| From: Florian Westphal <fw@strlen.de> |
| Subject: mm: fix BUG splat with kvmalloc + GFP_ATOMIC |
| Date: Mon, 26 Sep 2022 17:16:50 +0200 |
| |
| 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: a421ef303008 ("mm: allow !GFP_KERNEL allocations for kvmalloc") |
| Signed-off-by: Florian Westphal <fw@strlen.de> |
| Suggested-by: Michal Hocko <mhocko@suse.com> |
| Link: https://lore.kernel.org/linux-mm/Yy3MS2uhSgjF47dy@pc636/T/#t |
| Acked-by: Michal Hocko <mhocko@suse.com> |
| Reported-by: Martin Zaharinov <micron10@gmail.com> |
| Cc: Uladzislau Rezki (Sony) <urezki@gmail.com> |
| Cc: Vlastimil Babka <vbabka@suse.cz> |
| Cc: <stable@vger.kernel.org> |
| Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
| --- |
| |
| mm/util.c | 4 ++++ |
| 1 file changed, 4 insertions(+) |
| |
| --- a/mm/util.c~mm-fix-bug-splat-with-kvmalloc-gfp_atomic |
| +++ a/mm/util.c |
| @@ -619,6 +619,10 @@ void *kvmalloc_node(size_t size, gfp_t f |
| 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)); |
| _ |
