[PATCH] mm/vmalloc: Do not trigger BUG() on BH disabled context

[PATCH] mm/vmalloc: Do not trigger BUG() on BH disabled context

[Uladzislau Rezki (Sony)]

__get_vm_area_node() currently triggers a BUG() if in_interrupt()
returns true. However, in_interrupt() also reports true when BH
are disabled.

The bridge code can call rhashtable_lookup_insert_fast() with
bottom halves disabled:

__vlan_add()
 -> br_fdb_add_local()
  spin_lock_bh(&br->hash_lock); <-- Disable BH
   -> fdb_add_local()
    -> fdb_create()
     -> rhashtable_lookup_insert_fast()
      -> kvmalloc()
       -> vmalloc()
        -> __get_vm_area_node()
         -> BUG_ON(in_interrupt())
  spin_unlock_bh(&br->hash_lock)

this triggers the BUG() despite the caller not being in NMI or
hard IRQ context.

Replace the in_interrupt() check with in_nmi() || in_hardirq().

Cc: Ido Schimmel <idosch@nvidia.com>
Fixes: c6307674ed82 ("mm: kvmalloc: add non-blocking support for vmalloc")
Reported-by: syzbot+8b12fc6e0fb139765b58@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/69ff8c7c.050a0220.1036b8.000b.GAE@google.com/
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
---
 mm/vmalloc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 676851d5cfe7..273bbe49eaef 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -3209,7 +3209,7 @@ struct vm_struct *__get_vm_area_node(unsigned long size,
 	struct vm_struct *area;
 	unsigned long requested_size = size;
 
-	BUG_ON(in_interrupt());
+	BUG_ON(in_nmi() || in_hardirq());
 	size = ALIGN(size, 1ul << shift);
 	if (unlikely(!size))
 		return NULL;
-- 
2.47.3