On 26/06/28 09:59PM, Nuoqi Gui wrote: > For gotox, CFG construction models the indirect-jump target set in > insn_aux_data->jt, while do_check() later follows targets from the runtime > PTR_TO_INSN register's own INSN_ARRAY map. If the same gotox can be > reached with PTR_TO_INSN values from different maps, do_check() can accept > a target outside the calling subprog.
Can we use some human-readable description here? Please just explain that maps considered during the config stage must be a super-set of maps checked runtime. > The observed x86 JIT case can then enter another subprog without a matching > BPF call frame and crash when the program is run. Sorry, but why the x86 is still here? > > Fix this by rejecting gotox map targets outside the current gotox subprog. > Add a regression test covering the two-map cross-subprog case. > > v1 -> v2: > - Validate gotox runtime targets against the current subprog bounds instead > of scanning the CFG jump table. > - Fix the selftest expected error from -EACCES to -EINVAL. > > v2 -> v3: > - Drop the Validation section from the cover letter. > - Clarify that the crash was observed through the x86 JIT path while the > verifier invariant is generic. > - Simplify the cover letter and commit message. > - Remove the unused skel argument from the raw-insn selftest. > - Move the raw-insn selftest to the end of test_bpf_gotox(). > > v1: > > https://lore.kernel.org/bpf/20260609-f01-03-gotox-bpf-next-v1-0-b441d63a1...@mails.tsinghua.edu.cn/ > > v2: > > https://lore.kernel.org/bpf/20260613-f01-03-gotox-bpf-next-v2-send-v2-0-7c883b43f...@mails.tsinghua.edu.cn/ > > Signed-off-by: Nuoqi Gui <[email protected]> > --- > Nuoqi Gui (2): > bpf: Enforce gotox targets against subprog bounds > selftests/bpf: Add cross-subprog gotox target coverage > > kernel/bpf/verifier.c | 19 ++++++ > tools/testing/selftests/bpf/prog_tests/bpf_gotox.c | 73 > ++++++++++++++++++++++ > 2 files changed, 92 insertions(+) > --- > base-commit: 7bfb93e3475be9de894f1cecd3a727d3e1649b03 > change-id: 20260628-f01-03-gotox-bpf-next-1a7af91d2c82 > > Best regards, > -- > Nuoqi Gui <[email protected]> >
