On Tue, May 07, 2024 at 05:19:29PM +0800, Edward Adam Davis wrote:
> When got too small clean field, entry will never equal
> vstruct_end(&clean->field),
> the dead loop resulted in out of bounds access.
>
> Fixes: 12bf93a429c9 ("bcachefs: Add .to_text() methods for all superblock
> sections")
> Fixes: a37ad1a3aba9 ("bcachefs: sb-clean.c")
> Reported-and-tested-by: [email protected]
> Signed-off-by: Edward Adam Davis <[email protected]>
I've already got a patch up for this - the validation was missing as
well.
commit f39055220f6f98a180e3503fe05bbf9921c425c8
Author: Kent Overstreet <[email protected]>
Date: Sun May 5 22:28:00 2024 -0400
bcachefs: Add missing validation for superblock section clean
We were forgetting to check for jset entries that overrun the end of the
section - both in validate and to_text(); to_text() needs to be safe for
types that fail to validate.
Reported-by: [email protected]
Signed-off-by: Kent Overstreet <[email protected]>
diff --git a/fs/bcachefs/sb-clean.c b/fs/bcachefs/sb-clean.c
index 35ca3f138de6..194e55b11137 100644
--- a/fs/bcachefs/sb-clean.c
+++ b/fs/bcachefs/sb-clean.c
@@ -278,6 +278,17 @@ static int bch2_sb_clean_validate(struct bch_sb *sb,
return -BCH_ERR_invalid_sb_clean;
}
+ for (struct jset_entry *entry = clean->start;
+ entry != vstruct_end(&clean->field);
+ entry = vstruct_next(entry)) {
+ if ((void *) vstruct_next(entry) > vstruct_end(&clean->field)) {
+ prt_str(err, "entry type ");
+ bch2_prt_jset_entry_type(err, le16_to_cpu(entry->type));
+ prt_str(err, " overruns end of section");
+ return -BCH_ERR_invalid_sb_clean;
+ }
+ }
+
return 0;
}
@@ -295,6 +306,9 @@ static void bch2_sb_clean_to_text(struct printbuf *out,
struct bch_sb *sb,
for (entry = clean->start;
entry != vstruct_end(&clean->field);
entry = vstruct_next(entry)) {
+ if ((void *) vstruct_next(entry) > vstruct_end(&clean->field))
+ break;
+
if (entry->type == BCH_JSET_ENTRY_btree_keys &&
!entry->u64s)
continue;
