Re: [PATCH] macintosh:fix oob read in do_adb_query function
From: Kees Cook <hidden>
Date: 2022-07-13 18:54:26
On Wed, Jul 13, 2022 at 11:37:34PM +0800, Ning Qiang wrote:
In do_adb_query function of drivers/macintosh/adb.c, req->data is copy form userland. the parameter "req->data[2]" is Missing check, the array size of adb_handler[] is 16, so "adb_handler[ req->data[2]].original_address" and "adb_handler[ req->data[2]].handler_id" will lead to oob read. Signed-off-by: Ning Qiang <redacted>
Thanks for catching this! Do you have a reproducer for this? I'd expect CONFIG_UBSAN_BOUNDS=y to notice this at runtime, at least.
quoted hunk ↗ jump to hunk
--- drivers/macintosh/adb.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)diff --git a/drivers/macintosh/adb.c b/drivers/macintosh/adb.c index 439fab4eaa85..1bbb9ca08d40 100644 --- a/drivers/macintosh/adb.c +++ b/drivers/macintosh/adb.c@@ -647,7 +647,7 @@ do_adb_query(struct adb_request *req) switch(req->data[1]) { case ADB_QUERY_GETDEVINFO: - if (req->nbytes < 3) + if (req->nbytes < 3 || req->data[2] >= 16)
I'd prefer this was: + if (req->nbytes < 3 || req->data[2] >= ARRAY_SIZE(adb_handler)) so it's tied to the actual variable (if its size ever changes). With that: Reviewed-by: Kees Cook <redacted> -Kees
break; mutex_lock(&adb_handler_mutex); req->reply[0] = adb_handler[req->data[2]].original_address; -- 2.25.1
-- Kees Cook