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Elsukov" Date: Tue, 27 Nov 2018 09:04:06 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r341008 - head/sys/net X-SVN-Group: head X-SVN-Commit-Author: ae X-SVN-Commit-Paths: head/sys/net X-SVN-Commit-Revision: 341008 X-SVN-Commit-Repository: base MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Rspamd-Queue-Id: 01C356C918 X-Spamd-Result: default: False [1.65 / 15.00]; local_wl_from(0.00)[FreeBSD.org]; NEURAL_SPAM_LONG(0.51)[0.511,0]; NEURAL_SPAM_MEDIUM(0.69)[0.687,0]; ASN(0.00)[asn:11403, ipnet:2610:1c1:1::/48, country:US]; NEURAL_SPAM_SHORT(0.46)[0.456,0] X-Rspamd-Server: mx1.freebsd.org X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 27 Nov 2018 09:04:07 -0000 Author: ae Date: Tue Nov 27 09:04:06 2018 New Revision: 341008 URL: https://svnweb.freebsd.org/changeset/base/341008 Log: Fix possible panic during ifnet detach in rtsock. The panic can happen, when some application does dump of routing table using sysctl interface. To prevent this, set IFF_DYING flag in if_detach_internal() function, when ifnet under lock is removed from the chain. In sysctl_rtsock() take IFNET_RLOCK_NOSLEEP() to prevent ifnet detach during routes enumeration. In case, if some interface was detached in the time before we take the lock, add the check, that ifnet is not DYING. This prevents access to memory that could be freed after ifnet is unlinked. PR: 227720, 230498, 233306 Reviewed by: bz, eugen MFC after: 1 week Sponsored by: Yandex LLC Differential Revision: https://reviews.freebsd.org/D18338 Modified: head/sys/net/if.c head/sys/net/rtsock.c Modified: head/sys/net/if.c ============================================================================== --- head/sys/net/if.c Tue Nov 27 08:51:15 2018 (r341007) +++ head/sys/net/if.c Tue Nov 27 09:04:06 2018 (r341008) @@ -1068,6 +1068,8 @@ if_detach_internal(struct ifnet *ifp, int vmove, struc CK_STAILQ_FOREACH(iter, &V_ifnet, if_link) if (iter == ifp) { CK_STAILQ_REMOVE(&V_ifnet, ifp, ifnet, if_link); + if (!vmove) + ifp->if_flags |= IFF_DYING; found = 1; break; } Modified: head/sys/net/rtsock.c ============================================================================== --- head/sys/net/rtsock.c Tue Nov 27 08:51:15 2018 (r341007) +++ head/sys/net/rtsock.c Tue Nov 27 09:04:06 2018 (r341008) @@ -1559,6 +1559,8 @@ sysctl_dumpentry(struct radix_node *rn, void *vw) struct rt_addrinfo info; struct sockaddr_storage ss; + IFNET_RLOCK_NOSLEEP_ASSERT(); + if (w->w_op == NET_RT_FLAGS && !(rt->rt_flags & w->w_arg)) return 0; if ((rt->rt_flags & RTF_HOST) == 0 @@ -1571,7 +1573,7 @@ sysctl_dumpentry(struct radix_node *rn, void *vw) info.rti_info[RTAX_NETMASK] = rtsock_fix_netmask(rt_key(rt), rt_mask(rt), &ss); info.rti_info[RTAX_GENMASK] = 0; - if (rt->rt_ifp) { + if (rt->rt_ifp && !(rt->rt_ifp->if_flags & IFF_DYING)) { info.rti_info[RTAX_IFP] = rt->rt_ifp->if_addr->ifa_addr; info.rti_info[RTAX_IFA] = rt->rt_ifa->ifa_addr; if (rt->rt_ifp->if_flags & IFF_POINTOPOINT) @@ -1934,8 +1936,10 @@ sysctl_rtsock(SYSCTL_HANDLER_ARGS) rnh = rt_tables_get_rnh(fib, i); if (rnh != NULL) { RIB_RLOCK(rnh); + IFNET_RLOCK_NOSLEEP(); error = rnh->rnh_walktree(&rnh->head, sysctl_dumpentry, &w); + IFNET_RUNLOCK_NOSLEEP(); RIB_RUNLOCK(rnh); } else if (af != 0) error = EAFNOSUPPORT;