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Message-Id: <1645668456-22036-2-git-send-email-ross.philipson@oracle.com>
Date: Wed, 23 Feb 2022 21:07:35 -0500
From: Ross Philipson <ross.philipson@...cle.com>
To: linux-kernel@...r.kernel.org, x86@...nel.org
Cc: ross.philipson@...cle.com, daniel.kiper@...cle.com,
dpsmith@...rtussolutions.com, tglx@...utronix.de, mingo@...hat.com,
bp@...en8.de, hpa@...or.com, luto@...capital.net,
dave.hansen@...ux.intel.com, kanth.ghatraju@...cle.com,
trenchboot-devel@...glegroups.com
Subject: [PATCH v2 1/2] x86/boot: Fix memremap of setup_indirect structures
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@...cle.com>
---
arch/x86/kernel/e820.c | 41 +++++++++++++++++-------
arch/x86/kernel/kdebugfs.c | 37 ++++++++++++++++------
arch/x86/kernel/ksysfs.c | 77 ++++++++++++++++++++++++++++++++++++----------
arch/x86/kernel/setup.c | 34 +++++++++++++++-----
arch/x86/mm/ioremap.c | 24 ++++++++++++---
5 files changed, 166 insertions(+), 47 deletions(-)
diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c
index bc0657f..f267205 100644
--- a/arch/x86/kernel/e820.c
+++ b/arch/x86/kernel/e820.c
@@ -995,8 +995,10 @@ static int __init parse_memmap_opt(char *str)
*/
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(void)
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(void)
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);
diff --git a/arch/x86/kernel/kdebugfs.c b/arch/x86/kernel/kdebugfs.c
index 64b6da9..e2e89be 100644
--- a/arch/x86/kernel/kdebugfs.c
+++ b/arch/x86/kernel/kdebugfs.c
@@ -88,11 +88,13 @@ static ssize_t setup_data_read(struct file *file, char __user *user_buf,
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_nodes(struct dentry *parent)
error = -ENOMEM;
goto err_dir;
}
-
- 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;
+ pa_next = data->next;
+
+ 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_nodes(struct dentry *parent)
}
create_setup_data_node(d, no, node);
- pa_data = data->next;
+ pa_data = pa_next;
memunmap(data);
no++;
diff --git a/arch/x86/kernel/ksysfs.c b/arch/x86/kernel/ksysfs.c
index d0a1912..257892f 100644
--- a/arch/x86/kernel/ksysfs.c
+++ b/arch/x86/kernel/ksysfs.c
@@ -91,26 +91,41 @@ static int get_setup_data_paddr(int nr, u64 *paddr)
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(int nr, size_t *size)
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 *kobj,
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(struct file *fp,
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(struct file *fp,
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;
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index f7a132e..90d7e17 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -369,21 +369,41 @@ 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;
+ }
- pa_data = data->next;
- early_memunmap(data, sizeof(*data));
+ indirect = (struct setup_indirect *)data->data;
+
+ if (indirect->type != SETUP_INDIRECT)
+ memblock_reserve(indirect->addr, indirect->len);
+ }
+
+ pa_data = pa_next;
+ early_memunmap(data, len);
}
}
diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c
index 026031b..ab666c4 100644
--- a/arch/x86/mm/ioremap.c
+++ b/arch/x86/mm/ioremap.c
@@ -615,6 +615,7 @@ static bool memremap_is_efi_data(resource_size_t phys_addr,
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(resource_size_t phys_addr,
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(resource_size_t phys_addr,
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);
--
1.8.3.1
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