2022-11-02 16:40 UTC+0800 ~ Pu Lehui <pulehui@xxxxxxxxxxxxxxx>
> From: Pu Lehui <pulehui@xxxxxxxxxx>
>
> When using bpftool to pin {PROG, MAP, LINK} without FILE,
> segmentation fault will occur. The reson is that the lack
> of FILE will cause strlen to trigger NULL pointer dereference.
> The corresponding stacktrace is shown below:
>
> do_pin
> do_pin_any
> do_pin_fd
> mount_bpffs_for_pin
> strlen(name) <- NULL pointer dereference
>
> Fix it by adding validation to the common process.
>
> Fixes: 75a1e792c335 ("tools: bpftool: Allow all prog/map handles for pinning objects")
> Signed-off-by: Pu Lehui <pulehui@xxxxxxxxxx>
> ---
> tools/bpf/bpftool/common.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/tools/bpf/bpftool/common.c b/tools/bpf/bpftool/common.c
> index e4d33bc8bbbf..653c130a0aaa 100644
> --- a/tools/bpf/bpftool/common.c
> +++ b/tools/bpf/bpftool/common.c
> @@ -302,6 +302,9 @@ int do_pin_any(int argc, char **argv, int (*get_fd)(int *, char ***))
> int err;
> int fd;
>
> + if (!REQ_ARGS(3))
> + return -EINVAL;
> +
> fd = get_fd(&argc, &argv);
> if (fd < 0)
> return fd;
Good catch, and thanks for the fix!
Reviewed-by: Quentin Monnet <quentin@xxxxxxxxxxxxx>
