hulk inclusion category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/IAZLJE CVE: NA

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fix DTS2024100908489

Fixes: 221302d362d3 (“svm: add support for allocing memory which is within 4G physical address in svm_mmap”) Signed-off-by: Lin Ruifeng linruifeng4@huawei.com --- drivers/char/svm.c | 55 +++++++++++++++++++++++++++++++++------------- 1 file changed, 40 insertions(+), 15 deletions(-)

diff --git a/drivers/char/svm.c b/drivers/char/svm.c index 4cd04ca378ff..d7f70f2019e2 100644 --- a/drivers/char/svm.c +++ b/drivers/char/svm.c @@ -1503,6 +1503,40 @@ static int svm_proc_load_flag(int __user *arg) return put_user(flag, arg); }

+static void svm_vma_open(struct vm_area_struct *vma) +{ + struct page *page = vma->vm_private_data; + + if (page) + get_page(page); +} + +static void svm_vma_close(struct vm_area_struct *vma) +{ + struct page *page = vma->vm_private_data; + + put_page(page); +} + +/* avoid split */ +static int svm_vma_split(struct vm_area_struct *area, unsigned long addr) +{ + return -EINVAL; +} + +/* avoid mremap */ +static int svm_vma_mremap(struct vm_area_struct *area) +{ + return -EINVAL; +} + +static const struct vm_operations_struct svm_vma_ops = { + .open = svm_vma_open, + .close = svm_vma_close, + .split = svm_vma_split, + .mremap = svm_vma_mremap, +}; + static int svm_mmap(struct file *file, struct vm_area_struct *vma) { int err; @@ -1540,6 +1574,9 @@ static int svm_mmap(struct file *file, struct vm_area_struct *vma) dev_err(sdev->dev, "fail to remap 0x%pK err=%d\n", (void *)vma->vm_start, err); + + vma->vm_private_data = page; + vma->vm_ops = &svm_vma_ops; } else { if ((vma->vm_end < vma->vm_start) || ((vma->vm_end - vma->vm_start) > sdev->l2size)) @@ -1566,9 +1603,7 @@ static int svm_release_phys32(unsigned long __user *arg) { struct mm_struct *mm = current->mm; struct vm_area_struct *vma = NULL; - struct page *page = NULL; - pte_t *pte = NULL; - unsigned long phys, addr, offset; + unsigned long addr; unsigned int len = 0;

if (arg == NULL) @@ -1578,28 +1613,18 @@ static int svm_release_phys32(unsigned long __user *arg) return -EFAULT;

down_read(&mm->mmap_sem); - pte = svm_walk_pt(addr, NULL, &offset); - if (pte && pte_present(*pte)) { - phys = PFN_PHYS(pte_pfn(*pte)) + offset; - } else { - up_read(&mm->mmap_sem); - return -EINVAL; - }

vma = find_vma(mm, addr); - if (!vma) { + if (!vma || addr != vma->vm_start) { up_read(&mm->mmap_sem); return -EFAULT; }

- page = phys_to_page(phys); len = vma->vm_end - vma->vm_start;

- __free_pages(page, get_order(len)); - up_read(&mm->mmap_sem);

- return 0; + return vm_munmap(addr, len); }

static unsigned long svm_sp_alloc_mem(unsigned long __user *arg)