006c0e44ed
Extend prog_tests with two test cases: # ./test_progs --allow=verifier_netfilter_retcode #278/1 verifier_netfilter_retcode/bpf_exit with invalid return code. test1:OK #278/2 verifier_netfilter_retcode/bpf_exit with valid return code. test2:OK #278/3 verifier_netfilter_retcode/bpf_exit with valid return code. test3:OK #278/4 verifier_netfilter_retcode/bpf_exit with invalid return code. test4:OK #278 verifier_netfilter_retcode:OK This checks that only accept and drop (0,1) are permitted. NF_QUEUE could be implemented later if we can guarantee that attachment of such programs can be rejected if they get attached to a pf/hook that doesn't support async reinjection. NF_STOLEN could be implemented via trusted helpers that can guarantee that the skb will eventually be free'd. v4: test case for bpf_nf_ctx access checks, requested by Alexei Starovoitov. v5: also check ctx->{state,skb} can be dereferenced (Alexei). # ./test_progs --allow=verifier_netfilter_ctx #281/1 verifier_netfilter_ctx/netfilter invalid context access, size too short:OK #281/2 verifier_netfilter_ctx/netfilter invalid context access, size too short:OK #281/3 verifier_netfilter_ctx/netfilter invalid context access, past end of ctx:OK #281/4 verifier_netfilter_ctx/netfilter invalid context, write:OK #281/5 verifier_netfilter_ctx/netfilter valid context read and invalid write:OK #281/6 verifier_netfilter_ctx/netfilter test prog with skb and state read access:OK #281/7 verifier_netfilter_ctx/netfilter test prog with skb and state read access @unpriv:OK #281 verifier_netfilter_ctx:OK Summary: 1/7 PASSED, 0 SKIPPED, 0 FAILED This checks: 1/2: partial reads of ctx->{skb,state} are rejected 3. read access past sizeof(ctx) is rejected 4. write to ctx content, e.g. 'ctx->skb = NULL;' is rejected 5. ctx->state content cannot be altered 6. ctx->state and ctx->skb can be dereferenced 7. ... same program fails for unpriv (CAP_NET_ADMIN needed). Link: https://lore.kernel.org/bpf/20230419021152.sjq4gttphzzy6b5f@dhcp-172-26-102-232.dhcp.thefacebook.com/ Link: https://lore.kernel.org/bpf/20230420201655.77kkgi3dh7fesoll@MacBook-Pro-6.local/ Signed-off-by: Florian Westphal <fw@strlen.de> Link: https://lore.kernel.org/r/20230421170300.24115-8-fw@strlen.de Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.