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| author | Olivier Matz <olivier.matz@6wind.com> | 2019-06-06 09:15:18 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2019-06-06 10:29:21 -0700 |
| commit | 59e3e4b52663a9d97efbce7307f62e4bc5c9ce91 (patch) | |
| tree | 3b48e72c79b7c16b11ae80721bd9add3bce598fa | |
| parent | 4970b42d5c362bf873982db7d93245c5281e58f4 (diff) | |
| download | linux-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.c | 12 |
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 { |