The following commit has been merged into the locking/urgent branch of tip:

Commit-ID: 94cd8fa09f5f1ebdd4e90964b08b7f2cc4b36c43 Gitweb: https://git.kernel.org/tip/94cd8fa09f5f1ebdd4e90964b08b7f2cc4b36c43 Author: Mathieu Desnoyers mathieu.desnoyers@efficios.com AuthorDate: Wed, 14 Dec 2022 17:20:08 -05:00 Committer: Peter Zijlstra peterz@infradead.org CommitterDate: Tue, 27 Dec 2022 12:52:02 +01:00

futex: Fix futex_waitv() hrtimer debug object leak on kcalloc error

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 Signed-off-by: Peter Zijlstra (Intel) peterz@infradead.org Reviewed-by: Davidlohr Bueso dave@stgolabs.net Cc: stable@vger.kernel.org Cc: stable@vger.kernel.org # v5.16+ Link: https://lore.kernel.org/r/20221214222008.200393-1-mathieu.desnoyers@efficios... --- 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 086a22d..a807407 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; }