| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.19 95/95] mm/vmalloc.c: dont dereference possible NULL pointer in __vunmap() | Date | Mon, 1 Jun 2020 19:54:35 +0200 |
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From: Liviu Dudau <liviu@dudau.co.uk>
commit 6ade20327dbb808882888ed8ccded71e93067cf9 upstream.
find_vmap_area() can return a NULL pointer and we're going to dereference it without checking it first. Use the existing find_vm_area() function which does exactly what we want and checks for the NULL pointer.
Link: http://lkml.kernel.org/r/20181228171009.22269-1-liviu@dudau.co.uk Fixes: f3c01d2f3ade ("mm: vmalloc: avoid racy handling of debugobjects in vunmap") Signed-off-by: Liviu Dudau <liviu@dudau.co.uk> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Chintan Pandya <cpandya@codeaurora.org> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- mm/vmalloc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -1510,7 +1510,7 @@ static void __vunmap(const void *addr, i addr)) return; - area = find_vmap_area((unsigned long)addr)->vm; + area = find_vm_area(addr); if (unlikely(!area)) { WARN(1, KERN_ERR "Trying to vfree() nonexistent vm area (%p)\n", addr);
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