From fff4996b7db7955414ac74386efa5e07fd766b50 Mon Sep 17 00:00:00 2001 From: Mikulas Patocka Date: Mon, 14 Oct 2013 12:11:36 -0400 Subject: [PATCH] blk-core: Fix memory corruption if blkcg_init_queue fails 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: [] dump_stack+0x19/0x1b [] warn_slowpath_common+0x6b/0xa0 [] warn_slowpath_fmt+0x47/0x50 [] ? debug_check_no_obj_freed+0xcf/0x250 [] debug_print_object+0x85/0xa0 [] debug_check_no_obj_freed+0x203/0x250 [] kmem_cache_free+0x20c/0x3a0 [] blk_alloc_queue_node+0x2a9/0x2c0 [] blk_alloc_queue+0xe/0x10 [] dm_create+0x1a3/0x530 [dm_mod] [] ? list_version_get_info+0xe0/0xe0 [dm_mod] [] dev_create+0x57/0x2b0 [dm_mod] [] ? list_version_get_info+0xe0/0xe0 [dm_mod] [] ? list_version_get_info+0xe0/0xe0 [dm_mod] [] ctl_ioctl+0x268/0x500 [dm_mod] [] ? get_lock_stats+0x22/0x70 [] dm_ctl_ioctl+0xe/0x20 [dm_mod] [] do_vfs_ioctl+0x2ed/0x520 [] ? fget_light+0x377/0x4e0 [] SyS_ioctl+0x4b/0x90 [] 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 Acked-by: Tejun Heo Cc: stable@kernel.org # 2.6.37+ Signed-off-by: Jens Axboe --- block/blk-core.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/block/blk-core.c b/block/blk-core.c index 5e00b5a58f6a..0c611d89d748 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -645,10 +645,12 @@ struct request_queue *blk_alloc_queue_node(gfp_t gfp_mask, int node_id) __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); fail_q: -- 2.30.2