diff options
| author | Michal Hocko <mhocko@suse.com> | 2017-03-10 11:26:47 +1100 |
|---|---|---|
| committer | Stephen Rothwell <sfr@canb.auug.org.au> | 2017-03-10 13:24:06 +1100 |
| commit | f453127fc30668a9db4a1ee204932f4c7b10b0a9 (patch) | |
| tree | 49eb8de80415f60ea99b9dd1f35a9a0531ff55e0 | |
| parent | c057e849319d843a44ab39976df70cc7ca0dbffd (diff) | |
fs/xattr.c: zero out memory copied to userspace in getxattr
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>
| -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 c19a16323c2c..b9fb2a042cfa 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; } |