This is a note to let you know that I've just added the patch titled
net/packet: convert po->origdev to an atomic flag
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
net-packet-convert-po-origdev-to-an-atomic-flag.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 0f762a372ac1eff6707e6e481a49f400323597a9
Author: Eric Dumazet <edumazet@xxxxxxxxxx>
Date: Thu Mar 16 01:10:07 2023 +0000
net/packet: convert po->origdev to an atomic flag
[ Upstream commit ee5675ecdf7a4e713ed21d98a70c2871d6ebed01 ]
syzbot/KCAN reported that po->origdev can be read
while another thread is changing its value.
We can avoid this splat by converting this field
to an actual bit.
Following patches will convert remaining 1bit fields.
Fixes: 80feaacb8a64 ("[AF_PACKET]: Add option to return orig_dev to userspace.")
Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Reported-by: syzbot <syzkaller@xxxxxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index 1b3c54e0fbdfb..cb944ae999471 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -2149,7 +2149,7 @@ static int packet_rcv(struct sk_buff *skb, struct net_device *dev,
sll = &PACKET_SKB_CB(skb)->sa.ll;
sll->sll_hatype = dev->type;
sll->sll_pkttype = skb->pkt_type;
- if (unlikely(po->origdev))
+ if (unlikely(packet_sock_flag(po, PACKET_SOCK_ORIGDEV)))
sll->sll_ifindex = orig_dev->ifindex;
else
sll->sll_ifindex = dev->ifindex;
@@ -2422,7 +2422,7 @@ static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
sll->sll_hatype = dev->type;
sll->sll_protocol = skb->protocol;
sll->sll_pkttype = skb->pkt_type;
- if (unlikely(po->origdev))
+ if (unlikely(packet_sock_flag(po, PACKET_SOCK_ORIGDEV)))
sll->sll_ifindex = orig_dev->ifindex;
else
sll->sll_ifindex = dev->ifindex;
@@ -3883,9 +3883,7 @@ packet_setsockopt(struct socket *sock, int level, int optname, sockptr_t optval,
if (copy_from_sockptr(&val, optval, sizeof(val)))
return -EFAULT;
- lock_sock(sk);
- po->origdev = !!val;
- release_sock(sk);
+ packet_sock_flag_set(po, PACKET_SOCK_ORIGDEV, val);
return 0;
}
case PACKET_VNET_HDR:
@@ -4034,7 +4032,7 @@ static int packet_getsockopt(struct socket *sock, int level, int optname,
val = po->auxdata;
break;
case PACKET_ORIGDEV:
- val = po->origdev;
+ val = packet_sock_flag(po, PACKET_SOCK_ORIGDEV);
break;
case PACKET_VNET_HDR:
val = po->has_vnet_hdr;
diff --git a/net/packet/diag.c b/net/packet/diag.c
index 07812ae5ca073..e1ac9bb375b31 100644
--- a/net/packet/diag.c
+++ b/net/packet/diag.c
@@ -25,7 +25,7 @@ static int pdiag_put_info(const struct packet_sock *po, struct sk_buff *nlskb)
pinfo.pdi_flags |= PDI_RUNNING;
if (po->auxdata)
pinfo.pdi_flags |= PDI_AUXDATA;
- if (po->origdev)
+ if (packet_sock_flag(po, PACKET_SOCK_ORIGDEV))
pinfo.pdi_flags |= PDI_ORIGDEV;
if (po->has_vnet_hdr)
pinfo.pdi_flags |= PDI_VNETHDR;
diff --git a/net/packet/internal.h b/net/packet/internal.h
index 48af35b1aed25..178cd1852238d 100644
--- a/net/packet/internal.h
+++ b/net/packet/internal.h
@@ -116,9 +116,9 @@ struct packet_sock {
int copy_thresh;
spinlock_t bind_lock;
struct mutex pg_vec_lock;
+ unsigned long flags;
unsigned int running; /* bind_lock must be held */
unsigned int auxdata:1, /* writer must hold sock lock */
- origdev:1,
has_vnet_hdr:1,
tp_loss:1,
tp_tx_has_off:1;
@@ -144,4 +144,24 @@ static inline struct packet_sock *pkt_sk(struct sock *sk)
return (struct packet_sock *)sk;
}
+enum packet_sock_flags {
+ PACKET_SOCK_ORIGDEV,
+};
+
+static inline void packet_sock_flag_set(struct packet_sock *po,
+ enum packet_sock_flags flag,
+ bool val)
+{
+ if (val)
+ set_bit(flag, &po->flags);
+ else
+ clear_bit(flag, &po->flags);
+}
+
+static inline bool packet_sock_flag(const struct packet_sock *po,
+ enum packet_sock_flags flag)
+{
+ return test_bit(flag, &po->flags);
+}
+
#endif
