From 6fbabb20faed9c08f8b96de4182bd721cbd1cfcf Mon Sep 17 00:00:00 2001 From: Christoph Lameter Date: Mon, 8 Aug 2011 11:16:56 -0500 Subject: [PATCH] slub: Fix full list corruption if debugging is on When a slab is freed by __slab_free() and the slab can only contain a single object ever then it was full (and therefore not on the partial lists but on the full list in the debug case) before we reached slab_empty. This caused the following full list corruption when SLUB debugging was enabled: [ 5913.233035] ------------[ cut here ]------------ [ 5913.233097] WARNING: at lib/list_debug.c:53 __list_del_entry+0x8d/0x98() [ 5913.233101] Hardware name: Adamo 13 [ 5913.233105] list_del corruption. prev->next should be ffffea000434fd20, but was ffffea0004199520 [ 5913.233108] Modules linked in: nfs fscache fuse ebtable_nat ebtables ppdev parport_pc lp parport ipt_MASQUERADE iptable_nat nf_nat nfsd lockd nfs_acl auth_rpcgss xt_CHECKSUM sunrpc iptable_mangle bridge stp llc cpufreq_ondemand acpi_cpufreq freq_table mperf ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ipv6 ip6table_filter ip6_tables rfcomm bnep arc4 iwlagn snd_hda_codec_hdmi snd_hda_codec_idt snd_hda_intel btusb mac80211 snd_hda_codec bluetooth snd_hwdep snd_seq snd_seq_device snd_pcm usb_debug dell_wmi sparse_keymap cdc_ether usbnet cdc_acm uvcvideo cdc_wdm mii cfg80211 snd_timer dell_laptop videodev dcdbas snd microcode v4l2_compat_ioctl32 soundcore joydev tg3 pcspkr snd_page_alloc iTCO_wdt i2c_i801 rfkill iTCO_vendor_support wmi virtio_net kvm_intel kvm ipv6 xts gf128mul dm_crypt i915 drm_kms_helper drm i2c_algo_bit i2c_core video [last unloaded: scsi_wait_scan] [ 5913.233213] Pid: 0, comm: swapper Not tainted 3.0.0+ #127 [ 5913.233213] Call Trace: [ 5913.233213] [] warn_slowpath_common+0x83/0x9b [ 5913.233213] [] warn_slowpath_fmt+0x46/0x48 [ 5913.233213] [] __list_del_entry+0x8d/0x98 [ 5913.233213] [] list_del+0xe/0x2d [ 5913.233213] [] __slab_free+0x1db/0x235 [ 5913.233213] [] ? bvec_free_bs+0x35/0x37 [ 5913.233213] [] ? bvec_free_bs+0x35/0x37 [ 5913.233213] [] ? bvec_free_bs+0x35/0x37 [ 5913.233213] [] kmem_cache_free+0x88/0x102 [ 5913.233213] [] bvec_free_bs+0x35/0x37 [ 5913.233213] [] bio_free+0x34/0x64 [ 5913.233213] [] dm_bio_destructor+0x12/0x14 [ 5913.233213] [] bio_put+0x2b/0x2d [ 5913.233213] [] clone_endio+0x9e/0xb4 [ 5913.233213] [] bio_endio+0x2d/0x2f [ 5913.233213] [] crypt_dec_pending+0x5c/0x8b [dm_crypt] [ 5913.233213] [] crypt_endio+0x78/0x81 [dm_crypt] [ Full discussion here: https://lkml.org/lkml/2011/8/4/375 ] Make sure that we remove such a slab also from the full lists. Reported-and-tested-by: Dave Jones Reported-and-tested-by: Xiaotian Feng Signed-off-by: Christoph Lameter Signed-off-by: Pekka Enberg --- mm/slub.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/mm/slub.c b/mm/slub.c index eb5a8f93338a..5436fe2fbf9c 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -2387,11 +2387,13 @@ static void __slab_free(struct kmem_cache *s, struct page *page, slab_empty: if (prior) { /* - * Slab still on the partial list. + * Slab on the partial list. */ remove_partial(n, page); stat(s, FREE_REMOVE_PARTIAL); - } + } else + /* Slab must be on the full list */ + remove_full(s, page); spin_unlock_irqrestore(&n->list_lock, flags); stat(s, FREE_SLAB); -- 2.20.1