From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 48FEA606A326 for ; Thu, 5 Nov 2026 20:55:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=lists.infradead.org header.i=@lists.infradead.org header.a=rsa-sha256 header.s=bombadil.20210309 header.b=Xw2sYZQb; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=n1pRV84z DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:Reply-To:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id:Date: Content-Transfer-Encoding:Content-Type:References:In-Reply-To:Cc:To:Subject: From:Message-ID:MIME-Version:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Unsubscribe-Post:List-Owner; bh=hsy7qPadddcHp1yz4RskpjuPCs9z+iyUZQjRxWR0tno=; b=Xw2sYZQbaDuuNYZhdarL7SLIQ6 kVq37yT5t8xakRxklpqM24aWbBRjU5p9zbYw4+pxpIp+JbDm7W8XGuask9wvWzVzEcTeNO87UToop BF/rQ0PSIt0PW0Ebp+LYU/m9Ud/0aw62+ll2gm8WzBTW89LRYk+UQt+T6RTjWN7koYF75onfvzTNy CZfKsJ5dPNfybIYNGiX+q1KoKmeH4Dp5qsVsNGumTzD/8crfmsfufjh6MAV6wYXYjMZV5H3OPC5S0 ddTo3JAVscg+3+2yzqBaJPVyyWvLjqdtG/cmHvDIKKWKVb6nJnOBwVYxhYcjc9hR8/MvHRUt8yAUb llHwLbPQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.100.1 #2 (Red Hat Linux)) id 1xP3Bm-0000000ALVR-1ykK; Thu, 05 Nov 2026 19:31:59 +0000 Received: from tor.source.kernel.org ([172.105.4.254]) by bombadil.infradead.org with esmtps (Exim 4.100.1 #2 (Red Hat Linux)) id 1xP39y-0000000AKjK-1Uue for kexec@lists.infradead.org; Thu, 05 Nov 2026 19:30:06 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id C8743601DD; Thu, 5 Nov 2026 19:30:05 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D006D1F000C1; Thu, 5 Nov 2026 19:30:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793907005; bh=hsy7qPadddcHp1yz4RskpjuPCs9z+iyUZQjRxWR0tno=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=n1pRV84zJKUUtgUv1TYLImkQPkvmaqLjvwYZrx2oyTCwObzhdrQFqivFQJG2KSTyQ eTIbvYnu/am2gKJ0v2gg99xx3HGgCRhK3jtKYYV/hEN32FiOkUwOd5qfCd1EvNlRbU /wDWKpQlTW9sg368vKkBt979aVtHTwB7aqgs1lZ3cZ7yuOwpmH/5K72S+3ZXzvHDZJ zCVaJA/NGoQ3f5O/ZIg5OD8CZV38pYz/7PwHfRkFO2BSCEBpwk5KemMFv7yST4FY/7 ke1edsHonMb+SJ+aejvls7v7xGnvSnNsG3bwmscXuAXx4DTCqwdtiudcPMpO6x6AMq QMz7+TNSVPVMQ== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH RESEND v2 37/51] proc/vmcore: don't let vmcore_cleanup() run twice at once To: "Christian Brauner" Cc: "Linus Torvalds" , "Jann Horn" , "Josef Bacik" , "Chris Mason" , "Jeff Layton" , NeilBrown , "Eric Dumazet" , "Thomas Gleixner" , "Al Viro" , "Jonathan Corbet" , "Christoph Hellwig" , "Greg Kroah-Hartman" , "Joel Granados" , "Kees Cook" , "Jan Kara" , "Jan Kara" , linux-s390@vger.kernel.org, coreteam@netfilter.org, kexec@lists.infradead.org, linux-pci@vger.kernel.org, linux-hwmon@vger.kernel.org, linux-usb@vger.kernel.org, samba-technical@lists.samba.org, linux-m68k@lists.linux-m68k.org, linux-serial@vger.kernel.org, "Takashi Iwai" , linux-ext4@vger.kernel.org, "Chuck Lever" , tytso@mit.edu, "Heiko Carstens" , "Vasily Gorbik" , "Alexander Gordeev" , "Christian Borntraeger" In-Reply-To: <20261104-work-procfs-bugfixes-v2-37-021c84d852e0@kernel.org> References: <20261104-work-procfs-bugfixes-v2-0-021c84d852e0@kernel.org> <20261104-work-procfs-bugfixes-v2-37-021c84d852e0@kernel.org> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Thu, 05 Nov 2026 19:30:03 +0000 X-BeenThere: kexec@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: sashiko-reviews@lists.linux.dev Sender: "kexec" X-Spam-Status: No, score=-10.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=4.0.1 X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 X-Archived-By: > vmcore_cleanup() has a single caller, fadump's release_mem_store() on > powerpc. That checks fw_dump.dump_active without a lock and calls > vmcore_cleanup() without one, and kernfs only serializes the writers of > one open file. So two tasks that write to > /sys/kernel/fadump/release_mem through different files run > vmcore_cleanup() at the same time. >=20 > The first one removes /proc/vmcore and waits for its readers in > proc_remove(). The second one finds the entry already unlinked, returns > from proc_remove() right away and frees vmcore_list, the ELF headers > and the device dumps while those readers still walk them. Or both of > them free the same lists at once. >=20 > Serialize vmcore_cleanup() with a mutex of its own. It can't be > vmcore_mutex, removing /proc/vmcore calls release_vmcore() which takes > it. The second caller then finds nothing left to free. >=20 > Reported-by: Chris Mason > Fixes: b500afff11f6 ("fadump: Invalidate registration and release reserve= d memory for general use.") > Cc: stable@vger.kernel.org > Signed-off-by: Christian Brauner (Amutable) Sashiko has reviewed this patch and found no issues. --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20261104-work-procf= s-bugfixes-v2-0-021c84d852e0@kernel.org?part=3D37