Re: [PATCH] ceph: kstrdup() memory handling
From: 严正
Date: Mon Mar 23 2015 - 00:04:00 EST
> 在 2015年3月22日,00:54,Sanidhya Kashyap <sanidhya.gatech@xxxxxxxxx> 写道:
>
> Currently, there is no check for the kstrdup() for r_path2, r_path1 and snapdir_name
> as various locations as there is a possibility of failure during memory pressure.
> Therefore, returning ENOMEM where the checks have been missed.
>
> Signed-off-by: Sanidhya Kashyap <sanidhya.gatech@xxxxxxxxx>
> ---
> fs/ceph/dir.c | 11 +++++++++++
> fs/ceph/super.c | 8 ++++++++
> fs/ceph/xattr.c | 7 +++++++
> 3 files changed, 26 insertions(+)
>
> diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c
> index 83e9976..be32703 100644
> --- a/fs/ceph/dir.c
> +++ b/fs/ceph/dir.c
> @@ -344,6 +344,12 @@ more:
> req->r_direct_hash = ceph_frag_value(frag);
> req->r_direct_is_hash = true;
> req->r_path2 = kstrdup(fi->last_name, GFP_NOFS);
> + if (!req->r_path2) {
> + iput(inode);
> + ceph_mdsc_put_request(req);
> + return -ENOMEM;
> + }
> +
> req->r_readdir_offset = fi->next_offset;
> req->r_args.readdir.frag = cpu_to_le32(frag);
> err = ceph_mdsc_do_request(mdsc, NULL, req);
> @@ -758,6 +764,11 @@ static int ceph_symlink(struct inode *dir, struct dentry *dentry,
> req->r_dentry = dget(dentry);
> req->r_num_caps = 2;
> req->r_path2 = kstrdup(dest, GFP_NOFS);
> + if (!req->r_path2) {
> + err = -ENOMEM;
> + ceph_mdsc_put_request(req);
> + goto out;
> + }
> req->r_locked_dir = dir;
> req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
> req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
> diff --git a/fs/ceph/super.c b/fs/ceph/super.c
> index a63997b..8e68f53 100644
> --- a/fs/ceph/super.c
> +++ b/fs/ceph/super.c
> @@ -345,6 +345,9 @@ static int parse_mount_options(struct ceph_mount_options **pfsopt,
> fsopt->rsize = CEPH_RSIZE_DEFAULT;
> fsopt->rasize = CEPH_RASIZE_DEFAULT;
> fsopt->snapdir_name = kstrdup(CEPH_SNAPDIRNAME_DEFAULT, GFP_KERNEL);
> + if (!fsopt->snapdir_name)
> + goto out;
> +
> fsopt->caps_wanted_delay_min = CEPH_CAPS_WANTED_DELAY_MIN_DEFAULT;
> fsopt->caps_wanted_delay_max = CEPH_CAPS_WANTED_DELAY_MAX_DEFAULT;
> fsopt->cap_release_safety = CEPH_CAP_RELEASE_SAFETY_DEFAULT;
> @@ -730,6 +733,11 @@ static struct dentry *open_root_dentry(struct ceph_fs_client *fsc,
> if (IS_ERR(req))
> return ERR_CAST(req);
> req->r_path1 = kstrdup(path, GFP_NOFS);
> + if (!req->r_path1) {
> + root = ERR_PTR(-ENOMEM);
> + goto out;
> + }
> +
> req->r_ino1.ino = CEPH_INO_ROOT;
> req->r_ino1.snap = CEPH_NOSNAP;
> req->r_started = started;
> diff --git a/fs/ceph/xattr.c b/fs/ceph/xattr.c
> index 5a492ca..299eb83 100644
> --- a/fs/ceph/xattr.c
> +++ b/fs/ceph/xattr.c
> @@ -883,6 +883,11 @@ static int ceph_sync_setxattr(struct dentry *dentry, const char *name,
> req->r_num_caps = 1;
> req->r_args.setxattr.flags = cpu_to_le32(flags);
> req->r_path2 = kstrdup(name, GFP_NOFS);
> + if (!req->r_path2) {
> + ceph_mdsc_put_request(req);
> + err = -ENOMEM;
> + goto out;
> + }
>
> req->r_pagelist = pagelist;
> pagelist = NULL;
> @@ -1024,6 +1029,8 @@ static int ceph_send_removexattr(struct dentry *dentry, const char *name)
> req->r_inode_drop = CEPH_CAP_XATTR_SHARED;
> req->r_num_caps = 1;
> req->r_path2 = kstrdup(name, GFP_NOFS);
> + if (!req->r_path2)
> + return -ENOMEM;
>
> err = ceph_mdsc_do_request(mdsc, NULL, req);
> ceph_mdsc_put_request(req);
> --
Added to our testing branch (with some minor modifications. take inode/dentry references after kstrdup)
Thank
Yan, Zheng
> 2.1.0
>
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