diff options
| author | Francesco Ruggeri <fruggeri@aristanetworks.com> | 2012-09-13 15:03:37 -0700 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2012-10-10 03:30:45 +0100 |
| commit | 1b0abe96ea79c42e21604d08216fe773000dae2b (patch) | |
| tree | e92a94c8f7960899650e9c85493e71c91120271e /fs | |
| parent | 62ed89fa28e6ecff1e4e9fb9664276d02862a2bc (diff) | |
fs/proc: fix potential unregister_sysctl_table hang
commit 6bf6104573482570f7103d3e5ddf9574db43a363 upstream.
The unregister_sysctl_table() function hangs if all references to its
ctl_table_header structure are not dropped.
This can happen sometimes because of a leak in proc_sys_lookup():
proc_sys_lookup() gets a reference to the table via lookup_entry(), but
it does not release it when a subsequent call to sysctl_follow_link()
fails.
This patch fixes this leak by making sure the reference is always
dropped on return.
See also commit 076c3eed2c31 ("sysctl: Rewrite proc_sys_lookup
introducing find_entry and lookup_entry") which reorganized this code in
3.4.
Tested in Linux 3.4.4.
Signed-off-by: Francesco Ruggeri <fruggeri@aristanetworks.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/proc/proc_sysctl.c | 5 |
1 files changed, 2 insertions, 3 deletions
diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c index 53c3bcea56cf..0be1aa46d9d1 100644 --- a/fs/proc/proc_sysctl.c +++ b/fs/proc/proc_sysctl.c @@ -123,9 +123,6 @@ static struct dentry *proc_sys_lookup(struct inode *dir, struct dentry *dentry, err = ERR_PTR(-ENOMEM); inode = proc_sys_make_inode(dir->i_sb, h ? h : head, p); - if (h) - sysctl_head_finish(h); - if (!inode) goto out; @@ -134,6 +131,8 @@ static struct dentry *proc_sys_lookup(struct inode *dir, struct dentry *dentry, d_add(dentry, inode); out: + if (h) + sysctl_head_finish(h); sysctl_head_finish(head); return err; } |