History

usercopy: Handle vm_map_ram() areas

vmalloc does not allocate a vm_struct for vm_map_ram() areas. That causes us to deny usercopies from those areas. This affects XFS which uses vm_map_ram() for its directories. Fix this by calling find_vmap_area() instead of find_vm_area().

Matthew Wilcox (Oracle) committed 4 years ago

Commit 993d0b21 parent 57cd6d13 files · +6 −7Browse files

Unified · Split

3 files
  1. include/linux/vmalloc.h +1 −0
  2. mm/usercopy.c +4 −6
  3. mm/vmalloc.c +1 −1
include/linux/vmalloc.h+1−0
@@ -215,6 +215,7 @@ extern struct vm_struct *__get_vm_area_caller(unsigned long size, · 214 unmodified lines
215void free_vm_area(struct vm_struct *area);215void free_vm_area(struct vm_struct *area);
216extern struct vm_struct *remove_vm_area(const void *addr);216extern struct vm_struct *remove_vm_area(const void *addr);
217extern struct vm_struct *find_vm_area(const void *addr);217extern struct vm_struct *find_vm_area(const void *addr);
218struct vmap_area *find_vmap_area(unsigned long addr);
218 219
219static inline bool is_vm_area_hugepages(const void *addr)220static inline bool is_vm_area_hugepages(const void *addr)
220{221{
mm/usercopy.c+4−6
@@ -173,16 +173,14 @@ static inline void check_heap_object(const void *ptr, unsigned long n, · 172 unmodified lines
173 }173 }
174 174
175 if (is_vmalloc_addr(ptr)) {175 if (is_vmalloc_addr(ptr)) {
176 struct vm_struct *area = find_vm_area(ptr);176 struct vmap_area *area = find_vmap_area((unsigned long)ptr);
177 unsigned long offset;177 unsigned long offset;
178 178
179 if (!area) {179 if (!area)
180 usercopy_abort("vmalloc", "no area", to_user, 0, n);180 usercopy_abort("vmalloc", "no area", to_user, 0, n);
181 return;
182 }
183 181
184 offset = ptr - area->addr;182 offset = (unsigned long)ptr - area->va_start;
185 if (offset + n > get_vm_area_size(area))183 if ((unsigned long)ptr + n > area->va_end)
186 usercopy_abort("vmalloc", NULL, to_user, offset, n);184 usercopy_abort("vmalloc", NULL, to_user, offset, n);
187 return;185 return;
188 }186 }
mm/vmalloc.c+1−1
@@ -1798,7 +1798,7 @@ static void free_unmap_vmap_area(struct vmap_area *va) · 1797 unmodified lines
1798 free_vmap_area_noflush(va);1798 free_vmap_area_noflush(va);
1799}1799}
1800 1800
1801static struct vmap_area *find_vmap_area(unsigned long addr)1801struct vmap_area *find_vmap_area(unsigned long addr)
1802{1802{
1803 struct vmap_area *va;1803 struct vmap_area *va;
1804 1804