| Message ID | 20200527185700.14658-5-a.s.protopopov@gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | bpf: fix map permissions check and cleanup code around | expand |
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 4e6dee19a668..5e52765161f9 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -1468,7 +1468,8 @@ static int map_lookup_and_delete_elem(union bpf_attr *attr) map = __bpf_map_get(f); if (IS_ERR(map)) return PTR_ERR(map); - if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) { + if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ) || + !(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) { err = -EPERM; goto err_put; }
The map_lookup_and_delete_elem() function should check for both FMODE_CAN_WRITE and FMODE_CAN_READ permissions because it returns a map element to user space. Fixes: bd513cd08f10 ("bpf: add MAP_LOOKUP_AND_DELETE_ELEM syscall") Signed-off-by: Anton Protopopov <a.s.protopopov@gmail.com> --- kernel/bpf/syscall.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)