| Message ID | 20220926151650.15293-1-fw@strlen.de (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [v2,mm] mm: fix BUG splat with kvmalloc + GFP_ATOMIC | expand |
On Mon 26-09-22 17:16:50, Florian Westphal wrote: > 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. > > Reported-by: Martin Zaharinov <micron10@gmail.com> > Fixes: a421ef303008 ("mm: allow !GFP_KERNEL allocations for kvmalloc") > Suggested-by: Michal Hocko <mhocko@suse.com> > Link: https://lore.kernel.org/linux-mm/Yy3MS2uhSgjF47dy@pc636/T/#t > Signed-off-by: Florian Westphal <fw@strlen.de> Maybe we can extend this to GFP_NOWAIT capable vmalloc call but I am not sure this exists or whether this is something vmalloc maintainers want to commit to. This is a clear and trivial fixup of the above commit. I would add this to the stable tree as well. Acked-by: Michal Hocko <mhocko@suse.com> Thanks! > --- > mm/util.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/mm/util.c b/mm/util.c > index c9439c66d8cf..346e40177bc6 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)); > -- > 2.35.1
diff --git a/mm/util.c b/mm/util.c index c9439c66d8cf..346e40177bc6 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));
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. Reported-by: Martin Zaharinov <micron10@gmail.com> Fixes: a421ef303008 ("mm: allow !GFP_KERNEL allocations for kvmalloc") Suggested-by: Michal Hocko <mhocko@suse.com> Link: https://lore.kernel.org/linux-mm/Yy3MS2uhSgjF47dy@pc636/T/#t Signed-off-by: Florian Westphal <fw@strlen.de> --- mm/util.c | 4 ++++ 1 file changed, 4 insertions(+)