From 98d0945a74ba472af928237a17f4087e18d958f9 Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Mon, 26 Sep 2022 17:16:50 +0200 Subject: [PATCH] mm: fix BUG splat with kvmalloc + GFP_ATOMIC Martin Zaharinov reports BUG with 5.19.10 kernel: kernel BUG at mm/vmalloc.c:2437! invalid opcode: 0000 [#1] SMP CPU: 28 PID: 0 Comm: swapper/28 Tainted: G W O 5.19.9 #1 [..] RIP: 0010:__get_vm_area_node+0x120/0x130 __vmalloc_node_range+0x96/0x1e0 kvmalloc_node+0x92/0xb0 bucket_table_alloc.isra.0+0x47/0x140 rhashtable_try_insert+0x3a4/0x440 rhashtable_insert_slow+0x1b/0x30 [..] bucket_table_alloc uses kvzalloc(GPF_ATOMIC). If kmalloc fails, this now falls through to vmalloc and hits code paths that assume GFP_KERNEL. Link: https://lkml.kernel.org/r/20220926151650.15293-1-fw@strlen.de Fixes: 318e576ba783 ("mm: allow !GFP_KERNEL allocations for kvmalloc") Signed-off-by: Florian Westphal Suggested-by: Michal Hocko Link: https://lore.kernel.org/linux-mm/Yy3MS2uhSgjF47dy@pc636/T/#t Acked-by: Michal Hocko Reported-by: Martin Zaharinov Cc: Uladzislau Rezki (Sony) Cc: Vlastimil Babka Cc: Signed-off-by: Andrew Morton --- mm/util.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/mm/util.c b/mm/util.c index c9439c66d8cf4..346e40177bc65 100644 --- a/mm/util.c +++ b/mm/util.c @@ -619,6 +619,10 @@ void *kvmalloc_node(size_t size, gfp_t flags, int node) if (ret || size <= PAGE_SIZE) return ret; + /* non-sleeping allocations are not supported by vmalloc */ + if (!gfpflags_allow_blocking(flags)) + return NULL; + /* Don't even allow crazy sizes */ if (unlikely(size > INT_MAX)) { WARN_ON_ONCE(!(flags & __GFP_NOWARN)); -- 2.39.5