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| author | Kees Cook <keescook@chromium.org> | 2024-01-24 11:15:33 -0800 |
|---|---|---|
| committer | Kees Cook <keescook@chromium.org> | 2024-01-24 11:48:52 -0800 |
| commit | 90383cc07895183c75a0db2460301c2ffd912359 (patch) | |
| tree | ca41f9d32f052e063b48e864ac60171b55c300b5 | |
| parent | 84c39ec57d409e803a9bb6e4e85daf1243e0e80b (diff) | |
| download | lwn-90383cc07895183c75a0db2460301c2ffd912359.tar.gz lwn-90383cc07895183c75a0db2460301c2ffd912359.zip | |
exec: Distinguish in_execve from in_exec
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 <takedakn@nttdata.co.jp>
Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: linux-fsdevel@vger.kernel.org
Cc: linux-mm@kvack.org
Signed-off-by: Kees Cook <keescook@chromium.org>
| -rw-r--r-- | fs/exec.c | 1 | ||||
| -rw-r--r-- | include/linux/sched.h | 2 | ||||
| -rw-r--r-- | kernel/fork.c | 1 |
3 files changed, 3 insertions, 1 deletions
diff --git a/fs/exec.c b/fs/exec.c index 39d773021fff..d179abb78a1c 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -1633,6 +1633,7 @@ 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 cdb8ea53c365..ffe8f618ab86 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -920,7 +920,7 @@ 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 47ff3b35352e..0d944e92a43f 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -1748,6 +1748,7 @@ 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; |