Re: scatterlist.h backtrace from crypto ccm module

From: Tom Lendacky
Date: Thu Dec 05 2013 - 10:48:19 EST



On Thursday, December 05, 2013 09:03:02 AM Josh Boyer wrote:
> Hi All,
>
> We've had a report [1] of the backtrace below on the latest rawhide
> kernel, which is essentially Linus' tree as of yesterday. We aren't
> carrying any patches to crypto at the moment. It's basically hitting
> the second BUG_ON in the sg_page function:
>
> static inline struct page *sg_page(struct scatterlist *sg)
> {
> #ifdef CONFIG_DEBUG_SG
> BUG_ON(sg->sg_magic != SG_MAGIC);
> BUG_ON(sg_is_chain(sg));
> #endif
> return (struct page *)((sg)->page_link & ~0x3);
> }
>
> Any ideas on this one?

Looks like I introduced this when I added the chain pointer indicator
bit to fix a segfault I was seeing. I didn't try running with
CONFIG_DEBUG_SG enabled and so I didn't hit this. Try this patch and
see if it fixes it for you. If it does I'll re-send it with a
signed-off-by.

diff --git a/include/crypto/scatterwalk.h b/include/crypto/scatterwalk.h
index 13621cc..2913729 100644
--- a/include/crypto/scatterwalk.h
+++ b/include/crypto/scatterwalk.h
@@ -43,7 +43,7 @@ static inline struct scatterlist *scatterwalk_sg_next(struct scatterlist *sg)
if (sg_is_last(sg))
return NULL;

- return (++sg)->length ? sg : (void *)sg_page(sg);
+ return (++sg)->length ? sg : sg_chain_ptr(sg);
}

static inline void scatterwalk_crypto_chain(struct scatterlist *head,

Thanks,
Tom
>
> [1] https://bugzilla.redhat.com/show_bug.cgi?id=1038472
>
> josh
>
> [ 89.317139] ------------[ cut here ]------------
> [ 89.317210] kernel BUG at include/linux/scatterlist.h:99!
> [ 89.317272] invalid opcode: 0000 [#1] SMP
> [ 89.317326] Modules linked in: ccm ip6t_REJECT bnep bluetooth
> xt_conntrack ebtable_nat ebtable_broute bridge stp llc ebtable_filter
> ebtables ip6table_nat nf_conntrack_ipv6 nf_defrag_ipv6 nf_nat_ipv6
> ip6table_mangle ip6table_security ip6table_raw ip6table_filter
> ip6_tables iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4
> nf_nat nf_conntrack iptable_mangle iptable_security iptable_raw
> amd_freq_sensitivity kvm crct10dif_pclmul crc32_pclmul arc4
> crc32c_intel rtl8188ee rtl_pci rtlwifi ghash_clmulni_intel mac80211
> microcode snd_hda_codec_conexant cfg80211 joydev snd_hda_codec_hdmi
> serio_raw alx snd_hda_intel edac_core edac_mce_amd mdio k10temp
> fam15h_power snd_hda_codec snd_hwdep toshiba_acpi sparse_keymap
> snd_seq rfkill snd_seq_device wmi snd_pcm snd_page_alloc snd_timer snd
> shpchp soundcore video
> [ 89.318322] i2c_piix4 acpi_cpufreq binfmt_misc radeon i2c_algo_bit
> drm_kms_helper ttm drm i2c_core
> [ 89.318441] CPU: 3 PID: 809 Comm: cryptomgr_test Not tainted
> 3.13.0-0.rc2.git3.1.fc21.x86_64 #1
> [ 89.318535] Hardware name: TOSHIBA Satellite L75D-A/Larne, BIOS
> 1.10 05/16/2013
> [ 89.318616] task: ffff88003725cd70 ti: ffff880192ef2000 task.ti:
> ffff880192ef2000
> [ 89.318697] RIP: 0010:[<ffffffff81335a1e>] [<ffffffff81335a1e>]
> scatterwalk_pagedone+0xbe/0xc0
> [ 89.318803] RSP: 0018:ffff880192ef3940 EFLAGS: 00010202
> [ 89.318862] RAX: 0000000087654321 RBX: ffff880192ef39d0 RCX:
> 0000000000000000 [ 89.318940] RDX: ffff8800ac3649f1 RSI: 0000000000000000
> RDI: ffff880192ef39f0 [ 89.319017] RBP: ffff880192ef3940 R08:
> 00000000000001a0 R09: ffff8800b16071c8 [ 89.319094] R10: 0000000000000003
> R11: 0000000000000000 R12: 0000000000000017 [ 89.319170] R13:
> 0000000000000010 R14: ffff880192ef3a08 R15: ffff880192ef3a90 [ 89.319248]
> FS: 00007f2fb512b740(0000) GS:ffff880198c00000(0000)
> knlGS:0000000000000000
> [ 89.319335] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [ 89.319398] CR2: 00000032b540e930 CR3: 0000000001c0c000 CR4:
> 00000000000407e0 [ 89.319474] Stack:
> [ 89.319499] ffff880192ef3950 ffffffff81335a5d ffff880192ef3990
> ffffffff813389f3
> [ 89.319594] ffff880185c33588 0000000000000010 ffff880192ef3990
> ffff880192ef3c88
> [ 89.319686] ffff8800b16071a0 0000000000000000 ffff880192ef3a70
> ffffffff81345461
> [ 89.319779] Call Trace:
> [ 89.319814] [<ffffffff81335a5d>] scatterwalk_done+0x3d/0x50
> [ 89.319881] [<ffffffff813389f3>] blkcipher_walk_done+0x83/0x230
> [ 89.319952] [<ffffffff81345461>] crypto_ctr_crypt+0x121/0x2b0
> [ 89.320023] [<ffffffff8106c0d0>] ? aes_decrypt+0xa0/0xa0
> [ 89.320087] [<ffffffff81337e2d>] async_encrypt+0x3d/0x40
> [ 89.320150] [<ffffffff81337e2d>] ? async_encrypt+0x3d/0x40
> [ 89.320218] [<ffffffffa06aa270>] crypto_ccm_encrypt+0x2d0/0x320 [ccm]
> [ 89.320293] [<ffffffff81336c23>] ? setkey+0xb3/0xd0
> [ 89.320351] [<ffffffff8133e715>] __test_aead+0x445/0x1170
> [ 89.320417] [<ffffffff813333f5>] ? __crypto_alloc_tfm+0x45/0x170
> [ 89.323746] [<ffffffff81334bb5>] ? crypto_spawn_tfm+0x45/0x80
> [ 89.327078] [<ffffffff813334b1>] ? __crypto_alloc_tfm+0x101/0x170
> [ 89.330412] [<ffffffff8133f467>] test_aead+0x27/0xb0
> [ 89.333704] [<ffffffff8133f537>] alg_test_aead+0x47/0xb0
> [ 89.336976] [<ffffffff8133d30f>] alg_test+0x12f/0x390
> [ 89.340233] [<ffffffff81758700>] ? __schedule+0x350/0x970
> [ 89.343456] [<ffffffff8133be20>] ? crypto_unregister_pcomp+0x20/0x20
> [ 89.346687] [<ffffffff8133be61>] cryptomgr_test+0x41/0x50
> [ 89.349915] [<ffffffff8109ffdf>] kthread+0xff/0x120
> [ 89.353110] [<ffffffff8109fee0>] ? insert_kthread_work+0x80/0x80
> [ 89.356287] [<ffffffff8176797c>] ret_from_fork+0x7c/0xb0
> [ 89.359440] [<ffffffff8109fee0>] ? insert_kthread_work+0x80/0x80
> [ 89.362583] Code: 65 87 48 39 42 28 75 1e 48 8b 52 30 f6 c2 01 75
> 1a 48 83 e2 fc eb 97 66 0f 1f 44 00 00 31 d2 eb 8d e8 17 fe ff ff e8
> 2b f2 41 00 <0f> 0b 66 66 66 66 90 44 8b 47 08 4c 8b 0f 55 44 89 c0 48
> 89 e5
> [ 89.369485] RIP [<ffffffff81335a1e>] scatterwalk_pagedone+0xbe/0xc0
> [ 89.372881] RSP <ffff880192ef3940>
> [ 89.395650] ---[ end trace 96ffcb2518654453 ]---
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