diff options
| author | Michal Hocko <mhocko@suse.com> | 2017-04-17 01:34:50 +1000 |
|---|---|---|
| committer | Stephen Rothwell <sfr@canb.auug.org.au> | 2017-04-18 17:13:49 +1000 |
| commit | b74c17b400839d0d43396efe7ea6d77b847f0757 (patch) | |
| tree | 2ac4894a03e3575abfc515c87e37a4cba0611d9d /fs | |
| parent | f9e73b0f08b3d2fb514af6c12e6c5c62d51a9a31 (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>
Diffstat (limited to 'fs')
| -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 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; } |