From fb8e9df79b17cad37117ba7f2e5d202e7af12f42 Mon Sep 17 00:00:00 2001 From: Michael Bommarito Date: Sat, 6 Jun 2026 13:07:21 -0400 Subject: [PATCH] partitions: aix: bound the lvd scan to one sector 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 --- 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 f3c4174e003e9..5229298e636e3 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;