From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793831516; b=YVwWh0FSKnJh5x4JaYmlu6Qy/IQqkZPcrXULv3Jv4vQNHAL/Ra64Q2JD9QoHcaujm/oC +rAgBETFMd7b2Fiv7m3Op8IGo3SSC577dLGda/fMgOQx6uRV1QdD55fFEl0U2h3X492Up Cw0JN20RXogRMydpLfa1QZB0h98B0XoasWwnX1AsIYLxbXjo9fB/nnRqwZ9fHu3iOSRjm fSWKcRlS/BoXz2Bx/BUwM+3tO+2+VCdRqlVbie/CpDNbZzaKNTz9wUgO6ISx+myq1fvZU 1J5XQGJBEu4SVi66rzUrZQsVkEK6xYfgXgppdqx2oNZUaky+gv8ZvdYtTb1LEWyTvOA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793831516; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:X-stable:X-Patchwork-Hint: MIME-Version:Content-Transfer-Encoding; bh=YQiULbk6J/Wy4xlwmiRwGC77GEa/fYbAvwWoz25jV5I=; b=h/U2eWmgkSstYDbArDbTUmpcQtBYSvK8O0RzVVFekspbj7uk96S+GDu7sdIS4PiQtebo WL6MUk2DDUotIXRhGSqosieKjjtIREkywZVbWbPGa0LF6awlh/P+azmYFl/FZolnAOmbY d+tbCKJ27HoV3tWKuI90FzPPhuVxK4o5z661gmOU0PKdZuDUPhGGHMTFxBp//dgMpl/yi JFBb7odQXS2fe87KPxhirY38OX72U1bhnteg3gIXp+AUFtloBrJcf4eHWwjuEUULVARDF fLR+XfD377ZuDVJMxNMr/VPoBXlngS+YHtvsEV/iu4ZJ/OC+dk9pm4QRB+OthYgW9og== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=IU4TQUSi; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5C306606D80B; Wed, 4 Nov 2026 22:31:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=IU4TQUSi Received: by smtp.kernel.org (Postfix) with ESMTPSA id D9B071F0093A; Wed, 4 Nov 2026 22:31:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1793831516; bh=YQiULbk6J/Wy4xlwmiRwGC77GEa/fYbAvwWoz25jV5I=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=IU4TQUSioZHeaO+8+TUg+To1KkZ7niUd5rGS6RgHnrXrdOBaoK1Q8pxOSCKYnJSZs 6ZrPKk3nKWwIES6FXxgWg5h8PiZN5e0uqRBtuSOeIBARyYm0I3YLg9IcVfCfljxJyA eButDc/CWfss68RSP7wVBajmtfFu3aNaEu2RatD8= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Sean Young , Hans Verkuil Subject: [PATCH 6.18 0750/1005] media: rc: Fix use after free in bpf progs Date: Wed, 4 Nov 2026 16:08:03 -0500 Message-ID: <20261104211104.462556528@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261104211043.516122098@linuxfoundation.org> References: <20261104211043.516122098@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: patches@lists.linux.dev List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Sean Young commit f95a9f8472f97c30106513fc7494b7abad243949 upstream. Since commit dccc0c3ddf8f ("media: rc: fix race between unregister and urb/irq callbacks"), rcdev->raw is no longer set to NULL after device unregister. raw->progs could point to stale data. Fixes: dccc0c3ddf8f ("media: rc: fix race between unregister and urb/irq callbacks") Signed-off-by: Sean Young Cc: stable@vger.kernel.org Reviewed-by: Hans Verkuil Signed-off-by: Greg Kroah-Hartman --- drivers/media/rc/bpf-lirc.c | 18 +++++++++++++----- drivers/media/rc/rc-ir-raw.c | 11 +++-------- 2 files changed, 16 insertions(+), 13 deletions(-) --- a/drivers/media/rc/bpf-lirc.c +++ b/drivers/media/rc/bpf-lirc.c @@ -148,12 +148,13 @@ static int lirc_bpf_attach(struct rc_dev if (ret) return ret; - raw = rcdev->raw; - if (!raw) { + if (!rcdev->registered) { ret = -ENODEV; goto unlock; } + raw = rcdev->raw; + old_array = lirc_rcu_dereference(raw->progs); if (old_array && bpf_prog_array_length(old_array) >= BPF_MAX_PROGS) { ret = -E2BIG; @@ -186,12 +187,13 @@ static int lirc_bpf_detach(struct rc_dev if (ret) return ret; - raw = rcdev->raw; - if (!raw) { + if (!rcdev->registered) { ret = -ENODEV; goto unlock; } + raw = rcdev->raw; + old_array = lirc_rcu_dereference(raw->progs); ret = bpf_prog_array_copy(old_array, prog, NULL, 0, &new_array); /* @@ -235,7 +237,8 @@ void lirc_bpf_free(struct rc_dev *rcdev) struct bpf_prog_array_item *item; struct bpf_prog_array *array; - array = lirc_rcu_dereference(rcdev->raw->progs); + array = rcu_replace_pointer(rcdev->raw->progs, NULL, + lockdep_is_held(&ir_raw_handler_lock)); if (!array) return; @@ -316,6 +319,11 @@ int lirc_prog_query(const union bpf_attr if (ret) goto put; + if (!rcdev->registered) { + ret = -ENODEV; + goto unlock; + } + progs = lirc_rcu_dereference(rcdev->raw->progs); cnt = progs ? bpf_prog_array_length(progs) : 0; --- a/drivers/media/rc/rc-ir-raw.c +++ b/drivers/media/rc/rc-ir-raw.c @@ -650,8 +650,11 @@ void ir_raw_event_free(struct rc_dev *de { if (dev->raw) { timer_delete_sync(&dev->raw->edge_handle); + mutex_lock(&ir_raw_handler_lock); if (dev->raw->thread) put_task_struct(dev->raw->thread); + lirc_bpf_free(dev); + mutex_unlock(&ir_raw_handler_lock); kfree(dev->raw); dev->raw = NULL; } @@ -661,9 +664,6 @@ void ir_raw_event_unregister(struct rc_d { struct ir_raw_handler *handler; - if (!dev || !dev->raw) - return; - /* * After ir_raw_event_unregister() is called, an sync * call to ir_raw_event_handle() can still arrive. This function @@ -683,11 +683,6 @@ void ir_raw_event_unregister(struct rc_d lirc_bpf_free(dev); - /* - * A user can be calling bpf(BPF_PROG_{QUERY|ATTACH|DETACH}), so - * ensure that the raw member is null on unlock; this is how - * "device gone" is checked. - */ mutex_unlock(&ir_raw_handler_lock); }