Currently luo_file_ser, luo_file and liveupdate_file_op_args use the raw serialized_data which stores the phys address of the serialized data. There are two issues 1. It uses raw update, and there is not type safety check 2. user of liveupdate_file_op_args, uses virt_to_phys and phys_to_virt to convert the serializeable pointer to physical address and vice versa. User makes mistakes mistake to check the serializeable pointer/phys value check before converting like in memfd_luo. Converting them to serializeable pointer enforce type safety check ( it has its limitation as you can not have generic serializeable pointer for all the subsystem. So only void * is the only choice, and updating it require user to use KHOSER_COPY_TYPEUNSAFE) and the null value check. This patch also updates the memfd_luo to use the newly introduced the serializeable pointer. Which mitigates the issue of not checking args->serialized_data pointer before using it. Fixes: b3749f174d68 ("mm: memfd_luo: allow preserving memfd") Signed-off-by: Tarun Sahu --- include/linux/kho/abi/luo.h | 6 ++++-- include/linux/liveupdate.h | 4 ++-- kernel/liveupdate/luo_file.c | 24 ++++++++++++------------ mm/memfd_luo.c | 18 +++++++++--------- 4 files changed, 27 insertions(+), 25 deletions(-) diff --git a/include/linux/kho/abi/luo.h b/include/linux/kho/abi/luo.h index 46750a0ddf88..6b08fbf7ad59 100644 --- a/include/linux/kho/abi/luo.h +++ b/include/linux/kho/abi/luo.h @@ -119,17 +119,19 @@ #define LIVEUPDATE_HNDL_COMPAT_LENGTH 48 +#include + /** * struct luo_file_ser - Represents the serialized preserves files. * @compatible: File handler compatible string. - * @data: Private data + * @serialized_data: Serializable pointer union for private data. * @token: User provided token for this file * * If this structure is modified, LUO_SESSION_COMPATIBLE must be updated. */ struct luo_file_ser { char compatible[LIVEUPDATE_HNDL_COMPAT_LENGTH]; - u64 data; + DECLARE_KHOSER_PTR(serialized_data, void *); u64 token; } __packed; diff --git a/include/linux/liveupdate.h b/include/linux/liveupdate.h index 30c5a39ff9e9..8b3466801159 100644 --- a/include/linux/liveupdate.h +++ b/include/linux/liveupdate.h @@ -32,7 +32,7 @@ struct file; * @file: The file object. For retrieve: [OUT] The callback sets * this to the new file. For other ops: [IN] The caller sets * this to the file being operated on. - * @serialized_data: The opaque u64 handle, preserve/prepare/freeze may update + * @serialized_data: The serialized pointer union, preserve/prepare/freeze may update * this field. * @private_data: Private data for the file used to hold runtime state that * is not preserved. Set by the handler's .preserve() @@ -46,7 +46,7 @@ struct liveupdate_file_op_args { struct liveupdate_file_handler *handler; int retrieve_status; struct file *file; - u64 serialized_data; + DECLARE_KHOSER_PTR(serialized_data, void *); void *private_data; }; diff --git a/kernel/liveupdate/luo_file.c b/kernel/liveupdate/luo_file.c index a0a419085e28..c50c8239a34d 100644 --- a/kernel/liveupdate/luo_file.c +++ b/kernel/liveupdate/luo_file.c @@ -130,7 +130,7 @@ static DEFINE_XARRAY(luo_preserved_files); * @file: Pointer to the kernel's &struct file that is being preserved. * This is NULL in the new kernel until the file is successfully * retrieved. - * @serialized_data: The opaque u64 handle to the serialized state of the file. + * @serialized_data: The serialized pointer union to the serialized state of the file. * This handle is passed back to the handler's .freeze(), * .retrieve(), and .finish() callbacks, allowing it to track * and update its serialized state across phases. @@ -166,7 +166,7 @@ static DEFINE_XARRAY(luo_preserved_files); struct luo_file { struct liveupdate_file_handler *fh; struct file *file; - u64 serialized_data; + DECLARE_KHOSER_PTR(serialized_data, void *); void *private_data; int retrieve_status; struct mutex mutex; @@ -328,7 +328,7 @@ int luo_preserve_file(struct luo_file_set *file_set, u64 token, int fd) if (err) goto err_kfree; - luo_file->serialized_data = args.serialized_data; + KHOSER_COPY_TYPESAFE(luo_file->serialized_data, args.serialized_data); luo_file->private_data = args.private_data; list_add_tail(&luo_file->list, &file_set->files_list); file_set->count++; @@ -381,7 +381,7 @@ void luo_file_unpreserve_files(struct luo_file_set *file_set) args.handler = luo_file->fh; args.file = luo_file->file; - args.serialized_data = luo_file->serialized_data; + KHOSER_COPY_TYPESAFE(args.serialized_data, luo_file->serialized_data); args.private_data = luo_file->private_data; luo_file->fh->ops->unpreserve(&args); luo_flb_file_unpreserve(luo_file->fh); @@ -412,12 +412,12 @@ static int luo_file_freeze_one(struct luo_file_set *file_set, args.handler = luo_file->fh; args.file = luo_file->file; - args.serialized_data = luo_file->serialized_data; + KHOSER_COPY_TYPESAFE(args.serialized_data, luo_file->serialized_data); args.private_data = luo_file->private_data; err = luo_file->fh->ops->freeze(&args); if (!err) - luo_file->serialized_data = args.serialized_data; + KHOSER_COPY_TYPESAFE(luo_file->serialized_data, args.serialized_data); } return err; @@ -433,7 +433,7 @@ static void luo_file_unfreeze_one(struct luo_file_set *file_set, args.handler = luo_file->fh; args.file = luo_file->file; - args.serialized_data = luo_file->serialized_data; + KHOSER_COPY_TYPESAFE(args.serialized_data, luo_file->serialized_data); args.private_data = luo_file->private_data; luo_file->fh->ops->unfreeze(&args); @@ -515,7 +515,7 @@ int luo_file_freeze(struct luo_file_set *file_set, strscpy(file_ser[i].compatible, luo_file->fh->compatible, sizeof(file_ser[i].compatible)); - file_ser[i].data = luo_file->serialized_data; + KHOSER_COPY_TYPESAFE(file_ser[i].serialized_data, luo_file->serialized_data); file_ser[i].token = luo_file->token; i++; } @@ -621,7 +621,7 @@ int luo_retrieve_file(struct luo_file_set *file_set, u64 token, } args.handler = luo_file->fh; - args.serialized_data = luo_file->serialized_data; + KHOSER_COPY_TYPESAFE(args.serialized_data, luo_file->serialized_data); err = luo_file->fh->ops->retrieve(&args); if (err) { /* Keep the error code for later use. */ @@ -655,7 +655,7 @@ static int luo_file_can_finish_one(struct luo_file_set *file_set, args.handler = luo_file->fh; args.file = luo_file->file; - args.serialized_data = luo_file->serialized_data; + KHOSER_COPY_TYPESAFE(args.serialized_data, luo_file->serialized_data); args.retrieve_status = luo_file->retrieve_status; can_finish = luo_file->fh->ops->can_finish(&args); } @@ -672,7 +672,7 @@ static void luo_file_finish_one(struct luo_file_set *file_set, args.handler = luo_file->fh; args.file = luo_file->file; - args.serialized_data = luo_file->serialized_data; + KHOSER_COPY_TYPESAFE(args.serialized_data, luo_file->serialized_data); args.retrieve_status = luo_file->retrieve_status; luo_file->fh->ops->finish(&args); @@ -837,7 +837,7 @@ int luo_file_deserialize(struct luo_file_set *file_set, luo_file->fh = fh; luo_file->file = NULL; - luo_file->serialized_data = file_ser[i].data; + KHOSER_COPY_TYPESAFE(luo_file->serialized_data, file_ser[i].serialized_data); luo_file->token = file_ser[i].token; mutex_init(&luo_file->mutex); list_add_tail(&luo_file->list, &file_set->files_list); diff --git a/mm/memfd_luo.c b/mm/memfd_luo.c index 59de210bee5f..daf2c4c3da35 100644 --- a/mm/memfd_luo.c +++ b/mm/memfd_luo.c @@ -257,6 +257,7 @@ static void memfd_luo_unpreserve_folios(struct kho_vmalloc *kho_vmalloc, static int memfd_luo_preserve(struct liveupdate_file_op_args *args) { + DECLARE_KHOSER_PTR(sd, struct memfd_luo_ser *); struct inode *inode = file_inode(args->file); struct memfd_luo_folio_ser *folios_ser; struct memfd_luo_ser *ser; @@ -309,7 +310,8 @@ static int memfd_luo_preserve(struct liveupdate_file_op_args *args) inode_unlock(inode); args->private_data = folios_ser; - args->serialized_data = virt_to_phys(ser); + KHOSER_STORE_PTR(sd, ser); + KHOSER_COPY_TYPEUNSAFE(args->serialized_data, sd); return 0; @@ -325,11 +327,10 @@ static int memfd_luo_freeze(struct liveupdate_file_op_args *args) { struct memfd_luo_ser *ser; - if (WARN_ON_ONCE(!args->serialized_data)) + ser = KHOSER_LOAD_PTR(args->serialized_data); + if (WARN_ON_ONCE(!ser)) return -EINVAL; - ser = phys_to_virt(args->serialized_data); - /* * The pos might have changed since prepare. Everything else stays the * same. @@ -344,14 +345,13 @@ static void memfd_luo_unpreserve(struct liveupdate_file_op_args *args) struct inode *inode = file_inode(args->file); struct memfd_luo_ser *ser; - if (WARN_ON_ONCE(!args->serialized_data)) + ser = KHOSER_LOAD_PTR(args->serialized_data); + if (WARN_ON_ONCE(!ser)) return; inode_lock(inode); shmem_freeze(inode, false); - ser = phys_to_virt(args->serialized_data); - memfd_luo_unpreserve_folios(&ser->folios, args->private_data, ser->nr_folios); @@ -397,7 +397,7 @@ static void memfd_luo_finish(struct liveupdate_file_op_args *args) if (args->retrieve_status) return; - ser = phys_to_virt(args->serialized_data); + ser = KHOSER_LOAD_PTR(args->serialized_data); if (!ser) return; @@ -522,7 +522,7 @@ static int memfd_luo_retrieve(struct liveupdate_file_op_args *args) struct file *file; int err; - ser = phys_to_virt(args->serialized_data); + ser = KHOSER_LOAD_PTR(args->serialized_data); if (!ser) return -EINVAL; -- 2.54.0.1136.gdb2ca164c4-goog