From: Rasmus Villemoes Date: Mon, 10 Nov 2025 20:54:10 +0000 (+0100) Subject: disk/part.c: ensure strings in struct disk_partition are valid after successful get_info X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=3c2a9475334ae32997b3bce8d24b39c8ffa9fc67;p=thirdparty%2Fu-boot.git disk/part.c: ensure strings in struct disk_partition are valid after successful get_info Not all ->get_info implementations necessarily populate all the string members of struct disk_partition. Currently, only part_get_info_by_type() (and thereby part_get_info) ensure that the uuid strings are initialized; part_get_info_by_type() and part_get_info_by_uuid() do not. In fact, the latter could lead to a false positive match - if the ->get_info backend does not populate info->uuid, stale contents in info could cause the strncasecmp() to succeed. None of the functions currently ensure that the ->name and ->type strings are initialized. Instead of forcing all callers of any of these functions to pre-initialize info, or all implementations of the ->get_info method to ensure there are valid C strings in all four fields, create a small helper function and factor all invocations of ->get_info through that. This also consolidates the -ENOSYS check and standardizes on using log_debug() for reporting absence, instead of the current mix of PRINTF and log_debug(). It does mean we have to special-case -ENOSYS in the error cases inside the loops in the _by_uuid() and _by_name() functions, but it's still a net win in #LOC. Acked-by: Quentin Schulz Signed-off-by: Rasmus Villemoes Tested-by: Anshul Dalal --- diff --git a/cmd/gpt.c b/cmd/gpt.c index e18e5036a06..84221881c39 100644 --- a/cmd/gpt.c +++ b/cmd/gpt.c @@ -724,7 +724,7 @@ static int gpt_enumerate(struct blk_desc *desc) continue; for (i = 1; i < part_drv->max_entries; i++) { - ret = part_drv->get_info(desc, i, &pinfo); + ret = part_driver_get_info(part_drv, desc, i, &pinfo); if (ret) continue; @@ -820,7 +820,7 @@ static int gpt_setenv(struct blk_desc *desc, const char *name) int i; for (i = 1; i < part_drv->max_entries; i++) { - ret = part_drv->get_info(desc, i, &pinfo); + ret = part_driver_get_info(part_drv, desc, i, &pinfo); if (ret) continue; diff --git a/disk/part.c b/disk/part.c index be2b45d5a29..49a0fca6b89 100644 --- a/disk/part.c +++ b/disk/part.c @@ -72,6 +72,28 @@ struct part_driver *part_driver_lookup_type(struct blk_desc *desc) return NULL; } +static void disk_partition_clr(struct disk_partition *info) +{ + /* The common case is no UUID support */ + disk_partition_clr_uuid(info); + disk_partition_clr_type_guid(info); + info->name[0] = '\0'; + info->type[0] = '\0'; +} + +int part_driver_get_info(struct part_driver *drv, struct blk_desc *desc, int part, + struct disk_partition *info) +{ + if (!drv->get_info) { + log_debug("## Driver %s does not have the get_info() method\n", + drv->name); + return -ENOSYS; + } + + disk_partition_clr(info); + return drv->get_info(desc, part, info); +} + int part_get_type_by_name(const char *name) { struct part_driver *drv = @@ -322,12 +344,9 @@ int part_get_info_by_type(struct blk_desc *desc, int part, int part_type, struct disk_partition *info) { struct part_driver *drv; + int ret = -ENOENT; if (blk_enabled()) { - /* The common case is no UUID support */ - disk_partition_clr_uuid(info); - disk_partition_clr_type_guid(info); - if (part_type == PART_TYPE_UNKNOWN) { drv = part_driver_lookup_type(desc); } else { @@ -339,18 +358,16 @@ int part_get_info_by_type(struct blk_desc *desc, int part, int part_type, desc->part_type); return -EPROTONOSUPPORT; } - if (!drv->get_info) { - PRINTF("## Driver %s does not have the get_info() method\n", - drv->name); - return -ENOSYS; - } - if (drv->get_info(desc, part, info) == 0) { + + ret = part_driver_get_info(drv, desc, part, info); + if (ret && ret != -ENOSYS) { + ret = -ENOENT; + } else { PRINTF("## Valid %s partition found ##\n", drv->name); - return 0; } } - return -ENOENT; + return ret; } int part_get_info(struct blk_desc *desc, int part, @@ -657,15 +674,12 @@ int part_get_info_by_name(struct blk_desc *desc, const char *name, if (!part_drv) return -1; - if (!part_drv->get_info) { - log_debug("## Driver %s does not have the get_info() method\n", - part_drv->name); - return -ENOSYS; - } - for (i = 1; i < part_drv->max_entries; i++) { - ret = part_drv->get_info(desc, i, info); + ret = part_driver_get_info(part_drv, desc, i, info); if (ret != 0) { + /* -ENOSYS means no ->get_info method. */ + if (ret == -ENOSYS) + return ret; /* * Partition with this index can't be obtained, but * further partitions might be, so keep checking. @@ -695,15 +709,12 @@ int part_get_info_by_uuid(struct blk_desc *desc, const char *uuid, if (!part_drv) return -1; - if (!part_drv->get_info) { - log_debug("## Driver %s does not have the get_info() method\n", - part_drv->name); - return -ENOSYS; - } - for (i = 1; i < part_drv->max_entries; i++) { - ret = part_drv->get_info(desc, i, info); + ret = part_driver_get_info(part_drv, desc, i, info); if (ret != 0) { + /* -ENOSYS means no ->get_info method. */ + if (ret == -ENOSYS) + return ret; /* * Partition with this index can't be obtained, but * further partitions might be, so keep checking. diff --git a/include/part.h b/include/part.h index 6caaa6526aa..d940f8b5d0e 100644 --- a/include/part.h +++ b/include/part.h @@ -509,6 +509,22 @@ struct part_driver { int (*test)(struct blk_desc *desc); }; +/** + * part_driver_get_info() - Call the part_driver's get_info method + * + * On success, string members of info are guaranteed to be properly + * initialized, though they may be empty. + * + * @drv: Partition driver + * @desc: Block device descriptor + * @part: Partition number to read + * @info: Returned partition information + * + * Return: 0 on success, negative errno on failure. + */ +int part_driver_get_info(struct part_driver *drv, struct blk_desc *desc, int part, + struct disk_partition *info); + /* Declare a new U-Boot partition 'driver' */ #define U_BOOT_PART_TYPE(__name) \ ll_entry_declare(struct part_driver, __name, part_driver)