Eric Lee / smarc-ti-linux-kernel

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Commit 32bf08a6257b9c7380dcd040af3c0858eee3ef05

Authored by Alexei Starovoitov
Committed by David S. Miller
1 parent 78fd1d0ab0
Exists in ti-lsk-linux-4.1.y and in 10 other branches dlt-processor-sdk-linux-03.00.00.04, processor-sdk-linux-02.00.01, smarc-ti-lsk-linux-4.1.y, smarct3x-processor-sdk-04.01.00.06, smarct3x-processor-sdk-linux-02.00.01, smarct3x-processor-sdk-linux-03.00.00.04, smarct4x-800-processor-sdk-linux-02.00.01, smarct4x-processor-sdk-04.01.00.06, smarct4x-processor-sdk-linux-02.00.01, smarct4x-processor-sdk-linux-03.00.00.04

bpf: fix bug in eBPF verifier 

while comparing for verifier state equivalency the comparison
was missing a check for uninitialized register.
Make sure it does so and add a testcase.

Fixes: f1bca824dabb ("bpf: add search pruning optimization to verifier")
Cc: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Showing 2 changed files with 13 additions and 1 deletions Side-by-side Diff

kernel/bpf/verifier.c
Diff comments   View file @ 32bf08a
... ... @@ -1409,7 +1409,8 @@
1409 1409 if (memcmp(&old->regs[i], &cur->regs[i],
1410 1410 sizeof(old->regs[0])) != 0) {
1411 1411 if (old->regs[i].type == NOT_INIT ||
1412   - old->regs[i].type == UNKNOWN_VALUE)
  1412 + (old->regs[i].type == UNKNOWN_VALUE &&
  1413 + cur->regs[i].type != NOT_INIT))
1413 1414 continue;
1414 1415 return false;
1415 1416 }
samples/bpf/test_verifier.c
Diff comments   View file @ 32bf08a
... ... @@ -209,6 +209,17 @@
209 209 .result = REJECT,
210 210 },
211 211 {
  212 + "program doesn't init R0 before exit in all branches",
  213 + .insns = {
  214 + BPF_JMP_IMM(BPF_JGE, BPF_REG_1, 0, 2),
  215 + BPF_MOV64_IMM(BPF_REG_0, 1),
  216 + BPF_ALU64_IMM(BPF_ADD, BPF_REG_0, 2),
  217 + BPF_EXIT_INSN(),
  218 + },
  219 + .errstr = "R0 !read_ok",
  220 + .result = REJECT,
  221 + },
  222 + {
212 223 "stack out of bounds",
213 224 .insns = {
214 225 BPF_ST_MEM(BPF_DW, BPF_REG_10, 8, 0),