Eric Dumazet
2021-Apr-20 09:43 UTC
[PATCH net-next] virtio-net: fix use-after-free in page_to_skb()
From: Eric Dumazet <edumazet at google.com>
KASAN/syzbot had 4 reports, one of them being:
BUG: KASAN: slab-out-of-bounds in memcpy include/linux/fortify-string.h:191
[inline]
BUG: KASAN: slab-out-of-bounds in page_to_skb+0x5cf/0xb70
drivers/net/virtio_net.c:480
Read of size 12 at addr ffff888014a5f800 by task systemd-udevd/8445
CPU: 0 PID: 8445 Comm: systemd-udevd Not tainted
5.12.0-rc8-next-20210419-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google
01/01/2011
Call Trace:
<IRQ>
__dump_stack lib/dump_stack.c:79 [inline]
dump_stack+0x141/0x1d7 lib/dump_stack.c:120
print_address_description.constprop.0.cold+0x5b/0x2f8 mm/kasan/report.c:233
__kasan_report mm/kasan/report.c:419 [inline]
kasan_report.cold+0x7c/0xd8 mm/kasan/report.c:436
check_region_inline mm/kasan/generic.c:180 [inline]
kasan_check_range+0x13d/0x180 mm/kasan/generic.c:186
memcpy+0x20/0x60 mm/kasan/shadow.c:65
memcpy include/linux/fortify-string.h:191 [inline]
page_to_skb+0x5cf/0xb70 drivers/net/virtio_net.c:480
receive_mergeable drivers/net/virtio_net.c:1009 [inline]
receive_buf+0x2bc0/0x6250 drivers/net/virtio_net.c:1119
virtnet_receive drivers/net/virtio_net.c:1411 [inline]
virtnet_poll+0x568/0x10b0 drivers/net/virtio_net.c:1516
__napi_poll+0xaf/0x440 net/core/dev.c:6962
napi_poll net/core/dev.c:7029 [inline]
net_rx_action+0x801/0xb40 net/core/dev.c:7116
__do_softirq+0x29b/0x9fe kernel/softirq.c:559
invoke_softirq kernel/softirq.c:433 [inline]
__irq_exit_rcu+0x136/0x200 kernel/softirq.c:637
irq_exit_rcu+0x5/0x20 kernel/softirq.c:649
common_interrupt+0xa4/0xd0 arch/x86/kernel/irq.c:240
Fixes: fb32856b16ad ("virtio-net: page_to_skb() use build_skb when
there's sufficient tailroom")
Signed-off-by: Eric Dumazet <edumazet at google.com>
Reported-by: syzbot <syzkaller at googlegroups.com>
Reported-by: Guenter Roeck <linux at roeck-us.net>
Reported-by: Mat Martineau <mathew.j.martineau at linux.intel.com>
Cc: Xuan Zhuo <xuanzhuo at linux.alibaba.com>
Cc: Jason Wang <jasowang at redhat.com>
Cc: "Michael S. Tsirkin" <mst at redhat.com>
Cc: virtualization at lists.linux-foundation.org
---
drivers/net/virtio_net.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index
8cd76037c72481200ea3e8429e9fdfec005dad85..2e28c04aa6351d2b4016f7d277ce104c4970069d
100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -385,6 +385,7 @@ static struct sk_buff *page_to_skb(struct virtnet_info *vi,
struct sk_buff *skb;
struct virtio_net_hdr_mrg_rxbuf *hdr;
unsigned int copy, hdr_len, hdr_padded_len;
+ struct page *page_to_free = NULL;
int tailroom, shinfo_size;
char *p, *hdr_p;
@@ -445,7 +446,7 @@ static struct sk_buff *page_to_skb(struct virtnet_info *vi,
if (len)
skb_add_rx_frag(skb, 0, page, offset, len, truesize);
else
- put_page(page);
+ page_to_free = page;
goto ok;
}
@@ -479,6 +480,8 @@ static struct sk_buff *page_to_skb(struct virtnet_info *vi,
hdr = skb_vnet_hdr(skb);
memcpy(hdr, hdr_p, hdr_len);
}
+ if (page_to_free)
+ put_page(page_to_free);
if (metasize) {
__skb_pull(skb, metasize);
--
2.31.1.368.gbe11c130af-goog
Michael S. Tsirkin
2021-Apr-20 10:07 UTC
[PATCH net-next] virtio-net: fix use-after-free in page_to_skb()
On Tue, Apr 20, 2021 at 02:43:41AM -0700, Eric Dumazet wrote:> From: Eric Dumazet <edumazet at google.com> > > KASAN/syzbot had 4 reports, one of them being: > > BUG: KASAN: slab-out-of-bounds in memcpy include/linux/fortify-string.h:191 [inline] > BUG: KASAN: slab-out-of-bounds in page_to_skb+0x5cf/0xb70 drivers/net/virtio_net.c:480 > Read of size 12 at addr ffff888014a5f800 by task systemd-udevd/8445 > > CPU: 0 PID: 8445 Comm: systemd-udevd Not tainted 5.12.0-rc8-next-20210419-syzkaller #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 > Call Trace: > <IRQ> > __dump_stack lib/dump_stack.c:79 [inline] > dump_stack+0x141/0x1d7 lib/dump_stack.c:120 > print_address_description.constprop.0.cold+0x5b/0x2f8 mm/kasan/report.c:233 > __kasan_report mm/kasan/report.c:419 [inline] > kasan_report.cold+0x7c/0xd8 mm/kasan/report.c:436 > check_region_inline mm/kasan/generic.c:180 [inline] > kasan_check_range+0x13d/0x180 mm/kasan/generic.c:186 > memcpy+0x20/0x60 mm/kasan/shadow.c:65 > memcpy include/linux/fortify-string.h:191 [inline] > page_to_skb+0x5cf/0xb70 drivers/net/virtio_net.c:480 > receive_mergeable drivers/net/virtio_net.c:1009 [inline] > receive_buf+0x2bc0/0x6250 drivers/net/virtio_net.c:1119 > virtnet_receive drivers/net/virtio_net.c:1411 [inline] > virtnet_poll+0x568/0x10b0 drivers/net/virtio_net.c:1516 > __napi_poll+0xaf/0x440 net/core/dev.c:6962 > napi_poll net/core/dev.c:7029 [inline] > net_rx_action+0x801/0xb40 net/core/dev.c:7116 > __do_softirq+0x29b/0x9fe kernel/softirq.c:559 > invoke_softirq kernel/softirq.c:433 [inline] > __irq_exit_rcu+0x136/0x200 kernel/softirq.c:637 > irq_exit_rcu+0x5/0x20 kernel/softirq.c:649 > common_interrupt+0xa4/0xd0 arch/x86/kernel/irq.c:240 > > Fixes: fb32856b16ad ("virtio-net: page_to_skb() use build_skb when there's sufficient tailroom") > Signed-off-by: Eric Dumazet <edumazet at google.com> > Reported-by: syzbot <syzkaller at googlegroups.com> > Reported-by: Guenter Roeck <linux at roeck-us.net> > Reported-by: Mat Martineau <mathew.j.martineau at linux.intel.com> > Cc: Xuan Zhuo <xuanzhuo at linux.alibaba.com> > Cc: Jason Wang <jasowang at redhat.com> > Cc: "Michael S. Tsirkin" <mst at redhat.com> > Cc: virtualization at lists.linux-foundation.orgAcked-by: Michael S. Tsirkin <mst at redhat.com>> --- > drivers/net/virtio_net.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c > index 8cd76037c72481200ea3e8429e9fdfec005dad85..2e28c04aa6351d2b4016f7d277ce104c4970069d 100644 > --- a/drivers/net/virtio_net.c > +++ b/drivers/net/virtio_net.c > @@ -385,6 +385,7 @@ static struct sk_buff *page_to_skb(struct virtnet_info *vi, > struct sk_buff *skb; > struct virtio_net_hdr_mrg_rxbuf *hdr; > unsigned int copy, hdr_len, hdr_padded_len; > + struct page *page_to_free = NULL; > int tailroom, shinfo_size; > char *p, *hdr_p; > > @@ -445,7 +446,7 @@ static struct sk_buff *page_to_skb(struct virtnet_info *vi, > if (len) > skb_add_rx_frag(skb, 0, page, offset, len, truesize); > else > - put_page(page); > + page_to_free = page; > goto ok; > } > > @@ -479,6 +480,8 @@ static struct sk_buff *page_to_skb(struct virtnet_info *vi, > hdr = skb_vnet_hdr(skb); > memcpy(hdr, hdr_p, hdr_len); > } > + if (page_to_free) > + put_page(page_to_free); > > if (metasize) { > __skb_pull(skb, metasize); > -- > 2.31.1.368.gbe11c130af-goog
Guenter Roeck
2021-Apr-20 13:48 UTC
[PATCH net-next] virtio-net: fix use-after-free in page_to_skb()
On 4/20/21 2:43 AM, Eric Dumazet wrote:> From: Eric Dumazet <edumazet at google.com> > > KASAN/syzbot had 4 reports, one of them being: > > BUG: KASAN: slab-out-of-bounds in memcpy include/linux/fortify-string.h:191 [inline] > BUG: KASAN: slab-out-of-bounds in page_to_skb+0x5cf/0xb70 drivers/net/virtio_net.c:480 > Read of size 12 at addr ffff888014a5f800 by task systemd-udevd/8445 > > CPU: 0 PID: 8445 Comm: systemd-udevd Not tainted 5.12.0-rc8-next-20210419-syzkaller #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 > Call Trace: > <IRQ> > __dump_stack lib/dump_stack.c:79 [inline] > dump_stack+0x141/0x1d7 lib/dump_stack.c:120 > print_address_description.constprop.0.cold+0x5b/0x2f8 mm/kasan/report.c:233 > __kasan_report mm/kasan/report.c:419 [inline] > kasan_report.cold+0x7c/0xd8 mm/kasan/report.c:436 > check_region_inline mm/kasan/generic.c:180 [inline] > kasan_check_range+0x13d/0x180 mm/kasan/generic.c:186 > memcpy+0x20/0x60 mm/kasan/shadow.c:65 > memcpy include/linux/fortify-string.h:191 [inline] > page_to_skb+0x5cf/0xb70 drivers/net/virtio_net.c:480 > receive_mergeable drivers/net/virtio_net.c:1009 [inline] > receive_buf+0x2bc0/0x6250 drivers/net/virtio_net.c:1119 > virtnet_receive drivers/net/virtio_net.c:1411 [inline] > virtnet_poll+0x568/0x10b0 drivers/net/virtio_net.c:1516 > __napi_poll+0xaf/0x440 net/core/dev.c:6962 > napi_poll net/core/dev.c:7029 [inline] > net_rx_action+0x801/0xb40 net/core/dev.c:7116 > __do_softirq+0x29b/0x9fe kernel/softirq.c:559 > invoke_softirq kernel/softirq.c:433 [inline] > __irq_exit_rcu+0x136/0x200 kernel/softirq.c:637 > irq_exit_rcu+0x5/0x20 kernel/softirq.c:649 > common_interrupt+0xa4/0xd0 arch/x86/kernel/irq.c:240 > > Fixes: fb32856b16ad ("virtio-net: page_to_skb() use build_skb when there's sufficient tailroom") > Signed-off-by: Eric Dumazet <edumazet at google.com> > Reported-by: syzbot <syzkaller at googlegroups.com> > Reported-by: Guenter Roeck <linux at roeck-us.net> > Reported-by: Mat Martineau <mathew.j.martineau at linux.intel.com> > Cc: Xuan Zhuo <xuanzhuo at linux.alibaba.com> > Cc: Jason Wang <jasowang at redhat.com> > Cc: "Michael S. Tsirkin" <mst at redhat.com> > Cc: virtualization at lists.linux-foundation.org > --- > drivers/net/virtio_net.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c > index 8cd76037c72481200ea3e8429e9fdfec005dad85..2e28c04aa6351d2b4016f7d277ce104c4970069d 100644 > --- a/drivers/net/virtio_net.c > +++ b/drivers/net/virtio_net.c > @@ -385,6 +385,7 @@ static struct sk_buff *page_to_skb(struct virtnet_info *vi, > struct sk_buff *skb; > struct virtio_net_hdr_mrg_rxbuf *hdr; > unsigned int copy, hdr_len, hdr_padded_len; > + struct page *page_to_free = NULL; > int tailroom, shinfo_size; > char *p, *hdr_p; > > @@ -445,7 +446,7 @@ static struct sk_buff *page_to_skb(struct virtnet_info *vi, > if (len) > skb_add_rx_frag(skb, 0, page, offset, len, truesize); > else > - put_page(page); > + page_to_free = page; > goto ok; > } > > @@ -479,6 +480,8 @@ static struct sk_buff *page_to_skb(struct virtnet_info *vi, > hdr = skb_vnet_hdr(skb); > memcpy(hdr, hdr_p, hdr_len); > } > + if (page_to_free) > + put_page(page_to_free); > > if (metasize) { > __skb_pull(skb, metasize); >Unfortunately that doesn't fix the problem for me. With this patch applied on top of next-20210419, I still get the same crash as before: udhcpc: sending discover^M Unable to handle kernel paging request at virtual address 0000000000000004^M udhcpc(169): Oops -1^M pc = [<0000000000000004>] ra = [<fffffc0000b8c5b8>] ps = 0000 Not tainted^M pc is at 0x4^M ra is at napi_gro_receive+0x68/0x150^M v0 = 0000000000000000 t0 = 0000000000000008 t1 = 0000000000000000^M t2 = 0000000000000000 t3 = 000000000000000e t4 = 0000000000000038^M t5 = 000000000000ffff t6 = fffffc00002f298a t7 = fffffc0002c78000^M s0 = fffffc00010b3ca0 s1 = 0000000000000000 s2 = fffffc00011267e0^M s3 = 0000000000000000 s4 = fffffc00025f2008 s5 = fffffc00002f2940^M s6 = fffffc00025f2040^M a0 = fffffc00025f2008 a1 = fffffc00002f2940 a2 = fffffc0002ca000c^M a3 = fffffc00000250d0 a4 = 0000000effff0008 a5 = 0000000000000000^M t8 = fffffc00010b3c80 t9 = fffffc0002ca04cc t10= 0000000000000000^M t11= 00000000000004c0 pv = fffffc0000b8bc40 at = 0000000000000000^M gp = fffffc00010f9fb8 sp = 00000000df74db09^M Disabling lock debugging due to kernel taint^M Trace:^M [<fffffc0000b8c5b8>] napi_gro_receive+0x68/0x150^M [<fffffc00009b409c>] receive_buf+0x50c/0x1b80^M [<fffffc00009b58b8>] virtnet_poll+0x1a8/0x5b0^M [<fffffc00009b58ec>] virtnet_poll+0x1dc/0x5b0^M [<fffffc0000b8d17c>] __napi_poll+0x4c/0x270^M [<fffffc0000b8d670>] net_rx_action+0x130/0x2c0^M [<fffffc0000bd6cb0>] sch_direct_xmit+0x170/0x360^M [<fffffc0000bd7000>] __qdisc_run+0x160/0x6c0^M [<fffffc0000337b64>] do_softirq+0xa4/0xd0^M [<fffffc0000337ca4>] __local_bh_enable_ip+0x114/0x120^M [<fffffc0000b89554>] __dev_queue_xmit+0x484/0xa60^M [<fffffc0000cd072c>] packet_sendmsg+0xe7c/0x1ba0^M [<fffffc0000b53338>] __sys_sendto+0xf8/0x170^M [<fffffc0000cfec18>] _raw_spin_unlock+0x18/0x30^M [<fffffc0000a9bf7c>] ehci_irq+0x2cc/0x5c0^M [<fffffc0000a71334>] usb_hcd_irq+0x34/0x50^M [<fffffc0000b521bc>] move_addr_to_kernel+0x3c/0x60^M [<fffffc0000b532e4>] __sys_sendto+0xa4/0x170^M [<fffffc0000b533d4>] sys_sendto+0x24/0x40^M [<fffffc0000cfea38>] _raw_spin_lock+0x18/0x30^M [<fffffc0000cfec18>] _raw_spin_unlock+0x18/0x30^M [<fffffc0000325298>] clipper_enable_irq+0x98/0x100^M [<fffffc0000cfec18>] _raw_spin_unlock+0x18/0x30^M [<fffffc0000311514>] entSys+0xa4/0xc0^M ^M Code:^M 00000000 ^M 00063301 ^M 00000897 ^M 00001111 ^M 00001672 ^M ^M Kernel panic - not syncing: Aiee, killing interrupt handler!^M Guenter
Jason Wang
2021-Apr-21 02:15 UTC
[PATCH net-next] virtio-net: fix use-after-free in page_to_skb()
? 2021/4/20 ??5:43, Eric Dumazet ??:> From: Eric Dumazet <edumazet at google.com> > > KASAN/syzbot had 4 reports, one of them being: > > BUG: KASAN: slab-out-of-bounds in memcpy include/linux/fortify-string.h:191 [inline] > BUG: KASAN: slab-out-of-bounds in page_to_skb+0x5cf/0xb70 drivers/net/virtio_net.c:480 > Read of size 12 at addr ffff888014a5f800 by task systemd-udevd/8445 > > CPU: 0 PID: 8445 Comm: systemd-udevd Not tainted 5.12.0-rc8-next-20210419-syzkaller #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 > Call Trace: > <IRQ> > __dump_stack lib/dump_stack.c:79 [inline] > dump_stack+0x141/0x1d7 lib/dump_stack.c:120 > print_address_description.constprop.0.cold+0x5b/0x2f8 mm/kasan/report.c:233 > __kasan_report mm/kasan/report.c:419 [inline] > kasan_report.cold+0x7c/0xd8 mm/kasan/report.c:436 > check_region_inline mm/kasan/generic.c:180 [inline] > kasan_check_range+0x13d/0x180 mm/kasan/generic.c:186 > memcpy+0x20/0x60 mm/kasan/shadow.c:65 > memcpy include/linux/fortify-string.h:191 [inline] > page_to_skb+0x5cf/0xb70 drivers/net/virtio_net.c:480 > receive_mergeable drivers/net/virtio_net.c:1009 [inline] > receive_buf+0x2bc0/0x6250 drivers/net/virtio_net.c:1119 > virtnet_receive drivers/net/virtio_net.c:1411 [inline] > virtnet_poll+0x568/0x10b0 drivers/net/virtio_net.c:1516 > __napi_poll+0xaf/0x440 net/core/dev.c:6962 > napi_poll net/core/dev.c:7029 [inline] > net_rx_action+0x801/0xb40 net/core/dev.c:7116 > __do_softirq+0x29b/0x9fe kernel/softirq.c:559 > invoke_softirq kernel/softirq.c:433 [inline] > __irq_exit_rcu+0x136/0x200 kernel/softirq.c:637 > irq_exit_rcu+0x5/0x20 kernel/softirq.c:649 > common_interrupt+0xa4/0xd0 arch/x86/kernel/irq.c:240 > > Fixes: fb32856b16ad ("virtio-net: page_to_skb() use build_skb when there's sufficient tailroom") > Signed-off-by: Eric Dumazet <edumazet at google.com> > Reported-by: syzbot <syzkaller at googlegroups.com> > Reported-by: Guenter Roeck <linux at roeck-us.net> > Reported-by: Mat Martineau <mathew.j.martineau at linux.intel.com> > Cc: Xuan Zhuo <xuanzhuo at linux.alibaba.com> > Cc: Jason Wang <jasowang at redhat.com> > Cc: "Michael S. Tsirkin" <mst at redhat.com> > Cc: virtualization at lists.linux-foundation.org > ---Acked-by: Jason Wang <jasowang at redhat.com>> drivers/net/virtio_net.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c > index 8cd76037c72481200ea3e8429e9fdfec005dad85..2e28c04aa6351d2b4016f7d277ce104c4970069d 100644 > --- a/drivers/net/virtio_net.c > +++ b/drivers/net/virtio_net.c > @@ -385,6 +385,7 @@ static struct sk_buff *page_to_skb(struct virtnet_info *vi, > struct sk_buff *skb; > struct virtio_net_hdr_mrg_rxbuf *hdr; > unsigned int copy, hdr_len, hdr_padded_len; > + struct page *page_to_free = NULL; > int tailroom, shinfo_size; > char *p, *hdr_p; > > @@ -445,7 +446,7 @@ static struct sk_buff *page_to_skb(struct virtnet_info *vi, > if (len) > skb_add_rx_frag(skb, 0, page, offset, len, truesize); > else > - put_page(page); > + page_to_free = page; > goto ok; > } > > @@ -479,6 +480,8 @@ static struct sk_buff *page_to_skb(struct virtnet_info *vi, > hdr = skb_vnet_hdr(skb); > memcpy(hdr, hdr_p, hdr_len); > } > + if (page_to_free) > + put_page(page_to_free); > > if (metasize) { > __skb_pull(skb, metasize);