diff options
| author | Song Liu | 2022-03-21 11:00:08 -0700 |
|---|---|---|
| committer | Alexei Starovoitov | 2022-03-21 13:53:45 -0700 |
| commit | 96805674e5624b3c79780a2b41c7a3d6bc38dc76 (patch) | |
| tree | cb5323fa83da01aa49d7388482850e53fc6c627f /kernel/bpf | |
| parent | d56c9fe6a06820d5ef8188d96bf4345c7bdba249 (diff) | |
bpf: Fix bpf_prog_pack for multi-node setup
module_alloc requires num_online_nodes * PMD_SIZE to allocate huge pages.
bpf_prog_pack uses pack of size num_online_nodes * PMD_SIZE.
OTOH, module_alloc returns addresses that are PMD_SIZE aligned (instead of
num_online_nodes * PMD_SIZE aligned). Therefore, PMD_MASK should be used
to calculate pack_ptr in bpf_prog_pack_free().
Fixes: ef078600eec2 ("bpf: Select proper size for bpf_prog_pack")
Reported-by: syzbot+c946805b5ce6ab87df0b@syzkaller.appspotmail.com
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20220321180009.1944482-2-song@kernel.org
Diffstat (limited to 'kernel/bpf')
| -rw-r--r-- | kernel/bpf/core.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index 9d661e07e77c..f6b20fcbeb24 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -829,6 +829,7 @@ struct bpf_prog_pack { #define BPF_PROG_SIZE_TO_NBITS(size) (round_up(size, BPF_PROG_CHUNK_SIZE) / BPF_PROG_CHUNK_SIZE) static size_t bpf_prog_pack_size = -1; +static size_t bpf_prog_pack_mask = -1; static int bpf_prog_chunk_count(void) { @@ -850,8 +851,12 @@ static size_t select_bpf_prog_pack_size(void) /* Test whether we can get huge pages. If not just use PAGE_SIZE * packs. */ - if (!ptr || !is_vm_area_hugepages(ptr)) + if (!ptr || !is_vm_area_hugepages(ptr)) { size = PAGE_SIZE; + bpf_prog_pack_mask = PAGE_MASK; + } else { + bpf_prog_pack_mask = PMD_MASK; + } vfree(ptr); return size; @@ -935,7 +940,7 @@ static void bpf_prog_pack_free(struct bpf_binary_header *hdr) goto out; } - pack_ptr = (void *)((unsigned long)hdr & ~(bpf_prog_pack_size - 1)); + pack_ptr = (void *)((unsigned long)hdr & bpf_prog_pack_mask); list_for_each_entry(tmp, &pack_list, list) { if (tmp->ptr == pack_ptr) { |