From: Ma Wupeng mawupeng1@huawei.com

euleros inclusion category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I7WLVX

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Add overflow check for gmem prefetch/eagerfree.

Fixes: 3e01aec2b2e8 ("mm: gmem: Introduce hmadvise") Signed-off-by: Ma Wupeng mawupeng1@huawei.com --- mm/gmem.c | 30 +++++++++++++++++++++++++++--- 1 file changed, 27 insertions(+), 3 deletions(-)

diff --git a/mm/gmem.c b/mm/gmem.c index a710869d04a9..90a5b5fda284 100644 --- a/mm/gmem.c +++ b/mm/gmem.c @@ -622,12 +622,25 @@ static int hmadvise_do_prefetch(gm_dev_t *dev, unsigned long addr, size_t size) struct prefetch_data *data; struct vm_area_struct *vma; int res = GM_RET_SUCCESS; + unsigned long old_start; + + /* overflow */ + if (check_add_overflow(addr, size, &end)) + return -EINVAL; + + old_start = end;

/* Align addr by rounding outward to make page cover addr. */ - end = round_up(addr + size, page_size); + end = round_up(end, page_size); start = round_down(addr, page_size); size = end - start;

+ if (!end && old_start) + return -EINVAL; + + if (size == 0) + return 0; + mmap_read_lock(current->mm); vma = find_vma(current->mm, start); if (!vma || start < vma->vm_start || end > vma->vm_end) { @@ -675,19 +688,30 @@ static int hmadvise_do_eagerfree(unsigned long addr, size_t size) .size = page_size, .copy = false, }; + unsigned long old_start; vm_object_t *obj;

+ /* overflow */ + if (check_add_overflow(addr, size, &end)) + return -EINVAL; + + old_start = addr; + /* Align addr by rounding inward to avoid excessive page release. */ - end = round_down(addr + size, page_size); + end = round_down(end, page_size); start = round_up(addr, page_size); if (start >= end) return ret;

+ /* Check to see whether len was rounded up from small -ve to zero */ + if (old_start && !start) + return -EINVAL; + mmap_read_lock(current->mm); do { vma = find_vma(current->mm, start); if (!vma || !vma_is_peer_shared(vma)) { - pr_err("gmem: not peer-shared vma, skip dontneed\n"); + pr_info_ratelimited("gmem: not peer-shared vma, skip dontneed\n"); continue; } obj = vma->vm_obj;