[PATCH v3] bootconfig: use memblock_free_late to free xbc memory to buddy

2024-04-14 Thread qiang4 . zhang
From: Qiang Zhang 

On the time to free xbc memory in xbc_exit(), memblock may has handed
over memory to buddy allocator. So it doesn't make sense to free memory
back to memblock. memblock_free() called by xbc_exit() even causes UAF bugs
on architectures with CONFIG_ARCH_KEEP_MEMBLOCK disabled like x86.
Following KASAN logs shows this case.

This patch fixes the xbc memory free problem by calling memblock_free()
in early xbc init error rewind path and calling memblock_free_late() in
xbc exit path to free memory to buddy allocator.

[9.410890] 
==
[9.418962] BUG: KASAN: use-after-free in memblock_isolate_range+0x12d/0x260
[9.426850] Read of size 8 at addr 88845dd3 by task swapper/0/1

[9.435901] CPU: 9 PID: 1 Comm: swapper/0 Tainted: G U 
6.9.0-rc3-00208-g586b5dfb51b9 #5
[9.446403] Hardware name: Intel Corporation RPLP LP5 (CPU:RaptorLake)/RPLP 
LP5 (ID:13), BIOS IRPPN02.01.01.00.00.19.015.D- Dec 28 2023
[9.460789] Call Trace:
[9.463518]  
[9.465859]  dump_stack_lvl+0x53/0x70
[9.469949]  print_report+0xce/0x610
[9.473944]  ? __virt_addr_valid+0xf5/0x1b0
[9.478619]  ? memblock_isolate_range+0x12d/0x260
[9.483877]  kasan_report+0xc6/0x100
[9.487870]  ? memblock_isolate_range+0x12d/0x260
[9.493125]  memblock_isolate_range+0x12d/0x260
[9.498187]  memblock_phys_free+0xb4/0x160
[9.502762]  ? __pfx_memblock_phys_free+0x10/0x10
[9.508021]  ? mutex_unlock+0x7e/0xd0
[9.512111]  ? __pfx_mutex_unlock+0x10/0x10
[9.516786]  ? kernel_init_freeable+0x2d4/0x430
[9.521850]  ? __pfx_kernel_init+0x10/0x10
[9.526426]  xbc_exit+0x17/0x70
[9.529935]  kernel_init+0x38/0x1e0
[9.533829]  ? _raw_spin_unlock_irq+0xd/0x30
[9.538601]  ret_from_fork+0x2c/0x50
[9.542596]  ? __pfx_kernel_init+0x10/0x10
[9.547170]  ret_from_fork_asm+0x1a/0x30
[9.551552]  

[9.555649] The buggy address belongs to the physical page:
[9.561875] page: refcount:0 mapcount:0 mapping: index:0x1 
pfn:0x45dd30
[9.570821] flags: 0x200(node=0|zone=2)
[9.576271] page_type: 0x()
[9.580167] raw: 0200 ea0011774c48 ea0012ba1848 

[9.588823] raw: 0001   

[9.597476] page dumped because: kasan: bad access detected

[9.605362] Memory state around the buggy address:
[9.610714]  88845dd2ff00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
00
[9.618786]  88845dd2ff80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
00
[9.626857] >88845dd3: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff 
ff
[9.634930]^
[9.638534]  88845dd30080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff 
ff
[9.646605]  88845dd30100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff 
ff
[9.654675] 
==

Cc: sta...@vger.kernel.org
Signed-off-by: Qiang Zhang 
---
v3:
- add NULL pointer check in memblock_free_late() path.

v2:
- add an early flag in xbc_free_mem() to free memory back to memblock in
  xbc_init error path or put memory to buddy allocator in normal xbc_exit.
---
 include/linux/bootconfig.h |  7 ++-
 lib/bootconfig.c   | 19 +++
 2 files changed, 17 insertions(+), 9 deletions(-)

diff --git a/include/linux/bootconfig.h b/include/linux/bootconfig.h
index e5ee2c694401..3f4b4ac527ca 100644
--- a/include/linux/bootconfig.h
+++ b/include/linux/bootconfig.h
@@ -288,7 +288,12 @@ int __init xbc_init(const char *buf, size_t size, const 
char **emsg, int *epos);
 int __init xbc_get_info(int *node_size, size_t *data_size);
 
 /* XBC cleanup data structures */
-void __init xbc_exit(void);
+void __init _xbc_exit(bool early);
+
+static inline void xbc_exit(void)
+{
+   _xbc_exit(false);
+}
 
 /* XBC embedded bootconfig data in kernel */
 #ifdef CONFIG_BOOT_CONFIG_EMBED
diff --git a/lib/bootconfig.c b/lib/bootconfig.c
index c59d26068a64..8841554432d5 100644
--- a/lib/bootconfig.c
+++ b/lib/bootconfig.c
@@ -61,9 +61,12 @@ static inline void * __init xbc_alloc_mem(size_t size)
return memblock_alloc(size, SMP_CACHE_BYTES);
 }
 
-static inline void __init xbc_free_mem(void *addr, size_t size)
+static inline void __init xbc_free_mem(void *addr, size_t size, bool early)
 {
-   memblock_free(addr, size);
+   if (early)
+   memblock_free(addr, size);
+   else if (addr)
+   memblock_free_late(__pa(addr), size);
 }
 
 #else /* !__KERNEL__ */
@@ -73,7 +76,7 @@ static inline void *xbc_alloc_mem(size_t size)
return malloc(size);
 }
 
-static inline void xbc_free_mem(void *addr, size_t size)
+static inline void xbc_free_mem(void *addr, size_t size, bool early)
 {
free(addr);
 }
@@ -904,13 +907,13 @@ static int __init xbc_parse_tree(void)
  * If you need to r

[PATCH v2] bootconfig: use memblock_free_late to free xbc memory to buddy

2024-04-12 Thread qiang4 . zhang
From: Qiang Zhang 

On the time to free xbc memory in xbc_exit(), memblock may has handed
over memory to buddy allocator. So it doesn't make sense to free memory
back to memblock. memblock_free() called by xbc_exit() even causes UAF bugs
on architectures with CONFIG_ARCH_KEEP_MEMBLOCK disabled like x86.
Following KASAN logs shows this case.

This patch fixes the xbc memory free problem by calling memblock_free()
in early xbc init error rewind path and calling memblock_free_late() in
xbc exit path to free memory to buddy allocator.

[9.410890] 
==
[9.418962] BUG: KASAN: use-after-free in memblock_isolate_range+0x12d/0x260
[9.426850] Read of size 8 at addr 88845dd3 by task swapper/0/1

[9.435901] CPU: 9 PID: 1 Comm: swapper/0 Tainted: G U 
6.9.0-rc3-00208-g586b5dfb51b9 #5
[9.446403] Hardware name: Intel Corporation RPLP LP5 (CPU:RaptorLake)/RPLP 
LP5 (ID:13), BIOS IRPPN02.01.01.00.00.19.015.D- Dec 28 2023
[9.460789] Call Trace:
[9.463518]  
[9.465859]  dump_stack_lvl+0x53/0x70
[9.469949]  print_report+0xce/0x610
[9.473944]  ? __virt_addr_valid+0xf5/0x1b0
[9.478619]  ? memblock_isolate_range+0x12d/0x260
[9.483877]  kasan_report+0xc6/0x100
[9.487870]  ? memblock_isolate_range+0x12d/0x260
[9.493125]  memblock_isolate_range+0x12d/0x260
[9.498187]  memblock_phys_free+0xb4/0x160
[9.502762]  ? __pfx_memblock_phys_free+0x10/0x10
[9.508021]  ? mutex_unlock+0x7e/0xd0
[9.512111]  ? __pfx_mutex_unlock+0x10/0x10
[9.516786]  ? kernel_init_freeable+0x2d4/0x430
[9.521850]  ? __pfx_kernel_init+0x10/0x10
[9.526426]  xbc_exit+0x17/0x70
[9.529935]  kernel_init+0x38/0x1e0
[9.533829]  ? _raw_spin_unlock_irq+0xd/0x30
[9.538601]  ret_from_fork+0x2c/0x50
[9.542596]  ? __pfx_kernel_init+0x10/0x10
[9.547170]  ret_from_fork_asm+0x1a/0x30
[9.551552]  

[9.555649] The buggy address belongs to the physical page:
[9.561875] page: refcount:0 mapcount:0 mapping: index:0x1 
pfn:0x45dd30
[9.570821] flags: 0x200(node=0|zone=2)
[9.576271] page_type: 0x()
[9.580167] raw: 0200 ea0011774c48 ea0012ba1848 

[9.588823] raw: 0001   

[9.597476] page dumped because: kasan: bad access detected

[9.605362] Memory state around the buggy address:
[9.610714]  88845dd2ff00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
00
[9.618786]  88845dd2ff80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
00
[9.626857] >88845dd3: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff 
ff
[9.634930]^
[9.638534]  88845dd30080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff 
ff
[9.646605]  88845dd30100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff 
ff
[9.654675] 
==

Cc: sta...@vger.kernel.org
Signed-off-by: Qiang Zhang 
---
v2:
- add an early flag in xbc_free_mem() to free memory back to memblock in
  xbc_init error path or put memory to buddy allocator in normal xbc_exit.

---
 include/linux/bootconfig.h |  7 ++-
 lib/bootconfig.c   | 19 +++
 2 files changed, 17 insertions(+), 9 deletions(-)

diff --git a/include/linux/bootconfig.h b/include/linux/bootconfig.h
index e5ee2c694401..3f4b4ac527ca 100644
--- a/include/linux/bootconfig.h
+++ b/include/linux/bootconfig.h
@@ -288,7 +288,12 @@ int __init xbc_init(const char *buf, size_t size, const 
char **emsg, int *epos);
 int __init xbc_get_info(int *node_size, size_t *data_size);
 
 /* XBC cleanup data structures */
-void __init xbc_exit(void);
+void __init _xbc_exit(bool early);
+
+static inline void xbc_exit(void)
+{
+   _xbc_exit(false);
+}
 
 /* XBC embedded bootconfig data in kernel */
 #ifdef CONFIG_BOOT_CONFIG_EMBED
diff --git a/lib/bootconfig.c b/lib/bootconfig.c
index c59d26068a64..f9a45adc6307 100644
--- a/lib/bootconfig.c
+++ b/lib/bootconfig.c
@@ -61,9 +61,12 @@ static inline void * __init xbc_alloc_mem(size_t size)
return memblock_alloc(size, SMP_CACHE_BYTES);
 }
 
-static inline void __init xbc_free_mem(void *addr, size_t size)
+static inline void __init xbc_free_mem(void *addr, size_t size, bool early)
 {
-   memblock_free(addr, size);
+   if (early)
+   memblock_free(addr, size);
+   else
+   memblock_free_late(__pa(addr), size);
 }
 
 #else /* !__KERNEL__ */
@@ -73,7 +76,7 @@ static inline void *xbc_alloc_mem(size_t size)
return malloc(size);
 }
 
-static inline void xbc_free_mem(void *addr, size_t size)
+static inline void xbc_free_mem(void *addr, size_t size, bool early)
 {
free(addr);
 }
@@ -904,13 +907,13 @@ static int __init xbc_parse_tree(void)
  * If you need to reuse xbc_init() with new boot config, you can
  * use this.
  */
-voi

[PATCH RESEND] bootconfig: use memblock_free_late to free xbc memory to buddy

2024-04-11 Thread qiang4 . zhang
From: Qiang Zhang 

On the time to free xbc memory, memblock has handed over memory to buddy
allocator. So it doesn't make sense to free memory back to memblock.
memblock_free() called by xbc_exit() even causes UAF bugs on architectures
with CONFIG_ARCH_KEEP_MEMBLOCK disabled like x86. Following KASAN logs
shows this case.

[9.410890] 
==
[9.418962] BUG: KASAN: use-after-free in memblock_isolate_range+0x12d/0x260
[9.426850] Read of size 8 at addr 88845dd3 by task swapper/0/1

[9.435901] CPU: 9 PID: 1 Comm: swapper/0 Tainted: G U 
6.9.0-rc3-00208-g586b5dfb51b9 #5
[9.446403] Hardware name: Intel Corporation RPLP LP5 (CPU:RaptorLake)/RPLP 
LP5 (ID:13), BIOS IRPPN02.01.01.00.00.19.015.D- Dec 28 2023
[9.460789] Call Trace:
[9.463518]  
[9.465859]  dump_stack_lvl+0x53/0x70
[9.469949]  print_report+0xce/0x610
[9.473944]  ? __virt_addr_valid+0xf5/0x1b0
[9.478619]  ? memblock_isolate_range+0x12d/0x260
[9.483877]  kasan_report+0xc6/0x100
[9.487870]  ? memblock_isolate_range+0x12d/0x260
[9.493125]  memblock_isolate_range+0x12d/0x260
[9.498187]  memblock_phys_free+0xb4/0x160
[9.502762]  ? __pfx_memblock_phys_free+0x10/0x10
[9.508021]  ? mutex_unlock+0x7e/0xd0
[9.512111]  ? __pfx_mutex_unlock+0x10/0x10
[9.516786]  ? kernel_init_freeable+0x2d4/0x430
[9.521850]  ? __pfx_kernel_init+0x10/0x10
[9.526426]  xbc_exit+0x17/0x70
[9.529935]  kernel_init+0x38/0x1e0
[9.533829]  ? _raw_spin_unlock_irq+0xd/0x30
[9.538601]  ret_from_fork+0x2c/0x50
[9.542596]  ? __pfx_kernel_init+0x10/0x10
[9.547170]  ret_from_fork_asm+0x1a/0x30
[9.551552]  

[9.555649] The buggy address belongs to the physical page:
[9.561875] page: refcount:0 mapcount:0 mapping: index:0x1 
pfn:0x45dd30
[9.570821] flags: 0x200(node=0|zone=2)
[9.576271] page_type: 0x()
[9.580167] raw: 0200 ea0011774c48 ea0012ba1848 

[9.588823] raw: 0001   

[9.597476] page dumped because: kasan: bad access detected

[9.605362] Memory state around the buggy address:
[9.610714]  88845dd2ff00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
00
[9.618786]  88845dd2ff80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
00
[9.626857] >88845dd3: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff 
ff
[9.634930]^
[9.638534]  88845dd30080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff 
ff
[9.646605]  88845dd30100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff 
ff
[9.654675] 
==

Cc: sta...@vger.kernel.org
Signed-off-by: Qiang Zhang 
---
 lib/bootconfig.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/bootconfig.c b/lib/bootconfig.c
index c59d26068a64..4524ee944df0 100644
--- a/lib/bootconfig.c
+++ b/lib/bootconfig.c
@@ -63,7 +63,7 @@ static inline void * __init xbc_alloc_mem(size_t size)
 
 static inline void __init xbc_free_mem(void *addr, size_t size)
 {
-   memblock_free(addr, size);
+   memblock_free_late(__pa(addr), size);
 }
 
 #else /* !__KERNEL__ */
-- 
2.39.2




[PATCH] bootconfig: use memblock_free_late to free xbc memory to buddy

2024-04-11 Thread qiang4 . zhang
From: Qiang Zhang 

On the time to free xbc memory, memblock has handed over memory to buddy
allocator. So it doesn't make sense to free memory back to memblock.
memblock_free() called by xbc_exit() even causes UAF bugs on architectures
with CONFIG_ARCH_KEEP_MEMBLOCK disabled like x86. Following KASAN logs
shows this case.

[9.410890] 
==
[9.418962] BUG: KASAN: use-after-free in memblock_isolate_range+0x12d/0x260
[9.426850] Read of size 8 at addr 88845dd3 by task swapper/0/1

[9.435901] CPU: 9 PID: 1 Comm: swapper/0 Tainted: G U 
6.9.0-rc3-00208-g586b5dfb51b9 #5
[9.446403] Hardware name: Intel Corporation RPLP LP5 (CPU:RaptorLake)/RPLP 
LP5 (ID:13), BIOS IRPPN02.01.01.00.00.19.015.D- Dec 28 2023
[9.460789] Call Trace:
[9.463518]  
[9.465859]  dump_stack_lvl+0x53/0x70
[9.469949]  print_report+0xce/0x610
[9.473944]  ? __virt_addr_valid+0xf5/0x1b0
[9.478619]  ? memblock_isolate_range+0x12d/0x260
[9.483877]  kasan_report+0xc6/0x100
[9.487870]  ? memblock_isolate_range+0x12d/0x260
[9.493125]  memblock_isolate_range+0x12d/0x260
[9.498187]  memblock_phys_free+0xb4/0x160
[9.502762]  ? __pfx_memblock_phys_free+0x10/0x10
[9.508021]  ? mutex_unlock+0x7e/0xd0
[9.512111]  ? __pfx_mutex_unlock+0x10/0x10
[9.516786]  ? kernel_init_freeable+0x2d4/0x430
[9.521850]  ? __pfx_kernel_init+0x10/0x10
[9.526426]  xbc_exit+0x17/0x70
[9.529935]  kernel_init+0x38/0x1e0
[9.533829]  ? _raw_spin_unlock_irq+0xd/0x30
[9.538601]  ret_from_fork+0x2c/0x50
[9.542596]  ? __pfx_kernel_init+0x10/0x10
[9.547170]  ret_from_fork_asm+0x1a/0x30
[9.551552]  

[9.555649] The buggy address belongs to the physical page:
[9.561875] page: refcount:0 mapcount:0 mapping: index:0x1 
pfn:0x45dd30
[9.570821] flags: 0x200(node=0|zone=2)
[9.576271] page_type: 0x()
[9.580167] raw: 0200 ea0011774c48 ea0012ba1848 

[9.588823] raw: 0001   

[9.597476] page dumped because: kasan: bad access detected

[9.605362] Memory state around the buggy address:
[9.610714]  88845dd2ff00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
00
[9.618786]  88845dd2ff80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
00
[9.626857] >88845dd3: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff 
ff
[9.634930]^
[9.638534]  88845dd30080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff 
ff
[9.646605]  88845dd30100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff 
ff
[9.654675] 
==

Signed-off-by: Qiang Zhang 
---
 lib/bootconfig.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/bootconfig.c b/lib/bootconfig.c
index c59d26068a64..4524ee944df0 100644
--- a/lib/bootconfig.c
+++ b/lib/bootconfig.c
@@ -63,7 +63,7 @@ static inline void * __init xbc_alloc_mem(size_t size)
 
 static inline void __init xbc_free_mem(void *addr, size_t size)
 {
-   memblock_free(addr, size);
+   memblock_free_late(__pa(addr), size);
 }
 
 #else /* !__KERNEL__ */
-- 
2.39.2