From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=209.85.167.197 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1792458341; b=UKiuKm4SL5B6PpaKDzZgA9HHqdcNgg+sx8zM+EZqBdhMyhb0TwEWuu59FWqcCay+YKJU JCDuI8vnL4iuaRQQAxMRQkobhO/y6UfJUw5jXweBSZqzkwU3vX0gSwrgUmYh4rrG5atbg 8QCQzD1uHbnJYleAOpqov4TJ1/zZgiU4Kc0IhzIX8hDeMn3AdpbWJSsR80AnCT0OC2SgJ 8SbIeibKiRMJjuJfGHpXXIsDfwuM+Fc3vamM44RaOt6+Sgb3Zjr4olK+dBcxfXmBRPwBP 0f5/jYFF5a0IqYckfVT6R63RvuXVs7PytZIlQFOjCLKajcaMFwYR5RiITZpTHn8vntg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1792458341; h=DMARC-Filter:Received:X-Google-DKIM-Signature:X-Forwarded-Encrypted: X-Gm-Message-State:MIME-Version:X-Received:Date: X-Google-Appengine-App-Id:X-Google-Appengine-App-Id-Alias:Message-ID: Subject:From:To:Content-Type; bh=71xlRhy0KQqFKDLpjD4JcOfEoZi763hKFB0PEaFGPMA=; b=ITgsebF6BT/+U+bz2fu+ofDlA6BfKVEKz1P5nVZXa7ZFUG7+1RsRkg/GHlq1fsbsC0Ot HLH0VLYRHCAxzjgLQQiGkc1Z1Ma+/JzFaD8qDmLYgswBDBCZmvSouwmjYDvegTbal33bC p9oqRaCP9vZJt7Otqq8VxZYQir4P518vfSiw+7RVfhUXxbF6b5nhrq/vd89a5Pf8IZMpx sWUDpAlu4O/GuOc1fYWoahDb5YOSFVtwk2cK//y2K4WDvYnuIBlNj0nMLVElkNveWMqLC 4BAVjOz1AB0uQrbAH2ZzGvrvga3zHA+0ppOFVoZKe7vM15BXLSGHt7OCSUjvLj0buWg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=fail header.from=syzkaller.appspotmail.com; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com; arc=none smtp.remote-ip=209.85.167.197 Received: from mail-oi1-f197.google.com (mail-oi1-f197.google.com [209.85.167.197]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A272D606A319 for ; Tue, 20 Oct 2026 01:05:40 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org A272D606A319 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-f197.google.com with SMTP id 5614622812f47-4b597558c4cso4927122b6e.1 for ; Mon, 19 Oct 2026 18:05:40 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1792458339; x=1793063139; 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=71xlRhy0KQqFKDLpjD4JcOfEoZi763hKFB0PEaFGPMA=; b=SLirig9cCpJGbvtB2aLsmHMd+Do7xRFczXsoZpwvexP22rh2vSe2sAff/JDuoTm1Aw dCoaYaXjrmreMDhQoVTN9+u6ikA5ix6Q9EJsv9d/XfsLbaYaiFCHD25LSqpWzlkFYUFR vvXLMmnOCQztnDwfsPTQDW5cdKG90WhfrtU4u1iM+hy1M8ssKRLTHY7cgbAUQPw9iKgc A8dSwF/3CCTIIcPllU3f5+vb5XcoWfo1nqBshotiRp5Ay6wodVSGdtdjvFZacjiRwps8 RXUmKBUcJwOR9uldGq6KmPqQibqDyCDQirhHTDNUwTsJJA0E/BPyIhGzJHmwSJEY1nWu 7Ejw== X-Forwarded-Encrypted: i=1; AKwUvBzOahHJgKaXnaWmhD8BXePaRymq9bVTdLLkF5zHhL43liDYmwGHex8OX2IZzMetMPyGiXF0B4eO8GcSvYs=@vger.kernel.org X-Gm-Message-State: AFq9FYLECAOACSOTZZvwG0CHr62IyVbOKUrhL0JD6sI2V8u6PiRzuxho 1uD7kE+SsRQIrYPIMjPfN6w8E2Bz6FwUVeT7dB3MGWTI6jOZOytU55CBV5n4UsXE8AoIakcCJy9 amagWlWOZnzVRIfF7gnHXXBH4BQtPITIwdFLfaCB19lUGzLmaV9sqHrQOy7Y= X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 X-Received: by 2002:a05:6808:1914:b0:4cb:26a3:a0dc with SMTP id 5614622812f47-53ccd9ba7e5mr7738248b6e.20.1792458339574; Mon, 19 Oct 2026 18:05:39 -0700 (PDT) Date: Mon, 19 Oct 2026 18:05:39 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6ad6be63.a20cb897.960b0.0079.GAE@google.com> Subject: [syzbot] [cifs?] KASAN: slab-use-after-free Read in cifs_crypto_secmech_release 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: 045958acaa75 Merge tag 'net-7.3-rc8' of git://git.kernel.o.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=11ac9f01580000 kernel config: https://syzkaller.appspot.com/x/.config?x=3e4baf48b1a52e1 dashboard link: https://syzkaller.appspot.com/bug?extid=c2ec61adfbcb24e5ec20 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/02297297c905/disk-045958ac.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/7722daeec07b/vmlinux-045958ac.xz kernel image: https://storage.googleapis.com/syzbot-assets/c601e2d8abc7/bzImage-045958ac.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+c2ec61adfbcb24e5ec20@syzkaller.appspotmail.com CIFS: VFS: \\172.20.20.170 Error -512 sending data on socket to server ================================================================== BUG: KASAN: slab-use-after-free in cifs_crypto_secmech_release+0xed/0x120 fs/smb/client/cifsencrypt.c:512 Read of size 8 at addr ffff8880526ec490 by task syz.3.92/6393 CPU: 1 UID: 0 PID: 6393 Comm: syz.3.92 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/05/2026 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 cifs_crypto_secmech_release+0xed/0x120 fs/smb/client/cifsencrypt.c:512 cifs_put_tcp_session+0x240/0x3e0 fs/smb/client/connect.c:1740 cifs_mount_put_conns+0x2b3/0x340 fs/smb/client/connect.c:3554 cifs_mount+0x4ac/0xdb0 fs/smb/client/connect.c:3912 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:1932 fc_mount fs/namespace.c:1278 [inline] do_new_mount_fc fs/namespace.c:3885 [inline] do_new_mount fs/namespace.c:3961 [inline] path_mount+0x7d0/0x2850 fs/namespace.c:4312 do_mount fs/namespace.c:4325 [inline] __do_sys_mount fs/namespace.c:4543 [inline] __se_sys_mount fs/namespace.c:4520 [inline] __x64_sys_mount+0x293/0x310 fs/namespace.c:4520 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 RIP: 0033:0x7f35d7b9e559 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f35d5de0028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f35d7e26180 RCX: 00007f35d7b9e559 RDX: 0000200000000300 RSI: 0000200000000100 RDI: 0000200000000200 RBP: 00007f35d7c358b0 R08: 0000200000000400 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f35d7e26218 R14: 00007f35d7e26180 R15: 00007ffce1bc0ac8 Allocated by task 6393: 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:409 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:426 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+0x144/0x1f80 fs/smb/client/connect.c:1765 cifs_mount_get_session+0xc9/0x460 fs/smb/client/connect.c:3579 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:3869 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:1932 fc_mount fs/namespace.c:1278 [inline] do_new_mount_fc fs/namespace.c:3885 [inline] do_new_mount fs/namespace.c:3961 [inline] path_mount+0x7d0/0x2850 fs/namespace.c:4312 do_mount fs/namespace.c:4325 [inline] __do_sys_mount fs/namespace.c:4543 [inline] __se_sys_mount fs/namespace.c:4520 [inline] __x64_sys_mount+0x293/0x310 fs/namespace.c:4520 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 6394: 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:264 [inline] __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:296 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2748 [inline] slab_free mm/slub.c:6509 [inline] kfree+0x22b/0x6d0 mm/slub.c:6802 clean_demultiplex_info+0x997/0xe90 fs/smb/client/connect.c:1153 cifs_demultiplex_thread+0x5b5/0x2ea0 fs/smb/client/connect.c:1446 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 ffff8880526ec000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 1168 bytes inside of freed 4096-byte region [ffff8880526ec000, ffff8880526ed000) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x526e8 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 ffff88801d035140 dead000000000100 dead000000000122 raw: 0000000000000000 0000000000040004 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88801d035140 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 6393, tgid 6385 (syz.3.92), ts 190011878541 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:7418 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] __kmalloc_cache_noprof+0x4f4/0x6d0 mm/slub.c:5559 _kmalloc_noprof include/linux/slab.h:991 [inline] _kzalloc_noprof include/linux/slab.h:1312 [inline] cifs_get_tcp_session+0x144/0x1f80 fs/smb/client/connect.c:1765 cifs_mount_get_session+0xc9/0x460 fs/smb/client/connect.c:3579 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:3869 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:1932 fc_mount fs/namespace.c:1278 [inline] do_new_mount_fc fs/namespace.c:3885 [inline] do_new_mount fs/namespace.c:3961 [inline] path_mount+0x7d0/0x2850 fs/namespace.c:4312 do_mount fs/namespace.c:4325 [inline] __do_sys_mount fs/namespace.c:4543 [inline] __se_sys_mount fs/namespace.c:4520 [inline] __x64_sys_mount+0x293/0x310 fs/namespace.c:4520 page last free pid 6391 tgid 6385 ts 189990448004 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:361 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4683 [inline] kmem_cache_alloc_bulk_noprof+0x352/0x890 mm/slub.c:7543 __io_alloc_req_refill+0x9e/0x330 io_uring/io_uring.c:981 io_alloc_req io_uring/io_uring.h:537 [inline] io_submit_sqes.cold+0xf6/0x301 io_uring/io_uring.c:2039 __do_sys_io_uring_enter+0xa88/0x1b10 io_uring/io_uring.c:2640 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: ffff8880526ec380: fb fb fb fb fb fb fb f ffff8880526ec380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880526ec400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880526ec480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880526ec500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880526ec580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ================================================================== BUG: KASAN: slab-use-after-free in cifs_crypto_secmech_release+0xfa/0x120 fs/smb/client/cifsencrypt.c:516 Read of size 8 at addr ffff8880526ec498 by task syz.3.92/6393 CPU: 1 UID: 0 PID: 6393 Comm: syz.3.92 Tainted: G B syzkaller #0 PREEMPT(full) Tainted: [B]=BAD_PAGE Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/05/2026 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 cifs_crypto_secmech_release+0xfa/0x120 fs/smb/client/cifsencrypt.c:516 cifs_put_tcp_session+0x240/0x3e0 fs/smb/client/connect.c:1740 cifs_mount_put_conns+0x2b3/0x340 fs/smb/client/connect.c:3554 cifs_mount+0x4ac/0xdb0 fs/smb/client/connect.c:3912 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:1932 fc_mount fs/namespace.c:1278 [inline] do_new_mount_fc fs/namespace.c:3885 [inline] do_new_mount fs/namespace.c:3961 [inline] path_mount+0x7d0/0x2850 fs/namespace.c:4312 do_mount fs/namespace.c:4325 [inline] __do_sys_mount fs/namespace.c:4543 [inline] __se_sys_mount fs/namespace.c:4520 [inline] __x64_sys_mount+0x293/0x310 fs/namespace.c:4520 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 RIP: 0033:0x7f35d7b9e559 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f35d5de0028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f35d7e26180 RCX: 00007f35d7b9e559 RDX: 0000200000000300 RSI: 0000200000000100 RDI: 0000200000000200 RBP: 00007f35d7c358b0 R08: 0000200000000400 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f35d7e26218 R14: 00007f35d7e26180 R15: 00007ffce1bc0ac8 Allocated by task 6393: 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:409 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:426 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+0x144/0x1f80 fs/smb/client/connect.c:1765 cifs_mount_get_session+0xc9/0x460 fs/smb/client/connect.c:3579 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:3869 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:1932 fc_mount fs/namespace.c:1278 [inline] do_new_mount_fc fs/namespace.c:3885 [inline] do_new_mount fs/namespace.c:3961 [inline] path_mount+0x7d0/0x2850 fs/namespace.c:4312 do_mount fs/namespace.c:4325 [inline] __do_sys_mount fs/namespace.c:4543 [inline] __se_sys_mount fs/namespace.c:4520 [inline] __x64_sys_mount+0x293/0x310 fs/namespace.c:4520 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 6394: 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:264 [inline] __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:296 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2748 [inline] slab_free mm/slub.c:6509 [inline] kfree+0x22b/0x6d0 mm/slub.c:6802 clean_demultiplex_info+0x997/0xe90 fs/smb/client/connect.c:1153 cifs_demultiplex_thread+0x5b5/0x2ea0 fs/smb/client/connect.c:1446 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 ffff8880526ec000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 1176 bytes inside of freed 4096-byte region [ffff8880526ec000, ffff8880526ed000) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x526e8 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 ffff88801d035140 dead000000000100 dead000000000122 raw: 0000000000000000 0000000000040004 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88801d035140 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 6393, tgid 6385 (syz.3.92), ts 190011878541 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:7418 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] __kmalloc_cache_noprof+0x4f4/0x6d0 mm/slub.c:5559 _kmalloc_noprof include/linux/slab.h:991 [inline] _kzalloc_noprof include/linux/slab.h:1312 [inline] cifs_get_tcp_session+0x144/0x1f80 fs/smb/client/connect.c:1765 cifs_mount_get_session+0xc9/0x460 fs/smb/client/connect.c:3579 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:3869 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:1932 fc_mount fs/namespace.c:1278 [inline] do_new_mount_fc fs/namespace.c:3885 [inline] do_new_mount fs/namespace.c:3961 [inline] path_mount+0x7d0/0x2850 fs/namespace.c:4312 do_mount fs/namespace.c:4325 [inline] __do_sys_mount fs/namespace.c:4543 [inline] __se_sys_mount fs/namespace.c:4520 [inline] __x64_sys_mount+0x293/0x310 fs/namespace.c:4520 page last free pid 6391 tgid 6385 ts 189990448004 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:361 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4683 [inline] kmem_cache_alloc_bulk_noprof+0x352/0x890 mm/slub.c:7543 __io_alloc_req_refill+0x9e/0x330 io_uring/io_uring.c:981 io_alloc_req io_uring/io_uring.h:537 [inline] io_submit_sqes.cold+0xf6/0x301 io_uring/io_uring.c:2039 __do_sys_io_uring_enter+0xa88/0x1b10 io_uring/io_uring.c:2640 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: ffff8880526ec380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880526ec400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880526ec480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880526ec500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880526ec580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ================================================================== BUG: KASAN: slab-use-after-free in cifs_put_tcp_session+0x374/0x3e0 fs/smb/client/connect.c:1742 Read of size 8 at addr ffff8880526ec470 by task syz.3.92/6393 CPU: 1 UID: 0 PID: 6393 Comm: syz.3.92 Tainted: G B syzkaller #0 PREEMPT(full) Tainted: [B]=BAD_PAGE Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/05/2026 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 cifs_put_tcp_session+0x374/0x3e0 fs/smb/client/connect.c:1742 cifs_mount_put_conns+0x2b3/0x340 fs/smb/client/connect.c:3554 cifs_mount+0x4ac/0xdb0 fs/smb/client/connect.c:3912 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:1932 fc_mount fs/namespace.c:1278 [inline] do_new_mount_fc fs/namespace.c:3885 [inline] do_new_mount fs/namespace.c:3961 [inline] path_mount+0x7d0/0x2850 fs/namespace.c:4312 do_mount fs/namespace.c:4325 [inline] __do_sys_mount fs/namespace.c:4543 [inline] __se_sys_mount fs/namespace.c:4520 [inline] __x64_sys_mount+0x293/0x310 fs/namespace.c:4520 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 RIP: 0033:0x7f35d7b9e559 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f35d5de0028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f35d7e26180 RCX: 00007f35d7b9e559 RDX: 0000200000000300 RSI: 0000200000000100 RDI: 0000200000000200 RBP: 00007f35d7c358b0 R08: 0000200000000400 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f35d7e26218 R14: 00007f35d7e26180 R15: 00007ffce1bc0ac8 Allocated by task 6393: 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:409 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:426 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+0x144/0x1f80 fs/smb/client/connect.c:1765 cifs_mount_get_session+0xc9/0x460 fs/smb/client/connect.c:3579 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:3869 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:1932 fc_mount fs/namespace.c:1278 [inline] do_new_mount_fc fs/namespace.c:3885 [inline] do_new_mount fs/namespace.c:3961 [inline] path_mount+0x7d0/0x2850 fs/namespace.c:4312 do_mount fs/namespace.c:4325 [inline] __do_sys_mount fs/namespace.c:4543 [inline] __se_sys_mount fs/namespace.c:4520 [inline] __x64_sys_mount+0x293/0x310 fs/namespace.c:4520 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 6394: 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:264 [inline] __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:296 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2748 [inline] slab_free mm/slub.c:6509 [inline] kfree+0x22b/0x6d0 mm/slub.c:6802 clean_demultiplex_info+0x997/0xe90 fs/smb/client/connect.c:1153 cifs_demultiplex_thread+0x5b5/0x2ea0 fs/smb/client/connect.c:1446 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 ffff8880526ec000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 1136 bytes inside of freed 4096-byte region [ffff8880526ec000, ffff8880526ed000) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x526e8 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 ffff88801d035140 dead000000000100 dead000000000122 raw: 0000000000000000 0000000000040004 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88801d035140 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 6393, tgid 6385 (syz.3.92), ts 190011878541 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:7418 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] __kmalloc_cache_noprof+0x4f4/0x6d0 mm/slub.c:5559 _kmalloc_noprof include/linux/slab.h:991 [inline] _kzalloc_noprof include/linux/slab.h:1312 [inline] cifs_get_tcp_session+0x144/0x1f80 fs/smb/client/connect.c:1765 cifs_mount_get_session+0xc9/0x460 fs/smb/client/connect.c:3579 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:3869 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:1932 fc_mount fs/namespace.c:1278 [inline] do_new_mount_fc fs/namespace.c:3885 [inline] do_new_mount fs/namespace.c:3961 [inline] path_mount+0x7d0/0x2850 fs/namespace.c:4312 do_mount fs/namespace.c:4325 [inline] __do_sys_mount fs/namespace.c:4543 [inline] __se_sys_mount fs/namespace.c:4520 [inline] __x64_sys_mount+0x293/0x310 fs/namespace.c:4520 page last free pid 6391 tgid 6385 ts 189990448004 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:361 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4683 [inline] kmem_cache_alloc_bulk_noprof+0x352/0x890 mm/slub.c:7543 __io_alloc_req_refill+0x9e/0x330 io_uring/io_uring.c:981 io_alloc_req io_uring/io_uring.h:537 [inline] io_submit_sqes.cold+0xf6/0x301 io_uring/io_uring.c:2039 __do_sys_io_uring_enter+0xa88/0x1b10 io_uring/io_uring.c:2640 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: ffff8880526ec300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880526ec380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880526ec400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880526ec480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880526ec500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ================================================================== BUG: KASAN: slab-use-after-free in cifs_put_tcp_session+0x381/0x3e0 fs/smb/client/connect.c:1743 Write of size 8 at addr ffff8880526ec470 by task syz.3.92/6393 CPU: 1 UID: 0 PID: 6393 Comm: syz.3.92 Tainted: G B syzkaller #0 PREEMPT(full) Tainted: [B]=BAD_PAGE Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/05/2026 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 cifs_put_tcp_session+0x381/0x3e0 fs/smb/client/connect.c:1743 cifs_mount_put_conns+0x2b3/0x340 fs/smb/client/connect.c:3554 cifs_mount+0x4ac/0xdb0 fs/smb/client/connect.c:3912 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:1932 fc_mount fs/namespace.c:1278 [inline] do_new_mount_fc fs/namespace.c:3885 [inline] do_new_mount fs/namespace.c:3961 [inline] path_mount+0x7d0/0x2850 fs/namespace.c:4312 do_mount fs/namespace.c:4325 [inline] __do_sys_mount fs/namespace.c:4543 [inline] __se_sys_mount fs/namespace.c:4520 [inline] __x64_sys_mount+0x293/0x310 fs/namespace.c:4520 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 RIP: 0033:0x7f35d7b9e559 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f35d5de0028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f35d7e26180 RCX: 00007f35d7b9e559 RDX: 0000200000000300 RSI: 0000200000000100 RDI: 0000200000000200 RBP: 00007f35d7c358b0 R08: 0000200000000400 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f35d7e26218 R14: 00007f35d7e26180 R15: 00007ffce1bc0ac8 Allocated by task 6393: 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:409 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:426 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+0x144/0x1f80 fs/smb/client/connect.c:1765 cifs_mount_get_session+0xc9/0x460 fs/smb/client/connect.c:3579 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:3869 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:1932 fc_mount fs/namespace.c:1278 [inline] do_new_mount_fc fs/namespace.c:3885 [inline] do_new_mount fs/namespace.c:3961 [inline] path_mount+0x7d0/0x2850 fs/namespace.c:4312 do_mount fs/namespace.c:4325 [inline] __do_sys_mount fs/namespace.c:4543 [inline] __se_sys_mount fs/namespace.c:4520 [inline] __x64_sys_mount+0x293/0x310 fs/namespace.c:4520 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 6394: 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:264 [inline] __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:296 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2748 [inline] slab_free mm/slub.c:6509 [inline] kfree+0x22b/0x6d0 mm/slub.c:6802 clean_demultiplex_info+0x997/0xe90 fs/smb/client/connect.c:1153 cifs_demultiplex_thread+0x5b5/0x2ea0 fs/smb/client/connect.c:1446 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 ffff8880526ec000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 1136 bytes inside of freed 4096-byte region [ffff8880526ec000, ffff8880526ed000) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x526e8 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 ffff88801d035140 dead000000000100 dead000000000122 raw: 0000000000000000 0000000000040004 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88801d035140 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 6393, tgid 6385 (syz.3.92), ts 190011878541 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:7418 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] __kmalloc_cache_noprof+0x4f4/0x6d0 mm/slub.c:5559 _kmalloc_noprof include/linux/slab.h:991 [inline] _kzalloc_noprof include/linux/slab.h:1312 [inline] cifs_get_tcp_session+0x144/0x1f80 fs/smb/client/connect.c:1765 cifs_mount_get_session+0xc9/0x460 fs/smb/client/connect.c:3579 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:3869 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:1932 fc_mount fs/namespace.c:1278 [inline] do_new_mount_fc fs/namespace.c:3885 [inline] do_new_mount fs/namespace.c:3961 [inline] path_mount+0x7d0/0x2850 fs/namespace.c:4312 do_mount fs/namespace.c:4325 [inline] __do_sys_mount fs/namespace.c:4543 [inline] __se_sys_mount fs/namespace.c:4520 [inline] __x64_sys_mount+0x293/0x310 fs/namespace.c:4520 page last free pid 6391 tgid 6385 ts 189990448004 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:361 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4683 [inline] kmem_cache_alloc_bulk_noprof+0x352/0x890 mm/slub.c:7543 __io_alloc_req_refill+0x9e/0x330 io_uring/io_uring.c:981 io_alloc_req io_uring/io_uring.h:537 [inline] io_submit_sqes.cold+0xf6/0x301 io_uring/io_uring.c:2039 __do_sys_io_uring_enter+0xa88/0x1b10 io_uring/io_uring.c:2640 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: ffff8880526ec300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880526ec380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880526ec400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880526ec480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880526ec500: 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