From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5F2D9191 for ; Wed, 21 Aug 2024 00:07:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724198865; cv=none; b=rDTMj08gYuGElHjD0Dt2UH8L5jVcLLFDyxdK6q/gRmiz6617bWEwq8c/XJT2BddonFOdzrJZBv0bhAKJuL1EZVq/T2DtsnHGqKkMipPPz6ihRgE1ZpmEbuFJXyco73s+ienCZsNx8PFsK96i2pxBEkG/XNbiEazbcjQ7azKPQOE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724198865; c=relaxed/simple; bh=WCRbaBRnCbZY3KPWnK0TIoJhpXQWPa0O812qd+SIRYc=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=R/SC6Qp5cuv6LlPSMmThos0ccwexTzj1+t2oIP+9HjuaoowXxjyo7T32oX3bpyvFy/khC+UC1XCW38NKO8zgvh+DVXW9lMMbCgbnri7PnLzuVqOE0Mkrkj4Zp5a3mDOImSVA4GBV6hL8fRtNxWY5ELCzmCAocTKUGOXF+GAPpWM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=DQgc5Djr; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="DQgc5Djr" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 793C6C4AF09; Wed, 21 Aug 2024 00:07:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1724198864; bh=WCRbaBRnCbZY3KPWnK0TIoJhpXQWPa0O812qd+SIRYc=; h=From:To:Cc:Subject:Date:Reply-to:From; b=DQgc5DjrQTfNuj6pH7+Z/kqdzFiCMQHOZcui5RoO1dcvIqKDCS8+zqPPR0hJ04ZGr 29C8OnWRPLhiggTr1qO2Lpbs51OcYDFSgsBQHN8VZB2xwY427s6TAXu1OZ7JWFdiif fh+SZyAccqutmn/8wHlRqa7ohcazrE1Knt/qoZ3U= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2024-43869: perf: Fix event leak upon exec and file release Date: Wed, 21 Aug 2024 08:07:33 +0800 Message-ID: <2024082133-CVE-2024-43869-26aa@gregkh> X-Mailer: git-send-email 2.46.0 Precedence: bulk X-Mailing-List: linux-cve-announce@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Reply-to: , X-Developer-Signature: v=1; a=openpgp-sha256; l=3718; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=WCRbaBRnCbZY3KPWnK0TIoJhpXQWPa0O812qd+SIRYc=; b=owGbwMvMwCRo6H6F97bub03G02pJDGlH9Y9e52VcJ2vw5Wxea+K9bX+17xnI23RUR2sytv/iP eEjacjREcvCIMjEICumyPJlG8/R/RWHFL0MbU/DzGFlAhnCwMUpABNRrmaYK7fEXFfLSeViwRKj N6ufTCv1YXpRxTBX8sMZy4NLfr8LFSopTMrS6s7dnfwDAA== X-Developer-Key: i=gregkh@linuxfoundation.org; a=openpgp; fpr=F4B60CC5BF78C2214A313DCB3147D40DDB2DFB29 Content-Transfer-Encoding: 8bit Description =========== In the Linux kernel, the following vulnerability has been resolved: perf: Fix event leak upon exec and file release The perf pending task work is never waited upon the matching event release. In the case of a child event, released via free_event() directly, this can potentially result in a leaked event, such as in the following scenario that doesn't even require a weak IRQ work implementation to trigger: schedule() prepare_task_switch() =======> perf_event_overflow() event->pending_sigtrap = ... irq_work_queue(&event->pending_irq) <======= perf_event_task_sched_out() event_sched_out() event->pending_sigtrap = 0; atomic_long_inc_not_zero(&event->refcount) task_work_add(&event->pending_task) finish_lock_switch() =======> perf_pending_irq() //do nothing, rely on pending task work <======= begin_new_exec() perf_event_exit_task() perf_event_exit_event() // If is child event free_event() WARN(atomic_long_cmpxchg(&event->refcount, 1, 0) != 1) // event is leaked Similar scenarios can also happen with perf_event_remove_on_exec() or simply against concurrent perf_event_release(). Fix this with synchonizing against the possibly remaining pending task work while freeing the event, just like is done with remaining pending IRQ work. This means that the pending task callback neither need nor should hold a reference to the event, preventing it from ever beeing freed. The Linux kernel CVE team has assigned CVE-2024-43869 to this issue. Affected and fixed versions =========================== Issue introduced in 5.15.84 with commit 8bffa95ac19f and fixed in 5.15.165 with commit 9ad46f1fef42 Issue introduced in 6.1 with commit 517e6a301f34 and fixed in 6.1.103 with commit ed2c202dac55 Issue introduced in 6.1 with commit 517e6a301f34 and fixed in 6.6.44 with commit 104e258a0040 Issue introduced in 6.1 with commit 517e6a301f34 and fixed in 6.10.3 with commit f34d8307a73a Issue introduced in 6.1 with commit 517e6a301f34 and fixed in 6.11-rc1 with commit 3a5465418f5f Issue introduced in 6.0.14 with commit 78e1317a174e Please see https://www.kernel.org for a full list of currently supported kernel versions by the kernel community. Unaffected versions might change over time as fixes are backported to older supported kernel versions. The official CVE entry at https://cve.org/CVERecord/?id=CVE-2024-43869 will be updated if fixes are backported, please check that for the most up to date information about this issue. Affected files ============== The file(s) affected by this issue are: include/linux/perf_event.h kernel/events/core.c Mitigation ========== The Linux kernel CVE team recommends that you update to the latest stable kernel version for this, and many other bugfixes. Individual changes are never tested alone, but rather are part of a larger kernel release. Cherry-picking individual commits is not recommended or supported by the Linux kernel community at all. If however, updating to the latest release is impossible, the individual changes to resolve this issue can be found at these commits: https://git.kernel.org/stable/c/9ad46f1fef421d43cdab3a7d1744b2f43b54dae0 https://git.kernel.org/stable/c/ed2c202dac55423a52d7e2290f2888bf08b8ee99 https://git.kernel.org/stable/c/104e258a004037bc7dba9f6085c71dad6af57ad4 https://git.kernel.org/stable/c/f34d8307a73a18de5320fcc6f40403146d061891 https://git.kernel.org/stable/c/3a5465418f5fd970e86a86c7f4075be262682840