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nfs: fix regression in handling of context= option in NFSv4

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Setting the security context of a NFSv4 mount via the context= mount
option is currently broken. The NFSv4 codepath allocates a parsed
options struct, and then parses the mount options to fill it. It
eventually calls nfs4_remote_mount which calls security_init_mnt_opts.
That clobbers the lsm_opts struct that was populated earlier. This bug
also looks like it causes a small memory leak on each v4 mount where
context= is used.

Fix this by moving the initialization of the lsm_opts into
nfs_alloc_parsed_mount_data. Also, add a destructor for
nfs_parsed_mount_data to make it easier to free all of the allocations
hanging off of it, and to ensure that the security_free_mnt_opts is
called whenever security_init_mnt_opts is.

I believe this regression was introduced quite some time ago, probably
by commit c02d7adf.

Cc: stable@vger.kernel.org
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This commit is contained in:
Jeff Layton 2011-12-20 06:57:45 -05:00 committed by Trond Myklebust
parent 2edb6bc385
commit 8a0d551a59
1 changed files with 19 additions and 24 deletions
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43
fs/nfs/super.c
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@ -909,10 +909,24 @@ static struct nfs_parsed_mount_data *nfs_alloc_parsed_mount_data(unsigned int ve
data->auth_flavor_len = 1;
data->version = version;
data->minorversion = 0;
security_init_mnt_opts(&data->lsm_opts);
}
return data;
}
static void nfs_free_parsed_mount_data(struct nfs_parsed_mount_data *data)
{
if (data) {
kfree(data->client_address);
kfree(data->mount_server.hostname);
kfree(data->nfs_server.export_path);
kfree(data->nfs_server.hostname);
kfree(data->fscache_uniq);
security_free_mnt_opts(&data->lsm_opts);
kfree(data);
}
}
/*
* Sanity-check a server address provided by the mount command.
*
@ -2220,9 +2234,7 @@ static struct dentry *nfs_fs_mount(struct file_system_type *fs_type,
data = nfs_alloc_parsed_mount_data(NFS_DEFAULT_VERSION);
mntfh = nfs_alloc_fhandle();
if (data == NULL || mntfh == NULL)
goto out_free_fh;
security_init_mnt_opts(&data->lsm_opts);
goto out;
/* Validate the mount data */
error = nfs_validate_mount_data(raw_data, data, mntfh, dev_name);
@ -2234,8 +2246,6 @@ static struct dentry *nfs_fs_mount(struct file_system_type *fs_type,
#ifdef CONFIG_NFS_V4
if (data->version == 4) {
mntroot = nfs4_try_mount(flags, dev_name, data);
kfree(data->client_address);
kfree(data->nfs_server.export_path);
goto out;
}
#endif /* CONFIG_NFS_V4 */
@ -2290,13 +2300,8 @@ static struct dentry *nfs_fs_mount(struct file_system_type *fs_type,
s->s_flags |= MS_ACTIVE;
out:
kfree(data->nfs_server.hostname);
kfree(data->mount_server.hostname);
kfree(data->fscache_uniq);
security_free_mnt_opts(&data->lsm_opts);
out_free_fh:
nfs_free_parsed_mount_data(data);
nfs_free_fhandle(mntfh);
kfree(data);
return mntroot;
out_err_nosb:
@ -2623,9 +2628,7 @@ nfs4_remote_mount(struct file_system_type *fs_type, int flags,
mntfh = nfs_alloc_fhandle();
if (data == NULL || mntfh == NULL)
goto out_free_fh;
security_init_mnt_opts(&data->lsm_opts);
goto out;
/* Get a volume representation */
server = nfs4_create_server(data, mntfh);
@ -2677,13 +2680,10 @@ nfs4_remote_mount(struct file_system_type *fs_type, int flags,
s->s_flags |= MS_ACTIVE;
security_free_mnt_opts(&data->lsm_opts);
nfs_free_fhandle(mntfh);
return mntroot;
out:
security_free_mnt_opts(&data->lsm_opts);
out_free_fh:
nfs_free_fhandle(mntfh);
return ERR_PTR(error);
@ -2838,7 +2838,7 @@ static struct dentry *nfs4_mount(struct file_system_type *fs_type,
data = nfs_alloc_parsed_mount_data(4);
if (data == NULL)
goto out_free_data;
goto out;
/* Validate the mount data */
error = nfs4_validate_mount_data(raw_data, data, dev_name);
@ -2852,12 +2852,7 @@ static struct dentry *nfs4_mount(struct file_system_type *fs_type,
error = PTR_ERR(res);
out:
kfree(data->client_address);
kfree(data->nfs_server.export_path);
kfree(data->nfs_server.hostname);
kfree(data->fscache_uniq);
out_free_data:
kfree(data);
nfs_free_parsed_mount_data(data);
dprintk("<-- nfs4_mount() = %d%s\n", error,
error != 0 ? " [error]" : "");
return res;