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Diffstat (limited to 'fs/nfsd/vfs.c')
-rw-r--r--fs/nfsd/vfs.c98
1 files changed, 65 insertions, 33 deletions
diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index ab93fcf..99f8357 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -55,6 +55,7 @@
#include <linux/security.h>
#endif /* CONFIG_NFSD_V4 */
#include <linux/jhash.h>
+#include <linux/ima.h>
#include <asm/uaccess.h>
@@ -100,31 +101,35 @@ nfsd_cross_mnt(struct svc_rqst *rqstp, struct dentry **dpp,
{
struct svc_export *exp = *expp, *exp2 = NULL;
struct dentry *dentry = *dpp;
- struct vfsmount *mnt = mntget(exp->ex_path.mnt);
- struct dentry *mounts = dget(dentry);
+ struct path path = {.mnt = mntget(exp->ex_path.mnt),
+ .dentry = dget(dentry)};
int err = 0;
- while (follow_down(&mnt,&mounts)&&d_mountpoint(mounts));
+ while (d_mountpoint(path.dentry) && follow_down(&path))
+ ;
- exp2 = rqst_exp_get_by_name(rqstp, mnt, mounts);
+ exp2 = rqst_exp_get_by_name(rqstp, &path);
if (IS_ERR(exp2)) {
if (PTR_ERR(exp2) != -ENOENT)
err = PTR_ERR(exp2);
- dput(mounts);
- mntput(mnt);
+ path_put(&path);
goto out;
}
if ((exp->ex_flags & NFSEXP_CROSSMOUNT) || EX_NOHIDE(exp2)) {
/* successfully crossed mount point */
- exp_put(exp);
+ /*
+ * This is subtle: path.dentry is *not* on path.mnt
+ * at this point. The only reason we are safe is that
+ * original mnt is pinned down by exp, so we should
+ * put path *before* putting exp
+ */
+ *dpp = path.dentry;
+ path.dentry = dentry;
*expp = exp2;
- dput(dentry);
- *dpp = mounts;
- } else {
- exp_put(exp2);
- dput(mounts);
+ exp2 = exp;
}
- mntput(mnt);
+ path_put(&path);
+ exp_put(exp2);
out:
return err;
}
@@ -163,28 +168,29 @@ nfsd_lookup_dentry(struct svc_rqst *rqstp, struct svc_fh *fhp,
/* checking mountpoint crossing is very different when stepping up */
struct svc_export *exp2 = NULL;
struct dentry *dp;
- struct vfsmount *mnt = mntget(exp->ex_path.mnt);
- dentry = dget(dparent);
- while(dentry == mnt->mnt_root && follow_up(&mnt, &dentry))
+ struct path path = {.mnt = mntget(exp->ex_path.mnt),
+ .dentry = dget(dparent)};
+
+ while (path.dentry == path.mnt->mnt_root &&
+ follow_up(&path))
;
- dp = dget_parent(dentry);
- dput(dentry);
- dentry = dp;
+ dp = dget_parent(path.dentry);
+ dput(path.dentry);
+ path.dentry = dp;
- exp2 = rqst_exp_parent(rqstp, mnt, dentry);
+ exp2 = rqst_exp_parent(rqstp, &path);
if (PTR_ERR(exp2) == -ENOENT) {
- dput(dentry);
dentry = dget(dparent);
} else if (IS_ERR(exp2)) {
host_err = PTR_ERR(exp2);
- dput(dentry);
- mntput(mnt);
+ path_put(&path);
goto out_nfserr;
} else {
+ dentry = dget(path.dentry);
exp_put(exp);
exp = exp2;
}
- mntput(mnt);
+ path_put(&path);
}
} else {
fh_lock(fhp);
@@ -730,6 +736,8 @@ nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, int type,
flags, cred);
if (IS_ERR(*filp))
host_err = PTR_ERR(*filp);
+ else
+ ima_counts_get(*filp);
out_nfserr:
err = nfserrno(host_err);
out:
@@ -1010,6 +1018,7 @@ nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file,
host_err = vfs_writev(file, (struct iovec __user *)vec, vlen, &offset);
set_fs(oldfs);
if (host_err >= 0) {
+ *cnt = host_err;
nfsdstats.io_write += host_err;
fsnotify_modify(file->f_path.dentry);
}
@@ -1055,10 +1064,9 @@ nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file,
}
dprintk("nfsd: write complete host_err=%d\n", host_err);
- if (host_err >= 0) {
+ if (host_err >= 0)
err = 0;
- *cnt = host_err;
- } else
+ else
err = nfserrno(host_err);
out:
return err;
@@ -1885,8 +1893,8 @@ static int nfsd_buffered_filldir(void *__buf, const char *name, int namlen,
return 0;
}
-static int nfsd_buffered_readdir(struct file *file, filldir_t func,
- struct readdir_cd *cdp, loff_t *offsetp)
+static __be32 nfsd_buffered_readdir(struct file *file, filldir_t func,
+ struct readdir_cd *cdp, loff_t *offsetp)
{
struct readdir_data buf;
struct buffered_dirent *de;
@@ -1896,11 +1904,12 @@ static int nfsd_buffered_readdir(struct file *file, filldir_t func,
buf.dirent = (void *)__get_free_page(GFP_KERNEL);
if (!buf.dirent)
- return -ENOMEM;
+ return nfserrno(-ENOMEM);
offset = *offsetp;
while (1) {
+ struct inode *dir_inode = file->f_path.dentry->d_inode;
unsigned int reclen;
cdp->err = nfserr_eof; /* will be cleared on successful read */
@@ -1919,26 +1928,38 @@ static int nfsd_buffered_readdir(struct file *file, filldir_t func,
if (!size)
break;
+ /*
+ * Various filldir functions may end up calling back into
+ * lookup_one_len() and the file system's ->lookup() method.
+ * These expect i_mutex to be held, as it would within readdir.
+ */
+ host_err = mutex_lock_killable(&dir_inode->i_mutex);
+ if (host_err)
+ break;
+
de = (struct buffered_dirent *)buf.dirent;
while (size > 0) {
offset = de->offset;
if (func(cdp, de->name, de->namlen, de->offset,
de->ino, de->d_type))
- goto done;
+ break;
if (cdp->err != nfs_ok)
- goto done;
+ break;
reclen = ALIGN(sizeof(*de) + de->namlen,
sizeof(u64));
size -= reclen;
de = (struct buffered_dirent *)((char *)de + reclen);
}
+ mutex_unlock(&dir_inode->i_mutex);
+ if (size > 0) /* We bailed out early */
+ break;
+
offset = vfs_llseek(file, 0, SEEK_CUR);
}
- done:
free_page((unsigned long)(buf.dirent));
if (host_err)
@@ -2006,6 +2027,7 @@ nfsd_permission(struct svc_rqst *rqstp, struct svc_export *exp,
struct dentry *dentry, int acc)
{
struct inode *inode = dentry->d_inode;
+ struct path path;
int err;
if (acc == NFSD_MAY_NOP)
@@ -2078,7 +2100,17 @@ nfsd_permission(struct svc_rqst *rqstp, struct svc_export *exp,
if (err == -EACCES && S_ISREG(inode->i_mode) &&
acc == (NFSD_MAY_READ | NFSD_MAY_OWNER_OVERRIDE))
err = inode_permission(inode, MAY_EXEC);
+ if (err)
+ goto nfsd_out;
+ /* Do integrity (permission) checking now, but defer incrementing
+ * IMA counts to the actual file open.
+ */
+ path.mnt = exp->ex_path.mnt;
+ path.dentry = dentry;
+ err = ima_path_check(&path, acc & (MAY_READ | MAY_WRITE | MAY_EXEC),
+ IMA_COUNT_LEAVE);
+nfsd_out:
return err? nfserrno(err) : 0;
}
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