On Tue, Feb 24, 2026 at 4:35 PM T.J. Mercier <[email protected]> wrote: > > Dmabuf name allocations can be less than DMA_BUF_NAME_LEN characters, > but bpf_probe_read_kernel always tries to read exactly that many bytes. > If a name is less than DMA_BUF_NAME_LEN characters, > bpf_probe_read_kernel will read past the end. bpf_probe_read_kernel_str > stops at the first NUL terminator so use it instead, like > iter_dmabuf_for_each already does. > > Fixes: ae5d2c59ecd7 ("selftests/bpf: Add test for dmabuf_iter") > Reported-by: Sukadev Bhattiprolu <[email protected]>
Sukadev just let me know that Jerome Lee <[email protected]> should actually be the reporter here. > Signed-off-by: T.J. Mercier <[email protected]> > --- > tools/testing/selftests/bpf/progs/dmabuf_iter.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/tools/testing/selftests/bpf/progs/dmabuf_iter.c > b/tools/testing/selftests/bpf/progs/dmabuf_iter.c > index 13cdb11fdeb2..9cbb7442646e 100644 > --- a/tools/testing/selftests/bpf/progs/dmabuf_iter.c > +++ b/tools/testing/selftests/bpf/progs/dmabuf_iter.c > @@ -48,7 +48,7 @@ int dmabuf_collector(struct bpf_iter__dmabuf *ctx) > > /* Buffers are not required to be named */ > if (pname) { > - if (bpf_probe_read_kernel(name, sizeof(name), pname)) > + if (bpf_probe_read_kernel_str(name, sizeof(name), pname) < 0) > return 1; > > /* Name strings can be provided by userspace */ > -- > 2.53.0.414.gf7e9f6c205-goog >
