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authorMatthew Wilcox (Oracle) <willy@infradead.org>2022-06-12 22:32:25 +0100
committerKees Cook <keescook@chromium.org>2022-06-13 09:54:52 -0700
commit993d0b287e2ef7bee2e8b13b0ce4d2b5066f278e (patch)
tree853081efc2b49076ac29148901f66752393130ae /mm
parent57cd6d157eb479f0a8e820fd36b7240845c8a937 (diff)
downloadlinux-993d0b287e2ef7bee2e8b13b0ce4d2b5066f278e.tar.gz
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
Diffstat (limited to 'mm')
-rw-r--r--mm/usercopy.c10
-rw-r--r--mm/vmalloc.c2
2 files changed, 5 insertions, 7 deletions
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;