diff options
| author | Song Liu <song@kernel.org> | 2022-05-20 16:57:53 -0700 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2022-05-23 23:08:11 +0200 |
| commit | fe736565efb775620dbcf3c459c1cd80d3e868da (patch) | |
| tree | 36163c41f35163deb7c0604f8561b3074967bf47 /kernel/bpf | |
| parent | aadd1b678ebef81cc3ed23663253ae3749cdc673 (diff) | |
bpf: Introduce bpf_arch_text_invalidate for bpf_prog_pack
Introduce bpf_arch_text_invalidate and use it to fill unused part of the
bpf_prog_pack with illegal instructions when a BPF program is freed.
Fixes: 57631054fae6 ("bpf: Introduce bpf_prog_pack allocator")
Fixes: 33c9805860e5 ("bpf: Introduce bpf_jit_binary_pack_[alloc|finalize|free]")
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20220520235758.1858153-4-song@kernel.org
Diffstat (limited to 'kernel/bpf')
| -rw-r--r-- | kernel/bpf/core.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index 2d0c9d4696ad..cacd8684c3c4 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -968,6 +968,9 @@ static void bpf_prog_pack_free(struct bpf_binary_header *hdr) nbits = BPF_PROG_SIZE_TO_NBITS(hdr->size); pos = ((unsigned long)hdr - (unsigned long)pack_ptr) >> BPF_PROG_CHUNK_SHIFT; + WARN_ONCE(bpf_arch_text_invalidate(hdr, hdr->size), + "bpf_prog_pack bug: missing bpf_arch_text_invalidate?\n"); + bitmap_clear(pack->bitmap, pos, nbits); if (bitmap_find_next_zero_area(pack->bitmap, bpf_prog_chunk_count(), 0, bpf_prog_chunk_count(), 0) == 0) { @@ -2740,6 +2743,11 @@ void * __weak bpf_arch_text_copy(void *dst, void *src, size_t len) return ERR_PTR(-ENOTSUPP); } +int __weak bpf_arch_text_invalidate(void *dst, size_t len) +{ + return -ENOTSUPP; +} + DEFINE_STATIC_KEY_FALSE(bpf_stats_enabled_key); EXPORT_SYMBOL(bpf_stats_enabled_key); |