Messages in this thread Patch in this message | | | From | Mathieu Desnoyers <> | Subject | [RFC PATCH] futex: Fix futex_waitv() hrtimer debug object leak on kcalloc error | Date | Wed, 14 Dec 2022 17:20:08 -0500 |
| |
In a scenario where kcalloc() fails to allocate memory, the futex_waitv system call immediately returns -ENOMEM without invoking destroy_hrtimer_on_stack(). When CONFIG_DEBUG_OBJECTS_TIMERS=y, this results in leaking a timer debug object.
Fixes: bf69bad38cf6 ("futex: Implement sys_futex_waitv()") Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Andre Almeida <andrealmeid@collabora.com> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Darren Hart <dvhart@infradead.org> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: stable@vger.kernel.org # v5.16+ --- kernel/futex/syscalls.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-)
diff --git a/kernel/futex/syscalls.c b/kernel/futex/syscalls.c index 086a22d1adb7..a8074079b09e 100644 --- a/kernel/futex/syscalls.c +++ b/kernel/futex/syscalls.c @@ -286,19 +286,22 @@ SYSCALL_DEFINE5(futex_waitv, struct futex_waitv __user *, waiters, } futexv = kcalloc(nr_futexes, sizeof(*futexv), GFP_KERNEL); - if (!futexv) - return -ENOMEM; + if (!futexv) { + ret = -ENOMEM; + goto destroy_timer; + } ret = futex_parse_waitv(futexv, waiters, nr_futexes); if (!ret) ret = futex_wait_multiple(futexv, nr_futexes, timeout ? &to : NULL); + kfree(futexv); + +destroy_timer: if (timeout) { hrtimer_cancel(&to.timer); destroy_hrtimer_on_stack(&to.timer); } - - kfree(futexv); return ret; } -- 2.25.1
| |