From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
stable@vger.kernel.org, Li Zefan <lizefan@huawei.com>,
Tejun Heo <tj@kernel.org>
Subject: [ 24/30] cpuset: fix cpuset_print_task_mems_allowed() vs rename() race
Date: Fri, 1 Mar 2013 11:45:45 -0800 [thread overview]
Message-ID: <20130301194530.621601508@linuxfoundation.org> (raw)
In-Reply-To: <20130301194527.988540148@linuxfoundation.org>
3.0-stable review patch. If anyone has any objections, please let me know.
------------------
From: Li Zefan <lizefan@huawei.com>
commit 63f43f55c9bbc14f76b582644019b8a07dc8219a upstream.
rename() will change dentry->d_name. The result of this race can
be worse than seeing partially rewritten name, but we might access
a stale pointer because rename() will re-allocate memory to hold
a longer name.
It's safe in the protection of dentry->d_lock.
v2: check NULL dentry before acquiring dentry lock.
Signed-off-by: Li Zefan <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
kernel/cpuset.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -2499,8 +2499,16 @@ void cpuset_print_task_mems_allowed(stru
dentry = task_cs(tsk)->css.cgroup->dentry;
spin_lock(&cpuset_buffer_lock);
- snprintf(cpuset_name, CPUSET_NAME_LEN,
- dentry ? (const char *)dentry->d_name.name : "/");
+
+ if (!dentry) {
+ strcpy(cpuset_name, "/");
+ } else {
+ spin_lock(&dentry->d_lock);
+ strlcpy(cpuset_name, (const char *)dentry->d_name.name,
+ CPUSET_NAME_LEN);
+ spin_unlock(&dentry->d_lock);
+ }
+
nodelist_scnprintf(cpuset_nodelist, CPUSET_NODELIST_LEN,
tsk->mems_allowed);
printk(KERN_INFO "%s cpuset=%s mems_allowed=%s\n",
next prev parent reply other threads:[~2013-03-01 19:46 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-03-01 19:45 [ 00/30] 3.0.68-stable review Greg Kroah-Hartman
2013-03-01 19:45 ` [ 01/30] quota: autoload the quota_v2 module for QFMT_VFS_V1 quota format Greg Kroah-Hartman
2013-03-01 19:45 ` [ 02/30] iommu/amd: Initialize device table after dma_ops Greg Kroah-Hartman
2013-03-01 19:45 ` [ 03/30] posix-timer: Dont call idr_find() with out-of-range ID Greg Kroah-Hartman
2013-03-01 19:45 ` [ 04/30] ftrace: Call ftrace cleanup module notifier after all other notifiers Greg Kroah-Hartman
2013-03-01 19:45 ` [ 05/30] doc, xen: Mention earlyprintk=xen in the documentation Greg Kroah-Hartman
2013-03-01 19:45 ` [ 06/30] doc, kernel-parameters: Document console=hvc<n> Greg Kroah-Hartman
2013-03-01 19:45 ` [ 07/30] x86: Make sure we can boot in the case the BDA contains pure garbage Greg Kroah-Hartman
2013-03-01 19:45 ` [ 08/30] target: Add missing mapped_lun bounds checking during make_mappedlun setup Greg Kroah-Hartman
2013-03-01 19:45 ` [ 09/30] ocfs2: ac->ac_allow_chain_relink=0 wont disable group relink Greg Kroah-Hartman
2013-03-01 19:45 ` [ 10/30] xen-blkback: do not leak mode property Greg Kroah-Hartman
2013-03-01 19:45 ` [ 11/30] idr: fix a subtle bug in idr_get_next() Greg Kroah-Hartman
2013-03-01 19:45 ` [ 12/30] firewire: add minor number range check to fw_device_init() Greg Kroah-Hartman
2013-03-01 19:45 ` [ 13/30] sysctl: fix null checking in bin_dn_node_address() Greg Kroah-Hartman
2013-03-01 19:45 ` [ 14/30] media: rc: unlock on error in show_protocols() Greg Kroah-Hartman
2013-03-01 19:45 ` [ 15/30] ext4: fix race in ext4_mb_add_n_trim() Greg Kroah-Hartman
2013-03-01 19:45 ` [ 16/30] svcrpc: make svc_age_temp_xprts enqueue under sv_lock Greg Kroah-Hartman
2013-03-01 19:45 ` [ 17/30] vhost: fix length for cross region descriptor Greg Kroah-Hartman
2013-03-01 19:45 ` [ 18/30] ptrace: introduce signal_wake_up_state() and ptrace_signal_wake_up() Greg Kroah-Hartman
2013-03-01 19:45 ` [ 19/30] ptrace: ensure arch_ptrace/ptrace_request can never race with SIGKILL Greg Kroah-Hartman
2013-03-01 19:45 ` [ 20/30] wake_up_process() should be never used to wakeup a TASK_STOPPED/TRACED task Greg Kroah-Hartman
2013-03-01 19:45 ` [ 21/30] unbreak automounter support on 64-bit kernel with 32-bit userspace (v2) Greg Kroah-Hartman
2013-03-01 19:45 ` [ 22/30] x86: Do not leak kernel page mapping locations Greg Kroah-Hartman
2013-03-01 19:45 ` [ 23/30] x86/apic: Work around boot failure on HP ProLiant DL980 G7 Server systems Greg Kroah-Hartman
2013-03-01 19:45 ` Greg Kroah-Hartman [this message]
2013-03-01 19:45 ` [ 25/30] cgroup: fix exit() vs rmdir() race Greg Kroah-Hartman
2013-03-01 19:45 ` [ 26/30] dca: check against empty dca_domains list before unregister provider fix Greg Kroah-Hartman
2013-03-01 19:45 ` [ 27/30] s390/kvm: Fix store status for ACRS/FPRS fix Greg Kroah-Hartman
2013-03-01 19:45 ` [ 28/30] staging: comedi: ni_labpc: correct differential channel sequence for AI commands Greg Kroah-Hartman
2013-03-01 19:45 ` [ 29/30] staging: comedi: ni_labpc: set up command4 register *after* command3 Greg Kroah-Hartman
2013-03-01 19:45 ` [ 30/30] staging: comedi: check s->async for poll(), read() and write() Greg Kroah-Hartman
2013-03-02 3:58 ` [ 00/30] 3.0.68-stable review Shuah Khan
2013-03-03 11:47 ` Satoru Takeuchi
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