On Tuesday, 7 December 2021 05:35:04 CET Wen Gong wrote:
> Thanks Sven a lot for your analyze.
>
> I still can not reproduce it.
>
> I think it is because the write over skb->tail in scan, because the
> invalid address
Yes, I thought that I wanted to write about it but it might have gone into
another draft of the mail. So what I wanted to write was something like:
The information which is used in skb_zcopy_clear/skb_zcopy/skb_zcopy_is_nouarg
is coming from skb_shinfo. And skb_end_pointer is just a pointer to a region
at the end of the skb buffer (skb->end). And this got corrupted by something
Unfortunately this is correctly allocated memory and thus kasan cannot help
us with it.
[...]
> --- a/drivers/net/wireless/ath/ath11k/wmi.c
> +++ b/drivers/net/wireless/ath/ath11k/wmi.c
> @@ -2271,6 +2271,7 @@ int ath11k_wmi_send_scan_start_cmd(struct ath11k *ar,
> }
> }
>
> + ath11k_info(ar->ab, "%s ptr %px skb data %px len %d over %d",
> __func__, ptr, skb->data, skb->len, ((unsigned char
> *)ptr)-skb->data-skb->len);
> ret = ath11k_wmi_cmd_send(wmi, skb,
> WMI_START_SCAN_CMDID);
> if (ret) {
Changed the last part to:
ath11k_err(ar->ab, "%s ptr %px skb data %px len %d over %ld\n", __func__, ptr, skb->data, skb->len, ((unsigned char *)ptr) - skb->data - skb->len);
The output is:
ath11k_pci 0000:01:00.0: n_ssids 1
ath11k_pci 0000:01:00.0: ssid[0] len 0
ath11k_pci 0000:01:00.0: ath11k_wmi_send_scan_start_cmd ptr ffff9217101e82b4 skb data ffff9217101e804c len 616 over 0
But we are looking at the ath11k_ce_tx_process_cb function. So I would have
expected that it is related to something which as sent out. So the first thing
I did was to add some skb_dumps in the sent path (ath11k_htc_send) and in the
cleanup path (skb_zcopy_clear). Something like this (just the cleanup path
because otherwise I have to post a rather large diff):
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 819cc58ab051..c15512e2f30c 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -1547,8 +1547,10 @@ static inline void skb_zcopy_clear(struct sk_buff *skb, bool zerocopy_success)
struct ubuf_info *uarg = skb_zcopy(skb);
if (uarg) {
- if (!skb_zcopy_is_nouarg(skb))
+ if (!skb_zcopy_is_nouarg(skb)) {
+ skb_dump(KERN_ERR, skb, true);
uarg->callback(skb, uarg, zerocopy_success);
+ }
skb_shinfo(skb)->flags &= ~SKBFL_ALL_ZEROCOPY;
}
But interestingly, it already crashes to parse the fraglist in
ath11k_htc_send. So I've added some more dump to figure out where is breaks.
And I've noticed that it breaks after following section in
ath11k_wmi_send_scan_start_cmd
if (params->extraie.len)
memcpy(ptr, params->extraie.ptr,
params->extraie.len);
Here is the full output:
[ 30.641297] ath11k_wmi_send_scan_start_cmd:2357
[ 30.645873] skb len=616 headroom=76 headlen=616 tailroom=12
[ 30.645873] mac=(-1,-1) net=(0,-1) trans=-1
[ 30.645873] shinfo(txflags=0 nr_frags=0 gso(size=0 type=0 segs=0))
[ 30.645873] csum(0x0 ip_summed=0 complete_sw=0 valid=0 level=0)
[ 30.645873] hash(0x0 sw=0 l4=0) proto=0x0000 pkttype=0 iif=0
[ 30.673381] skb headroom: 00000000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[ 30.681073] skb headroom: 00000010: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[ 30.688758] skb headroom: 00000020: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[ 30.696465] skb headroom: 00000030: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[ 30.704197] skb headroom: 00000040: 00 00 00 00 00 00 00 00 00 00 00 00
[ 30.710852] skb linear: 00000000: 9c 00 4d 00 00 a0 00 00 01 00 00 00 00 00 00 00
[ 30.718538] skb linear: 00000010: 01 00 00 00 1f 00 00 00 32 00 00 00 96 00 00 00
[ 30.726271] skb linear: 00000020: 32 00 00 00 f4 01 00 00 00 00 00 00 00 00 00 00
[ 30.733954] skb linear: 00000030: 00 00 00 00 20 4e 00 00 05 00 00 00 10 00 00 00
[ 30.741636] skb linear: 00000040: 00 00 00 00 61 00 00 00 01 00 00 00 01 00 00 00
[ 30.749346] skb linear: 00000050: 08 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[ 30.757092] skb linear: 00000060: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[ 30.764795] skb linear: 00000070: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[ 30.772483] skb linear: 00000080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[ 30.780170] skb linear: 00000090: 00 00 00 00 28 00 00 00 1e 00 00 00 00 00 00 00
[ 30.787854] skb linear: 000000a0: 84 01 10 00 6c 09 00 00 71 09 00 00 76 09 00 00
[ 30.795541] skb linear: 000000b0: 7b 09 00 00 80 09 00 00 85 09 00 00 8a 09 00 00
[ 30.803236] skb linear: 000000c0: 8f 09 00 00 94 09 00 00 99 09 00 00 9e 09 00 00
[ 30.810933] skb linear: 000000d0: a3 09 00 00 a8 09 00 00 3c 14 00 00 50 14 00 00
[ 30.818620] skb linear: 000000e0: 64 14 00 00 78 14 00 00 8c 14 00 00 a0 14 00 00
[ 30.826322] skb linear: 000000f0: b4 14 00 00 c8 14 00 00 7c 15 00 00 90 15 00 00
[ 30.834018] skb linear: 00000100: a4 15 00 00 b8 15 00 00 cc 15 00 00 e0 15 00 00
[ 30.841712] skb linear: 00000110: f4 15 00 00 08 16 00 00 1c 16 00 00 30 16 00 00
[ 30.849402] skb linear: 00000120: 44 16 00 00 58 16 00 00 71 16 00 00 85 16 00 00
[ 30.857094] skb linear: 00000130: 99 16 00 00 ad 16 00 00 c1 16 00 00 43 17 00 00
[ 30.864776] skb linear: 00000140: 57 17 00 00 6b 17 00 00 7f 17 00 00 93 17 00 00
[ 30.872490] skb linear: 00000150: a7 17 00 00 bb 17 00 00 cf 17 00 00 e3 17 00 00
[ 30.880182] skb linear: 00000160: f7 17 00 00 0b 18 00 00 1f 18 00 00 33 18 00 00
[ 30.887882] skb linear: 00000170: 47 18 00 00 5b 18 00 00 6f 18 00 00 83 18 00 00
[ 30.895581] skb linear: 00000180: 97 18 00 00 ab 18 00 00 bf 18 00 00 d3 18 00 00
[ 30.903265] skb linear: 00000190: e7 18 00 00 fb 18 00 00 0f 19 00 00 23 19 00 00
[ 30.910974] skb linear: 000001a0: 37 19 00 00 4b 19 00 00 5f 19 00 00 73 19 00 00
[ 30.918675] skb linear: 000001b0: 87 19 00 00 9b 19 00 00 af 19 00 00 c3 19 00 00
[ 30.926418] skb linear: 000001c0: d7 19 00 00 eb 19 00 00 ff 19 00 00 13 1a 00 00
[ 30.934118] skb linear: 000001d0: 27 1a 00 00 3b 1a 00 00 4f 1a 00 00 63 1a 00 00
[ 30.941842] skb linear: 000001e0: 77 1a 00 00 8b 1a 00 00 9f 1a 00 00 b3 1a 00 00
[ 30.949537] skb linear: 000001f0: c7 1a 00 00 db 1a 00 00 ef 1a 00 00 03 1b 00 00
[ 30.957221] skb linear: 00000200: 17 1b 00 00 2b 1b 00 00 3f 1b 00 00 53 1b 00 00
[ 30.964912] skb linear: 00000210: 67 1b 00 00 7b 1b 00 00 8f 1b 00 00 a3 1b 00 00
[ 30.972614] skb linear: 00000220: b7 1b 00 00 cb 1b 00 00 24 00 13 00 00 00 00 00
[ 30.980315] skb linear: 00000230: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[ 30.988010] skb linear: 00000240: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[ 30.995696] skb linear: 00000250: 08 00 13 00 ff ff ff ff ff ff 00 00 08 00 11 00
[ 31.003394] skb linear: 00000260: 00 00 00 00 00 00 00 00
[ 31.009002] skb tailroom: 00000000: 00 00 00 00 00 00 00 00 00 00 00 00
[ 31.015646] ath11k_wmi_send_scan_start_cmd:2362
[ 31.020217] skb len=616 headroom=76 headlen=616 tailroom=12
[ 31.020217] mac=(-1,-1) net=(0,-1) trans=-1
[ 31.020217] shinfo(txflags=0 nr_frags=255 gso(size=0 type=265087 segs=0))
[ 31.020217] csum(0x0 ip_summed=0 complete_sw=0 valid=0 level=0)
[ 31.020217] hash(0x0 sw=0 l4=0) proto=0x0000 pkttype=0 iif=0
[ 31.048289] skb headroom: 00000000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[ 31.056015] skb headroom: 00000010: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[ 31.063714] skb headroom: 00000020: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[ 31.071425] skb headroom: 00000030: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[ 31.079141] skb headroom: 00000040: 00 00 00 00 00 00 00 00 00 00 00 00
[ 31.085787] skb linear: 00000000: 9c 00 4d 00 00 a0 00 00 01 00 00 00 00 00 00 00
[ 31.093518] skb linear: 00000010: 01 00 00 00 1f 00 00 00 32 00 00 00 96 00 00 00
[ 31.101239] skb linear: 00000020: 32 00 00 00 f4 01 00 00 00 00 00 00 00 00 00 00
[ 31.108947] skb linear: 00000030: 00 00 00 00 20 4e 00 00 05 00 00 00 10 00 00 00
[ 31.116630] skb linear: 00000040: 00 00 00 00 61 00 00 00 01 00 00 00 01 00 00 00
[ 31.124326] skb linear: 00000050: 08 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[ 31.132007] skb linear: 00000060: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[ 31.139708] skb linear: 00000070: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[ 31.147420] skb linear: 00000080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[ 31.155118] skb linear: 00000090: 00 00 00 00 28 00 00 00 1e 00 00 00 00 00 00 00
[ 31.162798] skb linear: 000000a0: 84 01 10 00 6c 09 00 00 71 09 00 00 76 09 00 00
[ 31.170486] skb linear: 000000b0: 7b 09 00 00 80 09 00 00 85 09 00 00 8a 09 00 00
[ 31.178175] skb linear: 000000c0: 8f 09 00 00 94 09 00 00 99 09 00 00 9e 09 00 00
[ 31.185876] skb linear: 000000d0: a3 09 00 00 a8 09 00 00 3c 14 00 00 50 14 00 00
[ 31.193593] skb linear: 000000e0: 64 14 00 00 78 14 00 00 8c 14 00 00 a0 14 00 00
[ 31.201278] skb linear: 000000f0: b4 14 00 00 c8 14 00 00 7c 15 00 00 90 15 00 00
[ 31.208969] skb linear: 00000100: a4 15 00 00 b8 15 00 00 cc 15 00 00 e0 15 00 00
[ 31.216655] skb linear: 00000110: f4 15 00 00 08 16 00 00 1c 16 00 00 30 16 00 00
[ 31.224346] skb linear: 00000120: 44 16 00 00 58 16 00 00 71 16 00 00 85 16 00 00
[ 31.232030] skb linear: 00000130: 99 16 00 00 ad 16 00 00 c1 16 00 00 43 17 00 00
[ 31.239739] skb linear: 00000140: 57 17 00 00 6b 17 00 00 7f 17 00 00 93 17 00 00
[ 31.247428] skb linear: 00000150: a7 17 00 00 bb 17 00 00 cf 17 00 00 e3 17 00 00
[ 31.255141] skb linear: 00000160: f7 17 00 00 0b 18 00 00 1f 18 00 00 33 18 00 00
[ 31.262840] skb linear: 00000170: 47 18 00 00 5b 18 00 00 6f 18 00 00 83 18 00 00
[ 31.270591] skb linear: 00000180: 97 18 00 00 ab 18 00 00 bf 18 00 00 d3 18 00 00
[ 31.278282] skb linear: 00000190: e7 18 00 00 fb 18 00 00 0f 19 00 00 23 19 00 00
[ 31.285965] skb linear: 000001a0: 37 19 00 00 4b 19 00 00 5f 19 00 00 73 19 00 00
[ 31.293675] skb linear: 000001b0: 87 19 00 00 9b 19 00 00 af 19 00 00 c3 19 00 00
[ 31.301361] skb linear: 000001c0: d7 19 00 00 eb 19 00 00 ff 19 00 00 13 1a 00 00
[ 31.309056] skb linear: 000001d0: 27 1a 00 00 3b 1a 00 00 4f 1a 00 00 63 1a 00 00
[ 31.316753] skb linear: 000001e0: 77 1a 00 00 8b 1a 00 00 9f 1a 00 00 b3 1a 00 00
[ 31.324441] skb linear: 000001f0: c7 1a 00 00 db 1a 00 00 ef 1a 00 00 03 1b 00 00
[ 31.332138] skb linear: 00000200: 17 1b 00 00 2b 1b 00 00 3f 1b 00 00 53 1b 00 00
[ 31.339840] skb linear: 00000210: 67 1b 00 00 7b 1b 00 00 8f 1b 00 00 a3 1b 00 00
[ 31.347520] skb linear: 00000220: b7 1b 00 00 cb 1b 00 00 24 00 13 00 00 00 00 00
[ 31.355232] skb linear: 00000230: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[ 31.362920] skb linear: 00000240: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[ 31.370607] skb linear: 00000250: 08 00 13 00 ff ff ff ff ff ff 00 00 08 00 11 00
[ 31.378331] skb linear: 00000260: 01 08 02 04 0b 16 0c 12
[ 31.383972] skb tailroom: 00000000: 18 24 32 04 30 48 60 6c 2d 1a e3 19
[ 31.390651] skb fraglist:
[ 31.393348] BUG: unable to handle page fault for address: 00000100000000bc
[ 31.400317] #PF: supervisor read access in kernel mode
[ 31.405624] #PF: error_code(0x0000) - not-present page
[ 31.410832] PGD 0 P4D 0
[ 31.413422] Oops: 0000 [#1] PREEMPT SMP NOPTI
[ 31.417881] CPU: 0 PID: 520 Comm: wpa_supplicant Not tainted 5.16.0-rc1+ #5
[ 31.424862] Hardware name: PC Engines apu2/apu2, BIOS v4.15.0.1 11/23/2021
[ 31.431750] RIP: 0010:skb_end_pointer+0x0/0xe
[ 31.436129] Code: dc ff ff ff c3 48 8b 07 48 83 e0 fe 48 83 c8 02 48 89 07 c3 8b 47 08 c3 89 77 08 c3 01 77 08 c3 29 77 08 c3 b8 00 00 00 00 c3 <8b> 87 bc 00 00 00 48 03 87 c0 00 00 00 c3 8b 87 bc 00 00 00 c3 e8
[ 31.454883] RSP: 0018:ffffb0edc0427490 EFLAGS: 00010282
[ 31.460116] RAX: ffff8ff9818b1ec0 RBX: 0000010000000000 RCX: 0000000000000000
[ 31.467267] RDX: 0000000000000001 RSI: 0000010000000000 RDI: 0000010000000000
[ 31.474408] RBP: ffff8ff9891a07c8 R08: 0000000000000000 R09: ffffb0edc0427370
[ 31.481549] R10: ffffb0edc0427368 R11: ffffffffa5cd22e8 R12: 0000000000000268
[ 31.488689] R13: 00000000ffffffff R14: 0000010000000000 R15: ffffffffc0f2198b
[ 31.495823] FS: 00007f2725a55c00(0000) GS:ffff8ff9aac00000(0000) knlGS:0000000000000000
[ 31.503936] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 31.509706] CR2: 00000100000000bc CR3: 00000001090bc000 CR4: 00000000000406f0
[ 31.516868] Call Trace:
[ 31.519325] <TASK>
[ 31.521433] skb_dump+0x24/0x53a
[ 31.524688] ? _printk+0x58/0x6f
[ 31.527938] skb_dump+0x532/0x53a
[ 31.531267] ath11k_wmi_send_scan_start_cmd.cold+0x5f2/0x793 [ath11k]
[ 31.537785] ath11k_mac_op_hw_scan+0x173/0x3f0 [ath11k]
[ 31.543086] drv_hw_scan+0x43/0x130 [mac80211]
[ 31.547690] __ieee80211_start_scan+0x152/0x6d0 [mac80211]
[ 31.553306] ieee80211_request_scan+0x2c/0x50 [mac80211]
[ 31.558738] rdev_scan+0x28/0xd0 [cfg80211]
[ 31.563117] nl80211_trigger_scan+0x3fe/0x680 [cfg80211]
[ 31.568584] genl_family_rcv_msg_doit+0xea/0x150
[ 31.573223] genl_rcv_msg+0xde/0x1d0
[ 31.576816] ? nl80211_send_scan_start+0x90/0x90 [cfg80211]
[ 31.582520] ? genl_get_cmd+0xd0/0xd0
[ 31.586191] netlink_rcv_skb+0x50/0xf0
[ 31.589958] genl_rcv+0x24/0x40
[ 31.593109] netlink_unicast+0x239/0x340
[ 31.597045] netlink_sendmsg+0x245/0x480
[ 31.600981] sock_sendmsg+0x5e/0x60
[ 31.604487] ____sys_sendmsg+0x22e/0x270
[ 31.608440] ? import_iovec+0x2d/0x30
[ 31.612123] ? sendmsg_copy_msghdr+0x7c/0xa0
[ 31.616406] ___sys_sendmsg+0x75/0xb0
[ 31.620081] ? __mod_lruvec_page_state+0x7d/0xc0
[ 31.624714] ? folio_add_lru+0x5c/0xa0
[ 31.628476] ? _raw_spin_unlock+0x16/0x30
[ 31.632506] ? __handle_mm_fault+0x1261/0x1520
[ 31.636965] __sys_sendmsg+0x59/0xa0
[ 31.640552] do_syscall_64+0x3b/0xc0
[ 31.644148] entry_SYSCALL_64_after_hwframe+0x44/0xae
[ 31.649208] RIP: 0033:0x7f2725ef6f33
[ 31.652797] Code: 64 89 02 48 c7 c0 ff ff ff ff eb b7 66 2e 0f 1f 84 00 00 00 00 00 90 64 8b 04 25 18 00 00 00 85 c0 75 14 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 55 c3 0f 1f 40 00 48 83 ec 28 89 54 24 1c 48
[ 31.671547] RSP: 002b:00007fff1b5f1668 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
[ 31.679122] RAX: ffffffffffffffda RBX: 0000564919260760 RCX: 00007f2725ef6f33
[ 31.686264] RDX: 0000000000000000 RSI: 00007fff1b5f16a0 RDI: 0000000000000005
[ 31.693406] RBP: 000056491928f6c0 R08: 0000000000000004 R09: 00007f2725fb6c00
[ 31.700547] R10: 00007fff1b5f178c R11: 0000000000000246 R12: 0000564919260670
[ 31.707689] R13: 00007fff1b5f16a0 R14: 0000000000000000 R15: 00007fff1b5f178c
[ 31.714834] </TASK>
[ 31.717031] Modules linked in: qrtr_mhi btusb btrtl btbcm btintel bluetooth jitterentropy_rng sha512_ssse3 sha512_generic drbg ansi_cprng amd64_edac ecdh_generic edac_mce_amd ecc kvm_amd kvm irqbypass qrtr crc32_pclmul ghash_clmulni_intel ath11k_pci mhi ath11k evdev pcengines_apuv2 qmi_helpers gpio_keys_polled gpio_amd_fch aesni_intel snd_pcm crypto_simd snd_timer sdhci_pci xhci_pci snd cqhci mac80211 soundcore ehci_pci sp5100_tco cryptd libarc4 xhci_hcd sdhci ehci_hcd pcspkr igb watchdog ptp cfg80211 mmc_core k10temp i2c_piix4 fam15h_power usbcore ccp pps_core sg dca rng_core i2c_algo_bit usb_common rfkill leds_gpio gpio_keys acpi_cpufreq button fuse drm configfs ip_tables x_tables autofs4 ext4 crc32c_generic crc16 mbcache jbd2 sd_mod t10_pi crc_t10dif crct10dif_generic ahci libahci libata crct10dif_pclmul scsi_mod crct10dif_common crc32c_intel scsi_common
[ 31.793074] CR2: 00000100000000bc
[ 31.796498] ---[ end trace 07252723010a83e6 ]---
[ 31.801261] RIP: 0010:skb_end_pointer+0x0/0xe
[ 31.805824] Code: dc ff ff ff c3 48 8b 07 48 83 e0 fe 48 83 c8 02 48 89 07 c3 8b 47 08 c3 89 77 08 c3 01 77 08 c3 29 77 08 c3 b8 00 00 00 00 c3 <8b> 87 bc 00 00 00 48 03 87 c0 00 00 00 c3 8b 87 bc 00 00 00 c3 e8
[ 31.824842] RSP: 0018:ffffb0edc0427490 EFLAGS: 00010282
[ 31.830105] RAX: ffff8ff9818b1ec0 RBX: 0000010000000000 RCX: 0000000000000000
[ 31.837270] RDX: 0000000000000001 RSI: 0000010000000000 RDI: 0000010000000000
[ 31.844441] RBP: ffff8ff9891a07c8 R08: 0000000000000000 R09: ffffb0edc0427370
[ 31.851614] R10: ffffb0edc0427368 R11: ffffffffa5cd22e8 R12: 0000000000000268
[ 31.858781] R13: 00000000ffffffff R14: 0000010000000000 R15: ffffffffc0f2198b
[ 31.866020] FS: 00007f2725a55c00(0000) GS:ffff8ff9aac00000(0000) knlGS:0000000000000000
[ 31.874141] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 31.879920] CR2: 00000100000000bc CR3: 00000001090bc000 CR4: 00000000000406f0
So the length calculated for the ath11k_wmi_alloc_skb is just wrong. Reason
for this is the extraie_len_with_pad which is only an u8. But the
params->extraie.len with the IEEE80211_HW_SINGLE_SCAN_ON_ALL_BANDS is for me
already 264. So the length will end up as 8 - but the length it occupies
is still 264.
But the problem is the length of the WMI_TLV_LEN. The params->extraie.len can
be up to 32 bit and WMI_TLV_LEN only has 16 bit. So the params->extraie.len
must also be size limited or we might run into a different problem.
Kind regards,
SvenAttachment:
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Description: This is a digitally signed message part.
