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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>
pull/1354/merge
Yadong Qi 2025-10-10 09:43:11 +08:00 committed by Andrew Morton
parent ca30ac479e
commit a739e6b557
1 changed files with 18 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

29
mm/vmalloc.c
View File

@ -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,