2025-02-11 18:38 UTC+0800 ~ Rong Tao <rtoax@xxxxxxxxxxx>
> From: Rong Tao <rongtao@xxxxxxxx>
>
> The size of struct bpf_map::name is BPF_OBJ_NAME_LEN (16).
>
> bpf(2) {
> map_create() {
> bpf_obj_name_cpy(map->name, attr->map_name, sizeof(attr->map_name));
> }
> }
>
> When specifying a map name using bpftool map create name, no error is
> reported if the name length is greater than 15.
>
> $ sudo bpftool map create /sys/fs/bpf/12345678901234567890 \
> type array key 4 value 4 entries 5 name 12345678901234567890
>
> Users will think that 12345678901234567890 is legal, but this name cannot
> be used to index a map.
>
> $ sudo bpftool map show name 12345678901234567890
> Error: can't parse name
>
> $ sudo bpftool map show
> ...
> 1249: array name 123456789012345 flags 0x0
> key 4B value 4B max_entries 5 memlock 304B
>
> $ sudo bpftool map show name 123456789012345
> 1249: array name 123456789012345 flags 0x0
> key 4B value 4B max_entries 5 memlock 304B
>
> The map name provided in the command line is truncated, but no error is
> reported. This submission checks the length of the map name.
>
> Signed-off-by: Rong Tao <rongtao@xxxxxxxx>
Reviewed-by: Quentin Monnet <qmo@xxxxxxxxxx>
Thank you!
