If the binary file in an execve system call is a suid executable, we add the PF_SUID flag to the process and all its future new children and threads. In a later commit, we will use this information to determine if it is safe to core dump such a process. Signed-off-by: Wander Lairson Costa <wander@xxxxxxxxxx> --- fs/exec.c | 4 ++++ include/linux/sched.h | 1 + kernel/fork.c | 2 ++ 3 files changed, 7 insertions(+) diff --git a/fs/exec.c b/fs/exec.c index 3913b335b95f..b4bd157a5282 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -1311,6 +1311,10 @@ int begin_new_exec(struct linux_binprm * bprm) me->flags &= ~(PF_RANDOMIZE | PF_FORKNOEXEC | PF_KTHREAD | PF_NOFREEZE | PF_NO_SETAFFINITY); + + if (bprm->suid_bin) + me->flags |= PF_SUID; + flush_thread(); me->personality &= ~bprm->per_clear; diff --git a/include/linux/sched.h b/include/linux/sched.h index e3b328b81ac0..f7811c42b004 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1651,6 +1651,7 @@ extern struct pid *cad_pid; #define PF_VCPU 0x00000001 /* I'm a virtual CPU */ #define PF_IDLE 0x00000002 /* I am an IDLE thread */ #define PF_EXITING 0x00000004 /* Getting shut down */ +#define PF_SUID 0x00000008 /* The process comes from a suid/sgid binary */ #define PF_IO_WORKER 0x00000010 /* Task is an IO worker */ #define PF_WQ_WORKER 0x00000020 /* I'm a workqueue worker */ #define PF_FORKNOEXEC 0x00000040 /* Forked but didn't exec */ diff --git a/kernel/fork.c b/kernel/fork.c index 231b1ba3ca9f..1e1ffff70d14 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -2080,6 +2080,8 @@ static __latent_entropy struct task_struct *copy_process( delayacct_tsk_init(p); /* Must remain after dup_task_struct() */ p->flags &= ~(PF_SUPERPRIV | PF_WQ_WORKER | PF_IDLE | PF_NO_SETAFFINITY); p->flags |= PF_FORKNOEXEC; + if (current->flags & PF_SUID) + p->flags |= PF_SUID; INIT_LIST_HEAD(&p->children); INIT_LIST_HEAD(&p->sibling); rcu_copy_process(p); -- 2.27.0
