@@ -8,28 +8,27 @@
#include <asm/cpufeature.h>
#include <asm/mte.h>
-#define for_each_mte_vma(vmi, vma) \
+#define for_each_mte_vma(cprm, i, m) \
if (system_supports_mte()) \
- for_each_vma(vmi, vma) \
- if (vma->vm_flags & VM_MTE)
+ for (i = 0, m = cprm->vma_meta; \
+ i < cprm->vma_count; \
+ i++, m = cprm->vma_meta + i) \
+ if (m->flags & VM_MTE)
-static unsigned long mte_vma_tag_dump_size(struct vm_area_struct *vma)
+static unsigned long mte_vma_tag_dump_size(struct core_vma_metadata *m)
{
- if (vma->vm_flags & VM_DONTDUMP)
- return 0;
-
- return vma_pages(vma) * MTE_PAGE_TAG_STORAGE;
+ return (m->dump_size >> PAGE_SHIFT) * MTE_PAGE_TAG_STORAGE;
}
/* Derived from dump_user_range(); start/end must be page-aligned */
static int mte_dump_tag_range(struct coredump_params *cprm,
- unsigned long start, unsigned long end)
+ unsigned long start, unsigned long len)
{
int ret = 1;
unsigned long addr;
void *tags = NULL;
- for (addr = start; addr < end; addr += PAGE_SIZE) {
+ for (addr = start; addr < start + len; addr += PAGE_SIZE) {
struct page *page = get_dump_page(addr);
/*
@@ -78,11 +77,11 @@ static int mte_dump_tag_range(struct coredump_params *cprm,
Elf_Half elf_core_extra_phdrs(struct coredump_params *cprm)
{
- struct vm_area_struct *vma;
+ int i;
+ struct core_vma_metadata *m;
int vma_count = 0;
- VMA_ITERATOR(vmi, current->mm, 0);
- for_each_mte_vma(vmi, vma)
+ for_each_mte_vma(cprm, i, m)
vma_count++;
return vma_count;
@@ -90,18 +89,18 @@ Elf_Half elf_core_extra_phdrs(struct coredump_params *cprm)
int elf_core_write_extra_phdrs(struct coredump_params *cprm, loff_t offset)
{
- struct vm_area_struct *vma;
- VMA_ITERATOR(vmi, current->mm, 0);
+ int i;
+ struct core_vma_metadata *m;
- for_each_mte_vma(vmi, vma) {
+ for_each_mte_vma(cprm, i, m) {
struct elf_phdr phdr;
phdr.p_type = PT_AARCH64_MEMTAG_MTE;
phdr.p_offset = offset;
- phdr.p_vaddr = vma->vm_start;
+ phdr.p_vaddr = m->start;
phdr.p_paddr = 0;
- phdr.p_filesz = mte_vma_tag_dump_size(vma);
- phdr.p_memsz = vma->vm_end - vma->vm_start;
+ phdr.p_filesz = mte_vma_tag_dump_size(m);
+ phdr.p_memsz = m->end - m->start;
offset += phdr.p_filesz;
phdr.p_flags = 0;
phdr.p_align = 0;
@@ -115,26 +114,23 @@ int elf_core_write_extra_phdrs(struct coredump_params *cprm, loff_t offset)
size_t elf_core_extra_data_size(struct coredump_params *cprm)
{
- struct vm_area_struct *vma;
+ int i;
+ struct core_vma_metadata *m;
size_t data_size = 0;
- VMA_ITERATOR(vmi, current->mm, 0);
- for_each_mte_vma(vmi, vma)
- data_size += mte_vma_tag_dump_size(vma);
+ for_each_mte_vma(cprm, i, m)
+ data_size += mte_vma_tag_dump_size(m);
return data_size;
}
int elf_core_write_extra_data(struct coredump_params *cprm)
{
- struct vm_area_struct *vma;
- VMA_ITERATOR(vmi, current->mm, 0);
-
- for_each_mte_vma(vmi, vma) {
- if (vma->vm_flags & VM_DONTDUMP)
- continue;
+ int i;
+ struct core_vma_metadata *m;
- if (!mte_dump_tag_range(cprm, vma->vm_start, vma->vm_end))
+ for_each_mte_vma(cprm, i, m) {
+ if (!mte_dump_tag_range(cprm, m->start, m->dump_size))
return 0;
}
The MTE coredump code in arch/arm64/kernel/elfcore.c iterates over the vma list without the mmap_lock held. This can race with another process or userfaultfd concurrently modifying the vma list. Change the for_each_mte_vma macro and its callers to instead use the vma snapshot taken by dump_vma_snapshot() and stored in the cprm object. Fixes: 6dd8b1a0b6cb ("arm64: mte: Dump the MTE tags in the core file") Cc: <stable@vger.kernel.org> # 5.18.x Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Reported-by: Seth Jenkins <sethjenkins@google.com> Suggested-by: Seth Jenkins <sethjenkins@google.com> Cc: Will Deacon <will@kernel.org> --- arch/arm64/kernel/elfcore.c | 56 +++++++++++++++++-------------------- 1 file changed, 26 insertions(+), 30 deletions(-)