Date: Fri, 31 Mar 2023 11:12:26 -0700 From: Gleb Smirnoff <glebius@freebsd.org> To: Mateusz Guzik <mjg@freebsd.org> Cc: src-committers@freebsd.org, dev-commits-src-all@freebsd.org, dev-commits-src-main@freebsd.org Subject: Re: git: f5a365e51fee - main - inet6: protect address manipulation with a lock Message-ID: <ZCciivj8ciSkj8ph@FreeBSD.org> In-Reply-To: <202303300847.32U8l1UM004219@gitrepo.freebsd.org> References: <202303300847.32U8l1UM004219@gitrepo.freebsd.org>
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Mateusz,
On Thu, Mar 30, 2023 at 08:47:01AM +0000, Mateusz Guzik wrote:
M> diff --git a/sys/netinet6/in6.c b/sys/netinet6/in6.c
M> index 27dc3550177c..3d967e9a40c7 100644
M> --- a/sys/netinet6/in6.c
M> +++ b/sys/netinet6/in6.c
M> @@ -168,6 +168,9 @@ static void in6_leave_proxy_ndp_mc(struct ifnet *, const struct in6_addr *);
M> #define ifa2ia6(ifa) ((struct in6_ifaddr *)(ifa))
M> #define ia62ifa(ia6) (&((ia6)->ia_ifa))
M>
M> +static struct sx in6_control_sx;
M> +SX_SYSINIT(in6_control_sx, &in6_control_sx, "in6_control");
M> +
M> void
M> in6_newaddrmsg(struct in6_ifaddr *ia, int cmd)
M> {
M> @@ -254,6 +257,7 @@ in6_control(struct socket *so, u_long cmd, void *data,
M> struct in6_aliasreq *ifra = (struct in6_aliasreq *)data;
M> struct sockaddr_in6 *sa6;
M> int error;
M> + bool control_locked = false;
M>
M> /*
M> * Compat to make pre-10.x ifconfig(8) operable.
M> @@ -411,6 +415,8 @@ in6_control(struct socket *so, u_long cmd, void *data,
M> if (td != NULL && (error = prison_check_ip6(td->td_ucred,
M> &sa6->sin6_addr)) != 0)
M> return (error);
M> + sx_xlock(&in6_control_sx);
M> + control_locked = true;
M> ia = in6ifa_ifpwithaddr(ifp, &sa6->sin6_addr);
M> } else
M> ia = NULL;
M> @@ -582,6 +588,9 @@ in6_control(struct socket *so, u_long cmd, void *data,
M>
M> error = 0;
M> out:
M> + if (control_locked)
M> + sx_xunlock(&in6_control_sx);
M> +
M> if (ia != NULL)
M> ifa_free(&ia->ia_ifa);
M> return (error);
Why do you prefer a bool over using sx_xlocked()?
--
Gleb Smirnoff
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