Messages in this thread Patch in this message | | | From | Jia-Ju Bai <> | Subject | [PATCH] mm: mempool: Fix a possible sleep-in-atomic-context bug in mempool_resize() | Date | Thu, 21 Jun 2018 11:07:14 +0800 |
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The kernel may sleep with holding a spinlock. The function call path (from bottom to top) in Linux-4.16.7 is:
[FUNC] remove_element(GFP_KERNEL) mm/mempool.c, 250: remove_element in mempool_resize mm/mempool.c, 247: _raw_spin_lock_irqsave in mempool_resize
To fix this bug, GFP_KERNEL is replaced with GFP_ATOMIC.
This bug is found by my static analysis tool (DSAC-2) and checked by my code review.
Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com> --- mm/mempool.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/mm/mempool.c b/mm/mempool.c index 5c9dce34719b..d33bd5d622e7 100644 --- a/mm/mempool.c +++ b/mm/mempool.c @@ -247,7 +247,7 @@ int mempool_resize(mempool_t *pool, int new_min_nr) spin_lock_irqsave(&pool->lock, flags); if (new_min_nr <= pool->min_nr) { while (new_min_nr < pool->curr_nr) { - element = remove_element(pool, GFP_KERNEL); + element = remove_element(pool, GFP_ATOMIC); spin_unlock_irqrestore(&pool->lock, flags); pool->free(element, pool->pool_data); spin_lock_irqsave(&pool->lock, flags); -- 2.17.0
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