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Date: Wed, 11 Jun 2008 09:35:10 -0400
From: Trond Myklebust <trond.myklebust@....uio.no>
To: Luoqi Chen <Luoqi.Chen@...on.com>
Cc: "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
"linux-nfs@...r.kernel.org" <linux-nfs@...r.kernel.org>
Subject: RE: NFS open/setuid/ftruncate problem
On Tue, 2008-06-10 at 22:24 -0700, Luoqi Chen wrote:
> > From: Trond Myklebust <Trond.Myklebust@...app.com>
> > Date: Tue, 10 Jun 2008 19:39:41 -0400
> > NFS: Fix the ftruncate() credential problem
> >
> > ftruncate() access checking is supposed to be performed at
> > open() time,
> > just like reads and writes.
> >
> Thanks, Trond. Is there any chance this patch could be
> included in the linux kernel in the near future? For now,
> I guess I'll workaround this problem by moving the ftruncate()
> to before setuid().
>
> -luoqi
>
> PS: I haven't tried the patch, just browsing through, and I noticed
> a typo, pointing out here to save some trouble for anyone who
> wants to give it a try (I guess gcc would issue a warning too),
>
> /* Search for an existing open(O_WRITE) file */
> - ctx = nfs_find_open_context(inode, cred, FMODE_WRITE);
> - if (ctx != NULL)
> - state = ctx->state;
> + if (sattr->ia_valid && ATTR_FILE) { <=== && should be &
> + ctx = nfs_file_open_context(sattr->ia_file);
> + if (ctx != NULL)
> + state = ctx->state;
> + }
Thanks for testing! I've refined the patch a bit so that it is less
intrusive w.r.t. common NFS code changes, and fixed a couple more bugs.
As long as the stability proves to be good, I see no reason why we can't
merge this once the 2.6.27 merge window opens.
Cheers
Trond
-----------------------------------------------------------------------
From: Trond Myklebust <Trond.Myklebust@...app.com>
Date: Tue, 10 Jun 2008 19:39:41 -0400
NFS: Fix the ftruncate() credential problem
ftruncate() access checking is supposed to be performed at open() time,
just like reads and writes.
Signed-off-by: Trond Myklebust <Trond.Myklebust@...app.com>
---
fs/nfs/inode.c | 4 ++--
fs/nfs/nfs3proc.c | 2 ++
fs/nfs/nfs4proc.c | 47 +++++++++++++++++++++++------------------------
fs/nfs/proc.c | 2 ++
4 files changed, 29 insertions(+), 26 deletions(-)
diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index 596c5d8..2e4ab4a 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -347,7 +347,7 @@ out_no_inode:
goto out;
}
-#define NFS_VALID_ATTRS (ATTR_MODE|ATTR_UID|ATTR_GID|ATTR_SIZE|ATTR_ATIME|ATTR_ATIME_SET|ATTR_MTIME|ATTR_MTIME_SET)
+#define NFS_VALID_ATTRS (ATTR_MODE|ATTR_UID|ATTR_GID|ATTR_SIZE|ATTR_ATIME|ATTR_ATIME_SET|ATTR_MTIME|ATTR_MTIME_SET|ATTR_FILE)
int
nfs_setattr(struct dentry *dentry, struct iattr *attr)
@@ -369,7 +369,7 @@ nfs_setattr(struct dentry *dentry, struct iattr *attr)
/* Optimization: if the end result is no change, don't RPC */
attr->ia_valid &= NFS_VALID_ATTRS;
- if (attr->ia_valid == 0)
+ if ((attr->ia_valid & ~ATTR_FILE) == 0)
return 0;
lock_kernel();
diff --git a/fs/nfs/nfs3proc.c b/fs/nfs/nfs3proc.c
index c3523ad..b14b378 100644
--- a/fs/nfs/nfs3proc.c
+++ b/fs/nfs/nfs3proc.c
@@ -129,6 +129,8 @@ nfs3_proc_setattr(struct dentry *dentry, struct nfs_fattr *fattr,
int status;
dprintk("NFS call setattr\n");
+ if (sattr->ia_valid & ATTR_FILE)
+ msg.rpc_cred = nfs_file_cred(sattr->ia_file);
nfs_fattr_init(fattr);
status = rpc_call_sync(NFS_CLIENT(inode), &msg, 0);
if (status == 0)
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 1293e0a..15084a0 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -1139,8 +1139,9 @@ static struct nfs4_state *nfs4_do_open(struct inode *dir, struct path *path, int
return res;
}
-static int _nfs4_do_setattr(struct inode *inode, struct nfs_fattr *fattr,
- struct iattr *sattr, struct nfs4_state *state)
+static int _nfs4_do_setattr(struct inode *inode, struct rpc_cred *cred,
+ struct nfs_fattr *fattr, struct iattr *sattr,
+ struct nfs4_state *state)
{
struct nfs_server *server = NFS_SERVER(inode);
struct nfs_setattrargs arg = {
@@ -1154,9 +1155,10 @@ static int _nfs4_do_setattr(struct inode *inode, struct nfs_fattr *fattr,
.server = server,
};
struct rpc_message msg = {
- .rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_SETATTR],
- .rpc_argp = &arg,
- .rpc_resp = &res,
+ .rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_SETATTR],
+ .rpc_argp = &arg,
+ .rpc_resp = &res,
+ .rpc_cred = cred,
};
unsigned long timestamp = jiffies;
int status;
@@ -1166,7 +1168,6 @@ static int _nfs4_do_setattr(struct inode *inode, struct nfs_fattr *fattr,
if (nfs4_copy_delegation_stateid(&arg.stateid, inode)) {
/* Use that stateid */
} else if (state != NULL) {
- msg.rpc_cred = state->owner->so_cred;
nfs4_copy_stateid(&arg.stateid, state, current->files);
} else
memcpy(&arg.stateid, &zero_stateid, sizeof(arg.stateid));
@@ -1177,15 +1178,16 @@ static int _nfs4_do_setattr(struct inode *inode, struct nfs_fattr *fattr,
return status;
}
-static int nfs4_do_setattr(struct inode *inode, struct nfs_fattr *fattr,
- struct iattr *sattr, struct nfs4_state *state)
+static int nfs4_do_setattr(struct inode *inode, struct rpc_cred *cred,
+ struct nfs_fattr *fattr, struct iattr *sattr,
+ struct nfs4_state *state)
{
struct nfs_server *server = NFS_SERVER(inode);
struct nfs4_exception exception = { };
int err;
do {
err = nfs4_handle_exception(server,
- _nfs4_do_setattr(inode, fattr, sattr, state),
+ _nfs4_do_setattr(inode, cred, fattr, sattr, state),
&exception);
} while (exception.retry);
return err;
@@ -1647,29 +1649,25 @@ static int
nfs4_proc_setattr(struct dentry *dentry, struct nfs_fattr *fattr,
struct iattr *sattr)
{
- struct rpc_cred *cred;
struct inode *inode = dentry->d_inode;
- struct nfs_open_context *ctx;
+ struct rpc_cred *cred = NULL;
struct nfs4_state *state = NULL;
int status;
nfs_fattr_init(fattr);
- cred = rpc_lookup_cred();
- if (IS_ERR(cred))
- return PTR_ERR(cred);
-
/* Search for an existing open(O_WRITE) file */
- ctx = nfs_find_open_context(inode, cred, FMODE_WRITE);
- if (ctx != NULL)
+ if (sattr->ia_valid & ATTR_FILE) {
+ struct nfs_open_context *ctx;
+
+ ctx = nfs_file_open_context(sattr->ia_file);
+ cred = ctx->cred;
state = ctx->state;
+ }
- status = nfs4_do_setattr(inode, fattr, sattr, state);
+ status = nfs4_do_setattr(inode, cred, fattr, sattr, state);
if (status == 0)
nfs_setattr_update_inode(inode, sattr);
- if (ctx != NULL)
- put_nfs_open_context(ctx);
- put_rpccred(cred);
return status;
}
@@ -1897,17 +1895,16 @@ nfs4_proc_create(struct inode *dir, struct dentry *dentry, struct iattr *sattr,
goto out;
}
state = nfs4_do_open(dir, &path, flags, sattr, cred);
- put_rpccred(cred);
d_drop(dentry);
if (IS_ERR(state)) {
status = PTR_ERR(state);
- goto out;
+ goto out_putcred;
}
d_add(dentry, igrab(state->inode));
nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
if (flags & O_EXCL) {
struct nfs_fattr fattr;
- status = nfs4_do_setattr(state->inode, &fattr, sattr, state);
+ status = nfs4_do_setattr(state->inode, cred, &fattr, sattr, state);
if (status == 0)
nfs_setattr_update_inode(state->inode, sattr);
nfs_post_op_update_inode(state->inode, &fattr);
@@ -1916,6 +1913,8 @@ nfs4_proc_create(struct inode *dir, struct dentry *dentry, struct iattr *sattr,
status = nfs4_intent_set_file(nd, &path, state);
else
nfs4_close_sync(&path, state, flags);
+out_putcred:
+ put_rpccred(cred);
out:
return status;
}
diff --git a/fs/nfs/proc.c b/fs/nfs/proc.c
index 5c35b02..c760558 100644
--- a/fs/nfs/proc.c
+++ b/fs/nfs/proc.c
@@ -129,6 +129,8 @@ nfs_proc_setattr(struct dentry *dentry, struct nfs_fattr *fattr,
sattr->ia_mode &= S_IALLUGO;
dprintk("NFS call setattr\n");
+ if (sattr->ia_valid & ATTR_FILE)
+ msg.rpc_cred = nfs_file_cred(sattr->ia_file);
nfs_fattr_init(fattr);
status = rpc_call_sync(NFS_CLIENT(inode), &msg, 0);
if (status == 0)
--
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