Date: Wed, 23 Oct 2019 23:20:49 +0000 (UTC) From: Eric Joyner <erj@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r353967 - head/sys/net Message-ID: <201910232320.x9NNKnEZ071116@repo.freebsd.org>
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Author: erj Date: Wed Oct 23 23:20:49 2019 New Revision: 353967 URL: https://svnweb.freebsd.org/changeset/base/353967 Log: iflib: call ether_ifdetach and netmap_detach before stop From Jake: Calling ether_ifdetach after iflib_stop leads to a potential race where a stale ifp pointer can remain in the route entry list for IPv6 traffic. This will potentially cause a page fault or other system instability if the ifp pointer is accessed. Move both iflib_netmap_detach and ether_ifdetach to be called prior to iflib_stop. This avoids the race above, and helps ensure that other ifp references are removed before stopping the interface. Submitted by: Jacob Keller <jacob.e.keller@intel.com> Reviewed by: erj@, gallatin@, jhb@ MFC after: 3 days Sponsored by: Intel Corporation Differential Revision: https://reviews.freebsd.org/D22071 Modified: head/sys/net/iflib.c Modified: head/sys/net/iflib.c ============================================================================== --- head/sys/net/iflib.c Wed Oct 23 23:10:12 2019 (r353966) +++ head/sys/net/iflib.c Wed Oct 23 23:20:49 2019 (r353967) @@ -703,6 +703,7 @@ static int iflib_altq_if_transmit(if_t ifp, struct mbu #endif static int iflib_register(if_ctx_t); static void iflib_deregister(if_ctx_t); +static void iflib_unregister_vlan_handlers(if_ctx_t ctx); static void iflib_init_locked(if_ctx_t ctx); static void iflib_add_device_sysctl_pre(if_ctx_t ctx); static void iflib_add_device_sysctl_post(if_ctx_t ctx); @@ -5007,6 +5008,9 @@ iflib_pseudo_deregister(if_ctx_t ctx) struct taskqgroup *tqg; iflib_fl_t fl; + /* Unregister VLAN event handlers early */ + iflib_unregister_vlan_handlers(ctx); + ether_ifdetach(ifp); /* XXX drain any dependent tasks */ tqg = qgroup_if_io_tqg; @@ -5080,12 +5084,16 @@ iflib_device_deregister(if_ctx_t ctx) ctx->ifc_flags |= IFC_IN_DETACH; STATE_UNLOCK(ctx); + /* Unregister VLAN handlers before calling iflib_stop() */ + iflib_unregister_vlan_handlers(ctx); + + iflib_netmap_detach(ifp); + ether_ifdetach(ifp); + CTX_LOCK(ctx); iflib_stop(ctx); CTX_UNLOCK(ctx); - iflib_netmap_detach(ifp); - ether_ifdetach(ifp); iflib_rem_pfil(ctx); if (ctx->ifc_led_dev != NULL) led_destroy(ctx->ifc_led_dev); @@ -5375,13 +5383,8 @@ iflib_register(if_ctx_t ctx) } static void -iflib_deregister(if_ctx_t ctx) +iflib_unregister_vlan_handlers(if_ctx_t ctx) { - if_t ifp = ctx->ifc_ifp; - - /* Remove all media */ - ifmedia_removeall(&ctx->ifc_media); - /* Unregister VLAN events */ if (ctx->ifc_vlan_attach_event != NULL) { EVENTHANDLER_DEREGISTER(vlan_config, ctx->ifc_vlan_attach_event); @@ -5391,6 +5394,19 @@ iflib_deregister(if_ctx_t ctx) EVENTHANDLER_DEREGISTER(vlan_unconfig, ctx->ifc_vlan_detach_event); ctx->ifc_vlan_detach_event = NULL; } + +} + +static void +iflib_deregister(if_ctx_t ctx) +{ + if_t ifp = ctx->ifc_ifp; + + /* Remove all media */ + ifmedia_removeall(&ctx->ifc_media); + + /* Ensure that VLAN event handlers are unregistered */ + iflib_unregister_vlan_handlers(ctx); /* Release kobject reference */ kobj_delete((kobj_t) ctx, NULL);
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