Jason Wang
2018-Mar-09 06:50 UTC
[PATCH net 0/3] Several fixes for vhost_net ptr_ring usage
Hi: This small series try to fix several bugs of ptr_ring usage in vhost_net. Please review. Thanks Alexander Potapenko (1): vhost_net: initialize rx_ring in vhost_net_open() Jason Wang (2): vhost_net: keep private_data and rx_ring synced vhost_net: examine pointer types during un-producing drivers/net/tun.c | 3 ++- drivers/vhost/net.c | 8 +++++--- include/linux/if_tun.h | 4 ++++ 3 files changed, 11 insertions(+), 4 deletions(-) -- 2.7.4
Jason Wang
2018-Mar-09 06:50 UTC
[PATCH net 1/3] vhost_net: initialize rx_ring in vhost_net_open()
From: Alexander Potapenko <glider at google.com>
KMSAN reported a use of uninit memory in vhost_net_buf_unproduce()
while trying to access n->vqs[VHOST_NET_VQ_TX].rx_ring:
=================================================================BUG: KMSAN: use
of uninitialized memory in vhost_net_buf_unproduce+0x7bb/0x9a0 drivers/vho
et.c:170
CPU: 0 PID: 3021 Comm: syz-fuzzer Not tainted 4.16.0-rc4+ #3853
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x185/0x1d0 lib/dump_stack.c:53
kmsan_report+0x142/0x1f0 mm/kmsan/kmsan.c:1093
__msan_warning_32+0x6c/0xb0 mm/kmsan/kmsan_instr.c:676
vhost_net_buf_unproduce+0x7bb/0x9a0 drivers/vhost/net.c:170
vhost_net_stop_vq drivers/vhost/net.c:974 [inline]
vhost_net_stop+0x146/0x380 drivers/vhost/net.c:982
vhost_net_release+0xb1/0x4f0 drivers/vhost/net.c:1015
__fput+0x49f/0xa00 fs/file_table.c:209
____fput+0x37/0x40 fs/file_table.c:243
task_work_run+0x243/0x2c0 kernel/task_work.c:113
tracehook_notify_resume include/linux/tracehook.h:191 [inline]
exit_to_usermode_loop arch/x86/entry/common.c:166 [inline]
prepare_exit_to_usermode+0x349/0x3b0 arch/x86/entry/common.c:196
syscall_return_slowpath+0xf3/0x6d0 arch/x86/entry/common.c:265
do_syscall_64+0x34d/0x450 arch/x86/entry/common.c:292
...
origin:
kmsan_save_stack_with_flags mm/kmsan/kmsan.c:303 [inline]
kmsan_internal_poison_shadow+0xb8/0x1b0 mm/kmsan/kmsan.c:213
kmsan_kmalloc_large+0x6f/0xd0 mm/kmsan/kmsan.c:392
kmalloc_large_node_hook mm/slub.c:1366 [inline]
kmalloc_large_node mm/slub.c:3808 [inline]
__kmalloc_node+0x100e/0x1290 mm/slub.c:3818
kmalloc_node include/linux/slab.h:554 [inline]
kvmalloc_node+0x1a5/0x2e0 mm/util.c:419
kvmalloc include/linux/mm.h:541 [inline]
vhost_net_open+0x64/0x5f0 drivers/vhost/net.c:921
misc_open+0x7b5/0x8b0 drivers/char/misc.c:154
chrdev_open+0xc28/0xd90 fs/char_dev.c:417
do_dentry_open+0xccb/0x1430 fs/open.c:752
vfs_open+0x272/0x2e0 fs/open.c:866
do_last fs/namei.c:3378 [inline]
path_openat+0x49ad/0x6580 fs/namei.c:3519
do_filp_open+0x267/0x640 fs/namei.c:3553
do_sys_open+0x6ad/0x9c0 fs/open.c:1059
SYSC_openat+0xc7/0xe0 fs/open.c:1086
SyS_openat+0x63/0x90 fs/open.c:1080
do_syscall_64+0x2f1/0x450 arch/x86/entry/common.c:287
=================================================================
Fixes: c67df11f6e480 ("vhost_net: try batch dequing from skb array")
Signed-off-by: Alexander Potapenko <glider at google.com>
Signed-off-by: Jason Wang <jasowang at redhat.com>
---
drivers/vhost/net.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index 610cba2..60f1080 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -948,6 +948,7 @@ static int vhost_net_open(struct inode *inode, struct file
*f)
n->vqs[i].done_idx = 0;
n->vqs[i].vhost_hlen = 0;
n->vqs[i].sock_hlen = 0;
+ n->vqs[i].rx_ring = NULL;
vhost_net_buf_init(&n->vqs[i].rxq);
}
vhost_dev_init(dev, vqs, VHOST_NET_VQ_MAX);
--
2.7.4
Jason Wang
2018-Mar-09 06:50 UTC
[PATCH net 2/3] vhost_net: keep private_data and rx_ring synced
We get pointer ring from the exported sock, this means we should keep
rx_ring and vq->private synced during both vq stop and backend set,
otherwise we may see stale rx_ring.
Fixes: c67df11f6e480 ("vhost_net: try batch dequing from skb array")
Signed-off-by: Michael S. Tsirkin <mst at redhat.com>
Signed-off-by: Jason Wang <jasowang at redhat.com>
---
drivers/vhost/net.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index 60f1080..efb9306 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -973,6 +973,7 @@ static struct socket *vhost_net_stop_vq(struct vhost_net *n,
vhost_net_disable_vq(n, vq);
vq->private_data = NULL;
vhost_net_buf_unproduce(nvq);
+ nvq->rx_ring = NULL;
mutex_unlock(&vq->mutex);
return sock;
}
@@ -1162,14 +1163,14 @@ static long vhost_net_set_backend(struct vhost_net *n,
unsigned index, int fd)
vhost_net_disable_vq(n, vq);
vq->private_data = sock;
vhost_net_buf_unproduce(nvq);
- if (index == VHOST_NET_VQ_RX)
- nvq->rx_ring = get_tap_ptr_ring(fd);
r = vhost_vq_init_access(vq);
if (r)
goto err_used;
r = vhost_net_enable_vq(n, vq);
if (r)
goto err_used;
+ if (index == VHOST_NET_VQ_RX)
+ nvq->rx_ring = get_tap_ptr_ring(fd);
oldubufs = nvq->ubufs;
nvq->ubufs = ubufs;
--
2.7.4
Jason Wang
2018-Mar-09 06:50 UTC
[PATCH net 3/3] vhost_net: examine pointer types during un-producing
After commit fc72d1d54dd9 ("tuntap: XDP transmission"), we can
actually queueing XDP pointers in the pointer ring, so we should
examine the pointer type before freeing the pointer.
Fixes: fc72d1d54dd9 ("tuntap: XDP transmission")
Reported-by: Michael S. Tsirkin <mst at redhat.com>
Acked-by: Michael S. Tsirkin <mst at redhat.com>
Signed-off-by: Jason Wang <jasowang at redhat.com>
---
drivers/net/tun.c | 3 ++-
drivers/vhost/net.c | 2 +-
include/linux/if_tun.h | 4 ++++
3 files changed, 7 insertions(+), 2 deletions(-)
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 7433bb2..28cfa64 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -655,7 +655,7 @@ static struct tun_struct *tun_enable_queue(struct tun_file
*tfile)
return tun;
}
-static void tun_ptr_free(void *ptr)
+void tun_ptr_free(void *ptr)
{
if (!ptr)
return;
@@ -667,6 +667,7 @@ static void tun_ptr_free(void *ptr)
__skb_array_destroy_skb(ptr);
}
}
+EXPORT_SYMBOL_GPL(tun_ptr_free);
static void tun_queue_purge(struct tun_file *tfile)
{
diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index efb9306..8139bc7 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -170,7 +170,7 @@ static void vhost_net_buf_unproduce(struct
vhost_net_virtqueue *nvq)
if (nvq->rx_ring && !vhost_net_buf_is_empty(rxq)) {
ptr_ring_unconsume(nvq->rx_ring, rxq->queue + rxq->head,
vhost_net_buf_get_size(rxq),
- __skb_array_destroy_skb);
+ tun_ptr_free);
rxq->head = rxq->tail = 0;
}
}
diff --git a/include/linux/if_tun.h b/include/linux/if_tun.h
index c5b0a75..fd00170 100644
--- a/include/linux/if_tun.h
+++ b/include/linux/if_tun.h
@@ -25,6 +25,7 @@ struct ptr_ring *tun_get_tx_ring(struct file *file);
bool tun_is_xdp_buff(void *ptr);
void *tun_xdp_to_ptr(void *ptr);
void *tun_ptr_to_xdp(void *ptr);
+void tun_ptr_free(void *ptr);
#else
#include <linux/err.h>
#include <linux/errno.h>
@@ -50,5 +51,8 @@ static inline void *tun_ptr_to_xdp(void *ptr)
{
return NULL;
}
+static inline void tun_ptr_free(void *ptr)
+{
+}
#endif /* CONFIG_TUN */
#endif /* __IF_TUN_H */
--
2.7.4
Michael S. Tsirkin
2018-Mar-09 16:55 UTC
[PATCH net 1/3] vhost_net: initialize rx_ring in vhost_net_open()
On Fri, Mar 09, 2018 at 02:50:32PM +0800, Jason Wang wrote:> From: Alexander Potapenko <glider at google.com> > > KMSAN reported a use of uninit memory in vhost_net_buf_unproduce() > while trying to access n->vqs[VHOST_NET_VQ_TX].rx_ring: > > =================================================================> BUG: KMSAN: use of uninitialized memory in vhost_net_buf_unproduce+0x7bb/0x9a0 drivers/vho > et.c:170 > CPU: 0 PID: 3021 Comm: syz-fuzzer Not tainted 4.16.0-rc4+ #3853 > Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014 > Call Trace: > __dump_stack lib/dump_stack.c:17 [inline] > dump_stack+0x185/0x1d0 lib/dump_stack.c:53 > kmsan_report+0x142/0x1f0 mm/kmsan/kmsan.c:1093 > __msan_warning_32+0x6c/0xb0 mm/kmsan/kmsan_instr.c:676 > vhost_net_buf_unproduce+0x7bb/0x9a0 drivers/vhost/net.c:170 > vhost_net_stop_vq drivers/vhost/net.c:974 [inline] > vhost_net_stop+0x146/0x380 drivers/vhost/net.c:982 > vhost_net_release+0xb1/0x4f0 drivers/vhost/net.c:1015 > __fput+0x49f/0xa00 fs/file_table.c:209 > ____fput+0x37/0x40 fs/file_table.c:243 > task_work_run+0x243/0x2c0 kernel/task_work.c:113 > tracehook_notify_resume include/linux/tracehook.h:191 [inline] > exit_to_usermode_loop arch/x86/entry/common.c:166 [inline] > prepare_exit_to_usermode+0x349/0x3b0 arch/x86/entry/common.c:196 > syscall_return_slowpath+0xf3/0x6d0 arch/x86/entry/common.c:265 > do_syscall_64+0x34d/0x450 arch/x86/entry/common.c:292 > ... > origin: > kmsan_save_stack_with_flags mm/kmsan/kmsan.c:303 [inline] > kmsan_internal_poison_shadow+0xb8/0x1b0 mm/kmsan/kmsan.c:213 > kmsan_kmalloc_large+0x6f/0xd0 mm/kmsan/kmsan.c:392 > kmalloc_large_node_hook mm/slub.c:1366 [inline] > kmalloc_large_node mm/slub.c:3808 [inline] > __kmalloc_node+0x100e/0x1290 mm/slub.c:3818 > kmalloc_node include/linux/slab.h:554 [inline] > kvmalloc_node+0x1a5/0x2e0 mm/util.c:419 > kvmalloc include/linux/mm.h:541 [inline] > vhost_net_open+0x64/0x5f0 drivers/vhost/net.c:921 > misc_open+0x7b5/0x8b0 drivers/char/misc.c:154 > chrdev_open+0xc28/0xd90 fs/char_dev.c:417 > do_dentry_open+0xccb/0x1430 fs/open.c:752 > vfs_open+0x272/0x2e0 fs/open.c:866 > do_last fs/namei.c:3378 [inline] > path_openat+0x49ad/0x6580 fs/namei.c:3519 > do_filp_open+0x267/0x640 fs/namei.c:3553 > do_sys_open+0x6ad/0x9c0 fs/open.c:1059 > SYSC_openat+0xc7/0xe0 fs/open.c:1086 > SyS_openat+0x63/0x90 fs/open.c:1080 > do_syscall_64+0x2f1/0x450 arch/x86/entry/common.c:287 > =================================================================> > Fixes: c67df11f6e480 ("vhost_net: try batch dequing from skb array") > Signed-off-by: Alexander Potapenko <glider at google.com> > Signed-off-by: Jason Wang <jasowang at redhat.com>Acked-by: Michael S. Tsirkin <mst at redhat.com>> --- > drivers/vhost/net.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c > index 610cba2..60f1080 100644 > --- a/drivers/vhost/net.c > +++ b/drivers/vhost/net.c > @@ -948,6 +948,7 @@ static int vhost_net_open(struct inode *inode, struct file *f) > n->vqs[i].done_idx = 0; > n->vqs[i].vhost_hlen = 0; > n->vqs[i].sock_hlen = 0; > + n->vqs[i].rx_ring = NULL; > vhost_net_buf_init(&n->vqs[i].rxq); > } > vhost_dev_init(dev, vqs, VHOST_NET_VQ_MAX); > -- > 2.7.4
Michael S. Tsirkin
2018-Mar-09 16:56 UTC
[PATCH net 2/3] vhost_net: keep private_data and rx_ring synced
On Fri, Mar 09, 2018 at 02:50:33PM +0800, Jason Wang wrote:> We get pointer ring from the exported sock, this means we should keep > rx_ring and vq->private synced during both vq stop and backend set, > otherwise we may see stale rx_ring. > > Fixes: c67df11f6e480 ("vhost_net: try batch dequing from skb array") > Signed-off-by: Michael S. Tsirkin <mst at redhat.com> > Signed-off-by: Jason Wang <jasowang at redhat.com>Acked-by: Michael S. Tsirkin <mst at redhat.com>> --- > drivers/vhost/net.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c > index 60f1080..efb9306 100644 > --- a/drivers/vhost/net.c > +++ b/drivers/vhost/net.c > @@ -973,6 +973,7 @@ static struct socket *vhost_net_stop_vq(struct vhost_net *n, > vhost_net_disable_vq(n, vq); > vq->private_data = NULL; > vhost_net_buf_unproduce(nvq); > + nvq->rx_ring = NULL; > mutex_unlock(&vq->mutex); > return sock; > } > @@ -1162,14 +1163,14 @@ static long vhost_net_set_backend(struct vhost_net *n, unsigned index, int fd) > vhost_net_disable_vq(n, vq); > vq->private_data = sock; > vhost_net_buf_unproduce(nvq); > - if (index == VHOST_NET_VQ_RX) > - nvq->rx_ring = get_tap_ptr_ring(fd); > r = vhost_vq_init_access(vq); > if (r) > goto err_used; > r = vhost_net_enable_vq(n, vq); > if (r) > goto err_used; > + if (index == VHOST_NET_VQ_RX) > + nvq->rx_ring = get_tap_ptr_ring(fd); > > oldubufs = nvq->ubufs; > nvq->ubufs = ubufs; > -- > 2.7.4
Michael S. Tsirkin
2018-Mar-09 16:57 UTC
[PATCH net 0/3] Several fixes for vhost_net ptr_ring usage
On Fri, Mar 09, 2018 at 02:50:31PM +0800, Jason Wang wrote:> Hi: > > This small series try to fix several bugs of ptr_ring usage in > vhost_net. Please review. > > ThanksACK series, thanks Jason!> Alexander Potapenko (1): > vhost_net: initialize rx_ring in vhost_net_open() > > Jason Wang (2): > vhost_net: keep private_data and rx_ring synced > vhost_net: examine pointer types during un-producing > > drivers/net/tun.c | 3 ++- > drivers/vhost/net.c | 8 +++++--- > include/linux/if_tun.h | 4 ++++ > 3 files changed, 11 insertions(+), 4 deletions(-) > > -- > 2.7.4
David Miller
2018-Mar-09 17:03 UTC
[PATCH net 0/3] Several fixes for vhost_net ptr_ring usage
From: Jason Wang <jasowang at redhat.com> Date: Fri, 9 Mar 2018 14:50:31 +0800> This small series try to fix several bugs of ptr_ring usage in > vhost_net. Please review.Series applied, thanks Jason.
Apparently Analagous Threads
- [PATCH net 0/3] Several fixes for vhost_net ptr_ring usage
- [PATCH net 1/3] vhost_net: initialize rx_ring in vhost_net_open()
- vhost changes (batched) in linux-next after 12/13 trigger random crashes in KVM guests after reboot
- vhost changes (batched) in linux-next after 12/13 trigger random crashes in KVM guests after reboot
- vhost changes (batched) in linux-next after 12/13 trigger random crashes in KVM guests after reboot