linux/kernel/bpf
Josef Bacik e2d2afe15e bpf: fix states equal logic for varlen access
If we have a branch that looks something like this

int foo = map->value;
if (condition) {
  foo += blah;
} else {
  foo = bar;
}
map->array[foo] = baz;

We will incorrectly assume that the !condition branch is equal to the condition
branch as the register for foo will be UNKNOWN_VALUE in both cases.  We need to
adjust this logic to only do this if we didn't do a varlen access after we
processed the !condition branch, otherwise we have different ranges and need to
check the other branch as well.

Fixes: 484611357c ("bpf: allow access into map value arrays")
Reported-by: Jann Horn <jannh@google.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-11-30 14:50:52 -05:00
..
Makefile bpf: introduce percpu_freelist 2016-03-08 15:28:31 -05:00
arraymap.c bpf: Add bpf_current_task_under_cgroup helper 2016-08-12 21:49:41 -07:00
core.c bpf: clean up put_cpu_var usage 2016-09-27 22:09:17 -04:00
hashtab.c bpf: fix htab map destruction when extra reserve is in use 2016-11-07 13:20:52 -05:00
helpers.c bpf: direct packet write and access for helpers for clsact progs 2016-09-20 23:32:11 -04:00
inode.c fs: Replace CURRENT_TIME with current_time() for inode timestamps 2016-09-27 21:06:21 -04:00
percpu_freelist.c bpf: introduce percpu_freelist 2016-03-08 15:28:31 -05:00
percpu_freelist.h bpf: introduce percpu_freelist 2016-03-08 15:28:31 -05:00
stackmap.c bpf: add BPF_CALL_x macros for declaring helpers 2016-09-09 19:36:04 -07:00
syscall.c bpf: fix map not being uncharged during map creation failure 2016-11-07 13:22:26 -05:00
verifier.c bpf: fix states equal logic for varlen access 2016-11-30 14:50:52 -05:00