From a59d6293e5372d7c35212932e083e2a541151eff Mon Sep 17 00:00:00 2001 From: Arend van Spriel Date: Wed, 23 May 2012 15:13:07 +0200 Subject: debugfs: change parameter check in debugfs_remove() functions The dentry parameter in debugfs_remove() and debugfs_remove_recursive() is checked being a NULL pointer. To make cleanup by callers easier this check is extended using the IS_ERR_OR_NULL macro instead because the debugfs_create_... functions can return a ERR_PTR() value. Signed-off-by: Arend van Spriel Signed-off-by: Greg Kroah-Hartman --- fs/debugfs/inode.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'fs') diff --git a/fs/debugfs/inode.c b/fs/debugfs/inode.c index b80bc846a15a..0de5e26870c3 100644 --- a/fs/debugfs/inode.c +++ b/fs/debugfs/inode.c @@ -498,7 +498,7 @@ void debugfs_remove(struct dentry *dentry) struct dentry *parent; int ret; - if (!dentry) + if (IS_ERR_OR_NULL(dentry)) return; parent = dentry->d_parent; @@ -530,7 +530,7 @@ void debugfs_remove_recursive(struct dentry *dentry) struct dentry *child; struct dentry *parent; - if (!dentry) + if (IS_ERR_OR_NULL(dentry)) return; parent = dentry->d_parent; -- cgit v1.2.3 From e5bcac61472ca627241b394d439decd00bba3aea Mon Sep 17 00:00:00 2001 From: Glauber Costa Date: Fri, 6 Jul 2012 13:09:07 +0400 Subject: sysfs: fail dentry revalidation after namespace change When we change the namespace tag of a sysfs entry, the associated dentry is still kept around. readdir() will work correctly and not display the old entries, but open() will still succeed, so will reads and writes. This will no longer happen if sysfs is remounted, hinting that this is a cache-related problem. I am using the following sequence to demonstrate that: shell1: ip link add type veth unshare -nm shell2: ip link set veth1 cat /sys/devices/virtual/net/veth1/ifindex Before that patch, this will succeed (fail to fail). After it, it will correctly return an error. Differently from a normal rename, which we handle fine, changing the object namespace will keep it's path intact. So this check seems necessary as well. [ v2: get type from parent, as suggested by Eric Biederman ] Signed-off-by: Glauber Costa CC: Tejun Heo Reviewed-by: "Eric W. Biederman" Signed-off-by: Greg Kroah-Hartman --- fs/sysfs/dir.c | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'fs') diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c index e6bb9b2a4cbe..c0bf38a21caa 100644 --- a/fs/sysfs/dir.c +++ b/fs/sysfs/dir.c @@ -307,6 +307,7 @@ static int sysfs_dentry_revalidate(struct dentry *dentry, struct nameidata *nd) { struct sysfs_dirent *sd; int is_dir; + int type; if (nd->flags & LOOKUP_RCU) return -ECHILD; @@ -326,6 +327,13 @@ static int sysfs_dentry_revalidate(struct dentry *dentry, struct nameidata *nd) if (strcmp(dentry->d_name.name, sd->s_name) != 0) goto out_bad; + /* The sysfs dirent has been moved to a different namespace */ + type = KOBJ_NS_TYPE_NONE; + if (sd->s_parent) + type = sysfs_ns_type(sd->s_parent); + if (type && (sysfs_info(dentry->d_sb)->ns[type] != sd->s_ns)) + goto out_bad; + mutex_unlock(&sysfs_mutex); out_valid: return 1; -- cgit v1.2.3 From 17f79be93d95bb0e46bd08681ec9c9e601869c15 Mon Sep 17 00:00:00 2001 From: Andrew Morton Date: Mon, 9 Jul 2012 16:13:36 -0700 Subject: sysfs: fail dentry revalidation after namespace change fix don't assume that KOBJ_NS_TYPE_NONE==0. Also save a test-n-branch. Cc: Eric W. Biederman Cc: Glauber Costa Cc: Tejun Heo Signed-off-by: Andrew Morton Acked-by: Serge E. Hallyn Signed-off-by: Greg Kroah-Hartman --- fs/sysfs/dir.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) (limited to 'fs') diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c index c0bf38a21caa..1cdfb53199aa 100644 --- a/fs/sysfs/dir.c +++ b/fs/sysfs/dir.c @@ -329,10 +329,12 @@ static int sysfs_dentry_revalidate(struct dentry *dentry, struct nameidata *nd) /* The sysfs dirent has been moved to a different namespace */ type = KOBJ_NS_TYPE_NONE; - if (sd->s_parent) + if (sd->s_parent) { type = sysfs_ns_type(sd->s_parent); - if (type && (sysfs_info(dentry->d_sb)->ns[type] != sd->s_ns)) - goto out_bad; + if (type != KOBJ_NS_TYPE_NONE && + sysfs_info(dentry->d_sb)->ns[type] != sd->s_ns) + goto out_bad; + } mutex_unlock(&sysfs_mutex); out_valid: -- cgit v1.2.3