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/9p') 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 --- fs/9p/vfs_file.c | 4 ++-- include/net/9p/client.h | 5 +++++ net/9p/client.c | 5 +++++ 3 files changed, 12 insertions(+), 2 deletions(-) (limited to 'net/9p') diff --git a/fs/9p/vfs_file.c b/fs/9p/vfs_file.c index d384a8b77ee8..aa5ecf479a57 100644 --- a/fs/9p/vfs_file.c +++ b/fs/9p/vfs_file.c @@ -183,7 +183,7 @@ static int v9fs_file_do_lock(struct file *filp, int cmd, struct file_lock *fl) else flock.length = fl->fl_end - fl->fl_start + 1; flock.proc_id = fl->fl_pid; - flock.client_id = utsname()->nodename; + flock.client_id = fid->clnt->name; if (IS_SETLKW(cmd)) flock.flags = P9_LOCK_FLAGS_BLOCK; @@ -260,7 +260,7 @@ static int v9fs_file_getlock(struct file *filp, struct file_lock *fl) else glock.length = fl->fl_end - fl->fl_start + 1; glock.proc_id = fl->fl_pid; - glock.client_id = utsname()->nodename; + glock.client_id = fid->clnt->name; res = p9_client_getlock_dotl(fid, &glock); if (res < 0) diff --git a/include/net/9p/client.h b/include/net/9p/client.h index 4c7c01a73911..c38a005bd0cf 100644 --- a/include/net/9p/client.h +++ b/include/net/9p/client.h @@ -26,6 +26,8 @@ #ifndef NET_9P_CLIENT_H #define NET_9P_CLIENT_H +#include + /* Number of requests per row */ #define P9_ROW_MAXTAG 255 @@ -134,6 +136,7 @@ struct p9_req_t { * @tagpool - transaction id accounting for session * @reqs - 2D array of requests * @max_tag - current maximum tag id allocated + * @name - node name used as client id * * The client structure is used to keep track of various per-client * state that has been instantiated. @@ -164,6 +167,8 @@ struct p9_client { struct p9_idpool *tagpool; struct p9_req_t *reqs[P9_ROW_MAXTAG]; int max_tag; + + char name[__NEW_UTS_LEN + 1]; }; /** 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