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authorJerry Snitselaar <jerry.snitselaar@oracle.com>2013-01-17 01:04:14 -0700
committerJames Morris <james.l.morris@oracle.com>2013-01-22 00:27:55 +1100
commit103a197c0c4ec936f5a243b5b092e4e49213f569 (patch)
treee39515c278a0f923537aaee97bef38aad671ab00
parenta67adb997419fb53540d4a4f79c6471c60bc69b6 (diff)
downloadlinux-topics-103a197c0c4ec936f5a243b5b092e4e49213f569.tar.gz
security/device_cgroup: lock assert fails in dev_exception_clean()
devcgroup_css_free() calls dev_exception_clean() without the devcgroup_mutex being locked. Shutting down a kvm virt was giving me the following trace: [36280.732764] ------------[ cut here ]------------ [36280.732778] WARNING: at /home/snits/dev/linux/security/device_cgroup.c:172 dev_exception_clean+0xa9/0xc0() [36280.732782] Hardware name: Studio XPS 8100 [36280.732785] Modules linked in: xt_REDIRECT fuse ebtable_nat ebtables ipt_MASQUERADE iptable_nat nf_nat_ipv4 nf_nat xt_CHECKSUM iptable_mangle bridge stp llc nf_conntrack_ipv4 ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ipv6 nf_defrag_ipv4 ip6table_filter it87 hwmon_vid xt_state nf_conntrack ip6_tables snd_hda_codec_hdmi snd_hda_codec_realtek snd_hda_intel snd_hda_codec snd_hwdep snd_seq coretemp snd_seq_device crc32c_intel snd_pcm snd_page_alloc snd_timer snd broadcom tg3 serio_raw i7core_edac edac_core ptp pps_core lpc_ich pcspkr mfd_core soundcore microcode i2c_i801 nfsd auth_rpcgss nfs_acl lockd vhost_net sunrpc tun macvtap macvlan kvm_intel kvm uinput binfmt_misc autofs4 usb_storage firewire_ohci firewire_core crc_itu_t radeon drm_kms_helper ttm [36280.732921] Pid: 933, comm: libvirtd Tainted: G W 3.8.0-rc3-00307-g4c217de #1 [36280.732922] Call Trace: [36280.732927] [<ffffffff81044303>] warn_slowpath_common+0x93/0xc0 [36280.732930] [<ffffffff8104434a>] warn_slowpath_null+0x1a/0x20 [36280.732932] [<ffffffff812deaf9>] dev_exception_clean+0xa9/0xc0 [36280.732934] [<ffffffff812deb2a>] devcgroup_css_free+0x1a/0x30 [36280.732938] [<ffffffff810ccd76>] cgroup_diput+0x76/0x210 [36280.732941] [<ffffffff8119eac0>] d_delete+0x120/0x180 [36280.732943] [<ffffffff81195cff>] vfs_rmdir+0xef/0x130 [36280.732945] [<ffffffff81195e47>] do_rmdir+0x107/0x1c0 [36280.732949] [<ffffffff8132d17e>] ? trace_hardirqs_on_thunk+0x3a/0x3f [36280.732951] [<ffffffff81198646>] sys_rmdir+0x16/0x20 [36280.732954] [<ffffffff8173bd82>] system_call_fastpath+0x16/0x1b [36280.732956] ---[ end trace ca39dced899a7d9f ]--- Signed-off-by: Jerry Snitselaar <jerry.snitselaar@oracle.com> Cc: stable@kernel.org Signed-off-by: James Morris <james.l.morris@oracle.com>
-rw-r--r--security/device_cgroup.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/security/device_cgroup.c b/security/device_cgroup.c
index 19ecc8de9e6..d794abcc4b3 100644
--- a/security/device_cgroup.c
+++ b/security/device_cgroup.c
@@ -215,7 +215,9 @@ static void devcgroup_css_free(struct cgroup *cgroup)
struct dev_cgroup *dev_cgroup;
dev_cgroup = cgroup_to_devcgroup(cgroup);
+ mutex_lock(&devcgroup_mutex);
dev_exception_clean(dev_cgroup);
+ mutex_unlock(&devcgroup_mutex);
kfree(dev_cgroup);
}