RE: [CRASH] crypto: virtio: crash when modprobing tcrypt on 5.5-rc7 / next-20200122
From: Gonglei (Arei)
Date: Sun Feb 23 2020 - 10:07:52 EST
> -----Original Message-----
> From: LABBE Corentin [mailto:clabbe@xxxxxxxxxxxx]
> Sent: Friday, February 21, 2020 3:16 AM
> To: Gonglei (Arei) <arei.gonglei@xxxxxxxxxx>
> Cc: jasowang@xxxxxxxxxx; herbert@xxxxxxxxxxxxxxxxxxx;
> davem@xxxxxxxxxxxxx; virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx;
> linux-crypto@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; mst@xxxxxxxxxx
> Subject: Re: [CRASH] crypto: virtio: crash when modprobing tcrypt on 5.5-rc7 /
> next-20200122
>
> On Tue, Feb 04, 2020 at 04:15:22AM -0500, Michael S. Tsirkin wrote:
> > On Thu, Jan 23, 2020 at 11:10:00AM +0100, LABBE Corentin wrote:
> > > Hello
> > >
> > > When modprobing tcrypt on qemu 4.1.0 I get a kernel panic on 5.5-rc7
> > > and next-20200122 qemu is started by:
> > > /usr/bin/qemu-system-x86_64 -cpu host -enable-kvm -nographic -net
> > > nic,model=e1000,macaddr=52:54:00:12:34:58 -net tap -m 512 -monitor
> > > none -object cryptodev-backend-builtin,id=cryptodev0 -device
> > > virtio-crypto-pci,id=crypto0,cryptodev=cryptodev0 -append
> > > 'console=ttyS0 root=/dev/ram0 ip=dhcp' -kernel
> > > /var/lib/lava/dispatcher/tmp/41332/deployimages-td18675m/kernel/bzIm
> > > age -initrd
> > > /var/lib/lava/dispatcher/tmp/41332/deployimages-td18675m/ramdisk/roo
> > > tfs.cpio.gz -drive
> > > format=qcow2,file=/var/lib/lava/dispatcher/tmp/41332/apply-overlay-g
> > > uest-icy4k1ol/lava-guest.qcow2,media=disk,if=ide,id=lavatest
> > >
> > > [ 112.771925] general protection fault: 0000 [#1] SMP PTI [
> > > 112.772686] CPU: 0 PID: 126 Comm: virtio0-engine Not tainted
> > > 5.5.0-rc7+ #1 [ 112.773576] Hardware name: QEMU Standard PC (i440FX
> > > + PIIX, 1996), BIOS
> > > ?-20190711_202441-buildvm-armv7-10.arm.fedoraproject.org-2.fc31
> > > 04/01/2014 [ 112.775319] RIP: 0010:sg_next+0x0/0x20 [ 112.775821]
> > > Code: cc cc cc cc cc cc cc cc cc cc c7 47 10 00 00 00 00 89 57 0c 48
> > > 89 37 89 4f 08 c3 0f 1f 44 00 00 66 2e 0f 1f 84 00 00 00 00 00 <f6>
> > > 07 02 75 17 48 8b 57 20 48 8d 47 20 48 89 d1 48 83 e1 fc 83 e2 [
> > > 112.778330] RSP: 0018:ffffa92440237d90 EFLAGS: 00010006 [
> > > 112.779071] RAX: fefefefe00000000 RBX: 000000000000000a RCX:
> > > fefefefe00000000 [ 112.780081] RDX: 0000000000000001 RSI:
> > > ffff9b19da1a2180 RDI: fefefefe00000000 [ 112.781081] RBP:
> > > ffff9b19da1a2198 R08: ffff9b19dfb24ee8 R09: 0000000000000a20 [
> > > 112.782079] R10: ffff9b19da125010 R11: 0000000000000000 R12:
> ffff9b19da1a21b8 [ 112.783079] R13: 0000000000000003 R14:
> ffff9b19da1a2180 R15: 0000000000000004 [ 112.784077] FS:
> 0000000000000000(0000) GS:ffff9b19de400000(0000)
> knlGS:0000000000000000 [ 112.785202] CS: 0010 DS: 0000 ES: 0000 CR0:
> 0000000080050033 [ 112.786030] CR2: 00007f18a157b050 CR3:
> 000000001040a004 CR4: 0000000000060ef0 [ 112.787034] Call Trace:
> > > [ 112.787393] virtqueue_add_sgs+0x4c/0x90 [ 112.787998]
> > > virtio_crypto_skcipher_crypt_req+0x310/0x3e0
> > > [ 112.788817] crypto_pump_work+0x10c/0x240 [ 112.789420] ?
> > > __kthread_init_worker+0x50/0x50 [ 112.790082]
> > > kthread_worker_fn+0x89/0x180 [ 112.790690] kthread+0x10e/0x130 [
> > > 112.791182] ? kthread_park+0x80/0x80 [ 112.791736]
> > > ret_from_fork+0x35/0x40 [ 112.792282] Modules linked in: cts lzo
> > > salsa20_generic camellia_x86_64 camellia_generic fcrypt pcbc tgr192
> > > anubis wp512 khazad tea michael_mic arc4 cast6_generic cast5_generic
> > > cast_common deflate sha512_ssse3 sha512_generic cfb ofb
> > > serpent_sse2_x86_64 serpent_generic lrw twofish_x86_64_3way
> > > twofish_x86_64 crypto_simd cryptd glue_helper twofish_generic
> > > twofish_common blowfish_x86_64 blowfish_generic blowfish_common md4
> > > tcrypt(+) [ 112.797652] ---[ end trace 4a8142d4a08c2518 ]--- [
> > > 112.798320] RIP: 0010:sg_next+0x0/0x20 [ 112.798865] Code: cc cc cc
> > > cc cc cc cc cc cc cc c7 47 10 00 00 00 00 89 57 0c 48 89 37 89 4f 08
> > > c3 0f 1f 44 00 00 66 2e 0f 1f 84 00 00 00 00 00 <f6> 07 02 75 17 48
> > > 8b 57 20 48 8d 47 20 48 89 d1 48 83 e1 fc 83 e2 [ 112.801452] RSP:
> > > 0018:ffffa92440237d90 EFLAGS: 00010006 [ 112.802189] RAX:
> > > fefefefe00000000 RBX: 000000000000000a RCX: fefefefe00000000 [
> > > 112.803190] RDX: 0000000000000001 RSI: ffff9b19da1a2180 RDI:
> > > fefefefe00000000 [ 112.804192] RBP: ffff9b19da1a2198 R08:
> > > ffff9b19dfb24ee8 R09: 0000000000000a20 [ 112.805201] R10:
> > > ffff9b19da125010 R11: 0000000000000000 R12: ffff9b19da1a21b8 [
> > > 112.806195] R13: 0000000000000003 R14: ffff9b19da1a2180 R15:
> > > 0000000000000004 [ 112.807222] FS: 0000000000000000(0000)
> > > GS:ffff9b19de400000(0000) knlGS:0000000000000000 [ 112.808352] CS:
> > > 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 112.809169] CR2:
> > > 00007f18a157b050 CR3: 000000001040a004 CR4: 0000000000060ef0
> > >
> > > I have tested also 5.4.14
> > > and I got random freeze with:
> > > qemu-system-x86_64: virtio: zero sized buffers are not allowed
> > >
> > > Regards
> >
> > Cc: Gonglei <arei.gonglei@xxxxxxxxxx>
> >
>
> Hello Gonglei
>
> Any plan to fix the driver ? It is broken since its introduction.
>
Thanks for your report firstly.
I've been busy launching new products recently, so I don't have much time
to invest in the open source community.
I spent some time investigating the BUG this weekend,
and IMO I found the root cause. The following patch, please help test it, thanks!
[PATCH] virtio-crypto: fix src/dst scatterlist calculation
Usually the next entry of one sg will be @sg@ + 1, but if this sg element
is part of a chained scatterlist, it could jump to the start of a new
scatterlist array. Let's fix it by sg_next() on calculation of src/dst
scatterlist.
BTW I add a check for sg_nents_for_len() its return value since
sg_nents_for_len() function could fail.
Signed-off-by: Gonglei <arei.gonglei@xxxxxxxxxx>
---
drivers/crypto/virtio/virtio_crypto_algs.c | 20 ++++++++++++++++----
1 file changed, 16 insertions(+), 4 deletions(-)
diff --git a/drivers/crypto/virtio/virtio_crypto_algs.c b/drivers/crypto/virtio/virtio_crypto_algs.c
index fd045e64..bde0539 100644
--- a/drivers/crypto/virtio/virtio_crypto_algs.c
+++ b/drivers/crypto/virtio/virtio_crypto_algs.c
@@ -355,8 +355,14 @@ static int virtio_crypto_skcipher_setkey(struct crypto_skcipher *tfm,
unsigned int num_out = 0, num_in = 0;
int sg_total;
uint8_t *iv;
+ struct scatterlist *sg;
src_nents = sg_nents_for_len(req->src, req->cryptlen);
+ if (src_nents < 0) {
+ pr_err("Invalid number of src SG.\n");
+ return src_nents;
+ }
+
dst_nents = sg_nents(req->dst);
pr_debug("virtio_crypto: Number of sgs (src_nents: %d, dst_nents: %d)\n",
@@ -442,12 +448,18 @@ static int virtio_crypto_skcipher_setkey(struct crypto_skcipher *tfm,
vc_sym_req->iv = iv;
/* Source data */
- for (i = 0; i < src_nents; i++)
- sgs[num_out++] = &req->src[i];
+ sg = req->src;
+ for (i = 0; sg && i < src_nents; sg = sg_next(sg)) {
+ i++;
+ sgs[num_out++] = sg;
+ }
/* Destination data */
- for (i = 0; i < dst_nents; i++)
- sgs[num_out + num_in++] = &req->dst[i];
+ sg = req->dst;
+ for (i = 0; sg && i < dst_nents; sg = sg_next(sg)) {
+ i++;
+ sgs[num_out + num_in++] = sg;
+ }
/* Status */
sg_init_one(&status_sg, &vc_req->status, sizeof(vc_req->status));
--
1.8.3.1
Regards
-Gonglei