From 3c2a9475334ae32997b3bce8d24b39c8ffa9fc67 Mon Sep 17 00:00:00 2001 From: Rasmus Villemoes Date: Mon, 10 Nov 2025 21:54:10 +0100 Subject: 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 --- disk/part.c | 63 ++++++++++++++++++++++++++++++++++++------------------------- 1 file changed, 37 insertions(+), 26 deletions(-) (limited to 'disk') 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. -- cgit v1.2.3