| Message ID | 20191009164929.17242-1-i.maximets@ovn.org |
|---|---|
| State | Accepted |
| Delegated to: | BPF Maintainers |
| Headers | show |
| Series | [bpf,v2] libbpf: fix passing uninitialized bytes to setsockopt | expand |
On Wed, Oct 9, 2019 at 9:49 AM Ilya Maximets <i.maximets@ovn.org> wrote: > > 'struct xdp_umem_reg' has 4 bytes of padding at the end that makes > valgrind complain about passing uninitialized stack memory to the > syscall: > > Syscall param socketcall.setsockopt() points to uninitialised byte(s) > at 0x4E7AB7E: setsockopt (in /usr/lib64/libc-2.29.so) > by 0x4BDE035: xsk_umem__create@@LIBBPF_0.0.4 (xsk.c:172) > Uninitialised value was created by a stack allocation > at 0x4BDDEBA: xsk_umem__create@@LIBBPF_0.0.4 (xsk.c:140) > > Padding bytes appeared after introducing of a new 'flags' field. > memset() is required to clear them. > > Fixes: 10d30e301732 ("libbpf: add flags to umem config") > Signed-off-by: Ilya Maximets <i.maximets@ovn.org> > --- > Thanks! Acked-by: Andrii Nakryiko <andriin@fb.com> > Version 2: > * Struct initializer replaced with explicit memset(). [Andrii] > > tools/lib/bpf/xsk.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/tools/lib/bpf/xsk.c b/tools/lib/bpf/xsk.c > index a902838f9fcc..9d5348086203 100644 > --- a/tools/lib/bpf/xsk.c > +++ b/tools/lib/bpf/xsk.c > @@ -163,6 +163,7 @@ int xsk_umem__create_v0_0_4(struct xsk_umem **umem_ptr, void *umem_area, > umem->umem_area = umem_area; > xsk_set_umem_config(&umem->config, usr_config); > > + memset(&mr, 0, sizeof(mr)); > mr.addr = (uintptr_t)umem_area; > mr.len = size; > mr.chunk_size = umem->config.frame_size; > -- > 2.17.1 >
On Wed, Oct 9, 2019 at 9:49 AM Ilya Maximets <i.maximets@ovn.org> wrote: > > 'struct xdp_umem_reg' has 4 bytes of padding at the end that makes > valgrind complain about passing uninitialized stack memory to the > syscall: > > Syscall param socketcall.setsockopt() points to uninitialised byte(s) > at 0x4E7AB7E: setsockopt (in /usr/lib64/libc-2.29.so) > by 0x4BDE035: xsk_umem__create@@LIBBPF_0.0.4 (xsk.c:172) > Uninitialised value was created by a stack allocation > at 0x4BDDEBA: xsk_umem__create@@LIBBPF_0.0.4 (xsk.c:140) > > Padding bytes appeared after introducing of a new 'flags' field. > memset() is required to clear them. > > Fixes: 10d30e301732 ("libbpf: add flags to umem config") > Signed-off-by: Ilya Maximets <i.maximets@ovn.org> Applied. Thanks
diff --git a/tools/lib/bpf/xsk.c b/tools/lib/bpf/xsk.c index a902838f9fcc..9d5348086203 100644 --- a/tools/lib/bpf/xsk.c +++ b/tools/lib/bpf/xsk.c @@ -163,6 +163,7 @@ int xsk_umem__create_v0_0_4(struct xsk_umem **umem_ptr, void *umem_area, umem->umem_area = umem_area; xsk_set_umem_config(&umem->config, usr_config); + memset(&mr, 0, sizeof(mr)); mr.addr = (uintptr_t)umem_area; mr.len = size; mr.chunk_size = umem->config.frame_size;
'struct xdp_umem_reg' has 4 bytes of padding at the end that makes valgrind complain about passing uninitialized stack memory to the syscall: Syscall param socketcall.setsockopt() points to uninitialised byte(s) at 0x4E7AB7E: setsockopt (in /usr/lib64/libc-2.29.so) by 0x4BDE035: xsk_umem__create@@LIBBPF_0.0.4 (xsk.c:172) Uninitialised value was created by a stack allocation at 0x4BDDEBA: xsk_umem__create@@LIBBPF_0.0.4 (xsk.c:140) Padding bytes appeared after introducing of a new 'flags' field. memset() is required to clear them. Fixes: 10d30e301732 ("libbpf: add flags to umem config") Signed-off-by: Ilya Maximets <i.maximets@ovn.org> --- Version 2: * Struct initializer replaced with explicit memset(). [Andrii] tools/lib/bpf/xsk.c | 1 + 1 file changed, 1 insertion(+)