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 <[email protected]> --- 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 8499a39c62f4..84d235f491a5 100644 --- a/kernel/power/power.h +++ b/kernel/power/power.h @@ -148,7 +148,7 @@ 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 5c96ff067c64..405eddbda4fc 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 6053ddddaf65..b2d708952aae 100644 --- a/kernel/power/swap.c +++ b/kernel/power/swap.c @@ -1100,8 +1100,8 @@ 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"); @@ -1441,8 +1441,8 @@ 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 3a4e70366f35..3aa41ba22129 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; -- 2.43.0
