From: Barnabás Pőcze pobrn@protonmail.com

mainline inclusion form mainline-v6.2-rc1 commit 2f117484329b233455ee278f2d9b0a4356835060 category: bugfix https://gitee.com/openeuler/kernel/issues/I8MCB5 CVE: NA

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When `timerqueue_getnext()` is called on an empty timer queue, it will use `rb_entry()` on a NULL pointer, which is invalid. Fix that by using `rb_entry_safe()` which handles NULL pointers.

This has not caused any issues so far because the offset of the `rb_node` member in `timerqueue_node` is 0, so `rb_entry()` is essentially a no-op.

Fixes: 511885d7061e ("lib/timerqueue: Rely on rbtree semantics for next timer") Signed-off-by: Barnabás Pőcze pobrn@protonmail.com Signed-off-by: Thomas Gleixner tglx@linutronix.de Link: https://lore.kernel.org/r/20221114195421.342929-1-pobrn@protonmail.com Signed-off-by: liwei liwei728@huawei.com --- include/linux/timerqueue.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/linux/timerqueue.h b/include/linux/timerqueue.h index f71c1ce1421f..bcc0afc62522 100644 --- a/include/linux/timerqueue.h +++ b/include/linux/timerqueue.h @@ -40,7 +40,7 @@ struct timerqueue_node *timerqueue_getnext(struct timerqueue_head *head) { struct rb_node *leftmost = rb_first_cached(&head->rb_root);

- return rb_entry(leftmost, struct timerqueue_node, node); + return rb_entry_safe(leftmost, struct timerqueue_node, node); }

static inline void timerqueue_init(struct timerqueue_node *node)