A user trying out SMBIOS "OEM strings" feature reported that the data they are exposing to the guest was truncated at 1023 bytes, which breaks the app consuming in the guest. After searching for the cause I eventually found that the QemuOpts parsing is using fixed length 1024 byte array for option values and 128 byte array for key names.
We can certainly debate whether it is sane to have such long command line argument values (it is not sane), but if the OS was capable of exec'ing QEMU with such an ARGV array, there is little good reason for imposing an artificial length restriction when parsing it. Even worse is that we silently truncate without reporting an error when hitting limits resulting in a semantically incorrect behaviour, possibly even leading to security flaws depending on the data that was truncated. Thus this patch series removes the artificial length limits by killing the fixed length buffers. Separately I intend to make it possible to read "OEM strings" data from a file, to avoid need to have long command line args. Daniel P. Berrangé (3): accel: use g_strsplit for parsing accelerator names opts: don't silently truncate long parameter keys opts: don't silently truncate long option values accel/accel.c | 16 +++--- hw/i386/multiboot.c | 33 +++++++---- include/qemu/option.h | 3 +- tests/test-qemu-opts.c | 18 ------ util/qemu-option.c | 150 ++++++++++++++++++++++++++----------------------- 5 files changed, 108 insertions(+), 112 deletions(-) -- 2.14.3