diff options
| author | Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> | 2026-05-07 15:43:59 +0000 |
|---|---|---|
| committer | Wei Liu <wei.liu@kernel.org> | 2026-07-22 23:51:30 +0000 |
| commit | a9708e550d11a53b22d932cdbfaa10c26346a2d0 (patch) | |
| tree | 71f67f645f7c95d52368f60bfdca3ab5506f3e66 | |
| parent | 649dd135491945afa544351e3e6d4a727de87020 (diff) | |
mshv: Fix sleeping under spinlock in mshv_portid_alloc
idr_alloc() is called with GFP_KERNEL inside idr_lock(), which holds a
spinlock. GFP_KERNEL allows the allocator to sleep, triggering a
sleeping-while-atomic bug.
Fix by using idr_preload(GFP_KERNEL) before taking the lock to
pre-allocate memory in a sleepable context, then idr_alloc() with
GFP_NOWAIT inside the spinlock-protected section.
Fixes: 621191d709b1 ("Drivers: hv: Introduce mshv_root module to expose /dev/mshv to VMMs")
Signed-off-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>
Reviewed-by: Anirudh Rayabharam (Microsoft) <anirudh@anirudhrb.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
| -rw-r--r-- | drivers/hv/mshv_portid_table.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/hv/mshv_portid_table.c b/drivers/hv/mshv_portid_table.c index c349af1f0aaa..6f59b3e37624 100644 --- a/drivers/hv/mshv_portid_table.c +++ b/drivers/hv/mshv_portid_table.c @@ -40,12 +40,14 @@ mshv_port_table_fini(void) int mshv_portid_alloc(struct port_table_info *info) { - int ret = 0; + int ret; + idr_preload(GFP_KERNEL); idr_lock(&port_table_idr); ret = idr_alloc(&port_table_idr, info, PORTID_MIN, - PORTID_MAX, GFP_KERNEL); + PORTID_MAX, GFP_NOWAIT); idr_unlock(&port_table_idr); + idr_preload_end(); return ret; } |