block/partitions/aix.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-)
aix_partition() reads the logical-volume descriptor array as a single
sector and then scans it:
if (numlvs && (d = read_part_sector(state, vgda_sector + 1, §))) {
struct lvd *p = (struct lvd *)d;
...
for (i = 0; foundlvs < numlvs && i < state->limit; i += 1) {
lvip[i].pps_per_lv = be16_to_cpu(p[i].num_lps);
p points at a single 512-byte sector, which holds 512 / sizeof(struct
lvd) = 16 entries, but the loop runs until foundlvs reaches the on-disk
numlvs or i reaches state->limit (DISK_MAX_PARTS, 256). numlvs is an
on-disk __be16 read straight from the volume group descriptor and is not
validated, so a crafted AIX image with numlvs larger than 16 and lvd
entries whose num_lps fields are zero (so foundlvs never advances) drives
the loop to read p[i] well past the end of the read sector buffer.
The 2014 off-by-one fix d97a86c170b4 hardened the matching write of
lvip[lv_ix] but left this read loop unbounded.
Bound the scan to the number of struct lvd entries that fit in the
sector that was actually read.
Fixes: 6ceea22bbbc8 ("partitions: add aix lvm partition support files")
Assisted-by: Claude:claude-opus-4-8
Signed-off-by: Michael Bommarito <michael.bommarito@gmail.com>
---
block/partitions/aix.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/block/partitions/aix.c b/block/partitions/aix.c
index 29b8f4cebb63d..6679e825ba329 100644
--- a/block/partitions/aix.c
+++ b/block/partitions/aix.c
@@ -208,7 +208,14 @@ int aix_partition(struct parsed_partitions *state)
if (n) {
int foundlvs = 0;
- for (i = 0; foundlvs < numlvs && i < state->limit; i += 1) {
+ /*
+ * The lvd array was read as a single sector; only the
+ * struct lvd entries that fit in it are valid. Bound the
+ * scan so an on-disk numlvs larger than that cannot walk
+ * the read buffer out of bounds.
+ */
+ for (i = 0; foundlvs < numlvs && i < state->limit &&
+ i < 512 / (int)sizeof(struct lvd); i += 1) {
lvip[i].pps_per_lv = be16_to_cpu(p[i].num_lps);
if (lvip[i].pps_per_lv)
foundlvs += 1;
base-commit: 5200f5f493f79f14bbdc349e402a40dfb32f23c8
--
2.53.0
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