[PATCH v2 0/2] x86/boot: Fix setup_indirect support

[PATCH v2 0/2] x86/boot: Fix setup_indirect support

[Ross Philipson]

The setup_indirect support for x86 setup_data was added in November
of 2019. Several issues were found in the implementation and these
two patches were created to address those issues.

These patches were originally posted as part of the larger TrenchBoot
patch set but are now being posted separately since they can be merged
independently of the TrenchBoot work.

Changes in v2:
 - Add checks and failure modes for when early_memremap and memremap
   fail.
 - Fix variable declarations to use reverse fir tree format.
 - Use local indirect variable and remove all the inline casts.
 - Misc. fixes to the commit messages.

Ross Philipson (2):
  x86/boot: Fix memremap of setup_indirect structures
  x86/boot: Add setup_indirect support in early_memremap_is_setup_data

 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      | 57 ++++++++++++++++++++++++++++++----
 5 files changed, 197 insertions(+), 49 deletions(-)

-- 
1.8.3.1

[PATCH v2 1/2] x86/boot: Fix memremap of setup_indirect structures

[Ross Philipson]

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>
---
 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

[PATCH v2 2/2] x86/boot: Add setup_indirect support in early_memremap_is_setup_data

[Ross Philipson]

The x86 boot documentation describes the setup_indirect structures and
how they are used. Only one of the two functions in ioremap.c that needed
to be modified to be aware of the introduction of setup_indirect
functionality was updated. Adds comparable support to the other function
where it was missing.

Fixes: b3c72fc9a78e ("x86/boot: Introduce setup_indirect")
Signed-off-by: Ross Philipson <ross.philipson@oracle.com>
---
 arch/x86/mm/ioremap.c | 33 +++++++++++++++++++++++++++++++--
 1 file changed, 31 insertions(+), 2 deletions(-)

diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c
index ab666c4..17a492c 100644
--- a/arch/x86/mm/ioremap.c
+++ b/arch/x86/mm/ioremap.c
@@ -676,22 +676,51 @@ static bool memremap_is_setup_data(resource_size_t phys_addr,
 static bool __init early_memremap_is_setup_data(resource_size_t phys_addr,
 						unsigned long size)
 {
+	struct setup_indirect *indirect;
 	struct setup_data *data;
 	u64 paddr, paddr_next;
 
 	paddr = boot_params.hdr.setup_data;
 	while (paddr) {
-		unsigned int len;
+		unsigned int len, size;
 
 		if (phys_addr == paddr)
 			return true;
 
 		data = early_memremap_decrypted(paddr, sizeof(*data));
+		if (!data) {
+			pr_warn("failed to early memremap setup_data entry\n");
+			return false;
+		}
+
+		size = sizeof(*data);
 
 		paddr_next = data->next;
 		len = data->len;
 
-		early_memunmap(data, sizeof(*data));
+		if ((phys_addr > paddr) && (phys_addr < (paddr + len))) {
+			early_memunmap(data, sizeof(*data));
+			return true;
+		}
+
+		if (data->type == SETUP_INDIRECT) {
+			size += len;
+			early_memunmap(data, sizeof(*data));
+			data = early_memremap_decrypted(paddr, size);
+			if (!data) {
+				pr_warn("failed to early memremap indirect setup_data\n");
+				return false;
+			}
+
+			indirect = (struct setup_indirect *)data->data;
+
+			if (indirect->type != SETUP_INDIRECT) {
+				paddr = indirect->addr;
+				len = indirect->len;
+			}
+		}
+
+		early_memunmap(data, size);
 
 		if ((phys_addr > paddr) && (phys_addr < (paddr + len)))
 			return true;
-- 
1.8.3.1

Re: [PATCH v2 0/2] x86/boot: Fix setup_indirect support

[Daniel Kiper]

On Wed, Feb 23, 2022 at 09:07:34PM -0500, Ross Philipson wrote:
> The setup_indirect support for x86 setup_data was added in November
> of 2019. Several issues were found in the implementation and these
> two patches were created to address those issues.
>
> These patches were originally posted as part of the larger TrenchBoot
> patch set but are now being posted separately since they can be merged
> independently of the TrenchBoot work.
>
> Changes in v2:
>  - Add checks and failure modes for when early_memremap and memremap
>    fail.
>  - Fix variable declarations to use reverse fir tree format.
>  - Use local indirect variable and remove all the inline casts.
>  - Misc. fixes to the commit messages.
>
> Ross Philipson (2):
>   x86/boot: Fix memremap of setup_indirect structures
>   x86/boot: Add setup_indirect support in early_memremap_is_setup_data

For both Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>...

Daniel

Re: [PATCH v2 0/2] x86/boot: Fix setup_indirect support

[Ross Philipson]

On 2/25/22 16:17, Daniel Kiper wrote:
> On Wed, Feb 23, 2022 at 09:07:34PM -0500, Ross Philipson wrote:
>> The setup_indirect support for x86 setup_data was added in November
>> of 2019. Several issues were found in the implementation and these
>> two patches were created to address those issues.
>>
>> These patches were originally posted as part of the larger TrenchBoot
>> patch set but are now being posted separately since they can be merged
>> independently of the TrenchBoot work.
>>
>> Changes in v2:
>>  - Add checks and failure modes for when early_memremap and memremap
>>    fail.
>>  - Fix variable declarations to use reverse fir tree format.
>>  - Use local indirect variable and remove all the inline casts.
>>  - Misc. fixes to the commit messages.
>>
>> Ross Philipson (2):
>>   x86/boot: Fix memremap of setup_indirect structures
>>   x86/boot: Add setup_indirect support in early_memremap_is_setup_data
> 
> For both Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>...
> 
> Daniel

Borislav,

Sorry to bug you. I am going on vacation starting next week and I just
wanted to get an idea if v2 looks good for merging in to you? If not I
could probably get a v3 out before I leave.

Thank you,
Ross Philipson

[tip: x86/urgent] x86/boot: Add setup_indirect support in early_memremap_is_setup_data()

[tip-bot2 for Ross Philipson]

The following commit has been merged into the x86/urgent branch of tip:

Commit-ID:     445c1470b6ef96440e7cfc42dfc160f5004fd149
Gitweb:        https://git.kernel.org/tip/445c1470b6ef96440e7cfc42dfc160f5004fd149
Author:        Ross Philipson <ross.philipson@oracle.com>
AuthorDate:    Wed, 23 Feb 2022 21:07:36 -05:00
Committer:     Borislav Petkov <bp@suse.de>
CommitterDate: Wed, 09 Mar 2022 12:49:46 +01:00

x86/boot: Add setup_indirect support in early_memremap_is_setup_data()

The x86 boot documentation describes the setup_indirect structures and
how they are used. Only one of the two functions in ioremap.c that needed
to be modified to be aware of the introduction of setup_indirect
functionality was updated. Adds comparable support to the other function
where it was missing.

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/1645668456-22036-3-git-send-email-ross.philipson@oracle.com
---
 arch/x86/mm/ioremap.c | 33 +++++++++++++++++++++++++++++++--
 1 file changed, 31 insertions(+), 2 deletions(-)

diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c
index ab666c4..17a492c 100644
--- a/arch/x86/mm/ioremap.c
+++ b/arch/x86/mm/ioremap.c
@@ -676,22 +676,51 @@ static bool memremap_is_setup_data(resource_size_t phys_addr,
 static bool __init early_memremap_is_setup_data(resource_size_t phys_addr,
 						unsigned long size)
 {
+	struct setup_indirect *indirect;
 	struct setup_data *data;
 	u64 paddr, paddr_next;
 
 	paddr = boot_params.hdr.setup_data;
 	while (paddr) {
-		unsigned int len;
+		unsigned int len, size;
 
 		if (phys_addr == paddr)
 			return true;
 
 		data = early_memremap_decrypted(paddr, sizeof(*data));
+		if (!data) {
+			pr_warn("failed to early memremap setup_data entry\n");
+			return false;
+		}
+
+		size = sizeof(*data);
 
 		paddr_next = data->next;
 		len = data->len;
 
-		early_memunmap(data, sizeof(*data));
+		if ((phys_addr > paddr) && (phys_addr < (paddr + len))) {
+			early_memunmap(data, sizeof(*data));
+			return true;
+		}
+
+		if (data->type == SETUP_INDIRECT) {
+			size += len;
+			early_memunmap(data, sizeof(*data));
+			data = early_memremap_decrypted(paddr, size);
+			if (!data) {
+				pr_warn("failed to early memremap indirect setup_data\n");
+				return false;
+			}
+
+			indirect = (struct setup_indirect *)data->data;
+
+			if (indirect->type != SETUP_INDIRECT) {
+				paddr = indirect->addr;
+				len = indirect->len;
+			}
+		}
+
+		early_memunmap(data, size);
 
 		if ((phys_addr > paddr) && (phys_addr < (paddr + len)))
 			return true;

[tip: x86/urgent] x86/boot: Fix memremap of setup_indirect structures

[tip-bot2 for Ross Philipson]

The following commit has been merged into the x86/urgent branch of tip:

Commit-ID:     7228918b34615ef6317edcd9a058a057bc54aa32
Gitweb:        https://git.kernel.org/tip/7228918b34615ef6317edcd9a058a057bc54aa32
Author:        Ross Philipson <ross.philipson@oracle.com>
AuthorDate:    Wed, 23 Feb 2022 21:07:35 -05:00
Committer:     Borislav Petkov <bp@suse.de>
CommitterDate: Wed, 09 Mar 2022 12:49:44 +01:00

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@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
---
 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 @@ 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(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 @@ create_setup_data_node(struct dentry *parent, int no,
 
 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);