[PATCH 3.10 075/173] blk-core: Fix memory corruption if blkcg_init_queue fails

Greg Kroah-Hartman
2013-12-02T21:00:31Z

From: Mikulas Patocka <mpatocka@redhat.com>

commit fff4996b7db7955414ac74386efa5e07fd766b50 upstream.

If blkcg_init_queue fails, blk_alloc_queue_node doesn't call bdi_destroy
to clean up structures allocated by the backing dev.

------------[ cut here ]------------
WARNING: at lib/debugobjects.c:260 debug_print_object+0x85/0xa0()
ODEBUG: free active (active state 0) object type: percpu_counter hint: (null)
Modules linked in: dm_loop dm_mod ip6table_filter ip6_tables uvesafb cfbcopyarea cfbimgblt cfbfillrect fbcon font bitblit fbcon_rotate fbcon_cw fbcon_ud fbcon_ccw softcursor fb fbdev ipt_MASQUERADE iptable_nat nf_nat_ipv4 msr nf_conntrack_ipv4 nf_defrag_ipv4 xt_state ipt_REJECT xt_tcpudp iptable_filter ip_tables x_tables bridge stp llc tun ipv6 cpufreq_userspace cpufreq_stats cpufreq_powersave cpufreq_ondemand cpufreq_conservative spadfs fuse hid_generic usbhid hid raid0 md_mod dmi_sysfs nf_nat_ftp nf_nat nf_conntrack_ftp nf_conntrack lm85 hwmon_vid snd_usb_audio snd_pcm_oss snd_mixer_oss snd_pcm snd_timer snd_page_alloc snd_hwdep snd_usbmidi_lib snd_rawmidi snd soundcore acpi_cpufreq freq_table mperf sata_svw serverworks kvm_amd ide_core ehci_pci ohci_hcd libata ehci_hcd kvm usbcore tg3 usb_common libphy k10temp pcspkr ptp i2c_piix4 i2c_core evdev microcode hwmon rtc_cmos pps_core e100 skge floppy mii processor button unix
CPU: 0 PID: 2739 Comm: lvchange Tainted: G W
3.10.15-devel #14
Hardware name: empty empty/S3992-E, BIOS 'V1.06 ' 06/09/2009
0000000000000009 ffff88023c3c1ae8 ffffffff813c8fd4 ffff88023c3c1b20
ffffffff810399eb ffff88043d35cd58 ffffffff81651940 ffff88023c3c1bf8
ffffffff82479d90 0000000000000005 ffff88023c3c1b80 ffffffff81039a67
Call Trace:
[<ffffffff813c8fd4>] dump_stack+0x19/0x1b
[<ffffffff810399eb>] warn_slowpath_common+0x6b/0xa0
[<ffffffff81039a67>] warn_slowpath_fmt+0x47/0x50
[<ffffffff8122aaaf>] ? debug_check_no_obj_freed+0xcf/0x250
[<ffffffff81229a15>] debug_print_object+0x85/0xa0
[<ffffffff8122abe3>] debug_check_no_obj_freed+0x203/0x250
[<ffffffff8113c4ac>] kmem_cache_free+0x20c/0x3a0
[<ffffffff811f6709>] blk_alloc_queue_node+0x2a9/0x2c0
[<ffffffff811f672e>] blk_alloc_queue+0xe/0x10
[<ffffffffa04c0093>] dm_create+0x1a3/0x530 [dm_mod]
[<ffffffffa04c6bb0>] ? list_version_get_info+0xe0/0xe0 [dm_mod]
[<ffffffffa04c6c07>] dev_create+0x57/0x2b0 [dm_mod]
[<ffffffffa04c6bb0>] ? list_version_get_info+0xe0/0xe0 [dm_mod]
[<ffffffffa04c6bb0>] ? list_version_get_info+0xe0/0xe0 [dm_mod]
[<ffffffffa04c6528>] ctl_ioctl+0x268/0x500 [dm_mod]
[<ffffffff81097662>] ? get_lock_stats+0x22/0x70
[<ffffffffa04c67ce>] dm_ctl_ioctl+0xe/0x20 [dm_mod]
[<ffffffff81161aad>] do_vfs_ioctl+0x2ed/0x520
[<ffffffff8116cfc7>] ? fget_light+0x377/0x4e0
[<ffffffff81161d2b>] SyS_ioctl+0x4b/0x90
[<ffffffff813cff16>] system_call_fastpath+0x1a/0x1f
---[ end trace 4b5ff0d55673d986 ]---
------------[ cut here ]------------

This fix should be backported to stable kernels starting with 2.6.37. Note
that in the kernels prior to 3.5 the affected code is different, but the
bug is still there - bdi_init is called and bdi_destroy isn't.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
block/blk-core.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -645,10 +645,12 @@ struct request_queue *blk_alloc_queue_no
__set_bit(QUEUE_FLAG_BYPASS, &q->queue_flags);

if (blkcg_init_queue(q))
- goto fail_id;
+ goto fail_bdi;

return q;

+fail_bdi:
+ bdi_destroy(&q->backing_dev_info);
fail_id:
ida_simple_remove(&blk_queue_ida, q->id);