diff options
| author | Michael Kelley <mhklinux@outlook.com> | 2025-04-21 09:31:34 -0700 |
|---|---|---|
| committer | Wei Liu <wei.liu@kernel.org> | 2025-04-25 21:13:53 +0000 |
| commit | 14ae3003e73e777c9b36385a7c86f754b50a1821 (patch) | |
| tree | 35fd7656680c2aeb45f7a314af0cea3854b8cb36 | |
| parent | 9bbb8a07fd65fca0f29a869ec3f2435761a6c676 (diff) | |
| download | linux-hyperv-fixes.tar.gz | |
Drivers: hv: Fix bad ref to hv_synic_eventring_tail when CPU goes offlinehyperv-fixes-signed-20250427hyperv-fixes-staginghyperv-fixes
When a CPU goes offline, hv_common_cpu_die() frees the
hv_synic_eventring_tail memory for the CPU. But in a normal VM (i.e., not
running in the root partition) the per-CPU memory has not been allocated,
resulting in a bad memory reference and oops when computing the argument
to kfree().
Fix this by freeing the memory only when running in the root partition.
Fixes: 04df7ac39943 ("Drivers: hv: Introduce per-cpu event ring tail")
Signed-off-by: Michael Kelley <mhklinux@outlook.com>
Reviewed-by: Nuno Das Neves <nunodasneves@linux.microsoft.com>
Link: https://lore.kernel.org/r/20250421163134.2024-1-mhklinux@outlook.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Message-ID: <20250421163134.2024-1-mhklinux@outlook.com>
| -rw-r--r-- | drivers/hv/hv_common.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/drivers/hv/hv_common.c b/drivers/hv/hv_common.c index a7d7494feaca13..59792e00cecf38 100644 --- a/drivers/hv/hv_common.c +++ b/drivers/hv/hv_common.c @@ -566,9 +566,11 @@ int hv_common_cpu_die(unsigned int cpu) * originally allocated memory is reused in hv_common_cpu_init(). */ - synic_eventring_tail = this_cpu_ptr(hv_synic_eventring_tail); - kfree(*synic_eventring_tail); - *synic_eventring_tail = NULL; + if (hv_root_partition()) { + synic_eventring_tail = this_cpu_ptr(hv_synic_eventring_tail); + kfree(*synic_eventring_tail); + *synic_eventring_tail = NULL; + } return 0; } |