From ea33cb6fc2788f9fe248d49e1c0b2553a58436ef Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Tue, 11 Jul 2023 11:20:44 +0300 Subject: accel/qaic: tighten bounds checking in encode_message() There are several issues in this code. The check at the start of the loop: if (user_len >= user_msg->len) { This check does not ensure that we have enough space for the trans_hdr (8 bytes). Instead the check needs to be: if (user_len > user_msg->len - sizeof(*trans_hdr)) { That subtraction is done as an unsigned long we want to avoid negatives. Add a lower bound to the start of the function. if (user_msg->len < sizeof(*trans_hdr)) There is a second integer underflow which can happen if trans_hdr->len is zero inside the encode_passthrough() function. memcpy(out_trans->data, in_trans->data, in_trans->hdr.len - sizeof(in_trans->hdr)); Instead of adding a check to encode_passthrough() it's better to check in this central place. Add that check: if (trans_hdr->len < sizeof(trans_hdr) The final concern is that the "user_len + trans_hdr->len" might have an integer overflow bug. Use size_add() to prevent that. - if (user_len + trans_hdr->len > user_msg->len) { + if (size_add(user_len, trans_hdr->len) > user_msg->len) { Fixes: 129776ac2e38 ("accel/qaic: Add control path") Signed-off-by: Dan Carpenter Reviewed-by: Pranjal Ramajor Asha Kanojiya Reviewed-by: Jeffrey Hugo Cc: stable@vger.kernel.org # 6.4.x Signed-off-by: Jeffrey Hugo Link: https://patchwork.freedesktop.org/patch/msgid/9a0cb0c1-a974-4f10-bc8d-94437983639a@moroto.mountain --- drivers/accel/qaic/qaic_control.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) (limited to 'drivers/accel') diff --git a/drivers/accel/qaic/qaic_control.c b/drivers/accel/qaic/qaic_control.c index 5c57f7b4494e..2fdd5959c52f 100644 --- a/drivers/accel/qaic/qaic_control.c +++ b/drivers/accel/qaic/qaic_control.c @@ -14,6 +14,7 @@ #include #include #include +#include #include #include #include @@ -748,7 +749,8 @@ static int encode_message(struct qaic_device *qdev, struct manage_msg *user_msg, int ret; int i; - if (!user_msg->count) { + if (!user_msg->count || + user_msg->len < sizeof(*trans_hdr)) { ret = -EINVAL; goto out; } @@ -765,12 +767,13 @@ static int encode_message(struct qaic_device *qdev, struct manage_msg *user_msg, } for (i = 0; i < user_msg->count; ++i) { - if (user_len >= user_msg->len) { + if (user_len > user_msg->len - sizeof(*trans_hdr)) { ret = -EINVAL; break; } trans_hdr = (struct qaic_manage_trans_hdr *)(user_msg->data + user_len); - if (user_len + trans_hdr->len > user_msg->len) { + if (trans_hdr->len < sizeof(trans_hdr) || + size_add(user_len, trans_hdr->len) > user_msg->len) { ret = -EINVAL; break; } -- cgit v1.2.3