[PATCH 5.16 113/121] x86/boot: Fix memremap of setup_indirect structures

Greg Kroah-Hartman
2022-03-14T12:33:48Z

From: Ross Philipson <ross.philipson@oracle.com>

commit 7228918b34615ef6317edcd9a058a057bc54aa32 upstream.

As documented, the setup_indirect structure is nested inside
the setup_data structures in the setup_data list. The code currently
accesses the fields inside the setup_indirect structure but only
the sizeof(struct setup_data) is being memremapped. No crash
occurred but this is just due to how the area is remapped under the
covers.

Properly memremap both the setup_data and setup_indirect structures
in these cases before accessing them.

Fixes: b3c72fc9a78e ("x86/boot: Introduce setup_indirect")
Signed-off-by: Ross Philipson <ross.philipson@oracle.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/1645668456-22036-2-git-send-email-ross.philipson@oracle.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/x86/kernel/e820.c | 41 +++++++++++++++++------
arch/x86/kernel/kdebugfs.c | 35 +++++++++++++++-----
arch/x86/kernel/ksysfs.c | 77 +++++++++++++++++++++++++++++++++++----------
arch/x86/kernel/setup.c | 34 +++++++++++++++----
arch/x86/mm/ioremap.c | 24 +++++++++++---
5 files changed, 165 insertions(+), 46 deletions(-)

--- a/arch/x86/kernel/e820.c
+++ b/arch/x86/kernel/e820.c
@@ -995,8 +995,10 @@ early_param("memmap", parse_memmap_opt);
*/
void __init e820__reserve_setup_data(void)
{
+ struct setup_indirect *indirect;
struct setup_data *data;
- u64 pa_data;
+ u64 pa_data, pa_next;
+ u32 len;

pa_data = boot_params.hdr.setup_data;
if (!pa_data)
@@ -1004,6 +1006,14 @@ void __init e820__reserve_setup_data(voi

while (pa_data) {
data = early_memremap(pa_data, sizeof(*data));
+ if (!data) {
+ pr_warn("e820: failed to memremap setup_data entry\n");
+ return;
+ }
+
+ len = sizeof(*data);
+ pa_next = data->next;
+
e820__range_update(pa_data, sizeof(*data)+data->len, E820_TYPE_RAM, E820_TYPE_RESERVED_KERN);

/*
@@ -1015,18 +1025,27 @@ void __init e820__reserve_setup_data(voi
sizeof(*data) + data->len,
E820_TYPE_RAM, E820_TYPE_RESERVED_KERN);

- if (data->type == SETUP_INDIRECT &&
- ((struct setup_indirect *)data->data)->type != SETUP_INDIRECT) {
- e820__range_update(((struct setup_indirect *)data->data)->addr,
- ((struct setup_indirect *)data->data)->len,
- E820_TYPE_RAM, E820_TYPE_RESERVED_KERN);
- e820__range_update_kexec(((struct setup_indirect *)data->data)->addr,
- ((struct setup_indirect *)data->data)->len,
- E820_TYPE_RAM, E820_TYPE_RESERVED_KERN);
+ if (data->type == SETUP_INDIRECT) {
+ len += data->len;
+ early_memunmap(data, sizeof(*data));
+ data = early_memremap(pa_data, len);
+ if (!data) {
+ pr_warn("e820: failed to memremap indirect setup_data\n");
+ return;
+ }
+
+ indirect = (struct setup_indirect *)data->data;
+
+ if (indirect->type != SETUP_INDIRECT) {
+ e820__range_update(indirect->addr, indirect->len,
+ E820_TYPE_RAM, E820_TYPE_RESERVED_KERN);
+ e820__range_update_kexec(indirect->addr, indirect->len,
+ E820_TYPE_RAM, E820_TYPE_RESERVED_KERN);
+ }
}

- pa_data = data->next;
- early_memunmap(data, sizeof(*data));
+ pa_data = pa_next;
+ early_memunmap(data, len);
}

e820__update_table(e820_table);
--- a/arch/x86/kernel/kdebugfs.c
+++ b/arch/x86/kernel/kdebugfs.c
@@ -88,11 +88,13 @@ create_setup_data_node(struct dentry *pa

static int __init create_setup_data_nodes(struct dentry *parent)
{
+ struct setup_indirect *indirect;
struct setup_data_node *node;
struct setup_data *data;
- int error;
+ u64 pa_data, pa_next;
struct dentry *d;
- u64 pa_data;
+ int error;
+ u32 len;
int no = 0;

d = debugfs_create_dir("setup_data", parent);
@@ -112,12 +114,29 @@ static int __init create_setup_data_node
error = -ENOMEM;
goto err_dir;
}
+ pa_next = data->next;

- if (data->type == SETUP_INDIRECT &&
- ((struct setup_indirect *)data->data)->type != SETUP_INDIRECT) {
- node->paddr = ((struct setup_indirect *)data->data)->addr;
- node->type = ((struct setup_indirect *)data->data)->type;
- node->len = ((struct setup_indirect *)data->data)->len;
+ if (data->type == SETUP_INDIRECT) {
+ len = sizeof(*data) + data->len;
+ memunmap(data);
+ data = memremap(pa_data, len, MEMREMAP_WB);
+ if (!data) {
+ kfree(node);
+ error = -ENOMEM;
+ goto err_dir;
+ }
+
+ indirect = (struct setup_indirect *)data->data;
+
+ if (indirect->type != SETUP_INDIRECT) {
+ node->paddr = indirect->addr;
+ node->type = indirect->type;
+ node->len = indirect->len;
+ } else {
+ node->paddr = pa_data;
+ node->type = data->type;
+ node->len = data->len;
+ }
} else {
node->paddr = pa_data;
node->type = data->type;
@@ -125,7 +144,7 @@ static int __init create_setup_data_node
}

create_setup_data_node(d, no, node);
- pa_data = data->next;
+ pa_data = pa_next;

memunmap(data);
no++;
--- a/arch/x86/kernel/ksysfs.c
+++ b/arch/x86/kernel/ksysfs.c
@@ -91,26 +91,41 @@ static int get_setup_data_paddr(int nr,

static int __init get_setup_data_size(int nr, size_t *size)
{
- int i = 0;
+ u64 pa_data = boot_params.hdr.setup_data, pa_next;
+ struct setup_indirect *indirect;
struct setup_data *data;
- u64 pa_data = boot_params.hdr.setup_data;
+ int i = 0;
+ u32 len;

while (pa_data) {
data = memremap(pa_data, sizeof(*data), MEMREMAP_WB);
if (!data)
return -ENOMEM;
+ pa_next = data->next;
+
if (nr == i) {
- if (data->type == SETUP_INDIRECT &&
- ((struct setup_indirect *)data->data)->type != SETUP_INDIRECT)
- *size = ((struct setup_indirect *)data->data)->len;
- else
+ if (data->type == SETUP_INDIRECT) {
+ len = sizeof(*data) + data->len;
+ memunmap(data);
+ data = memremap(pa_data, len, MEMREMAP_WB);
+ if (!data)
+ return -ENOMEM;
+
+ indirect = (struct setup_indirect *)data->data;
+
+ if (indirect->type != SETUP_INDIRECT)
+ *size = indirect->len;
+ else
+ *size = data->len;
+ } else {
*size = data->len;
+ }

memunmap(data);
return 0;
}

- pa_data = data->next;
+ pa_data = pa_next;
memunmap(data);
i++;
}
@@ -120,9 +135,11 @@ static int __init get_setup_data_size(in
static ssize_t type_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
+ struct setup_indirect *indirect;
+ struct setup_data *data;
int nr, ret;
u64 paddr;
- struct setup_data *data;
+ u32 len;

ret = kobj_to_setup_data_nr(kobj, &nr);
if (ret)
@@ -135,10 +152,20 @@ static ssize_t type_show(struct kobject
if (!data)
return -ENOMEM;

- if (data->type == SETUP_INDIRECT)
- ret = sprintf(buf, "0x%x\n", ((struct setup_indirect *)data->data)->type);
- else
+ if (data->type == SETUP_INDIRECT) {
+ len = sizeof(*data) + data->len;
+ memunmap(data);
+ data = memremap(paddr, len, MEMREMAP_WB);
+ if (!data)
+ return -ENOMEM;
+
+ indirect = (struct setup_indirect *)data->data;
+
+ ret = sprintf(buf, "0x%x\n", indirect->type);
+ } else {
ret = sprintf(buf, "0x%x\n", data->type);
+ }
+
memunmap(data);
return ret;
}
@@ -149,9 +176,10 @@ static ssize_t setup_data_data_read(stru
char *buf,
loff_t off, size_t count)
{
+ struct setup_indirect *indirect;
+ struct setup_data *data;
int nr, ret = 0;
u64 paddr, len;
- struct setup_data *data;
void *p;

ret = kobj_to_setup_data_nr(kobj, &nr);
@@ -165,10 +193,27 @@ static ssize_t setup_data_data_read(stru
if (!data)
return -ENOMEM;

- if (data->type == SETUP_INDIRECT &&
- ((struct setup_indirect *)data->data)->type != SETUP_INDIRECT) {
- paddr = ((struct setup_indirect *)data->data)->addr;
- len = ((struct setup_indirect *)data->data)->len;
+ if (data->type == SETUP_INDIRECT) {
+ len = sizeof(*data) + data->len;
+ memunmap(data);
+ data = memremap(paddr, len, MEMREMAP_WB);
+ if (!data)
+ return -ENOMEM;
+
+ indirect = (struct setup_indirect *)data->data;
+
+ if (indirect->type != SETUP_INDIRECT) {
+ paddr = indirect->addr;
+ len = indirect->len;
+ } else {
+ /*
+ * Even though this is technically undefined, return
+ * the data as though it is a normal setup_data struct.
+ * This will at least allow it to be inspected.
+ */
+ paddr += sizeof(*data);
+ len = data->len;
+ }
} else {
paddr += sizeof(*data);
len = data->len;
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -368,21 +368,41 @@ static void __init parse_setup_data(void

static void __init memblock_x86_reserve_range_setup_data(void)
{
+ struct setup_indirect *indirect;
struct setup_data *data;
- u64 pa_data;
+ u64 pa_data, pa_next;
+ u32 len;

pa_data = boot_params.hdr.setup_data;
while (pa_data) {
data = early_memremap(pa_data, sizeof(*data));
+ if (!data) {
+ pr_warn("setup: failed to memremap setup_data entry\n");
+ return;
+ }
+
+ len = sizeof(*data);
+ pa_next = data->next;
+
memblock_reserve(pa_data, sizeof(*data) + data->len);

- if (data->type == SETUP_INDIRECT &&
- ((struct setup_indirect *)data->data)->type != SETUP_INDIRECT)
- memblock_reserve(((struct setup_indirect *)data->data)->addr,
- ((struct setup_indirect *)data->data)->len);
+ if (data->type == SETUP_INDIRECT) {
+ len += data->len;
+ early_memunmap(data, sizeof(*data));
+ data = early_memremap(pa_data, len);
+ if (!data) {
+ pr_warn("setup: failed to memremap indirect setup_data\n");
+ return;
+ }
+
+ indirect = (struct setup_indirect *)data->data;
+
+ if (indirect->type != SETUP_INDIRECT)
+ memblock_reserve(indirect->addr, indirect->len);
+ }

- pa_data = data->next;
- early_memunmap(data, sizeof(*data));
+ pa_data = pa_next;
+ early_memunmap(data, len);
}
}

--- a/arch/x86/mm/ioremap.c
+++ b/arch/x86/mm/ioremap.c
@@ -615,6 +615,7 @@ static bool memremap_is_efi_data(resourc
static bool memremap_is_setup_data(resource_size_t phys_addr,
unsigned long size)
{
+ struct setup_indirect *indirect;
struct setup_data *data;
u64 paddr, paddr_next;

@@ -627,6 +628,10 @@ static bool memremap_is_setup_data(resou

data = memremap(paddr, sizeof(*data),
MEMREMAP_WB | MEMREMAP_DEC);
+ if (!data) {
+ pr_warn("failed to memremap setup_data entry\n");
+ return false;
+ }

paddr_next = data->next;
len = data->len;
@@ -636,10 +641,21 @@ static bool memremap_is_setup_data(resou
return true;
}

- if (data->type == SETUP_INDIRECT &&
- ((struct setup_indirect *)data->data)->type != SETUP_INDIRECT) {
- paddr = ((struct setup_indirect *)data->data)->addr;
- len = ((struct setup_indirect *)data->data)->len;
+ if (data->type == SETUP_INDIRECT) {
+ memunmap(data);
+ data = memremap(paddr, sizeof(*data) + len,
+ MEMREMAP_WB | MEMREMAP_DEC);
+ if (!data) {
+ pr_warn("failed to memremap indirect setup_data\n");
+ return false;
+ }
+
+ indirect = (struct setup_indirect *)data->data;
+
+ if (indirect->type != SETUP_INDIRECT) {
+ paddr = indirect->addr;
+ len = indirect->len;
+ }
}

memunmap(data);