From: Michal Hocko <mhocko@xxxxxxxx>
getxattr uses vmalloc to allocate memory if kzalloc fails. This is
filled by vfs_getxattr and then copied to the userspace. vmalloc,
however, doesn't zero out the memory so if the specific implementation
of the xattr handler is sloppy we can theoretically expose a kernel
memory. There is no real sign this is really the case but let's make
sure this will not happen and use vzalloc instead.
Fixes: 779302e67835 ("fs/xattr.c:getxattr(): improve handling of allocation failures")
Cc: stable # 3.6+
Acked-by: Kees Cook <keescook@xxxxxxxxxxxx>
Spotted-by: Vlastimil Babka <vbabka@xxxxxxx>
Signed-off-by: Michal Hocko <mhocko@xxxxxxxx>
---
fs/xattr.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/xattr.c b/fs/xattr.c
index 7e3317cf4045..94f49a082dd2 100644
--- a/fs/xattr.c
+++ b/fs/xattr.c
@@ -530,7 +530,7 @@ getxattr(struct dentry *d, const char __user *name, void __user *value,
size = XATTR_SIZE_MAX;
kvalue = kzalloc(size, GFP_KERNEL | __GFP_NOWARN);
if (!kvalue) {
- kvalue = vmalloc(size);
+ kvalue = vzalloc(size);
if (!kvalue)
return -ENOMEM;
}
--
2.11.0
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