Maxim Mikityanskiy 349e83c0cf bpf: Fix the off-by-two error in range markings ... commit 2fa7d94afc1afbb4d702760c058dc2d7ed30f226 upstream. The first commit cited below attempts to fix the off-by-one error that appeared in some comparisons with an open range. Due to this error, arithmetically equivalent pieces of code could get different verdicts from the verifier, for example (pseudocode): // 1. Passes the verifier: if (data + 8 > data_end) return early read *(u64 *)data, i.e. [data; data+7] // 2. Rejected by the verifier (should still pass): if (data + 7 >= data_end) return early read *(u64 *)data, i.e. [data; data+7] The attempted fix, however, shifts the range by one in a wrong direction, so the bug not only remains, but also such piece of code starts failing in the verifier: // 3. Rejected by the verifier, but the check is stricter than in #1. if (data + 8 >= data_end) return early read *(u64 *)data, i.e. [data; data+7] The change performed by that fix converted an off-by-one bug into off-by-two. The second commit cited below added the BPF selftests written to ensure than code chunks like #3 are rejected, however, they should be accepted. This commit fixes the off-by-two error by adjusting new_range in the right direction and fixes the tests by changing the range into the one that should actually fail. Fixes: fb2a311a31 ("bpf: fix off by one for range markings with L{T, E} patterns") Fixes: b37242c773 ("bpf: add test cases to bpf selftests to cover all access tests") Signed-off-by: Maxim Mikityanskiy <maximmi@nvidia.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20211130181607.593149-1-maximmi@nvidia.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2021-12-14 11:32:36 +01:00
..
preload
arraymap.c	bpf: Fix potential race in tail call compatibility check	2021-11-02 19:48:21 +01:00
bpf_inode_storage.c
bpf_iter.c
bpf_local_storage.c
bpf_lru_list.c
bpf_lru_list.h
bpf_lsm.c
bpf_struct_ops_types.h
bpf_struct_ops.c	bpf: Handle return value of BPF_PROG_TYPE_STRUCT_OPS prog	2021-10-06 15:55:50 +02:00
btf.c
cgroup.c
core.c	bpf: Prevent increasing bpf_jit_limit above max	2021-11-18 14:03:42 +01:00
cpumap.c
devmap.c
disasm.c
disasm.h
dispatcher.c
hashtab.c
helpers.c	bpf: Fix potentially incorrect results with bpf_get_local_storage()	2021-09-03 10:09:31 +02:00
inode.c
local_storage.c	bpf: Fix NULL pointer dereference in bpf_get_local_storage() helper	2021-09-03 10:09:21 +02:00
lpm_trie.c
Makefile
map_in_map.c
map_in_map.h
map_iter.c
net_namespace.c
offload.c
percpu_freelist.c
percpu_freelist.h
prog_iter.c
queue_stack_maps.c
reuseport_array.c
ringbuf.c
stackmap.c	bpf: Fix integer overflow in prealloc_elems_and_freelist()	2021-10-13 10:04:26 +02:00
syscall.c	bpf: Fix toctou on read-only map's constant scalar tracking	2021-12-01 09:18:58 +01:00
sysfs_btf.c
task_iter.c
tnum.c
trampoline.c
verifier.c	bpf: Fix the off-by-two error in range markings	2021-12-14 11:32:36 +01:00