4.18-stable review patch. If anyone has any objections, please let me know.
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From: Tushar Dave tushar.n.dave@oracle.com
[ Upstream commit 4c3d795cb012a378855543a775408fba1ccff6f2 ]
Helper bpg_msg_pull_data() can allocate multiple pages while linearizing multiple scatterlist elements into one shared page. However, if the shared page has size > PAGE_SIZE, using copy_page_to_iter() causes below warning.
e.g. [ 6367.019832] WARNING: CPU: 2 PID: 7410 at lib/iov_iter.c:825 page_copy_sane.part.8+0x0/0x8
To avoid above warning, use __GFP_COMP while allocating multiple contiguous pages.
Fixes: 015632bb30da ("bpf: sk_msg program helper bpf_sk_msg_pull_data") Signed-off-by: Tushar Dave tushar.n.dave@oracle.com Signed-off-by: Daniel Borkmann daniel@iogearbox.net Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/core/filter.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/net/core/filter.c +++ b/net/core/filter.c @@ -2334,7 +2334,8 @@ BPF_CALL_4(bpf_msg_pull_data, if (unlikely(bytes_sg_total > copy)) return -EINVAL;
- page = alloc_pages(__GFP_NOWARN | GFP_ATOMIC, get_order(copy)); + page = alloc_pages(__GFP_NOWARN | GFP_ATOMIC | __GFP_COMP, + get_order(copy)); if (unlikely(!page)) return -ENOMEM; p = page_address(page);