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| author | Olivier Matz <olivier.matz@6wind.com> | 2019-06-06 09:15:18 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-06-11 12:22:47 +0200 |
| commit | 9890fe2f907e6ac4749886741850583b0243663f (patch) | |
| tree | 2b2fb88c15c769325146887bf13f622048805c8f | |
| parent | efae37a44b4522855bbbfb2b17827346e79100e7 (diff) | |
| download | linux-rt-9890fe2f907e6ac4749886741850583b0243663f.tar.gz | |
ipv6: use READ_ONCE() for inet->hdrincl as in ipv4
[ Upstream commit 59e3e4b52663a9d97efbce7307f62e4bc5c9ce91 ]
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -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 b8d7100792b1..301978df650e 100644 --- a/net/ipv6/raw.c +++ b/net/ipv6/raw.c @@ -774,6 +774,7 @@ static int rawv6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) struct sockcm_cookie sockc; struct ipcm6_cookie ipc6; int addr_len = msg->msg_namelen; + int hdrincl; u16 proto; int err; @@ -787,6 +788,13 @@ 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. */ @@ -904,7 +912,7 @@ 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) @@ -927,7 +935,7 @@ 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); else { ipc6.opt = opt; |