diff options
| author | Michal Hocko <mhocko@suse.com> | 2017-05-08 15:57:24 -0700 |
|---|---|---|
| committer | Sasha Levin <alexander.levin@verizon.com> | 2017-06-13 09:29:21 -0400 |
| commit | fda7c899dd7618887e18953f3499f131b6d5da66 (patch) | |
| tree | 04f245999c3e91bceb064b07df54870942aabcfd | |
| parent | 273225634fef092a063010d0eb48232bda2895af (diff) | |
fs/xattr.c: zero out memory copied to userspace in getxattr
[ Upstream commit 81be3dee96346fbe08c31be5ef74f03f6b63cf68 ]
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")
Link: http://lkml.kernel.org/r/20170306103327.2766-1-mhocko@kernel.org
Acked-by: Kees Cook <keescook@chromium.org>
Reported-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Michal Hocko <mhocko@suse.com>
Cc: <stable@vger.kernel.org> [3.6+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
| -rw-r--r-- | fs/xattr.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/xattr.c b/fs/xattr.c index 4ef698549e31..81d4695a6115 100644 --- a/fs/xattr.c +++ b/fs/xattr.c @@ -442,7 +442,7 @@ getxattr(struct dentry *d, const char __user *name, void __user *value, size = XATTR_SIZE_MAX; kvalue = kzalloc(size, GFP_KERNEL | __GFP_NOWARN); if (!kvalue) { - vvalue = vmalloc(size); + vvalue = vzalloc(size); if (!vvalue) return -ENOMEM; kvalue = vvalue; |