From 1e5c6649ff0a2049511bafa297277234011a5c58 Mon Sep 17 00:00:00 2001 From: "Yan, Zheng" Date: Mon, 24 Mar 2014 13:00:54 +0800 Subject: [PATCH] ceph: check buffer size in ceph_vxattrcb_layout() If buffer size is zero, return the size of layout vxattr. If buffer size is not zero, check if it is large enough for layout vxattr. Signed-off-by: Yan, Zheng --- fs/ceph/xattr.c | 34 +++++++++++++++++++++++++--------- 1 file changed, 25 insertions(+), 9 deletions(-) diff --git a/fs/ceph/xattr.c b/fs/ceph/xattr.c index 2dbd668..28549d5 100644 --- a/fs/ceph/xattr.c +++ b/fs/ceph/xattr.c @@ -64,32 +64,48 @@ static bool ceph_vxattrcb_layout_exists(struct ceph_inode_info *ci) } static size_t ceph_vxattrcb_layout(struct ceph_inode_info *ci, char *val, - size_t size) + size_t size) { int ret; struct ceph_fs_client *fsc = ceph_sb_to_client(ci->vfs_inode.i_sb); struct ceph_osd_client *osdc = &fsc->client->osdc; s64 pool = ceph_file_layout_pg_pool(ci->i_layout); const char *pool_name; + char buf[128]; dout("ceph_vxattrcb_layout %p\n", &ci->vfs_inode); down_read(&osdc->map_sem); pool_name = ceph_pg_pool_name_by_id(osdc->osdmap, pool); - if (pool_name) - ret = snprintf(val, size, - "stripe_unit=%lld stripe_count=%lld object_size=%lld pool=%s", + if (pool_name) { + size_t len = strlen(pool_name); + ret = snprintf(buf, sizeof(buf), + "stripe_unit=%lld stripe_count=%lld object_size=%lld pool=", (unsigned long long)ceph_file_layout_su(ci->i_layout), (unsigned long long)ceph_file_layout_stripe_count(ci->i_layout), - (unsigned long long)ceph_file_layout_object_size(ci->i_layout), - pool_name); - else - ret = snprintf(val, size, + (unsigned long long)ceph_file_layout_object_size(ci->i_layout)); + if (!size) { + ret += len; + } else if (ret + len > size) { + ret = -ERANGE; + } else { + memcpy(val, buf, ret); + memcpy(val + ret, pool_name, len); + ret += len; + } + } else { + ret = snprintf(buf, sizeof(buf), "stripe_unit=%lld stripe_count=%lld object_size=%lld pool=%lld", (unsigned long long)ceph_file_layout_su(ci->i_layout), (unsigned long long)ceph_file_layout_stripe_count(ci->i_layout), (unsigned long long)ceph_file_layout_object_size(ci->i_layout), (unsigned long long)pool); - + if (size) { + if (ret <= size) + memcpy(val, buf, ret); + else + ret = -ERANGE; + } + } up_read(&osdc->map_sem); return ret; } -- 2.7.4