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authorOlivier Matz <olivier.matz@6wind.com>2019-06-06 09:15:18 +0200
committerDavid S. Miller <davem@davemloft.net>2019-06-06 10:29:21 -0700
commit59e3e4b52663a9d97efbce7307f62e4bc5c9ce91 (patch)
tree3b48e72c79b7c16b11ae80721bd9add3bce598fa
parent4970b42d5c362bf873982db7d93245c5281e58f4 (diff)
downloadlinux-59e3e4b52663a9d97efbce7307f62e4bc5c9ce91.tar.bz2
ipv6: use READ_ONCE() for inet->hdrincl as in ipv4
As it was done in commit 8f659a03a0ba ("net: ipv4: fix for a race condition in raw_sendmsg") and commit 20b50d79974e ("net: ipv4: emulate READ_ONCE() on ->hdrincl bit-field in raw_sendmsg()") for ipv4, copy the value of inet->hdrincl in a local variable, to avoid introducing a race condition in the next commit. Signed-off-by: Olivier Matz <olivier.matz@6wind.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--net/ipv6/raw.c12
1 files changed, 10 insertions, 2 deletions
diff --git a/net/ipv6/raw.c b/net/ipv6/raw.c
index 96a3559f2a09..af2f9a833c4e 100644
--- a/net/ipv6/raw.c
+++ b/net/ipv6/raw.c
@@ -783,6 +783,7 @@ static int rawv6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
struct flowi6 fl6;
struct ipcm6_cookie ipc6;
int addr_len = msg->msg_namelen;
+ int hdrincl;
u16 proto;
int err;
@@ -796,6 +797,13 @@ static int rawv6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
if (msg->msg_flags & MSG_OOB)
return -EOPNOTSUPP;
+ /* hdrincl should be READ_ONCE(inet->hdrincl)
+ * but READ_ONCE() doesn't work with bit fields.
+ * Doing this indirectly yields the same result.
+ */
+ hdrincl = inet->hdrincl;
+ hdrincl = READ_ONCE(hdrincl);
+
/*
* Get and verify the address.
*/
@@ -908,7 +916,7 @@ static int rawv6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
fl6.flowi6_oif = np->ucast_oif;
security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
- if (inet->hdrincl)
+ if (hdrincl)
fl6.flowi6_flags |= FLOWI_FLAG_KNOWN_NH;
if (ipc6.tclass < 0)
@@ -931,7 +939,7 @@ static int rawv6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
goto do_confirm;
back_from_confirm:
- if (inet->hdrincl)
+ if (hdrincl)
err = rawv6_send_hdrinc(sk, msg, len, &fl6, &dst,
msg->msg_flags, &ipc6.sockc);
else {