From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 795064A6CD0 for ; Thu, 3 Sep 2026 12:55:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788440123; cv=none; b=rxa0nDsJb8Sdh4BJ0gkVcAKi59Amy8NQoUcWbjIakpC7A+3CzwMtSUWgNhcH/7/Gi5RrpRpXVsE80aPpgeBrHtuEL58flHph5wx+f1q4cw/HfD0LoD59zKCZE7QIbsd9F8VddIBfQPKhOhOkud/aMY0TgXELnttyfw0Qlnqa5IU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788440123; c=relaxed/simple; bh=JwMPtFgaeBxeWywdmpBi7X5eMXlWHAAxrd/vLczVvTo=; h=Subject:To:Cc:From:Date:Message-ID:MIME-Version:Content-Type; b=kIO38//9Csq2O+tlkOiM4ODg+Ign6SOXk+bm7KXyW1Hqc6rGYnEb4+nG7yZXRLB9CLpZLSW7gvniE8siu/3/UH4goEuJwfwP+kvZ++kYC/s6bJ29PUuY7XjJcGgBrHNMQ2P+9U/qBPACxk/KkqAUZwPnZXKS2UA4zm+AlGYNOAI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=FQBfOjlm; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="FQBfOjlm" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D6A0D1F000E9; Thu, 3 Sep 2026 12:55:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1788440122; bh=+fkKXxIjAwL9KdB6dOG7AVl4VY/hxRkLJ4pnw8AK+Ds=; h=Subject:To:Cc:From:Date; b=FQBfOjlmJIunt4SMDVHkiO5qZRefmkTifItt8Gue46Z/1BAeeOOpH9H2ZyIBMuHjO BhKQT48jH+JrYNeIf5MFVTwfZX3swkIe6ChwLrMBUQTjKqgXpe7Y9QMnJeHyHJL+FG nIfsOrkhF9a+9eMdHzCbzwpB0vPuxi497bNObTzM= Subject: FAILED: patch "[PATCH] usb: gadget: f_fs: Fix Use-After-Free in AIO error path" failed to apply to 6.18-stable tree To: nkapron@google.com,gregkh@linuxfoundation.org,xingyuj@google.com Cc: From: Date: Thu, 03 Sep 2026 14:41:31 +0200 Message-ID: <2026090331-width-covenant-cd4e@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit The patch below does not apply to the 6.18-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.18.y git checkout FETCH_HEAD git cherry-pick -x e78dcb1f7ec271449c54984dc90c62a5ba272de7 # git commit -s git send-email --to '' --in-reply-to '2026090331-width-covenant-cd4e@gregkh' --subject-prefix 'PATCH 6.18.y' 'HEAD^..' Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From e78dcb1f7ec271449c54984dc90c62a5ba272de7 Mon Sep 17 00:00:00 2001 From: Neill Kapron Date: Fri, 24 Jul 2026 23:51:00 +0000 Subject: [PATCH] usb: gadget: f_fs: Fix Use-After-Free in AIO error path In ffs_epfile_write_iter() and ffs_epfile_read_iter(), when ffs_epfile_io() fails with an error other than -EIOCBQUEUED, the io_data structure (`p`) is freed. However, for AIO operations, the kiocb cancel function was already armed and kiocb->private was set to `p`. If a concurrent cancel operation (such as sys_io_cancel()) executes after ffs_epfile_io() fails but before the function frees `p`, a Use-After-Free can occur when the cancellation handler accesses the freed pointer. To securely fix this race condition, we must properly un-arm the cancellation. Invoking `kiocb->ki_complete()` does exactly this by acquiring `ctx->ctx_lock` and safely removing the kiocb from the active sequence. In doing so, it ensures that a parallel io_cancel can no longer discover the kiocb, effectively closing the race window. We then return -EIOCBQUEUED to notify the VFS layer that the kiocb has been consumed and it should avoid attempting to complete the request again or triggering subsequent completion handlers. Fixes: de2080d41b5d ("gadget/function/f_fs.c: close leaks") Cc: stable@vger.kernel.org Reported-by: Xingyu Jin Assisted-by: Antigravity:gemini-3.1-pro Signed-off-by: Neill Kapron Link: https://patch.msgid.link/20260724235100.106011-1-nkapron@google.com Signed-off-by: Greg Kroah-Hartman diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c index cfa05266e551..43962e05eacf 100644 --- a/drivers/usb/gadget/function/f_fs.c +++ b/drivers/usb/gadget/function/f_fs.c @@ -1296,8 +1296,10 @@ static ssize_t ffs_epfile_write_iter(struct kiocb *kiocb, struct iov_iter *from) if (res == -EIOCBQUEUED) return res; if (p->aio) { + kiocb->ki_complete(kiocb, res); mmdrop(p->mm); kfree(p); + return -EIOCBQUEUED; } else { *from = p->data; } @@ -1345,9 +1347,11 @@ static ssize_t ffs_epfile_read_iter(struct kiocb *kiocb, struct iov_iter *to) return res; if (p->aio) { + kiocb->ki_complete(kiocb, res); mmdrop(p->mm); kfree(p->to_free); kfree(p); + return -EIOCBQUEUED; } else { *to = p->data; }