] cifs_reconnect fs/smb/client/connect.c:604 [inline] cifs_readv_from_socket+0x7c1/0xa30 fs/smb/client/connect.c:743 cifs_read_from_socket+0xb8/0x100 fs/smb/client/connect.c:798 cifs_demultiplex_thread+0x2db/0x2ea0 fs/smb/client/connect.c:1288 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 The buggy address belongs to the object at ffff888021aca000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 120 bytes inside of freed 4096-byte region [ffff888021aca000, ffff888021acb000) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x21ac8 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 ffff88801c02e140 dead000000000100 dead000000000122 raw: 0000000000000000 0000000000040004 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88801c02e140 dead000000000100 dead000000000122 head: 0000000000000000 0000000000040004 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 0xd2040(__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 4981, tgid 4981 (udevadm), ts 33953960392 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] __do_kmalloc_node mm/slub.c:5413 [inline] __kmalloc_noprof+0x67c/0x840 mm/slub.c:5439 _kmalloc_noprof include/linux/slab.h:995 [inline] tomoyo_realpath_from_path+0xb6/0x690 security/tomoyo/realpath.c:251 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_check_open_permission+0x2af/0x3c0 security/tomoyo/file.c:776 tomoyo_file_open+0x6b/0x90 security/tomoyo/tomoyo.c:334 security_file_open+0xb5/0x1e0 security/security.c:2739 do_dentry_open+0x588/0x14d0 fs/open.c:973 vfs_open+0x82/0x3f0 fs/open.c:1101 do_open fs/namei.c:4837 [inline] path_openat+0x19fa/0x2440 fs/namei.c:5000 do_file_open+0x20e/0x430 fs/namei.c:5029 do_sys_openat2+0x10f/0x1e0 fs/open.c:1417 page last free pid 4981 tgid 4981 ts 33942031212 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] __kmalloc_cache_noprof+0x278/0x6d0 mm/slub.c:5559 _kmalloc_noprof include/linux/slab.h:991 [inline] _kzalloc_noprof include/linux/slab.h:1312 [inline] kernfs_get_open_node fs/kernfs/file.c:536 [inline] kernfs_fop_open+0x9fa/0xd50 fs/kernfs/file.c:711 do_dentry_open+0x6ab/0x14d0 fs/open.c:996 vfs_open+0x82/0x3f0 fs/open.c:1101 do_open fs/namei.c:4837 [inline] path_openat+0x19fa/0x2440 fs/namei.c:5000 do_file_open+0x20e/0x430 fs/namei.c:5029 do_sys_openat2+0x10f/0x1e0 fs/open.c:1417 do_sys_open fs/open.c:1423 [inline] __do_sys_openat fs/open.c:1439 [inline] __se_sys_openat fs/open.c:1434 [inline] __x64_sys_openat+0x12d/0x210 fs/open.c:1434 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff888021ac9f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888021ac9f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888021aca000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888021aca080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888021aca100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== --- This report is generated by a bot. 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