From: SeongJae Park Date: Mon, 14 Dec 2020 09:04:18 +0000 (+0100) Subject: [2/5] xen/xenbus: Add 'will_handle' callback support in xenbus_watch_path() X-Git-Tag: archive/raspbian/5.10.4-1+rpi1^2^2~20 X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=fee0f49bcb864b9bcabedfdb92cbbbac50da4ea6;p=linux.git [2/5] xen/xenbus: Add 'will_handle' callback support in xenbus_watch_path() Origin: https://git.kernel.org/linus/2e85d32b1c865bec703ce0c962221a5e955c52c2 Bug: https://xenbits.xen.org/xsa/advisory-349.html Bug-Debian-Security: https://security-tracker.debian.org/tracker/CVE-2020-29568 Some code does not directly make 'xenbus_watch' object and call 'register_xenbus_watch()' but use 'xenbus_watch_path()' instead. This commit adds support of 'will_handle' callback in the 'xenbus_watch_path()' and it's wrapper, 'xenbus_watch_pathfmt()'. This is part of XSA-349 Cc: stable@vger.kernel.org Signed-off-by: SeongJae Park Reported-by: Michael Kurth Reported-by: Pawel Wieczorkiewicz Reviewed-by: Juergen Gross Signed-off-by: Juergen Gross Gbp-Pq: Topic bugfix/all Gbp-Pq: Name xen-xenbus-Add-will_handle-callback-support-in-xenbu.patch --- diff --git a/drivers/block/xen-blkback/xenbus.c b/drivers/block/xen-blkback/xenbus.c index 684b6f11c80..7e71c7fc101 100644 --- a/drivers/block/xen-blkback/xenbus.c +++ b/drivers/block/xen-blkback/xenbus.c @@ -667,7 +667,8 @@ static int xen_blkbk_probe(struct xenbus_device *dev, /* setup back pointer */ be->blkif->be = be; - err = xenbus_watch_pathfmt(dev, &be->backend_watch, backend_changed, + err = xenbus_watch_pathfmt(dev, &be->backend_watch, NULL, + backend_changed, "%s/%s", dev->nodename, "physical-device"); if (err) goto fail; diff --git a/drivers/net/xen-netback/xenbus.c b/drivers/net/xen-netback/xenbus.c index 00f6f8dc56c..6f10e0998f1 100644 --- a/drivers/net/xen-netback/xenbus.c +++ b/drivers/net/xen-netback/xenbus.c @@ -824,7 +824,7 @@ static void connect(struct backend_info *be) xenvif_carrier_on(be->vif); unregister_hotplug_status_watch(be); - err = xenbus_watch_pathfmt(dev, &be->hotplug_status_watch, + err = xenbus_watch_pathfmt(dev, &be->hotplug_status_watch, NULL, hotplug_status_changed, "%s/%s", dev->nodename, "hotplug-status"); if (!err) diff --git a/drivers/xen/xen-pciback/xenbus.c b/drivers/xen/xen-pciback/xenbus.c index 4b99ec3dec5..e7c692cfb2c 100644 --- a/drivers/xen/xen-pciback/xenbus.c +++ b/drivers/xen/xen-pciback/xenbus.c @@ -689,7 +689,7 @@ static int xen_pcibk_xenbus_probe(struct xenbus_device *dev, /* watch the backend node for backend configuration information */ err = xenbus_watch_path(dev, dev->nodename, &pdev->be_watch, - xen_pcibk_be_watch); + NULL, xen_pcibk_be_watch); if (err) goto out; diff --git a/drivers/xen/xenbus/xenbus_client.c b/drivers/xen/xenbus/xenbus_client.c index 7b569f17103..4cd0c525022 100644 --- a/drivers/xen/xenbus/xenbus_client.c +++ b/drivers/xen/xenbus/xenbus_client.c @@ -130,19 +130,22 @@ EXPORT_SYMBOL_GPL(xenbus_strstate); */ int xenbus_watch_path(struct xenbus_device *dev, const char *path, struct xenbus_watch *watch, + bool (*will_handle)(struct xenbus_watch *, + const char *, const char *), void (*callback)(struct xenbus_watch *, const char *, const char *)) { int err; watch->node = path; - watch->will_handle = NULL; + watch->will_handle = will_handle; watch->callback = callback; err = register_xenbus_watch(watch); if (err) { watch->node = NULL; + watch->will_handle = NULL; watch->callback = NULL; xenbus_dev_fatal(dev, err, "adding watch on %s", path); } @@ -169,6 +172,8 @@ EXPORT_SYMBOL_GPL(xenbus_watch_path); */ int xenbus_watch_pathfmt(struct xenbus_device *dev, struct xenbus_watch *watch, + bool (*will_handle)(struct xenbus_watch *, + const char *, const char *), void (*callback)(struct xenbus_watch *, const char *, const char *), const char *pathfmt, ...) @@ -185,7 +190,7 @@ int xenbus_watch_pathfmt(struct xenbus_device *dev, xenbus_dev_fatal(dev, -ENOMEM, "allocating path for watch"); return -ENOMEM; } - err = xenbus_watch_path(dev, path, watch, callback); + err = xenbus_watch_path(dev, path, watch, will_handle, callback); if (err) kfree(path); diff --git a/drivers/xen/xenbus/xenbus_probe.c b/drivers/xen/xenbus/xenbus_probe.c index 38725d97d90..4c3d1b84aa0 100644 --- a/drivers/xen/xenbus/xenbus_probe.c +++ b/drivers/xen/xenbus/xenbus_probe.c @@ -136,7 +136,7 @@ static int watch_otherend(struct xenbus_device *dev) container_of(dev->dev.bus, struct xen_bus_type, bus); return xenbus_watch_pathfmt(dev, &dev->otherend_watch, - bus->otherend_changed, + NULL, bus->otherend_changed, "%s/%s", dev->otherend, "state"); } diff --git a/include/xen/xenbus.h b/include/xen/xenbus.h index baa88bf0b9b..c8574d1b814 100644 --- a/include/xen/xenbus.h +++ b/include/xen/xenbus.h @@ -204,10 +204,14 @@ void xenbus_probe(struct work_struct *); int xenbus_watch_path(struct xenbus_device *dev, const char *path, struct xenbus_watch *watch, + bool (*will_handle)(struct xenbus_watch *, + const char *, const char *), void (*callback)(struct xenbus_watch *, const char *, const char *)); -__printf(4, 5) +__printf(5, 6) int xenbus_watch_pathfmt(struct xenbus_device *dev, struct xenbus_watch *watch, + bool (*will_handle)(struct xenbus_watch *, + const char *, const char *), void (*callback)(struct xenbus_watch *, const char *, const char *), const char *pathfmt, ...);