linux/kernel/bpf
Daniel Borkmann 3612af783c bpf: fix sanitation rewrite in case of non-pointers
Marek reported that he saw an issue with the below snippet in that
timing measurements where off when loaded as unpriv while results
were reasonable when loaded as privileged:

    [...]
    uint64_t a = bpf_ktime_get_ns();
    uint64_t b = bpf_ktime_get_ns();
    uint64_t delta = b - a;
    if ((int64_t)delta > 0) {
    [...]

Turns out there is a bug where a corner case is missing in the fix
d3bd7413e0 ("bpf: fix sanitation of alu op with pointer / scalar
type from different paths"), namely fixup_bpf_calls() only checks
whether aux has a non-zero alu_state, but it also needs to test for
the case of BPF_ALU_NON_POINTER since in both occasions we need to
skip the masking rewrite (as there is nothing to mask).

Fixes: d3bd7413e0 ("bpf: fix sanitation of alu op with pointer / scalar type from different paths")
Reported-by: Marek Majkowski <marek@cloudflare.com>
Reported-by: Arthur Fabre <afabre@cloudflare.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/netdev/CAJPywTJqP34cK20iLM5YmUMz9KXQOdu1-+BZrGMAGgLuBWz7fg@mail.gmail.com/T/
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-03-01 21:24:08 -08:00
..
Makefile
arraymap.c
bpf_lru_list.c
bpf_lru_list.h
btf.c
cgroup.c
core.c
cpumap.c
devmap.c
disasm.c
disasm.h
hashtab.c
helpers.c
inode.c
local_storage.c
lpm_trie.c
map_in_map.c
map_in_map.h
offload.c
percpu_freelist.c
percpu_freelist.h
queue_stack_maps.c
reuseport_array.c
stackmap.c
syscall.c
tnum.c
verifier.c
xskmap.c