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From: Adarsh Das <adarshdas950@gmail.com>
To: gregkh@linuxfoundation.org
Cc: dakr@kernel.org, driver-core@lists.linux.dev,
	linux-kernel@vger.kernel.org, rafael@kernel.org,
	stable@vger.kernel.org,
	syzbot+4393dfdddf166f2de2b0@syzkaller.appspotmail.com
Subject: Re: [PATCH] kobject: fix uevent socket use-after-free on net namespace delete
Date: Thu, 17 Sep 2026 20:48:30 +0530	[thread overview]
Message-ID: <20260917151830.89024-1-adarshdas950@gmail.com> (raw)
In-Reply-To: <2026091756-widen-doozy-399c@gregkh>

Hi,

Sorry, I wasn't aware of the Assisted-by tag before. Should I send a
V2 with it?

For testing I ran syzbot's C repro with -smp 4 on master, with
multiple parallel instances of the repro. I was able to reproduce
the bug:

  BUG: KASAN: slab-use-after-free in kobject_uevent_env+
  Read of size 8 at addr ffff88800fa7f090 by task kworker/u16:5
  CPU: 3
  Workqueue: ib-unreg-wq ib_unregister_work
  Call Trace:
    kasan_report
    kobject_uevent_env+0xc71/0xd90
    device_del+0x7c7/0xcf0
    disable_device+0x1d2/0x260
    __ib_unregister_device+0x26b/0x400
    ib_unregister_work+0x19/0x30
    worker_thread
    kthread
  Allocated by task 498:
    uevent_net_init+0xe5/0x340
    setup_net
    copy_net_ns
    unshare_nsproxy_namespaces
    ksys_unshare
  Freed by task 63:
    kfree
    ops_undo_list
    cleanup_net
    worker_thread
  The buggy address belongs to the cache kmalloc-32 of size 32

With this patch applied, I ran the same repro repeatedly (including
parallel runs) and did not see the KASAN error anymore.

  reply	other threads:[~2026-09-17 15:18 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-09-17 14:42 Adarsh Das
2026-09-17 14:51 ` Greg KH
2026-09-17 15:18   ` Adarsh Das [this message]
2026-09-17 15:21     ` Greg KH
2026-09-17 17:08 ` [PATCH v2] " Adarsh Das
2026-09-17 17:08 ` Adarsh Das
2026-09-17 17:40   ` Greg KH
2026-09-18  6:08     ` [PATCH v3] " Adarsh Das
2026-09-18  8:14       ` Greg KH
2026-09-18  8:14       ` Greg KH

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