From: Gaosheng Cui cuigaosheng1@huawei.com
commit 8cf0a1bc12870d148ae830a4ba88cfdf0e879cee upstream.
In cap_inode_getsecurity(), we will use vfs_getxattr_alloc() to complete the memory allocation of tmpbuf, if we have completed the memory allocation of tmpbuf, but failed to call handler->get(...), there will be a memleak in below logic:
|-- ret = (int)vfs_getxattr_alloc(mnt_userns, ...) | /* ^^^ alloc for tmpbuf */ |-- value = krealloc(*xattr_value, error + 1, flags) | /* ^^^ alloc memory */ |-- error = handler->get(handler, ...) | /* error! */ |-- *xattr_value = value | /* xattr_value is &tmpbuf (memory leak!) */
So we will try to free(tmpbuf) after vfs_getxattr_alloc() fails to fix it.
Cc: stable@vger.kernel.org Fixes: 8db6c34f1dbc ("Introduce v3 namespaced file capabilities") Signed-off-by: Gaosheng Cui cuigaosheng1@huawei.com Acked-by: Serge Hallyn serge@hallyn.com [PM: subject line and backtrace tweaks] Signed-off-by: Paul Moore paul@paul-moore.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- security/commoncap.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
--- a/security/commoncap.c +++ b/security/commoncap.c @@ -398,8 +398,10 @@ int cap_inode_getsecurity(struct inode * &tmpbuf, size, GFP_NOFS); dput(dentry);
- if (ret < 0 || !tmpbuf) - return ret; + if (ret < 0 || !tmpbuf) { + size = ret; + goto out_free; + }
fs_ns = inode->i_sb->s_user_ns; cap = (struct vfs_cap_data *) tmpbuf;