[PATCH 6.6 087/175] PM: hibernate: Dont ignore return from set_memory_ro()

Greg Kroah-Hartman
2026-03-31T16:27:21Z

From: Christophe Leroy <christophe.leroy@csgroup.eu>

[ Upstream commit f4311756a83fb01c28a9bf841cbb7eb2b318eebf ]

set_memory_ro() and set_memory_rw() can fail, leaving memory
unprotected.

Take the returned value into account and abort in case of
failure.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Stable-dep-of: 734eba62cd32 ("PM: hibernate: Drain trailing zero pages on userspace restore")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
kernel/power/power.h | 2 +-
kernel/power/snapshot.c | 25 ++++++++++++++++---------
kernel/power/swap.c | 8 ++++----
kernel/power/user.c | 4 +++-
4 files changed, 24 insertions(+), 15 deletions(-)

diff --git a/kernel/power/power.h b/kernel/power/power.h
index 62a7cb452a4be..3ea663f1ad1e2 100644
--- a/kernel/power/power.h
+++ b/kernel/power/power.h
@@ -152,7 +152,7 @@ extern unsigned int snapshot_additional_pages(struct zone *zone);
extern unsigned long snapshot_get_image_size(void);
extern int snapshot_read_next(struct snapshot_handle *handle);
extern int snapshot_write_next(struct snapshot_handle *handle);
-extern void snapshot_write_finalize(struct snapshot_handle *handle);
+int snapshot_write_finalize(struct snapshot_handle *handle);
extern int snapshot_image_loaded(struct snapshot_handle *handle);

extern bool hibernate_acquire(void);
diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c
index 50a15408c3fca..ea52417375a4e 100644
--- a/kernel/power/snapshot.c
+++ b/kernel/power/snapshot.c
@@ -58,22 +58,24 @@ static inline void hibernate_restore_protection_end(void)
hibernate_restore_protection_active = false;
}

-static inline void hibernate_restore_protect_page(void *page_address)
+static inline int __must_check hibernate_restore_protect_page(void *page_address)
{
if (hibernate_restore_protection_active)
- set_memory_ro((unsigned long)page_address, 1);
+ return set_memory_ro((unsigned long)page_address, 1);
+ return 0;
}

-static inline void hibernate_restore_unprotect_page(void *page_address)
+static inline int hibernate_restore_unprotect_page(void *page_address)
{
if (hibernate_restore_protection_active)
- set_memory_rw((unsigned long)page_address, 1);
+ return set_memory_rw((unsigned long)page_address, 1);
+ return 0;
}
#else
static inline void hibernate_restore_protection_begin(void) {}
static inline void hibernate_restore_protection_end(void) {}
-static inline void hibernate_restore_protect_page(void *page_address) {}
-static inline void hibernate_restore_unprotect_page(void *page_address) {}
+static inline int __must_check hibernate_restore_protect_page(void *page_address) {return 0; }
+static inline int hibernate_restore_unprotect_page(void *page_address) {return 0; }
#endif /* CONFIG_STRICT_KERNEL_RWX && CONFIG_ARCH_HAS_SET_MEMORY */

@@ -2832,7 +2834,9 @@ int snapshot_write_next(struct snapshot_handle *handle)
}
} else {
copy_last_highmem_page();
- hibernate_restore_protect_page(handle->buffer);
+ error = hibernate_restore_protect_page(handle->buffer);
+ if (error)
+ return error;
handle->buffer = get_buffer(&orig_bm, &ca);
if (IS_ERR(handle->buffer))
return PTR_ERR(handle->buffer);
@@ -2858,15 +2862,18 @@ int snapshot_write_next(struct snapshot_handle *handle)
* stored in highmem. Additionally, it recycles bitmap memory that's not
* necessary any more.
*/
-void snapshot_write_finalize(struct snapshot_handle *handle)
+int snapshot_write_finalize(struct snapshot_handle *handle)
{
+ int error;
+
copy_last_highmem_page();
- hibernate_restore_protect_page(handle->buffer);
+ error = hibernate_restore_protect_page(handle->buffer);
/* Do that only if we have loaded the image entirely */
if (handle->cur > 1 && handle->cur > nr_meta_pages + nr_copy_pages + nr_zero_pages) {
memory_bm_recycle(&orig_bm);
free_highmem_data();
}
+ return error;
}

int snapshot_image_loaded(struct snapshot_handle *handle)
diff --git a/kernel/power/swap.c b/kernel/power/swap.c
index d71c590550d28..8c162e18e1645 100644
--- a/kernel/power/swap.c
+++ b/kernel/power/swap.c
@@ -1099,8 +1099,8 @@ static int load_image(struct swap_map_handle *handle,
ret = err2;
if (!ret) {
pr_info("Image loading done\n");
- snapshot_write_finalize(snapshot);
- if (!snapshot_image_loaded(snapshot))
+ ret = snapshot_write_finalize(snapshot);
+ if (!ret && !snapshot_image_loaded(snapshot))
ret = -ENODATA;
}
swsusp_show_speed(start, stop, nr_to_read, "Read");
@@ -1440,8 +1440,8 @@ static int load_image_lzo(struct swap_map_handle *handle,
stop = ktime_get();
if (!ret) {
pr_info("Image loading done\n");
- snapshot_write_finalize(snapshot);
- if (!snapshot_image_loaded(snapshot))
+ ret = snapshot_write_finalize(snapshot);
+ if (!ret && !snapshot_image_loaded(snapshot))
ret = -ENODATA;
if (!ret) {
if (swsusp_header->flags & SF_CRC32_MODE) {
diff --git a/kernel/power/user.c b/kernel/power/user.c
index 3a4e70366f354..3aa41ba22129d 100644
--- a/kernel/power/user.c
+++ b/kernel/power/user.c
@@ -317,7 +317,9 @@ static long snapshot_ioctl(struct file *filp, unsigned int cmd,
break;

case SNAPSHOT_ATOMIC_RESTORE:
- snapshot_write_finalize(&data->handle);
+ error = snapshot_write_finalize(&data->handle);
+ if (error)
+ break;
if (data->mode != O_WRONLY || !data->frozen ||
!snapshot_image_loaded(&data->handle)) {
error = -EPERM;
--
2.53.0