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 E172581738; Fri, 2 Feb 2024 18:39:57 +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=1706899198; cv=none; b=fFRZQvhPye7yUGI+Ydm4IRWyd52i22N/vESJ3E/YvuzA5pk3ij0lu5+rG1JdDJl31GveaJYPSk7Osf7GUqvq9r/pnPwjT0n7K8/25c4MAKB30yQD17nrUC0PceX3QpX/dBJ3DXhQE68ZAQZ8Yrd/Y+EHMYwc9Vg9y7pU6M6e12I= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706899198; c=relaxed/simple; bh=/GgaPwcxXLMGw96QHxTmcd+p19bQxwEOIwtu1eiz/68=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=fAiAZe99ohnASUnPehI/5KAzlCgh30ToSvPRdIGQgKLZieFg62ZEiJekQj95jelXRh9/px//sp56mE0LQOtXP+UDT1MKQ8UBB5XCXoceiHK4BtXzSvvg28eewLqD2o8VSbKkMs6TjVKYGCpqJPNrao6HcKbeOvoDifhIuhbCeB8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Jl+YNTKR; 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="Jl+YNTKR" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 40F2FC433F1; Fri, 2 Feb 2024 18:39:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1706899196; bh=/GgaPwcxXLMGw96QHxTmcd+p19bQxwEOIwtu1eiz/68=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Jl+YNTKRZO5Z+q5sSVrCvBMLinJwzJiFHevf5cc0E850wSV7g+8YJQDZQyUeUF+mE 66v1RL822OouIsrLjzuoqzw8bNc1yXUogCD+igc/h3yBOt8YMeJfcrRG9GHa63sYD3 XRGw5dMxqGwVmSesZthdsLiKHZcZnluV+fl4+VmvkVayQR0LdJjPGMJxrw9o+0NaJ0 2z4Sy9mhBDn/qWCVktFC3bWRAljG6V9F26iTRI2yE9E4wbQcW3acwzKyK6Qk2IRHPB Hwa4u+UJBC677Us4mNUGr0Ok4VJMcyFeueoAcbelWSSpNNGBcg31n0n5m3znMryapY 96Og3VM/HUQfg== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Kees Cook , Kentaro Takeda , Tetsuo Handa , Alexander Viro , Christian Brauner , Jan Kara , Eric Biederman , Andrew Morton , Sebastian Andrzej Siewior , linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, Sasha Levin , mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com, vincent.guittot@linaro.org, surenb@google.com, mst@redhat.com, michael.christie@oracle.com, mjguzik@gmail.com, npiggin@gmail.com, zhangpeng.00@bytedance.com, hca@linux.ibm.com Subject: [PATCH AUTOSEL 6.7 18/23] exec: Distinguish in_execve from in_exec Date: Fri, 2 Feb 2024 13:39:14 -0500 Message-ID: <20240202183926.540467-18-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240202183926.540467-1-sashal@kernel.org> References: <20240202183926.540467-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.7.3 Content-Transfer-Encoding: 8bit From: Kees Cook [ Upstream commit 90383cc07895183c75a0db2460301c2ffd912359 ] Just to help distinguish the fs->in_exec flag from the current->in_execve flag, add comments in check_unsafe_exec() and copy_fs() for more context. Also note that in_execve is only used by TOMOYO now. Cc: Kentaro Takeda Cc: Tetsuo Handa Cc: Alexander Viro Cc: Christian Brauner Cc: Jan Kara Cc: Eric Biederman Cc: Andrew Morton Cc: Sebastian Andrzej Siewior Cc: linux-fsdevel@vger.kernel.org Cc: linux-mm@kvack.org Signed-off-by: Kees Cook Signed-off-by: Sasha Levin --- fs/exec.c | 1 + include/linux/sched.h | 2 +- kernel/fork.c | 1 + 3 files changed, 3 insertions(+), 1 deletion(-) diff --git a/fs/exec.c b/fs/exec.c index 4aa19b24f281..3842066d5b0b 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -1588,6 +1588,7 @@ static void check_unsafe_exec(struct linux_binprm *bprm) } rcu_read_unlock(); + /* "users" and "in_exec" locked for copy_fs() */ if (p->fs->users > n_fs) bprm->unsafe |= LSM_UNSAFE_SHARE; else diff --git a/include/linux/sched.h b/include/linux/sched.h index 292c31697248..de0e2752c5b2 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -917,7 +917,7 @@ struct task_struct { unsigned sched_rt_mutex:1; #endif - /* Bit to tell LSMs we're in execve(): */ + /* Bit to tell TOMOYO we're in execve(): */ unsigned in_execve:1; unsigned in_iowait:1; #ifndef TIF_RESTORE_SIGMASK diff --git a/kernel/fork.c b/kernel/fork.c index 10917c3e1f03..0a08837e1443 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -1754,6 +1754,7 @@ static int copy_fs(unsigned long clone_flags, struct task_struct *tsk) if (clone_flags & CLONE_FS) { /* tsk->fs is already what we want */ spin_lock(&fs->lock); + /* "users" and "in_exec" locked for check_unsafe_exec() */ if (fs->in_exec) { spin_unlock(&fs->lock); return -EAGAIN; -- 2.43.0