From: Jamin Lin <jamin_...@aspeedtech.com>
The maximum padding size is either 64 or 128 bytes and should always be smaller
than "req_len". If "padding_size" exceeds "req_len", then
"req_len - padding_size" underflows due to "uint32_t" data type, leading to a
large incorrect value (e.g., `0xFFXXXXXX`). This causes an out-of-bounds memory
access, potentially leading to a buffer overflow.
Added a check to ensure "padding_size" does not exceed "req_len" before
computing "pad_offset". This prevents "req_len - padding_size" from underflowing
and avoids accessing invalid memory.
Signed-off-by: Jamin Lin <jamin_...@aspeedtech.com>
Reviewed-by: Cédric Le Goater <c...@redhat.com>
Fixes: 5cd7d8564a8b563da724b9e6264c967f0a091afa ("aspeed/hace: Support AST2600
HACE ")
Link:
https://lore.kernel.org/qemu-devel/20250321092623.2097234-3-jamin_...@aspeedtech.com
Signed-off-by: Cédric Le Goater <c...@redhat.com>
---
hw/misc/aspeed_hace.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/hw/misc/aspeed_hace.c b/hw/misc/aspeed_hace.c
index 32a5dbded3c6..d75da3335336 100644
--- a/hw/misc/aspeed_hace.c
+++ b/hw/misc/aspeed_hace.c
@@ -128,6 +128,11 @@ static bool has_padding(AspeedHACEState *s, struct iovec
*iov,
if (*total_msg_len <= s->total_req_len) {
uint32_t padding_size = s->total_req_len - *total_msg_len;
uint8_t *padding = iov->iov_base;
+
+ if (padding_size > req_len) {
+ return false;
+ }
+
*pad_offset = req_len - padding_size;
if (padding[*pad_offset] == 0x80) {
return true;
--
2.49.0
