generic: deny write to uImage.FIT sub-image partitions

Set policy bit to force read-only mode on uImage.FIT filesystem
sub-images mapped as block partitions by the FIT partition parser.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>
This commit is contained in:
Daniel Golle 2022-01-11 00:00:36 +00:00
parent 9ea2a9923a
commit 9072333533
3 changed files with 15 additions and 7 deletions

View File

@ -233,7 +233,7 @@ int parse_fit_partitions(struct parsed_partitions *state, u64 fit_start_sector,
strlcat(state->pp_buf, tmp, PAGE_SIZE);
state->parts[*slot].has_info = true;
state->parts[*slot].flags |= ADDPART_FLAG_READONLY;
if (config_loadables && !strcmp(image_name, config_loadables)) {
printk(KERN_DEBUG "FIT: selecting configured loadable \"%s\" to be root filesystem\n", image_name);
state->parts[*slot].flags |= ADDPART_FLAG_ROOTDEV;

View File

@ -1,10 +1,11 @@
--- a/block/blk.h
+++ b/block/blk.h
@@ -361,6 +361,7 @@ char *disk_name(struct gendisk *hd, int
@@ -361,6 +361,8 @@ char *disk_name(struct gendisk *hd, int
#define ADDPART_FLAG_NONE 0
#define ADDPART_FLAG_RAID 1
#define ADDPART_FLAG_WHOLEDISK 2
+#define ADDPART_FLAG_ROOTDEV 4
+#define ADDPART_FLAG_READONLY 4
+#define ADDPART_FLAG_ROOTDEV 8
void delete_partition(struct hd_struct *part);
int bdev_add_partition(struct block_device *bdev, int partno,
sector_t start, sector_t length);
@ -108,13 +109,16 @@
#ifdef CONFIG_FAIL_MAKE_REQUEST
&dev_attr_fail.attr,
#endif
@@ -701,6 +722,11 @@ static bool blk_add_partition(struct gen
@@ -701,6 +722,14 @@ static bool blk_add_partition(struct gen
(state->parts[p].flags & ADDPART_FLAG_RAID))
md_autodetect_dev(part_to_dev(part)->devt);
+#ifdef CONFIG_FIT_PARTITION
+ if ((state->parts[p].flags & ADDPART_FLAG_ROOTDEV) && ROOT_DEV == 0)
+ ROOT_DEV = part_to_dev(part)->devt;
+
+ if (state->parts[p].flags & ADDPART_FLAG_READONLY)
+ part->policy = true;
+#endif
+
return true;

View File

@ -91,13 +91,16 @@
#ifdef CONFIG_FAIL_MAKE_REQUEST
&dev_attr_fail.attr,
#endif
@@ -641,6 +659,10 @@ rescan:
@@ -641,6 +659,13 @@ rescan:
if (state->parts[p].flags & ADDPART_FLAG_RAID)
md_autodetect_dev(part_to_dev(part)->devt);
#endif
+#ifdef CONFIG_FIT_PARTITION
+ if ((state->parts[p].flags & ADDPART_FLAG_ROOTDEV) && ROOT_DEV == 0)
+ ROOT_DEV = part_to_dev(part)->devt;
+
+ if (state->parts[p].flags & ADDPART_FLAG_READONLY)
+ part->policy = true;
+#endif
}
free_partitions(state);
@ -124,11 +127,12 @@
#endif
--- a/include/linux/genhd.h
+++ b/include/linux/genhd.h
@@ -614,6 +614,7 @@ struct unixware_disklabel {
@@ -614,6 +614,8 @@ struct unixware_disklabel {
#define ADDPART_FLAG_NONE 0
#define ADDPART_FLAG_RAID 1
#define ADDPART_FLAG_WHOLEDISK 2
+#define ADDPART_FLAG_ROOTDEV 4
+#define ADDPART_FLAG_READONLY 4
+#define ADDPART_FLAG_ROOTDEV 8
extern int blk_alloc_devt(struct hd_struct *part, dev_t *devt);
extern void blk_free_devt(dev_t devt);