On Fri, Apr 10, 2020 at 11:06:12AM +0900, Daniel T. Lee wrote:
> From commit 65c93628599d ("bpftool: Add struct_ops support"),
> a new type of command struct_ops has been added.
>
> This command requires kernel CONFIG_DEBUG_INFO_BTF=y, and for retrieving
> btf info, get_btf_vmlinux() is used.
>
> When running this command on kernel without BTF debug info, this will
> lead to 'btf_vmlinux' variable contains invalid(error) pointer. And by
> this, btf_free() causes a segfault when executing 'bpftool struct_ops'.
>
> This commit adds pointer validation with IS_ERR not to free invalid
> pointer, and this will fix the segfault issue.
>
> Signed-off-by: Daniel T. Lee <danieltimlee@xxxxxxxxx>
Fixes: 65c93628599d ("bpftool: Add struct_ops support")
Acked-by: Martin KaFai Lau
Thanks for the fix! Please add the Fixes tag in the future.
