From e0d6cb9cd3a3ac8a3b8e5b22b83c4f8619786f22 Mon Sep 17 00:00:00 2001 From: Michael Marineau Date: Sun, 11 Aug 2013 00:53:45 -0400 Subject: 9p: send uevent after adding/removing mount_tag attribute This driver adds an attribute to the existing virtio device so a CHANGE event is required in order udev rules to make use of it. The ADD event happens before this driver is probed and unlike a more typical driver like a block device there isn't a higher level device to watch for. Signed-off-by: Michael Marineau Signed-off-by: Eric Van Hensbergen --- net/9p/trans_virtio.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'net') diff --git a/net/9p/trans_virtio.c b/net/9p/trans_virtio.c index e1c26b101830..990afab2be1b 100644 --- a/net/9p/trans_virtio.c +++ b/net/9p/trans_virtio.c @@ -577,6 +577,10 @@ static int p9_virtio_probe(struct virtio_device *vdev) mutex_lock(&virtio_9p_lock); list_add_tail(&chan->chan_list, &virtio_chan_list); mutex_unlock(&virtio_9p_lock); + + /* Let udev rules use the new mount_tag attribute. */ + kobject_uevent(&(vdev->dev.kobj), KOBJ_CHANGE); + return 0; out_free_tag: @@ -654,6 +658,7 @@ static void p9_virtio_remove(struct virtio_device *vdev) list_del(&chan->chan_list); mutex_unlock(&virtio_9p_lock); sysfs_remove_file(&(vdev->dev.kobj), &dev_attr_mount_tag.attr); + kobject_uevent(&(vdev->dev.kobj), KOBJ_CHANGE); kfree(chan->tag); kfree(chan->vc_wq); kfree(chan); -- cgit v1.2.3 From 50192abe02929586111fb33f216060a9341875f1 Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Wed, 21 Aug 2013 18:24:47 +0100 Subject: fs/9p: avoid accessing utsname after namespace has been torn down During trinity fuzzing in a kvmtool guest, I stumbled across the following: Unable to handle kernel NULL pointer dereference at virtual address 00000004 PC is at v9fs_file_do_lock+0xc8/0x1a0 LR is at v9fs_file_do_lock+0x48/0x1a0 [] (v9fs_file_do_lock+0xc8/0x1a0) from [] (locks_remove_flock+0x8c/0x124) [] (locks_remove_flock+0x8c/0x124) from [] (__fput+0x58/0x1e4) [] (__fput+0x58/0x1e4) from [] (task_work_run+0xac/0xe8) [] (task_work_run+0xac/0xe8) from [] (do_exit+0x6bc/0x8d8) [] (do_exit+0x6bc/0x8d8) from [] (do_group_exit+0x3c/0xb0) [] (do_group_exit+0x3c/0xb0) from [] (__wake_up_parent+0x0/0x18) I believe this is due to an attempt to access utsname()->nodename, after exit_task_namespaces() has been called, leaving current->nsproxy->uts_ns as NULL and causing the above dereference. A similar issue was fixed for lockd in 9a1b6bf818e7 ("LOCKD: Don't call utsname()->nodename from nlmclnt_setlockargs"), so this patch attempts something similar for 9pfs. Cc: Eric Van Hensbergen Cc: Ron Minnich Cc: Latchesar Ionkov Cc: Trond Myklebust Signed-off-by: Will Deacon Signed-off-by: Eric Van Hensbergen --- net/9p/client.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'net') diff --git a/net/9p/client.c b/net/9p/client.c index 8b93cae2d11d..0e49b288e574 100644 --- a/net/9p/client.c +++ b/net/9p/client.c @@ -992,6 +992,7 @@ struct p9_client *p9_client_create(const char *dev_name, char *options) { int err; struct p9_client *clnt; + char *client_id; err = 0; clnt = kmalloc(sizeof(struct p9_client), GFP_KERNEL); @@ -1000,6 +1001,10 @@ struct p9_client *p9_client_create(const char *dev_name, char *options) clnt->trans_mod = NULL; clnt->trans = NULL; + + client_id = utsname()->nodename; + memcpy(clnt->name, client_id, strlen(client_id) + 1); + spin_lock_init(&clnt->lock); INIT_LIST_HEAD(&clnt->fidlist); -- cgit v1.2.3