microcode_update_helper() may return early while holding cpu_add_remove_lock, hence preventing any writers from taking it again.
Leave through the `put` label instead so it's properly released. Signed-off-by: Alejandro Vallejo <[email protected]> --- xen/arch/x86/cpu/microcode/core.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/xen/arch/x86/cpu/microcode/core.c b/xen/arch/x86/cpu/microcode/core.c index c1033f3bc2..e65af4b82e 100644 --- a/xen/arch/x86/cpu/microcode/core.c +++ b/xen/arch/x86/cpu/microcode/core.c @@ -599,7 +599,8 @@ static long cf_check microcode_update_helper(void *data) printk(XENLOG_WARNING "CPU%u is expected to lead ucode loading (but got CPU%u)\n", nmi_cpu, cpumask_first(&cpu_online_map)); - return -EPERM; + ret = -EPERM; + goto put; } patch = parse_blob(buffer->buffer, buffer->len); -- 2.34.1
