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 C9D4319C540; Tue, 30 Sep 2025 22:04:23 +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=1759269863; cv=none; b=ZUZ3xHnSbqD+d0KlBSCpY2hbLex9byB02HevyIO7Af6Uz17MD8EfqDizhKKUPesuBfnVJRIEDcwb6kB6TWax/k9zfsi8DquQ73fYISOSkbNXUE46c3CqcyzKNv1OPDMyptyr3+2scBE3YFFm0hWuKS1qVKZXkvM+4P3/loMxTXM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1759269863; c=relaxed/simple; bh=OpwwMbhJZ2rP3NRKllcR4zXPav8iTuPDNfNUf+Ss5qg=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=qpCqlimvQO7NhdRfVYZ1grp7x44WmL4GHy11w8LQJoiVf7/6IAm5Ijmh+uaG7xVxAdQ5le/CFXaesajCkXXVjcafFkHSSRP4vkutYBpJvY8M+M50BC1G9jBkLDAB1SG5qILzQ+33VzMsQ1ia5yp554O4O9rZGEhmBZsvmOMgkI4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=U2EleeKZ; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="U2EleeKZ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 384A1C4CEF0; Tue, 30 Sep 2025 22:04:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1759269863; bh=OpwwMbhJZ2rP3NRKllcR4zXPav8iTuPDNfNUf+Ss5qg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=U2EleeKZjQ1Omw1IsbFLaA1ULnAEHgUFQgnUl1id/tS1ccvWAEhAfEnNi7wuhNvJS tndXrzAEXbjsk53JF44IC6455DjclVyhDtDnS7O5w8Zn9sPgOdEsT8REZeUGoj0d7o 4kcn89dLbrR8nqcacTt0klC9XYLBxOsfFVLSAztvlmZNAa+S4DePAWjLOuBDkRjCxX KX9yS5m4kto3HVylOWHFl/3pDxOrG73oRaWJ8er5QHSbzrgP/GO/TWlEeBHlQZtGml oj0yOzEX0sfDfyB7AJ4A0oatNkNndFfdAYtSlJtLYTi25FKiVsqIn7lQoWUzDy9t2o elJrTZ+EPYGMw== Date: Tue, 30 Sep 2025 15:04:22 -0700 From: Kees Cook To: syzbot Cc: brauner@kernel.org, jack@suse.cz, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, syzkaller-bugs@googlegroups.com, viro@zeniv.linux.org.uk Subject: Re: [syzbot] [fs?] [mm?] WARNING in path_noexec (2) Message-ID: <202509301457.30490A014C@keescook> References: <68dc3ade.a70a0220.10c4b.015b.GAE@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <68dc3ade.a70a0220.10c4b.015b.GAE@google.com> On Tue, Sep 30, 2025 at 01:17:34PM -0700, syzbot wrote: > Reported-by: syzbot+a9391462075ffb9f77c6@syzkaller.appspotmail.com > > ------------[ cut here ]------------ > WARNING: CPU: 1 PID: 6000 at fs/exec.c:119 path_noexec+0x1af/0x200 fs/exec.c:118 Christian, this is: bool path_noexec(const struct path *path) { /* If it's an anonymous inode make sure that we catch any shenanigans. */ VFS_WARN_ON_ONCE(IS_ANON_FILE(d_inode(path->dentry)) && !(path->mnt->mnt_sb->s_iflags & SB_I_NOEXEC)); return (path->mnt->mnt_flags & MNT_NOEXEC) || (path->mnt->mnt_sb->s_iflags & SB_I_NOEXEC); } > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=13e5fd6f980000 I think is from the created fd_dma_buf. I expect this would fix it: diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c index 2bcf9ceca997..6e2ab1a4560d 100644 --- a/drivers/dma-buf/dma-buf.c +++ b/drivers/dma-buf/dma-buf.c @@ -189,6 +189,8 @@ static int dma_buf_fs_init_context(struct fs_context *fc) { struct pseudo_fs_context *ctx; + fc->s_iflags |= SB_I_NOEXEC; + fc->s_iflags |= SB_I_NODEV; ctx = init_pseudo(fc, DMA_BUF_MAGIC); if (!ctx) return -ENOMEM; Which reminds me, this still isn't landed either for secretmem: https://lore.kernel.org/all/20250707171735.GE1880847@ZenIV/ -- Kees Cook