diff options
| author | Yadong Qi <yadong.qi@linux.alibaba.com> | 2025-10-10 09:43:11 +0800 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2025-11-16 17:28:02 -0800 |
| commit | a739e6b557af0939ed4031419374f2c563e95b68 (patch) | |
| tree | 6fd5543dac85d758c0d9be39986da275eba5e7b4 /mm/vmalloc.c | |
| parent | ca30ac479e6cf7a210dcad32fa2ee99ca0357e91 (diff) | |
mm: vmalloc: WARN_ON if mapping size is not PAGE_SIZE aligned
In mm/vmalloc.c, the function vmap_pte_range() assumes that the mapping
size is aligned to PAGE_SIZE. If this assumption is violated, the loop
will become infinite because the termination condition (`addr != end`)
will never be met. This can lead to overwriting other VA ranges and/or
random pages physically follow the page table.
It's the caller's responsibility to ensure that the mapping size is
aligned to PAGE_SIZE. However, the memory corruption is hard to root
cause. To identify the programming error in the caller easier, check
whether the mapping size is PAGE_SIZE aligned with WARN_ON_ONCE().
[yadong.qi@linux.alibaba.com: fix uninitialized value issue]
Closes: https://lore.kernel.org/r/202510110050.VG9YKMRK-lkp@intel.com/
Link: https://lkml.kernel.org/r/20251010014311.1689-1-yadong.qi@linux.alibaba.com
Signed-off-by: Yadong Qi <yadong.qi@linux.alibaba.com>
Reviewed-by: Huang Ying <ying.huang@linux.alibaba.com>
Reviewed-by: Dev Jain <dev.jain@arm.com>
Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/vmalloc.c')
| -rw-r--r-- | mm/vmalloc.c | 29 |
1 files changed, 18 insertions, 11 deletions
diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 9a63c91c6150..dcc95931ea9d 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -100,6 +100,9 @@ static int vmap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end, struct page *page; unsigned long size = PAGE_SIZE; + if (WARN_ON_ONCE(!PAGE_ALIGNED(end - addr))) + return -EINVAL; + pfn = phys_addr >> PAGE_SHIFT; pte = pte_alloc_kernel_track(pmd, addr, mask); if (!pte) @@ -167,6 +170,7 @@ static int vmap_pmd_range(pud_t *pud, unsigned long addr, unsigned long end, { pmd_t *pmd; unsigned long next; + int err = 0; pmd = pmd_alloc_track(&init_mm, pud, addr, mask); if (!pmd) @@ -180,10 +184,11 @@ static int vmap_pmd_range(pud_t *pud, unsigned long addr, unsigned long end, continue; } - if (vmap_pte_range(pmd, addr, next, phys_addr, prot, max_page_shift, mask)) - return -ENOMEM; + err = vmap_pte_range(pmd, addr, next, phys_addr, prot, max_page_shift, mask); + if (err) + break; } while (pmd++, phys_addr += (next - addr), addr = next, addr != end); - return 0; + return err; } static int vmap_try_huge_pud(pud_t *pud, unsigned long addr, unsigned long end, @@ -217,6 +222,7 @@ static int vmap_pud_range(p4d_t *p4d, unsigned long addr, unsigned long end, { pud_t *pud; unsigned long next; + int err = 0; pud = pud_alloc_track(&init_mm, p4d, addr, mask); if (!pud) @@ -230,11 +236,11 @@ static int vmap_pud_range(p4d_t *p4d, unsigned long addr, unsigned long end, continue; } - if (vmap_pmd_range(pud, addr, next, phys_addr, prot, - max_page_shift, mask)) - return -ENOMEM; + err = vmap_pmd_range(pud, addr, next, phys_addr, prot, max_page_shift, mask); + if (err) + break; } while (pud++, phys_addr += (next - addr), addr = next, addr != end); - return 0; + return err; } static int vmap_try_huge_p4d(p4d_t *p4d, unsigned long addr, unsigned long end, @@ -268,6 +274,7 @@ static int vmap_p4d_range(pgd_t *pgd, unsigned long addr, unsigned long end, { p4d_t *p4d; unsigned long next; + int err = 0; p4d = p4d_alloc_track(&init_mm, pgd, addr, mask); if (!p4d) @@ -281,11 +288,11 @@ static int vmap_p4d_range(pgd_t *pgd, unsigned long addr, unsigned long end, continue; } - if (vmap_pud_range(p4d, addr, next, phys_addr, prot, - max_page_shift, mask)) - return -ENOMEM; + err = vmap_pud_range(p4d, addr, next, phys_addr, prot, max_page_shift, mask); + if (err) + break; } while (p4d++, phys_addr += (next - addr), addr = next, addr != end); - return 0; + return err; } static int vmap_range_noflush(unsigned long addr, unsigned long end, |