diff options
| author | Matthew Wilcox (Oracle) <willy@infradead.org> | 2022-06-12 22:32:25 +0100 |
|---|---|---|
| committer | Kees Cook <keescook@chromium.org> | 2022-06-13 09:54:52 -0700 |
| commit | 993d0b287e2ef7bee2e8b13b0ce4d2b5066f278e (patch) | |
| tree | 853081efc2b49076ac29148901f66752393130ae | |
| parent | 57cd6d157eb479f0a8e820fd36b7240845c8a937 (diff) | |
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().
Fixes: 0aef499f3172 ("mm/usercopy: Detect vmalloc overruns")
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Tested-by: Zorro Lang <zlang@redhat.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220612213227.3881769-2-willy@infradead.org
| -rw-r--r-- | include/linux/vmalloc.h | 1 | ||||
| -rw-r--r-- | mm/usercopy.c | 10 | ||||
| -rw-r--r-- | mm/vmalloc.c | 2 |
3 files changed, 6 insertions, 7 deletions
diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h index b159c2789961..096d48aa3437 100644 --- a/include/linux/vmalloc.h +++ b/include/linux/vmalloc.h @@ -215,6 +215,7 @@ extern struct vm_struct *__get_vm_area_caller(unsigned long size, void free_vm_area(struct vm_struct *area); extern struct vm_struct *remove_vm_area(const void *addr); extern struct vm_struct *find_vm_area(const void *addr); +struct vmap_area *find_vmap_area(unsigned long addr); static inline bool is_vm_area_hugepages(const void *addr) { diff --git a/mm/usercopy.c b/mm/usercopy.c index baeacc735b83..cd4b41d9bf76 100644 --- a/mm/usercopy.c +++ b/mm/usercopy.c @@ -173,16 +173,14 @@ static inline void check_heap_object(const void *ptr, unsigned long n, } if (is_vmalloc_addr(ptr)) { - struct vm_struct *area = find_vm_area(ptr); + struct vmap_area *area = find_vmap_area((unsigned long)ptr); unsigned long offset; - if (!area) { + if (!area) usercopy_abort("vmalloc", "no area", to_user, 0, n); - return; - } - offset = ptr - area->addr; - if (offset + n > get_vm_area_size(area)) + offset = (unsigned long)ptr - area->va_start; + if ((unsigned long)ptr + n > area->va_end) usercopy_abort("vmalloc", NULL, to_user, offset, n); return; } diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 07db42455dd4..effd1ff6a4b4 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -1798,7 +1798,7 @@ static void free_unmap_vmap_area(struct vmap_area *va) free_vmap_area_noflush(va); } -static struct vmap_area *find_vmap_area(unsigned long addr) +struct vmap_area *find_vmap_area(unsigned long addr) { struct vmap_area *va; |