From: Gaosheng Cui <cuigaosheng1@huawei.com> stable inclusion from stable-v4.19.265 commit 90577bcc01c4188416a47269f8433f70502abe98 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I63UEU CVE: NA -------------------------------- 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> Signed-off-by: Yongqiang Liu <liuyongqiang13@huawei.com> --- security/commoncap.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/security/commoncap.c b/security/commoncap.c index 1fd370e8820f..ca35b508d301 100644 --- a/security/commoncap.c +++ b/security/commoncap.c @@ -398,8 +398,10 @@ int cap_inode_getsecurity(struct inode *inode, const char *name, void **buffer, &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; -- 2.25.1