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author | Li Zefan <lizefan@huawei.com> | 2014-02-25 19:28:44 +0800 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-02-25 07:37:52 -0800 |
commit | fed95bab8d29b928fcf6225be72d37ded452e8a2 (patch) | |
tree | 45acbc72b0e58cc47d261b6346f99a5896dea85e /fs/sysfs | |
parent | 6d0abeca3242a88cab8232e4acd7e2bf088f3bc2 (diff) | |
download | linux-next-fed95bab8d29b928fcf6225be72d37ded452e8a2.tar.gz |
sysfs: fix namespace refcnt leak
As mount() and kill_sb() is not a one-to-one match, we shoudn't get
ns refcnt unconditionally in sysfs_mount(), and instead we should
get the refcnt only when kernfs_mount() allocated a new superblock.
v2:
- Changed the name of the new argument, suggested by Tejun.
- Made the argument optional, suggested by Tejun.
v3:
- Make the new argument as second-to-last arg, suggested by Tejun.
Signed-off-by: Li Zefan <lizefan@huawei.com>
Acked-by: Tejun Heo <tj@kernel.org>
---
fs/kernfs/mount.c | 8 +++++++-
fs/sysfs/mount.c | 5 +++--
include/linux/kernfs.h | 9 +++++----
3 files changed, 15 insertions(+), 7 deletions(-)
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs/sysfs')
-rw-r--r-- | fs/sysfs/mount.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/fs/sysfs/mount.c b/fs/sysfs/mount.c index 6211230814fd..3eaf5c6622eb 100644 --- a/fs/sysfs/mount.c +++ b/fs/sysfs/mount.c @@ -27,6 +27,7 @@ static struct dentry *sysfs_mount(struct file_system_type *fs_type, { struct dentry *root; void *ns; + bool new_sb; if (!(flags & MS_KERNMOUNT)) { if (!capable(CAP_SYS_ADMIN) && !fs_fully_visible(fs_type)) @@ -37,8 +38,8 @@ static struct dentry *sysfs_mount(struct file_system_type *fs_type, } ns = kobj_ns_grab_current(KOBJ_NS_TYPE_NET); - root = kernfs_mount_ns(fs_type, flags, sysfs_root, ns); - if (IS_ERR(root)) + root = kernfs_mount_ns(fs_type, flags, sysfs_root, &new_sb, ns); + if (IS_ERR(root) || !new_sb) kobj_ns_drop(KOBJ_NS_TYPE_NET, ns); return root; } |