diff mbox series

[net,v2] virtio/vsock: Fix uninit-value in virtio_transport_recv_pkt()

Message ID 20231104150531.257952-1-syoshida@redhat.com
State New
Headers
Series [net,v2] virtio/vsock: Fix uninit-value in virtio_transport_recv_pkt() |

Commit Message

Shigeru Yoshida Nov. 4, 2023, 3:05 p.m. UTC 
  KMSAN reported the following uninit-value access issue:

=====================================================
BUG: KMSAN: uninit-value in virtio_transport_recv_pkt+0x1dfb/0x26a0 net/vmw_vsock/virtio_transport_common.c:1421
 virtio_transport_recv_pkt+0x1dfb/0x26a0 net/vmw_vsock/virtio_transport_common.c:1421
 vsock_loopback_work+0x3bb/0x5a0 net/vmw_vsock/vsock_loopback.c:120
 process_one_work kernel/workqueue.c:2630 [inline]
 process_scheduled_works+0xff6/0x1e60 kernel/workqueue.c:2703
 worker_thread+0xeca/0x14d0 kernel/workqueue.c:2784
 kthread+0x3cc/0x520 kernel/kthread.c:388
 ret_from_fork+0x66/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304

Uninit was stored to memory at:
 virtio_transport_space_update net/vmw_vsock/virtio_transport_common.c:1274 [inline]
 virtio_transport_recv_pkt+0x1ee8/0x26a0 net/vmw_vsock/virtio_transport_common.c:1415
 vsock_loopback_work+0x3bb/0x5a0 net/vmw_vsock/vsock_loopback.c:120
 process_one_work kernel/workqueue.c:2630 [inline]
 process_scheduled_works+0xff6/0x1e60 kernel/workqueue.c:2703
 worker_thread+0xeca/0x14d0 kernel/workqueue.c:2784
 kthread+0x3cc/0x520 kernel/kthread.c:388
 ret_from_fork+0x66/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304

Uninit was created at:
 slab_post_alloc_hook+0x105/0xad0 mm/slab.h:767
 slab_alloc_node mm/slub.c:3478 [inline]
 kmem_cache_alloc_node+0x5a2/0xaf0 mm/slub.c:3523
 kmalloc_reserve+0x13c/0x4a0 net/core/skbuff.c:559
 __alloc_skb+0x2fd/0x770 net/core/skbuff.c:650
 alloc_skb include/linux/skbuff.h:1286 [inline]
 virtio_vsock_alloc_skb include/linux/virtio_vsock.h:66 [inline]
 virtio_transport_alloc_skb+0x90/0x11e0 net/vmw_vsock/virtio_transport_common.c:58
 virtio_transport_reset_no_sock net/vmw_vsock/virtio_transport_common.c:957 [inline]
 virtio_transport_recv_pkt+0x1279/0x26a0 net/vmw_vsock/virtio_transport_common.c:1387
 vsock_loopback_work+0x3bb/0x5a0 net/vmw_vsock/vsock_loopback.c:120
 process_one_work kernel/workqueue.c:2630 [inline]
 process_scheduled_works+0xff6/0x1e60 kernel/workqueue.c:2703
 worker_thread+0xeca/0x14d0 kernel/workqueue.c:2784
 kthread+0x3cc/0x520 kernel/kthread.c:388
 ret_from_fork+0x66/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304

CPU: 1 PID: 10664 Comm: kworker/1:5 Not tainted 6.6.0-rc3-00146-g9f3ebbef746f #3
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-1.fc38 04/01/2014
Workqueue: vsock-loopback vsock_loopback_work
=====================================================

The following simple reproducer can cause the issue described above:

int main(void)
{
  int sock;
  struct sockaddr_vm addr = {
    .svm_family = AF_VSOCK,
    .svm_cid = VMADDR_CID_ANY,
    .svm_port = 1234,
  };

  sock = socket(AF_VSOCK, SOCK_STREAM, 0);
  connect(sock, (struct sockaddr *)&addr, sizeof(addr));
  return 0;
}

This issue occurs because the `buf_alloc` and `fwd_cnt` fields of the
`struct virtio_vsock_hdr` are not initialized when a new skb is allocated
in `virtio_transport_init_hdr()`. This patch resolves the issue by
initializing these fields during allocation.

Fixes: 71dc9ec9ac7d ("virtio/vsock: replace virtio_vsock_pkt with sk_buff")
Reported-and-tested-by: syzbot+0c8ce1da0ac31abbadcd@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=0c8ce1da0ac31abbadcd
Signed-off-by: Shigeru Yoshida <syoshida@redhat.com>
---
v1->v2:
- Rebase on the latest net tree
https://lore.kernel.org/all/20231026150154.3536433-1-syoshida@redhat.com/
---
 net/vmw_vsock/virtio_transport_common.c | 2 ++
 1 file changed, 2 insertions(+)

Comments

David Wei Nov. 4, 2023, 6:28 p.m. UTC | #1 
On 2023-11-04 08:05, Shigeru Yoshida wrote:
> KMSAN reported the following uninit-value access issue:
> 
> =====================================================
> BUG: KMSAN: uninit-value in virtio_transport_recv_pkt+0x1dfb/0x26a0 net/vmw_vsock/virtio_transport_common.c:1421
>  virtio_transport_recv_pkt+0x1dfb/0x26a0 net/vmw_vsock/virtio_transport_common.c:1421
>  vsock_loopback_work+0x3bb/0x5a0 net/vmw_vsock/vsock_loopback.c:120
>  process_one_work kernel/workqueue.c:2630 [inline]
>  process_scheduled_works+0xff6/0x1e60 kernel/workqueue.c:2703
>  worker_thread+0xeca/0x14d0 kernel/workqueue.c:2784
>  kthread+0x3cc/0x520 kernel/kthread.c:388
>  ret_from_fork+0x66/0x80 arch/x86/kernel/process.c:147
>  ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304
> 
> Uninit was stored to memory at:
>  virtio_transport_space_update net/vmw_vsock/virtio_transport_common.c:1274 [inline]
>  virtio_transport_recv_pkt+0x1ee8/0x26a0 net/vmw_vsock/virtio_transport_common.c:1415
>  vsock_loopback_work+0x3bb/0x5a0 net/vmw_vsock/vsock_loopback.c:120
>  process_one_work kernel/workqueue.c:2630 [inline]
>  process_scheduled_works+0xff6/0x1e60 kernel/workqueue.c:2703
>  worker_thread+0xeca/0x14d0 kernel/workqueue.c:2784
>  kthread+0x3cc/0x520 kernel/kthread.c:388
>  ret_from_fork+0x66/0x80 arch/x86/kernel/process.c:147
>  ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304
> 
> Uninit was created at:
>  slab_post_alloc_hook+0x105/0xad0 mm/slab.h:767
>  slab_alloc_node mm/slub.c:3478 [inline]
>  kmem_cache_alloc_node+0x5a2/0xaf0 mm/slub.c:3523
>  kmalloc_reserve+0x13c/0x4a0 net/core/skbuff.c:559
>  __alloc_skb+0x2fd/0x770 net/core/skbuff.c:650
>  alloc_skb include/linux/skbuff.h:1286 [inline]
>  virtio_vsock_alloc_skb include/linux/virtio_vsock.h:66 [inline]
>  virtio_transport_alloc_skb+0x90/0x11e0 net/vmw_vsock/virtio_transport_common.c:58
>  virtio_transport_reset_no_sock net/vmw_vsock/virtio_transport_common.c:957 [inline]
>  virtio_transport_recv_pkt+0x1279/0x26a0 net/vmw_vsock/virtio_transport_common.c:1387
>  vsock_loopback_work+0x3bb/0x5a0 net/vmw_vsock/vsock_loopback.c:120
>  process_one_work kernel/workqueue.c:2630 [inline]
>  process_scheduled_works+0xff6/0x1e60 kernel/workqueue.c:2703
>  worker_thread+0xeca/0x14d0 kernel/workqueue.c:2784
>  kthread+0x3cc/0x520 kernel/kthread.c:388
>  ret_from_fork+0x66/0x80 arch/x86/kernel/process.c:147
>  ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304
> 
> CPU: 1 PID: 10664 Comm: kworker/1:5 Not tainted 6.6.0-rc3-00146-g9f3ebbef746f #3
> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-1.fc38 04/01/2014
> Workqueue: vsock-loopback vsock_loopback_work
> =====================================================
> 
> The following simple reproducer can cause the issue described above:
> 
> int main(void)
> {
>   int sock;
>   struct sockaddr_vm addr = {
>     .svm_family = AF_VSOCK,
>     .svm_cid = VMADDR_CID_ANY,
>     .svm_port = 1234,
>   };
> 
>   sock = socket(AF_VSOCK, SOCK_STREAM, 0);
>   connect(sock, (struct sockaddr *)&addr, sizeof(addr));
>   return 0;
> }
> 
> This issue occurs because the `buf_alloc` and `fwd_cnt` fields of the
> `struct virtio_vsock_hdr` are not initialized when a new skb is allocated
> in `virtio_transport_init_hdr()`. This patch resolves the issue by
> initializing these fields during allocation.
> 
> Fixes: 71dc9ec9ac7d ("virtio/vsock: replace virtio_vsock_pkt with sk_buff")
> Reported-and-tested-by: syzbot+0c8ce1da0ac31abbadcd@syzkaller.appspotmail.com
> Closes: https://syzkaller.appspot.com/bug?extid=0c8ce1da0ac31abbadcd
> Signed-off-by: Shigeru Yoshida <syoshida@redhat.com>
> ---
> v1->v2:
> - Rebase on the latest net tree
> https://lore.kernel.org/all/20231026150154.3536433-1-syoshida@redhat.com/
> ---
>  net/vmw_vsock/virtio_transport_common.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c
> index e22c81435ef7..dc65dd4d26df 100644
> --- a/net/vmw_vsock/virtio_transport_common.c
> +++ b/net/vmw_vsock/virtio_transport_common.c
> @@ -130,6 +130,8 @@ static void virtio_transport_init_hdr(struct sk_buff *skb,
>  	hdr->dst_port	= cpu_to_le32(dst_port);
>  	hdr->flags	= cpu_to_le32(info->flags);
>  	hdr->len	= cpu_to_le32(payload_len);
> +	hdr->buf_alloc	= cpu_to_le32(0);
> +	hdr->fwd_cnt	= cpu_to_le32(0);

This change looks good to me.

I did notice that payload_len in virtio_transport_init_hdr is size_t but
len in struct virtio_vsock_hdr is __le32. But I don't think this is an
issue other than wasting some stack space, though.

>  }
>  
>  static void virtio_transport_copy_nonlinear_skb(const struct sk_buff *skb,
Stefano Garzarella Nov. 6, 2023, 8:42 a.m. UTC | #2 
On Sun, Nov 05, 2023 at 12:05:31AM +0900, Shigeru Yoshida wrote:
>KMSAN reported the following uninit-value access issue:
>
>=====================================================
>BUG: KMSAN: uninit-value in virtio_transport_recv_pkt+0x1dfb/0x26a0 net/vmw_vsock/virtio_transport_common.c:1421
> virtio_transport_recv_pkt+0x1dfb/0x26a0 net/vmw_vsock/virtio_transport_common.c:1421
> vsock_loopback_work+0x3bb/0x5a0 net/vmw_vsock/vsock_loopback.c:120
> process_one_work kernel/workqueue.c:2630 [inline]
> process_scheduled_works+0xff6/0x1e60 kernel/workqueue.c:2703
> worker_thread+0xeca/0x14d0 kernel/workqueue.c:2784
> kthread+0x3cc/0x520 kernel/kthread.c:388
> ret_from_fork+0x66/0x80 arch/x86/kernel/process.c:147
> ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304
>
>Uninit was stored to memory at:
> virtio_transport_space_update net/vmw_vsock/virtio_transport_common.c:1274 [inline]
> virtio_transport_recv_pkt+0x1ee8/0x26a0 net/vmw_vsock/virtio_transport_common.c:1415
> vsock_loopback_work+0x3bb/0x5a0 net/vmw_vsock/vsock_loopback.c:120
> process_one_work kernel/workqueue.c:2630 [inline]
> process_scheduled_works+0xff6/0x1e60 kernel/workqueue.c:2703
> worker_thread+0xeca/0x14d0 kernel/workqueue.c:2784
> kthread+0x3cc/0x520 kernel/kthread.c:388
> ret_from_fork+0x66/0x80 arch/x86/kernel/process.c:147
> ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304
>
>Uninit was created at:
> slab_post_alloc_hook+0x105/0xad0 mm/slab.h:767
> slab_alloc_node mm/slub.c:3478 [inline]
> kmem_cache_alloc_node+0x5a2/0xaf0 mm/slub.c:3523
> kmalloc_reserve+0x13c/0x4a0 net/core/skbuff.c:559
> __alloc_skb+0x2fd/0x770 net/core/skbuff.c:650
> alloc_skb include/linux/skbuff.h:1286 [inline]
> virtio_vsock_alloc_skb include/linux/virtio_vsock.h:66 [inline]
> virtio_transport_alloc_skb+0x90/0x11e0 net/vmw_vsock/virtio_transport_common.c:58
> virtio_transport_reset_no_sock net/vmw_vsock/virtio_transport_common.c:957 [inline]
> virtio_transport_recv_pkt+0x1279/0x26a0 net/vmw_vsock/virtio_transport_common.c:1387
> vsock_loopback_work+0x3bb/0x5a0 net/vmw_vsock/vsock_loopback.c:120
> process_one_work kernel/workqueue.c:2630 [inline]
> process_scheduled_works+0xff6/0x1e60 kernel/workqueue.c:2703
> worker_thread+0xeca/0x14d0 kernel/workqueue.c:2784
> kthread+0x3cc/0x520 kernel/kthread.c:388
> ret_from_fork+0x66/0x80 arch/x86/kernel/process.c:147
> ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304
>
>CPU: 1 PID: 10664 Comm: kworker/1:5 Not tainted 6.6.0-rc3-00146-g9f3ebbef746f #3
>Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-1.fc38 04/01/2014
>Workqueue: vsock-loopback vsock_loopback_work
>=====================================================
>
>The following simple reproducer can cause the issue described above:
>
>int main(void)
>{
>  int sock;
>  struct sockaddr_vm addr = {
>    .svm_family = AF_VSOCK,
>    .svm_cid = VMADDR_CID_ANY,
>    .svm_port = 1234,
>  };
>
>  sock = socket(AF_VSOCK, SOCK_STREAM, 0);
>  connect(sock, (struct sockaddr *)&addr, sizeof(addr));
>  return 0;
>}
>
>This issue occurs because the `buf_alloc` and `fwd_cnt` fields of the
>`struct virtio_vsock_hdr` are not initialized when a new skb is allocated
>in `virtio_transport_init_hdr()`. This patch resolves the issue by
>initializing these fields during allocation.
>
>Fixes: 71dc9ec9ac7d ("virtio/vsock: replace virtio_vsock_pkt with sk_buff")
>Reported-and-tested-by: syzbot+0c8ce1da0ac31abbadcd@syzkaller.appspotmail.com
>Closes: https://syzkaller.appspot.com/bug?extid=0c8ce1da0ac31abbadcd
>Signed-off-by: Shigeru Yoshida <syoshida@redhat.com>
>---
>v1->v2:
>- Rebase on the latest net tree
>https://lore.kernel.org/all/20231026150154.3536433-1-syoshida@redhat.com/
>---
> net/vmw_vsock/virtio_transport_common.c | 2 ++
> 1 file changed, 2 insertions(+)

The patch remained the same, so you could bring back my R-b ;-)
In any case:

Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>

Thanks,
Stefano

>
>diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c
>index e22c81435ef7..dc65dd4d26df 100644
>--- a/net/vmw_vsock/virtio_transport_common.c
>+++ b/net/vmw_vsock/virtio_transport_common.c
>@@ -130,6 +130,8 @@ static void virtio_transport_init_hdr(struct sk_buff *skb,
> 	hdr->dst_port	= cpu_to_le32(dst_port);
> 	hdr->flags	= cpu_to_le32(info->flags);
> 	hdr->len	= cpu_to_le32(payload_len);
>+	hdr->buf_alloc	= cpu_to_le32(0);
>+	hdr->fwd_cnt	= cpu_to_le32(0);
> }
>
> static void virtio_transport_copy_nonlinear_skb(const struct sk_buff *skb,
>-- 
>2.41.0
>
patchwork-bot+netdevbpf@kernel.org Nov. 8, 2023, 3:10 a.m. UTC | #3 
Hello:

This patch was applied to netdev/net.git (main)
by Jakub Kicinski <kuba@kernel.org>:

On Sun,  5 Nov 2023 00:05:31 +0900 you wrote:
> KMSAN reported the following uninit-value access issue:
> 
> =====================================================
> BUG: KMSAN: uninit-value in virtio_transport_recv_pkt+0x1dfb/0x26a0 net/vmw_vsock/virtio_transport_common.c:1421
>  virtio_transport_recv_pkt+0x1dfb/0x26a0 net/vmw_vsock/virtio_transport_common.c:1421
>  vsock_loopback_work+0x3bb/0x5a0 net/vmw_vsock/vsock_loopback.c:120
>  process_one_work kernel/workqueue.c:2630 [inline]
>  process_scheduled_works+0xff6/0x1e60 kernel/workqueue.c:2703
>  worker_thread+0xeca/0x14d0 kernel/workqueue.c:2784
>  kthread+0x3cc/0x520 kernel/kthread.c:388
>  ret_from_fork+0x66/0x80 arch/x86/kernel/process.c:147
>  ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304
> 
> [...]

Here is the summary with links:
  - [net,v2] virtio/vsock: Fix uninit-value in virtio_transport_recv_pkt()
    https://git.kernel.org/netdev/net/c/34c4effacfc3

You are awesome, thank you!
diff mbox series

Patch

diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c
index e22c81435ef7..dc65dd4d26df 100644
--- a/net/vmw_vsock/virtio_transport_common.c
+++ b/net/vmw_vsock/virtio_transport_common.c
@@ -130,6 +130,8 @@  static void virtio_transport_init_hdr(struct sk_buff *skb,
 	hdr->dst_port	= cpu_to_le32(dst_port);
 	hdr->flags	= cpu_to_le32(info->flags);
 	hdr->len	= cpu_to_le32(payload_len);
+	hdr->buf_alloc	= cpu_to_le32(0);
+	hdr->fwd_cnt	= cpu_to_le32(0);
 }
 
 static void virtio_transport_copy_nonlinear_skb(const struct sk_buff *skb,