| Message ID | 20230605150116.29911-1-alejandro.vallejo@cloud.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | x86/microcode: Add missing unlock in microcode_update_helper() | expand |
On 05/06/2023 4:01 pm, Alejandro Vallejo wrote: > 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. Fixes: 5ed12565aa32 ("microcode: rendezvous CPUs in NMI handler and load ucode") > Signed-off-by: Alejandro Vallejo <alejandro.vallejo@cloud.com> Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com> I'll add the fixes on commit. ~Andrew
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);
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 <alejandro.vallejo@cloud.com> --- xen/arch/x86/cpu/microcode/core.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)