diff options
| author | Olivier Matz <olivier.matz@6wind.com> | 2019-06-06 09:15:18 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-06-11 12:21:46 +0200 |
| commit | ee6e0cec59b37e2ce8ec0676d57ffa34e996455b (patch) | |
| tree | 6d9e3ec4fa6f9591136bdeff0b6b1f73e78f14a4 /net | |
| parent | 4b83a95655b800350281421f0e64c6d17b3d18db (diff) | |
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>
Diffstat (limited to '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 ab315fe26a05..ac428311965f 100644 --- a/net/ipv6/raw.c +++ b/net/ipv6/raw.c @@ -782,6 +782,7 @@ 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; @@ -795,6 +796,13 @@ 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. */ @@ -913,7 +921,7 @@ 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) @@ -936,7 +944,7 @@ 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; |