| Age | Commit message (Collapse) | Author |
|---|
|
Previously, the verifier was treating all PTR_TO_STACK registers passed
to a helper call as potentially written to by the helper. However, all
calls to check_stack_range_initialized() already have precise access type
information available.
Rather than treat ACCESS_HELPER as a proxy for BPF_WRITE, pass
enum bpf_access_type to check_stack_range_initialized() to more
precisely track helper arguments.
One benefit from this precision is that registers tracked as valid
spills and passed as a read-only helper argument remain tracked after
the call. Rather than being marked STACK_MISC afterwards.
An additional benefit is the verifier logs are also more precise. For
this particular error, users will enjoy a slightly clearer message. See
included selftest updates for examples.
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Daniel Xu <dxu@dxuuu.xyz>
Link: https://lore.kernel.org/r/ff885c0e5859e0cd12077c3148ff0754cad4f7ed.1736886479.git.dxu@dxuuu.xyz
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
|
Add a __caps_unpriv annotation so that tests requiring specific
capabilities while dropping the rest can conveniently specify them
during selftest declaration instead of munging with capabilities at
runtime from the testing binary.
While at it, let us convert test_verifier_mtu to use this new support
instead.
Since we do not want to include linux/capability.h, we only defined the
four main capabilities BPF subsystem deals with in bpf_misc.h for use in
tests. If the user passes a CAP_SYS_NICE or anything else that's not
defined in the header, capability parsing code will return a warning.
Also reject strtol returning 0. CAP_CHOWN = 0 but we'll never need to
use it, and strtol doesn't errno on failed conversion. Fail the test in
such a case.
The original diff for this idea is available at link [0].
[0]: https://lore.kernel.org/bpf/a1e48f5d9ae133e19adc6adf27e19d585e06bab4.camel@gmail.com
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
[ Kartikeya: rebase on bpf-next, add warn to parse_caps, convert test_verifier_mtu ]
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20241204044757.1483141-4-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
|
Add a small test to pass an uninitialized mtu_len to the bpf_check_mtu()
helper to probe whether the verifier rejects it under !CAP_PERFMON.
# ./vmtest.sh -- ./test_progs -t verifier_mtu
[...]
./test_progs -t verifier_mtu
[ 1.414712] tsc: Refined TSC clocksource calibration: 3407.993 MHz
[ 1.415327] clocksource: tsc: mask: 0xffffffffffffffff max_cycles: 0x311fcd52370, max_idle_ns: 440795242006 ns
[ 1.416463] clocksource: Switched to clocksource tsc
[ 1.429842] bpf_testmod: loading out-of-tree module taints kernel.
[ 1.430283] bpf_testmod: module verification failed: signature and/or required key missing - tainting kernel
#510/1 verifier_mtu/uninit/mtu: write rejected:OK
#510 verifier_mtu:OK
Summary: 1/1 PASSED, 0 SKIPPED, 0 FAILED
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20241021152809.33343-5-daniel@iogearbox.net
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
