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authorLinus Torvalds <torvalds@linux-foundation.org>2021-02-21 13:06:08 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2021-02-21 13:06:08 -0800
commit4a037ad5d115b2cc79a5071a7854475f365476fa (patch)
treee456c2eee7b3de32e34612370ce9120af4525ddc
parentd310ec03a34e92a77302edb804f7d68ee4f01ba0 (diff)
parent871997bc9e423f05c7da7c9178e62dde5df2a7f8 (diff)
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Merge tag 'for-linus-5.12-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip
Pull xen updates from Juergen Gross: "A series of Xen related security fixes, all related to limited error handling in Xen backend drivers" * tag 'for-linus-5.12-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: xen-blkback: fix error handling in xen_blkbk_map() xen-scsiback: don't "handle" error by BUG() xen-netback: don't "handle" error by BUG() xen-blkback: don't "handle" error by BUG() xen/arm: don't ignore return errors from set_phys_to_machine Xen/gntdev: correct error checking in gntdev_map_grant_pages() Xen/gntdev: correct dev_bus_addr handling in gntdev_map_grant_pages() Xen/x86: also check kernel mapping in set_foreign_p2m_mapping() Xen/x86: don't bail early from clear_foreign_p2m_mapping()
-rw-r--r--arch/arm/xen/p2m.c6
-rw-r--r--arch/x86/xen/p2m.c15
-rw-r--r--drivers/block/xen-blkback/blkback.c32
-rw-r--r--drivers/net/xen-netback/netback.c4
-rw-r--r--drivers/xen/gntdev.c37
-rw-r--r--drivers/xen/xen-scsiback.c4
-rw-r--r--include/xen/grant_table.h1
7 files changed, 53 insertions, 46 deletions
diff --git a/arch/arm/xen/p2m.c b/arch/arm/xen/p2m.c
index e52950a43f2e..fd6e3aafe272 100644
--- a/arch/arm/xen/p2m.c
+++ b/arch/arm/xen/p2m.c
@@ -95,8 +95,10 @@ int set_foreign_p2m_mapping(struct gnttab_map_grant_ref *map_ops,
for (i = 0; i < count; i++) {
if (map_ops[i].status)
continue;
- set_phys_to_machine(map_ops[i].host_addr >> XEN_PAGE_SHIFT,
- map_ops[i].dev_bus_addr >> XEN_PAGE_SHIFT);
+ if (unlikely(!set_phys_to_machine(map_ops[i].host_addr >> XEN_PAGE_SHIFT,
+ map_ops[i].dev_bus_addr >> XEN_PAGE_SHIFT))) {
+ return -ENOMEM;
+ }
}
return 0;
diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c
index 3301875dd196..b5949e5a83ec 100644
--- a/arch/x86/xen/p2m.c
+++ b/arch/x86/xen/p2m.c
@@ -712,7 +712,8 @@ int set_foreign_p2m_mapping(struct gnttab_map_grant_ref *map_ops,
unsigned long mfn, pfn;
/* Do not add to override if the map failed. */
- if (map_ops[i].status)
+ if (map_ops[i].status != GNTST_okay ||
+ (kmap_ops && kmap_ops[i].status != GNTST_okay))
continue;
if (map_ops[i].flags & GNTMAP_contains_pte) {
@@ -750,17 +751,15 @@ int clear_foreign_p2m_mapping(struct gnttab_unmap_grant_ref *unmap_ops,
unsigned long mfn = __pfn_to_mfn(page_to_pfn(pages[i]));
unsigned long pfn = page_to_pfn(pages[i]);
- if (mfn == INVALID_P2M_ENTRY || !(mfn & FOREIGN_FRAME_BIT)) {
+ if (mfn != INVALID_P2M_ENTRY && (mfn & FOREIGN_FRAME_BIT))
+ set_phys_to_machine(pfn, INVALID_P2M_ENTRY);
+ else
ret = -EINVAL;
- goto out;
- }
-
- set_phys_to_machine(pfn, INVALID_P2M_ENTRY);
}
if (kunmap_ops)
ret = HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref,
- kunmap_ops, count);
-out:
+ kunmap_ops, count) ?: ret;
+
return ret;
}
EXPORT_SYMBOL_GPL(clear_foreign_p2m_mapping);
diff --git a/drivers/block/xen-blkback/blkback.c b/drivers/block/xen-blkback/blkback.c
index 9ebf53903d7b..da16121140ca 100644
--- a/drivers/block/xen-blkback/blkback.c
+++ b/drivers/block/xen-blkback/blkback.c
@@ -794,8 +794,13 @@ again:
pages[i]->persistent_gnt = persistent_gnt;
} else {
if (gnttab_page_cache_get(&ring->free_pages,
- &pages[i]->page))
- goto out_of_memory;
+ &pages[i]->page)) {
+ gnttab_page_cache_put(&ring->free_pages,
+ pages_to_gnt,
+ segs_to_map);
+ ret = -ENOMEM;
+ goto out;
+ }
addr = vaddr(pages[i]->page);
pages_to_gnt[segs_to_map] = pages[i]->page;
pages[i]->persistent_gnt = NULL;
@@ -811,10 +816,8 @@ again:
break;
}
- if (segs_to_map) {
+ if (segs_to_map)
ret = gnttab_map_refs(map, NULL, pages_to_gnt, segs_to_map);
- BUG_ON(ret);
- }
/*
* Now swizzle the MFN in our domain with the MFN from the other domain
@@ -830,7 +833,7 @@ again:
gnttab_page_cache_put(&ring->free_pages,
&pages[seg_idx]->page, 1);
pages[seg_idx]->handle = BLKBACK_INVALID_HANDLE;
- ret |= 1;
+ ret |= !ret;
goto next;
}
pages[seg_idx]->handle = map[new_map_idx].handle;
@@ -882,17 +885,18 @@ next:
}
segs_to_map = 0;
last_map = map_until;
- if (map_until != num)
+ if (!ret && map_until != num)
goto again;
- return ret;
-
-out_of_memory:
- pr_alert("%s: out of memory\n", __func__);
- gnttab_page_cache_put(&ring->free_pages, pages_to_gnt, segs_to_map);
- for (i = last_map; i < num; i++)
+out:
+ for (i = last_map; i < num; i++) {
+ /* Don't zap current batch's valid persistent grants. */
+ if(i >= last_map + segs_to_map)
+ pages[i]->persistent_gnt = NULL;
pages[i]->handle = BLKBACK_INVALID_HANDLE;
- return -ENOMEM;
+ }
+
+ return ret;
}
static int xen_blkbk_map_seg(struct pending_req *pending_req)
diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c
index 19a27dce79d2..e5c73f819662 100644
--- a/drivers/net/xen-netback/netback.c
+++ b/drivers/net/xen-netback/netback.c
@@ -1343,13 +1343,11 @@ int xenvif_tx_action(struct xenvif_queue *queue, int budget)
return 0;
gnttab_batch_copy(queue->tx_copy_ops, nr_cops);
- if (nr_mops != 0) {
+ if (nr_mops != 0)
ret = gnttab_map_refs(queue->tx_map_ops,
NULL,
queue->pages_to_map,
nr_mops);
- BUG_ON(ret);
- }
work_done = xenvif_tx_submit(queue);
diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c
index a36b71286bcf..5447c5156b2e 100644
--- a/drivers/xen/gntdev.c
+++ b/drivers/xen/gntdev.c
@@ -309,44 +309,47 @@ int gntdev_map_grant_pages(struct gntdev_grant_map *map)
* to the kernel linear addresses of the struct pages.
* These ptes are completely different from the user ptes dealt
* with find_grant_ptes.
+ * Note that GNTMAP_device_map isn't needed here: The
+ * dev_bus_addr output field gets consumed only from ->map_ops,
+ * and by not requesting it when mapping we also avoid needing
+ * to mirror dev_bus_addr into ->unmap_ops (and holding an extra
+ * reference to the page in the hypervisor).
*/
+ unsigned int flags = (map->flags & ~GNTMAP_device_map) |
+ GNTMAP_host_map;
+
for (i = 0; i < map->count; i++) {
unsigned long address = (unsigned long)
pfn_to_kaddr(page_to_pfn(map->pages[i]));
BUG_ON(PageHighMem(map->pages[i]));
- gnttab_set_map_op(&map->kmap_ops[i], address,
- map->flags | GNTMAP_host_map,
+ gnttab_set_map_op(&map->kmap_ops[i], address, flags,
map->grants[i].ref,
map->grants[i].domid);
gnttab_set_unmap_op(&map->kunmap_ops[i], address,
- map->flags | GNTMAP_host_map, -1);
+ flags, -1);
}
}
pr_debug("map %d+%d\n", map->index, map->count);
err = gnttab_map_refs(map->map_ops, use_ptemod ? map->kmap_ops : NULL,
map->pages, map->count);
- if (err)
- return err;
for (i = 0; i < map->count; i++) {
- if (map->map_ops[i].status) {
+ if (map->map_ops[i].status == GNTST_okay)
+ map->unmap_ops[i].handle = map->map_ops[i].handle;
+ else if (!err)
err = -EINVAL;
- continue;
- }
- map->unmap_ops[i].handle = map->map_ops[i].handle;
- if (use_ptemod)
- map->kunmap_ops[i].handle = map->kmap_ops[i].handle;
-#ifdef CONFIG_XEN_GRANT_DMA_ALLOC
- else if (map->dma_vaddr) {
- unsigned long bfn;
+ if (map->flags & GNTMAP_device_map)
+ map->unmap_ops[i].dev_bus_addr = map->map_ops[i].dev_bus_addr;
- bfn = pfn_to_bfn(page_to_pfn(map->pages[i]));
- map->unmap_ops[i].dev_bus_addr = __pfn_to_phys(bfn);
+ if (use_ptemod) {
+ if (map->kmap_ops[i].status == GNTST_okay)
+ map->kunmap_ops[i].handle = map->kmap_ops[i].handle;
+ else if (!err)
+ err = -EINVAL;
}
-#endif
}
return err;
}
diff --git a/drivers/xen/xen-scsiback.c b/drivers/xen/xen-scsiback.c
index 8b59897b2df9..f3024942fbdf 100644
--- a/drivers/xen/xen-scsiback.c
+++ b/drivers/xen/xen-scsiback.c
@@ -386,12 +386,12 @@ static int scsiback_gnttab_data_map_batch(struct gnttab_map_grant_ref *map,
return 0;
err = gnttab_map_refs(map, NULL, pg, cnt);
- BUG_ON(err);
for (i = 0; i < cnt; i++) {
if (unlikely(map[i].status != GNTST_okay)) {
pr_err("invalid buffer -- could not remap it\n");
map[i].handle = SCSIBACK_INVALID_HANDLE;
- err = -ENOMEM;
+ if (!err)
+ err = -ENOMEM;
} else {
get_page(pg[i]);
}
diff --git a/include/xen/grant_table.h b/include/xen/grant_table.h
index b9c937b3a149..0b1182a3cf41 100644
--- a/include/xen/grant_table.h
+++ b/include/xen/grant_table.h
@@ -157,6 +157,7 @@ gnttab_set_map_op(struct gnttab_map_grant_ref *map, phys_addr_t addr,
map->flags = flags;
map->ref = ref;
map->dom = domid;
+ map->status = 1; /* arbitrary positive value */
}
static inline void