From 29bb322683fcc49ac4b4dd36d8b3a229181af675 Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Tue, 5 Jul 2022 13:44:26 +0200 Subject: [PATCH] 4.19-stable patches added patches: net-usb-qmi_wwan-add-telit-0x1060-composition.patch net-usb-qmi_wwan-add-telit-0x1070-composition.patch xen-arm-fix-race-in-rb-tree-based-p2m-accounting.patch xen-blkfront-fix-leaking-data-in-shared-pages.patch xen-blkfront-force-data-bouncing-when-backend-is-untrusted.patch xen-netfront-fix-leaking-data-in-shared-pages.patch xen-netfront-force-data-bouncing-when-backend-is-untrusted.patch --- ...mi_wwan-add-telit-0x1060-composition.patch | 31 +++ ...mi_wwan-add-telit-0x1070-composition.patch | 36 ++++ queue-4.19/series | 7 + ...race-in-rb-tree-based-p2m-accounting.patch | 72 +++++++ ...ont-fix-leaking-data-in-shared-pages.patch | 54 +++++ ...a-bouncing-when-backend-is-untrusted.patch | 203 ++++++++++++++++++ ...ont-fix-leaking-data-in-shared-pages.patch | 35 +++ ...a-bouncing-when-backend-is-untrusted.patch | 125 +++++++++++ 8 files changed, 563 insertions(+) create mode 100644 queue-4.19/net-usb-qmi_wwan-add-telit-0x1060-composition.patch create mode 100644 queue-4.19/net-usb-qmi_wwan-add-telit-0x1070-composition.patch create mode 100644 queue-4.19/xen-arm-fix-race-in-rb-tree-based-p2m-accounting.patch create mode 100644 queue-4.19/xen-blkfront-fix-leaking-data-in-shared-pages.patch create mode 100644 queue-4.19/xen-blkfront-force-data-bouncing-when-backend-is-untrusted.patch create mode 100644 queue-4.19/xen-netfront-fix-leaking-data-in-shared-pages.patch create mode 100644 queue-4.19/xen-netfront-force-data-bouncing-when-backend-is-untrusted.patch diff --git a/queue-4.19/net-usb-qmi_wwan-add-telit-0x1060-composition.patch b/queue-4.19/net-usb-qmi_wwan-add-telit-0x1060-composition.patch new file mode 100644 index 00000000000..ce6799817f9 --- /dev/null +++ b/queue-4.19/net-usb-qmi_wwan-add-telit-0x1060-composition.patch @@ -0,0 +1,31 @@ +From 8d17a33b076d24aa4861f336a125c888fb918605 Mon Sep 17 00:00:00 2001 +From: Carlo Lobrano +Date: Fri, 3 Sep 2021 14:09:53 +0200 +Subject: net: usb: qmi_wwan: add Telit 0x1060 composition + +From: Carlo Lobrano + +commit 8d17a33b076d24aa4861f336a125c888fb918605 upstream. + +This patch adds support for Telit LN920 0x1060 composition + +0x1060: tty, adb, rmnet, tty, tty, tty, tty + +Signed-off-by: Carlo Lobrano +Signed-off-by: David S. Miller +Cc: Fabio Porcedda +Signed-off-by: Greg Kroah-Hartman +--- + drivers/net/usb/qmi_wwan.c | 1 + + 1 file changed, 1 insertion(+) + +--- a/drivers/net/usb/qmi_wwan.c ++++ b/drivers/net/usb/qmi_wwan.c +@@ -1318,6 +1318,7 @@ static const struct usb_device_id produc + {QMI_QUIRK_SET_DTR(0x1bc7, 0x1031, 3)}, /* Telit LE910C1-EUX */ + {QMI_QUIRK_SET_DTR(0x1bc7, 0x1040, 2)}, /* Telit LE922A */ + {QMI_QUIRK_SET_DTR(0x1bc7, 0x1050, 2)}, /* Telit FN980 */ ++ {QMI_QUIRK_SET_DTR(0x1bc7, 0x1060, 2)}, /* Telit LN920 */ + {QMI_FIXED_INTF(0x1bc7, 0x1100, 3)}, /* Telit ME910 */ + {QMI_FIXED_INTF(0x1bc7, 0x1101, 3)}, /* Telit ME910 dual modem */ + {QMI_FIXED_INTF(0x1bc7, 0x1200, 5)}, /* Telit LE920 */ diff --git a/queue-4.19/net-usb-qmi_wwan-add-telit-0x1070-composition.patch b/queue-4.19/net-usb-qmi_wwan-add-telit-0x1070-composition.patch new file mode 100644 index 00000000000..c128762631f --- /dev/null +++ b/queue-4.19/net-usb-qmi_wwan-add-telit-0x1070-composition.patch @@ -0,0 +1,36 @@ +From 94f2a444f28a649926c410eb9a38afb13a83ebe0 Mon Sep 17 00:00:00 2001 +From: Daniele Palmas +Date: Fri, 10 Dec 2021 10:57:22 +0100 +Subject: net: usb: qmi_wwan: add Telit 0x1070 composition +MIME-Version: 1.0 +Content-Type: text/plain; charset=UTF-8 +Content-Transfer-Encoding: 8bit + +From: Daniele Palmas + +commit 94f2a444f28a649926c410eb9a38afb13a83ebe0 upstream. + +Add the following Telit FN990 composition: + +0x1070: tty, adb, rmnet, tty, tty, tty, tty + +Signed-off-by: Daniele Palmas +Acked-by: Bjørn Mork +Link: https://lore.kernel.org/r/20211210095722.22269-1-dnlplm@gmail.com +Signed-off-by: Jakub Kicinski +Cc: Fabio Porcedda +Signed-off-by: Greg Kroah-Hartman +--- + drivers/net/usb/qmi_wwan.c | 1 + + 1 file changed, 1 insertion(+) + +--- a/drivers/net/usb/qmi_wwan.c ++++ b/drivers/net/usb/qmi_wwan.c +@@ -1319,6 +1319,7 @@ static const struct usb_device_id produc + {QMI_QUIRK_SET_DTR(0x1bc7, 0x1040, 2)}, /* Telit LE922A */ + {QMI_QUIRK_SET_DTR(0x1bc7, 0x1050, 2)}, /* Telit FN980 */ + {QMI_QUIRK_SET_DTR(0x1bc7, 0x1060, 2)}, /* Telit LN920 */ ++ {QMI_QUIRK_SET_DTR(0x1bc7, 0x1070, 2)}, /* Telit FN990 */ + {QMI_FIXED_INTF(0x1bc7, 0x1100, 3)}, /* Telit ME910 */ + {QMI_FIXED_INTF(0x1bc7, 0x1101, 3)}, /* Telit ME910 dual modem */ + {QMI_FIXED_INTF(0x1bc7, 0x1200, 5)}, /* Telit LE920 */ diff --git a/queue-4.19/series b/queue-4.19/series index 9e8d24894fb..1c9cc3fa209 100644 --- a/queue-4.19/series +++ b/queue-4.19/series @@ -24,3 +24,10 @@ hwmon-ibmaem-don-t-call-platform_device_del-if-platf.patch net-dsa-bcm_sf2-force-pause-link-settings.patch sit-use-min.patch ipv6-sit-fix-ipip6_tunnel_get_prl-return-value.patch +xen-blkfront-fix-leaking-data-in-shared-pages.patch +xen-netfront-fix-leaking-data-in-shared-pages.patch +xen-netfront-force-data-bouncing-when-backend-is-untrusted.patch +xen-blkfront-force-data-bouncing-when-backend-is-untrusted.patch +xen-arm-fix-race-in-rb-tree-based-p2m-accounting.patch +net-usb-qmi_wwan-add-telit-0x1060-composition.patch +net-usb-qmi_wwan-add-telit-0x1070-composition.patch diff --git a/queue-4.19/xen-arm-fix-race-in-rb-tree-based-p2m-accounting.patch b/queue-4.19/xen-arm-fix-race-in-rb-tree-based-p2m-accounting.patch new file mode 100644 index 00000000000..fdd808837fb --- /dev/null +++ b/queue-4.19/xen-arm-fix-race-in-rb-tree-based-p2m-accounting.patch @@ -0,0 +1,72 @@ +From foo@baz Tue Jul 5 01:04:37 PM CEST 2022 +From: Oleksandr Tyshchenko +Date: Fri, 1 Jul 2022 09:57:42 +0200 +Subject: xen/arm: Fix race in RB-tree based P2M accounting + +From: Oleksandr Tyshchenko + +commit b75cd218274e01d026dc5240e86fdeb44bbed0c8 upstream. + +During the PV driver life cycle the mappings are added to +the RB-tree by set_foreign_p2m_mapping(), which is called from +gnttab_map_refs() and are removed by clear_foreign_p2m_mapping() +which is called from gnttab_unmap_refs(). As both functions end +up calling __set_phys_to_machine_multi() which updates the RB-tree, +this function can be called concurrently. + +There is already a "p2m_lock" to protect against concurrent accesses, +but the problem is that the first read of "phys_to_mach.rb_node" +in __set_phys_to_machine_multi() is not covered by it, so this might +lead to the incorrect mappings update (removing in our case) in RB-tree. + +In my environment the related issue happens rarely and only when +PV net backend is running, the xen_add_phys_to_mach_entry() claims +that it cannot add new pfn <-> mfn mapping to the tree since it is +already exists which results in a failure when mapping foreign pages. + +But there might be other bad consequences related to the non-protected +root reads such use-after-free, etc. + +While at it, also fix the similar usage in __pfn_to_mfn(), so +initialize "struct rb_node *n" with the "p2m_lock" held in both +functions to avoid possible bad consequences. + +This is CVE-2022-33744 / XSA-406. + +Signed-off-by: Oleksandr Tyshchenko +Reviewed-by: Stefano Stabellini +Signed-off-by: Juergen Gross +Signed-off-by: Greg Kroah-Hartman +--- + arch/arm/xen/p2m.c | 6 ++++-- + 1 file changed, 4 insertions(+), 2 deletions(-) + +--- a/arch/arm/xen/p2m.c ++++ b/arch/arm/xen/p2m.c +@@ -61,11 +61,12 @@ out: + + unsigned long __pfn_to_mfn(unsigned long pfn) + { +- struct rb_node *n = phys_to_mach.rb_node; ++ struct rb_node *n; + struct xen_p2m_entry *entry; + unsigned long irqflags; + + read_lock_irqsave(&p2m_lock, irqflags); ++ n = phys_to_mach.rb_node; + while (n) { + entry = rb_entry(n, struct xen_p2m_entry, rbnode_phys); + if (entry->pfn <= pfn && +@@ -151,10 +152,11 @@ bool __set_phys_to_machine_multi(unsigne + int rc; + unsigned long irqflags; + struct xen_p2m_entry *p2m_entry; +- struct rb_node *n = phys_to_mach.rb_node; ++ struct rb_node *n; + + if (mfn == INVALID_P2M_ENTRY) { + write_lock_irqsave(&p2m_lock, irqflags); ++ n = phys_to_mach.rb_node; + while (n) { + p2m_entry = rb_entry(n, struct xen_p2m_entry, rbnode_phys); + if (p2m_entry->pfn <= pfn && diff --git a/queue-4.19/xen-blkfront-fix-leaking-data-in-shared-pages.patch b/queue-4.19/xen-blkfront-fix-leaking-data-in-shared-pages.patch new file mode 100644 index 00000000000..9c96e6cdc4b --- /dev/null +++ b/queue-4.19/xen-blkfront-fix-leaking-data-in-shared-pages.patch @@ -0,0 +1,54 @@ +From foo@baz Tue Jul 5 01:04:37 PM CEST 2022 +From: Roger Pau Monne +Date: Wed, 30 Mar 2022 09:03:48 +0200 +Subject: xen/blkfront: fix leaking data in shared pages + +From: Roger Pau Monne + +commit 2f446ffe9d737e9a844b97887919c4fda18246e7 upstream. + +When allocating pages to be used for shared communication with the +backend always zero them, this avoids leaking unintended data present +on the pages. + +This is CVE-2022-26365, part of XSA-403. + +Signed-off-by: Roger Pau Monné +Reviewed-by: Jan Beulich +Reviewed-by: Juergen Gross +Signed-off-by: Juergen Gross +Signed-off-by: Greg Kroah-Hartman +--- + drivers/block/xen-blkfront.c | 7 ++++--- + 1 file changed, 4 insertions(+), 3 deletions(-) + +--- a/drivers/block/xen-blkfront.c ++++ b/drivers/block/xen-blkfront.c +@@ -301,7 +301,7 @@ static int fill_grant_buffer(struct blkf + goto out_of_memory; + + if (info->feature_persistent) { +- granted_page = alloc_page(GFP_NOIO); ++ granted_page = alloc_page(GFP_NOIO | __GFP_ZERO); + if (!granted_page) { + kfree(gnt_list_entry); + goto out_of_memory; +@@ -1744,7 +1744,7 @@ static int setup_blkring(struct xenbus_d + for (i = 0; i < info->nr_ring_pages; i++) + rinfo->ring_ref[i] = GRANT_INVALID_REF; + +- sring = alloc_pages_exact(ring_size, GFP_NOIO); ++ sring = alloc_pages_exact(ring_size, GFP_NOIO | __GFP_ZERO); + if (!sring) { + xenbus_dev_fatal(dev, -ENOMEM, "allocating shared ring"); + return -ENOMEM; +@@ -2283,7 +2283,8 @@ static int blkfront_setup_indirect(struc + + BUG_ON(!list_empty(&rinfo->indirect_pages)); + for (i = 0; i < num; i++) { +- struct page *indirect_page = alloc_page(GFP_KERNEL); ++ struct page *indirect_page = alloc_page(GFP_KERNEL | ++ __GFP_ZERO); + if (!indirect_page) + goto out_of_memory; + list_add(&indirect_page->lru, &rinfo->indirect_pages); diff --git a/queue-4.19/xen-blkfront-force-data-bouncing-when-backend-is-untrusted.patch b/queue-4.19/xen-blkfront-force-data-bouncing-when-backend-is-untrusted.patch new file mode 100644 index 00000000000..d26bbc40db5 --- /dev/null +++ b/queue-4.19/xen-blkfront-force-data-bouncing-when-backend-is-untrusted.patch @@ -0,0 +1,203 @@ +From foo@baz Tue Jul 5 01:04:37 PM CEST 2022 +From: Roger Pau Monne +Date: Thu, 7 Apr 2022 13:04:24 +0200 +Subject: xen/blkfront: force data bouncing when backend is untrusted + +From: Roger Pau Monne + +commit 2400617da7eebf9167d71a46122828bc479d64c9 upstream. + +Split the current bounce buffering logic used with persistent grants +into it's own option, and allow enabling it independently of +persistent grants. This allows to reuse the same code paths to +perform the bounce buffering required to avoid leaking contiguous data +in shared pages not part of the request fragments. + +Reporting whether the backend is to be trusted can be done using a +module parameter, or from the xenstore frontend path as set by the +toolstack when adding the device. + +This is CVE-2022-33742, part of XSA-403. + +Signed-off-by: Roger Pau Monné +Reviewed-by: Juergen Gross +Signed-off-by: Juergen Gross +Signed-off-by: Greg Kroah-Hartman +--- + drivers/block/xen-blkfront.c | 49 +++++++++++++++++++++++++++++-------------- + 1 file changed, 34 insertions(+), 15 deletions(-) + +--- a/drivers/block/xen-blkfront.c ++++ b/drivers/block/xen-blkfront.c +@@ -151,6 +151,10 @@ static unsigned int xen_blkif_max_ring_o + module_param_named(max_ring_page_order, xen_blkif_max_ring_order, int, 0444); + MODULE_PARM_DESC(max_ring_page_order, "Maximum order of pages to be used for the shared ring"); + ++static bool __read_mostly xen_blkif_trusted = true; ++module_param_named(trusted, xen_blkif_trusted, bool, 0644); ++MODULE_PARM_DESC(trusted, "Is the backend trusted"); ++ + #define BLK_RING_SIZE(info) \ + __CONST_RING_SIZE(blkif, XEN_PAGE_SIZE * (info)->nr_ring_pages) + +@@ -211,6 +215,7 @@ struct blkfront_info + unsigned int feature_discard:1; + unsigned int feature_secdiscard:1; + unsigned int feature_persistent:1; ++ unsigned int bounce:1; + unsigned int discard_granularity; + unsigned int discard_alignment; + /* Number of 4KB segments handled */ +@@ -300,7 +305,7 @@ static int fill_grant_buffer(struct blkf + if (!gnt_list_entry) + goto out_of_memory; + +- if (info->feature_persistent) { ++ if (info->bounce) { + granted_page = alloc_page(GFP_NOIO | __GFP_ZERO); + if (!granted_page) { + kfree(gnt_list_entry); +@@ -320,7 +325,7 @@ out_of_memory: + list_for_each_entry_safe(gnt_list_entry, n, + &rinfo->grants, node) { + list_del(&gnt_list_entry->node); +- if (info->feature_persistent) ++ if (info->bounce) + __free_page(gnt_list_entry->page); + kfree(gnt_list_entry); + i--; +@@ -366,7 +371,7 @@ static struct grant *get_grant(grant_ref + /* Assign a gref to this page */ + gnt_list_entry->gref = gnttab_claim_grant_reference(gref_head); + BUG_ON(gnt_list_entry->gref == -ENOSPC); +- if (info->feature_persistent) ++ if (info->bounce) + grant_foreign_access(gnt_list_entry, info); + else { + /* Grant access to the GFN passed by the caller */ +@@ -390,7 +395,7 @@ static struct grant *get_indirect_grant( + /* Assign a gref to this page */ + gnt_list_entry->gref = gnttab_claim_grant_reference(gref_head); + BUG_ON(gnt_list_entry->gref == -ENOSPC); +- if (!info->feature_persistent) { ++ if (!info->bounce) { + struct page *indirect_page; + + /* Fetch a pre-allocated page to use for indirect grefs */ +@@ -705,7 +710,7 @@ static int blkif_queue_rw_req(struct req + .grant_idx = 0, + .segments = NULL, + .rinfo = rinfo, +- .need_copy = rq_data_dir(req) && info->feature_persistent, ++ .need_copy = rq_data_dir(req) && info->bounce, + }; + + /* +@@ -1026,11 +1031,12 @@ static void xlvbd_flush(struct blkfront_ + { + blk_queue_write_cache(info->rq, info->feature_flush ? true : false, + info->feature_fua ? true : false); +- pr_info("blkfront: %s: %s %s %s %s %s\n", ++ pr_info("blkfront: %s: %s %s %s %s %s %s %s\n", + info->gd->disk_name, flush_info(info), + "persistent grants:", info->feature_persistent ? + "enabled;" : "disabled;", "indirect descriptors:", +- info->max_indirect_segments ? "enabled;" : "disabled;"); ++ info->max_indirect_segments ? "enabled;" : "disabled;", ++ "bounce buffer:", info->bounce ? "enabled" : "disabled;"); + } + + static int xen_translate_vdev(int vdevice, int *minor, unsigned int *offset) +@@ -1265,7 +1271,7 @@ static void blkif_free_ring(struct blkfr + if (!list_empty(&rinfo->indirect_pages)) { + struct page *indirect_page, *n; + +- BUG_ON(info->feature_persistent); ++ BUG_ON(info->bounce); + list_for_each_entry_safe(indirect_page, n, &rinfo->indirect_pages, lru) { + list_del(&indirect_page->lru); + __free_page(indirect_page); +@@ -1282,7 +1288,7 @@ static void blkif_free_ring(struct blkfr + 0, 0UL); + rinfo->persistent_gnts_c--; + } +- if (info->feature_persistent) ++ if (info->bounce) + __free_page(persistent_gnt->page); + kfree(persistent_gnt); + } +@@ -1303,7 +1309,7 @@ static void blkif_free_ring(struct blkfr + for (j = 0; j < segs; j++) { + persistent_gnt = rinfo->shadow[i].grants_used[j]; + gnttab_end_foreign_access(persistent_gnt->gref, 0, 0UL); +- if (info->feature_persistent) ++ if (info->bounce) + __free_page(persistent_gnt->page); + kfree(persistent_gnt); + } +@@ -1493,7 +1499,7 @@ static int blkif_completion(unsigned lon + data.s = s; + num_sg = s->num_sg; + +- if (bret->operation == BLKIF_OP_READ && info->feature_persistent) { ++ if (bret->operation == BLKIF_OP_READ && info->bounce) { + for_each_sg(s->sg, sg, num_sg, i) { + BUG_ON(sg->offset + sg->length > PAGE_SIZE); + +@@ -1552,7 +1558,7 @@ static int blkif_completion(unsigned lon + * Add the used indirect page back to the list of + * available pages for indirect grefs. + */ +- if (!info->feature_persistent) { ++ if (!info->bounce) { + indirect_page = s->indirect_grants[i]->page; + list_add(&indirect_page->lru, &rinfo->indirect_pages); + } +@@ -1847,6 +1853,10 @@ static int talk_to_blkback(struct xenbus + if (!info) + return -ENODEV; + ++ /* Check if backend is trusted. */ ++ info->bounce = !xen_blkif_trusted || ++ !xenbus_read_unsigned(dev->nodename, "trusted", 1); ++ + max_page_order = xenbus_read_unsigned(info->xbdev->otherend, + "max-ring-page-order", 0); + ring_page_order = min(xen_blkif_max_ring_order, max_page_order); +@@ -2273,10 +2283,10 @@ static int blkfront_setup_indirect(struc + if (err) + goto out_of_memory; + +- if (!info->feature_persistent && info->max_indirect_segments) { ++ if (!info->bounce && info->max_indirect_segments) { + /* +- * We are using indirect descriptors but not persistent +- * grants, we need to allocate a set of pages that can be ++ * We are using indirect descriptors but don't have a bounce ++ * buffer, we need to allocate a set of pages that can be + * used for mapping indirect grefs + */ + int num = INDIRECT_GREFS(grants) * BLK_RING_SIZE(info); +@@ -2376,6 +2386,8 @@ static void blkfront_gather_backend_feat + info->feature_persistent = + !!xenbus_read_unsigned(info->xbdev->otherend, + "feature-persistent", 0); ++ if (info->feature_persistent) ++ info->bounce = true; + + indirect_segments = xenbus_read_unsigned(info->xbdev->otherend, + "feature-max-indirect-segments", 0); +@@ -2751,6 +2763,13 @@ static void blkfront_delay_work(struct w + struct blkfront_info *info; + bool need_schedule_work = false; + ++ /* ++ * Note that when using bounce buffers but not persistent grants ++ * there's no need to run blkfront_delay_work because grants are ++ * revoked in blkif_completion or else an error is reported and the ++ * connection is closed. ++ */ ++ + mutex_lock(&blkfront_mutex); + + list_for_each_entry(info, &info_list, info_list) { diff --git a/queue-4.19/xen-netfront-fix-leaking-data-in-shared-pages.patch b/queue-4.19/xen-netfront-fix-leaking-data-in-shared-pages.patch new file mode 100644 index 00000000000..cdc5458f206 --- /dev/null +++ b/queue-4.19/xen-netfront-fix-leaking-data-in-shared-pages.patch @@ -0,0 +1,35 @@ +From foo@baz Tue Jul 5 01:04:37 PM CEST 2022 +From: Roger Pau Monne +Date: Wed, 6 Apr 2022 17:38:04 +0200 +Subject: xen/netfront: fix leaking data in shared pages + +From: Roger Pau Monne + +commit 307c8de2b02344805ebead3440d8feed28f2f010 upstream. + +When allocating pages to be used for shared communication with the +backend always zero them, this avoids leaking unintended data present +on the pages. + +This is CVE-2022-33740, part of XSA-403. + +Signed-off-by: Roger Pau Monné +Reviewed-by: Jan Beulich +Reviewed-by: Juergen Gross +Signed-off-by: Juergen Gross +Signed-off-by: Greg Kroah-Hartman +--- + drivers/net/xen-netfront.c | 2 +- + 1 file changed, 1 insertion(+), 1 deletion(-) + +--- a/drivers/net/xen-netfront.c ++++ b/drivers/net/xen-netfront.c +@@ -261,7 +261,7 @@ static struct sk_buff *xennet_alloc_one_ + if (unlikely(!skb)) + return NULL; + +- page = alloc_page(GFP_ATOMIC | __GFP_NOWARN); ++ page = alloc_page(GFP_ATOMIC | __GFP_NOWARN | __GFP_ZERO); + if (!page) { + kfree_skb(skb); + return NULL; diff --git a/queue-4.19/xen-netfront-force-data-bouncing-when-backend-is-untrusted.patch b/queue-4.19/xen-netfront-force-data-bouncing-when-backend-is-untrusted.patch new file mode 100644 index 00000000000..bd3497e318f --- /dev/null +++ b/queue-4.19/xen-netfront-force-data-bouncing-when-backend-is-untrusted.patch @@ -0,0 +1,125 @@ +From foo@baz Tue Jul 5 01:04:37 PM CEST 2022 +From: Roger Pau Monne +Date: Thu, 7 Apr 2022 12:20:06 +0200 +Subject: xen/netfront: force data bouncing when backend is untrusted + +From: Roger Pau Monne + +commit 4491001c2e0fa69efbb748c96ec96b100a5cdb7e upstream. + +Bounce all data on the skbs to be transmitted into zeroed pages if the +backend is untrusted. This avoids leaking data present in the pages +shared with the backend but not part of the skb fragments. This +requires introducing a new helper in order to allocate skbs with a +size multiple of XEN_PAGE_SIZE so we don't leak contiguous data on the +granted pages. + +Reporting whether the backend is to be trusted can be done using a +module parameter, or from the xenstore frontend path as set by the +toolstack when adding the device. + +This is CVE-2022-33741, part of XSA-403. + +Signed-off-by: Roger Pau Monné +Reviewed-by: Juergen Gross +Signed-off-by: Juergen Gross +Signed-off-by: Greg Kroah-Hartman +--- + drivers/net/xen-netfront.c | 50 +++++++++++++++++++++++++++++++++++++++++++-- + 1 file changed, 48 insertions(+), 2 deletions(-) + +--- a/drivers/net/xen-netfront.c ++++ b/drivers/net/xen-netfront.c +@@ -63,6 +63,10 @@ module_param_named(max_queues, xennet_ma + MODULE_PARM_DESC(max_queues, + "Maximum number of queues per virtual interface"); + ++static bool __read_mostly xennet_trusted = true; ++module_param_named(trusted, xennet_trusted, bool, 0644); ++MODULE_PARM_DESC(trusted, "Is the backend trusted"); ++ + #define XENNET_TIMEOUT (5 * HZ) + + static const struct ethtool_ops xennet_ethtool_ops; +@@ -163,6 +167,9 @@ struct netfront_info { + /* Is device behaving sane? */ + bool broken; + ++ /* Should skbs be bounced into a zeroed buffer? */ ++ bool bounce; ++ + atomic_t rx_gso_checksum_fixup; + }; + +@@ -593,6 +600,34 @@ static void xennet_mark_tx_pending(struc + queue->tx_link[i] = TX_PENDING; + } + ++struct sk_buff *bounce_skb(const struct sk_buff *skb) ++{ ++ unsigned int headerlen = skb_headroom(skb); ++ /* Align size to allocate full pages and avoid contiguous data leaks */ ++ unsigned int size = ALIGN(skb_end_offset(skb) + skb->data_len, ++ XEN_PAGE_SIZE); ++ struct sk_buff *n = alloc_skb(size, GFP_ATOMIC | __GFP_ZERO); ++ ++ if (!n) ++ return NULL; ++ ++ if (!IS_ALIGNED((uintptr_t)n->head, XEN_PAGE_SIZE)) { ++ WARN_ONCE(1, "misaligned skb allocated\n"); ++ kfree_skb(n); ++ return NULL; ++ } ++ ++ /* Set the data pointer */ ++ skb_reserve(n, headerlen); ++ /* Set the tail pointer and length */ ++ skb_put(n, skb->len); ++ ++ BUG_ON(skb_copy_bits(skb, -headerlen, n->head, headerlen + skb->len)); ++ ++ skb_copy_header(n, skb); ++ return n; ++} ++ + #define MAX_XEN_SKB_FRAGS (65536 / XEN_PAGE_SIZE + 1) + + static netdev_tx_t xennet_start_xmit(struct sk_buff *skb, struct net_device *dev) +@@ -645,9 +680,13 @@ static netdev_tx_t xennet_start_xmit(str + + /* The first req should be at least ETH_HLEN size or the packet will be + * dropped by netback. ++ * ++ * If the backend is not trusted bounce all data to zeroed pages to ++ * avoid exposing contiguous data on the granted page not belonging to ++ * the skb. + */ +- if (unlikely(PAGE_SIZE - offset < ETH_HLEN)) { +- nskb = skb_copy(skb, GFP_ATOMIC); ++ if (np->bounce || unlikely(PAGE_SIZE - offset < ETH_HLEN)) { ++ nskb = bounce_skb(skb); + if (!nskb) + goto drop; + dev_consume_skb_any(skb); +@@ -1953,6 +1992,10 @@ static int talk_to_netback(struct xenbus + + info->netdev->irq = 0; + ++ /* Check if backend is trusted. */ ++ info->bounce = !xennet_trusted || ++ !xenbus_read_unsigned(dev->nodename, "trusted", 1); ++ + /* Check if backend supports multiple queues */ + max_queues = xenbus_read_unsigned(info->xbdev->otherend, + "multi-queue-max-queues", 1); +@@ -2106,6 +2149,9 @@ static int xennet_connect(struct net_dev + err = talk_to_netback(np->xbdev, np); + if (err) + return err; ++ if (np->bounce) ++ dev_info(&np->xbdev->dev, ++ "bouncing transmitted data to zeroed pages\n"); + + /* talk_to_netback() sets the correct number of queues */ + num_queues = dev->real_num_tx_queues; -- 2.47.3