From: Kees Cook <[email protected]>
[ 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 <[email protected]>
Cc: Tetsuo Handa <[email protected]>
Cc: Alexander Viro <[email protected]>
Cc: Christian Brauner <[email protected]>
Cc: Jan Kara <[email protected]>
Cc: Eric Biederman <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Sebastian Andrzej Siewior <[email protected]>
Cc: [email protected]
Cc: [email protected]
Signed-off-by: Kees Cook <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
---
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 983295c0b8ac..b809f4a39296 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -1565,6 +1565,7 @@ 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 aa015416c569..65cfe85de8d5 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -806,7 +806,7 @@ struct task_struct {
*/
unsigned sched_remote_wakeup:1;
- /* 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 633b0af1d1a7..906dbaf25058 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1452,6 +1452,7 @@ 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
Hi!
> From: Kees Cook <[email protected]>
>
> [ 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.
These are just a whitespace changes, we should not need them.
Best regards,
Pavel
> +++ b/fs/exec.c
> @@ -1565,6 +1565,7 @@ 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 aa015416c569..65cfe85de8d5 100644
> --- a/include/linux/sched.h
> +++ b/include/linux/sched.h
> @@ -806,7 +806,7 @@ struct task_struct {
> */
> unsigned sched_remote_wakeup:1;
>
> - /* 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 633b0af1d1a7..906dbaf25058 100644
> --- a/kernel/fork.c
> +++ b/kernel/fork.c
> @@ -1452,6 +1452,7 @@ 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;
--
DENX Software Engineering GmbH, Managing Director: Erika Unter
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
On Sun, Feb 18, 2024 at 08:12:56PM +0100, Pavel Machek wrote:
>Hi!
>
>> From: Kees Cook <[email protected]>
>>
>> [ 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.
>
>These are just a whitespace changes, we should not need them.
Dropped, thanks!
--
Thanks,
Sasha