diff options
| author | Francesco Ruggeri <fruggeri@aristanetworks.com> | 2012-09-13 15:03:37 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-09-17 10:32:03 -0700 |
| commit | 6bf6104573482570f7103d3e5ddf9574db43a363 (patch) | |
| tree | 4aa02983bfffbe0d623c0163822354b48693eca0 | |
| parent | 5698bd757d55b1bb87edd1a9744ab09c142abfc2 (diff) | |
fs/proc: fix potential unregister_sysctl_table hang
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>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -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 dfafeb2b05a0..eb7cc91b7258 100644 --- a/fs/proc/proc_sysctl.c +++ b/fs/proc/proc_sysctl.c @@ -462,9 +462,6 @@ 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; @@ -473,6 +470,8 @@ 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; } |