From: Thomas Gleixner <tglx@linutronix.de>
To: LKML <linux-kernel@vger.kernel.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>,
Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@kernel.org>, Oleg Nesterov <oleg@redhat.com>,
Michael Kerrisk <mtk.manpages@googlemail.com>,
Kees Cook <keescook@chromium.org>
Subject: [patch V2 5/6] posix-cpu-timers: Return PTR_ERR() from lookup_task()
Date: Mon, 23 Sep 2019 16:54:40 +0200 [thread overview]
Message-ID: <20190923145528.856703803@linutronix.de> (raw)
In-Reply-To: 20190923145435.507024424@linutronix.de
To prepare for changing the return code to -EPERM when the ptrace
permission check fails, use PTR_ERR() to return the error information from
lookup_task() and fixup all call sites.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
V2: New patch
---
kernel/time/posix-cpu-timers.c | 22 ++++++++++++----------
1 file changed, 12 insertions(+), 10 deletions(-)
--- a/kernel/time/posix-cpu-timers.c
+++ b/kernel/time/posix-cpu-timers.c
@@ -63,7 +63,7 @@ static struct task_struct *lookup_task(c
p = find_task_by_vpid(pid);
if (!p)
- return p;
+ return ERR_PTR(-EINVAL);
if (gettime) {
/*
@@ -103,11 +103,11 @@ static struct task_struct *lookup_task(c
* the timer is destroyed.
*/
if (!has_group_leader_pid(p))
- return NULL;
+ return ERR_PTR(-EINVAL);
}
/* Decide based on the ptrace permissions. */
- return ptrace_may_access(p, mode) ? p : NULL;
+ return ptrace_may_access(p, mode) ? p : ERR_PTR(-EINVAL);
}
static struct task_struct *__get_task_for_clock(const clockid_t clock,
@@ -118,11 +118,11 @@ static struct task_struct *__get_task_fo
struct task_struct *p;
if (CPUCLOCK_WHICH(clock) >= CPUCLOCK_MAX)
- return NULL;
+ return ERR_PTR(-EINVAL);
rcu_read_lock();
p = lookup_task(pid, thread, gettime);
- if (p && getref)
+ if (!IS_ERR(p) && getref)
get_task_struct(p);
rcu_read_unlock();
return p;
@@ -140,7 +140,9 @@ static inline struct task_struct *get_ta
static inline int validate_clock_permissions(const clockid_t clock)
{
- return __get_task_for_clock(clock, false, false) ? 0 : -EINVAL;
+ struct task_struct *res = __get_task_for_clock(clock, false, false);
+
+ return IS_ERR(res) ? PTR_ERR(res) : 0;
}
/*
@@ -391,8 +393,8 @@ static int posix_cpu_clock_get(const clo
u64 t;
tsk = get_task_for_clock_get(clock);
- if (!tsk)
- return -EINVAL;
+ if (IS_ERR(tsk))
+ return PTR_ERR(tsk);
if (CPUCLOCK_PERTHREAD(clock))
t = cpu_clock_sample(clkid, tsk);
@@ -413,8 +415,8 @@ static int posix_cpu_timer_create(struct
{
struct task_struct *p = get_task_for_clock(new_timer->it_clock);
- if (!p)
- return -EINVAL;
+ if (IS_ERR(p))
+ return PTR_ERR(p);
new_timer->kclock = &clock_posix_cpu;
timerqueue_init(&new_timer->it.cpu.node);
next prev parent reply other threads:[~2019-09-23 14:56 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-23 14:54 [patch V2 0/6] posix-cpu-timers: Fix bogus permission checks Thomas Gleixner
2019-09-23 14:54 ` [patch V2 1/6] posix-cpu-timers: Restrict timer_create() permissions Thomas Gleixner
2019-09-23 14:54 ` [patch V2 2/6] posix-cpu-timers: Restrict clock_gettime() permissions Thomas Gleixner
2019-09-23 14:54 ` [patch V2 3/6] posix-cpu-timers: Sanitize thread clock permissions Thomas Gleixner
2019-09-23 14:54 ` [patch V2 4/6] posix-cpu-timers: Make PID=0 and PID=self handling consistent Thomas Gleixner
2019-09-23 14:54 ` Thomas Gleixner [this message]
2019-09-23 15:43 ` [patch V2 5/6] posix-cpu-timers: Return PTR_ERR() from lookup_task() Frederic Weisbecker
2019-09-23 14:54 ` [patch V2 6/6] posix-cpu-timers: Return -EPERM if ptrace permission check fails Thomas Gleixner
2019-09-23 15:46 ` Frederic Weisbecker
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