@@ -655,7 +655,7 @@ struct page *get_signal_page(void)
PAGE_SIZE / sizeof(u32));
/* Give the signal return code some randomness */
- offset = 0x200 + (get_random_int() & 0x7fc);
+ offset = 0x200 + (get_random_u16() & 0x7fc);
signal_return_offset = offset;
/* Copy signal return handlers into the page */
@@ -67,7 +67,7 @@ static void invoke_syscall(struct pt_regs *regs, unsigned int scno,
*
* The resulting 5 bits of entropy is seen in SP[8:4].
*/
- choose_random_kstack_offset(get_random_int() & 0x1FF);
+ choose_random_kstack_offset(get_random_u16() & 0x1FF);
}
static inline bool has_syscall_work(unsigned long flags)
@@ -230,7 +230,7 @@ unsigned long arch_align_stack(unsigned long sp)
static inline unsigned long brk_rnd(void)
{
- return (get_random_int() & BRK_RND_MASK) << PAGE_SHIFT;
+ return (get_random_u16() & BRK_RND_MASK) << PAGE_SHIFT;
}
unsigned long arch_randomize_brk(struct mm_struct *mm)
@@ -354,7 +354,7 @@ static unsigned long vdso_addr(unsigned long start, unsigned int len)
unsigned int offset;
/* This loses some more bits than a modulo, but is cheaper */
- offset = get_random_int() & (PTRS_PER_PTE - 1);
+ offset = get_random_u16() & (PTRS_PER_PTE - 1);
return start + (offset << PAGE_SHIFT);
}
@@ -927,7 +927,7 @@ static void generate_random_bytes(u8 *buf, size_t count)
b = 0xff;
break;
default:
- b = (u8)prandom_u32();
+ b = get_random_u8();
break;
}
memset(buf, b, count);
@@ -935,8 +935,8 @@ static void generate_random_bytes(u8 *buf, size_t count)
break;
case 2:
/* Ascending or descending bytes, plus optional mutations */
- increment = (u8)prandom_u32();
- b = (u8)prandom_u32();
+ increment = get_random_u8();
+ b = get_random_u8();
for (i = 0; i < count; i++, b += increment)
buf[i] = b;
mutate_buffer(buf, count);
@@ -944,7 +944,7 @@ static void generate_random_bytes(u8 *buf, size_t count)
default:
/* Fully random bytes */
for (i = 0; i < count; i++)
- buf[i] = (u8)prandom_u32();
+ buf[i] = get_random_u8();
}
}
@@ -870,7 +870,7 @@ static void precalculate_color(struct tpg_data *tpg, int k)
g = tpg_colors[col].g;
b = tpg_colors[col].b;
} else if (tpg->pattern == TPG_PAT_NOISE) {
- r = g = b = prandom_u32_max(256);
+ r = g = b = get_random_u8();
} else if (k == TPG_COLOR_RANDOM) {
r = g = b = tpg->qual_offset + prandom_u32_max(196);
} else if (k >= TPG_COLOR_RAMP) {
@@ -104,8 +104,8 @@ ssize_t vivid_radio_rx_read(struct file *file, char __user *buf,
break;
case 2:
rds.block |= V4L2_RDS_BLOCK_ERROR;
- rds.lsb = prandom_u32_max(256);
- rds.msb = prandom_u32_max(256);
+ rds.lsb = get_random_u8();
+ rds.msb = get_random_u8();
break;
case 3: /* Skip block altogether */
if (i)
@@ -1467,7 +1467,7 @@ static void make_established(struct sock *sk, u32 snd_isn, unsigned int opt)
tp->write_seq = snd_isn;
tp->snd_nxt = snd_isn;
tp->snd_una = snd_isn;
- inet_sk(sk)->inet_id = prandom_u32();
+ inet_sk(sk)->inet_id = get_random_u16();
assign_rxopt(sk, opt);
if (tp->rcv_wnd > (RCV_BUFSIZ_M << 10))
@@ -438,7 +438,7 @@ static int transmit(struct baycom_state *bc, int cnt, unsigned char stat)
if ((--bc->hdlctx.slotcnt) > 0)
return 0;
bc->hdlctx.slotcnt = bc->ch_params.slottime;
- if (prandom_u32_max(256) > bc->ch_params.ppersist)
+ if (get_random_u8() > bc->ch_params.ppersist)
return 0;
}
}
@@ -377,7 +377,7 @@ void hdlcdrv_arbitrate(struct net_device *dev, struct hdlcdrv_state *s)
if ((--s->hdlctx.slotcnt) > 0)
return;
s->hdlctx.slotcnt = s->ch_params.slottime;
- if (prandom_u32_max(256) > s->ch_params.ppersist)
+ if (get_random_u8() > s->ch_params.ppersist)
return;
start_tx(dev, s);
}
@@ -626,7 +626,7 @@ static void yam_arbitrate(struct net_device *dev)
yp->slotcnt = yp->slot / 10;
/* is random > persist ? */
- if (prandom_u32_max(256) > yp->pers)
+ if (get_random_u8() > yp->pers)
return;
yam_start_tx(dev, yp);
@@ -310,7 +310,7 @@ static __init bool randomized_test(void)
for (k = 0; k < 4; ++k)
mutated[k] = (mutated[k] & mutate_mask[k]) |
(~mutate_mask[k] &
- prandom_u32_max(256));
+ get_random_u8());
cidr = prandom_u32_max(32) + 1;
peer = peers[prandom_u32_max(NUM_PEERS)];
if (wg_allowedips_insert_v4(&t,
@@ -354,7 +354,7 @@ static __init bool randomized_test(void)
for (k = 0; k < 4; ++k)
mutated[k] = (mutated[k] & mutate_mask[k]) |
(~mutate_mask[k] &
- prandom_u32_max(256));
+ get_random_u8());
cidr = prandom_u32_max(128) + 1;
peer = peers[prandom_u32_max(NUM_PEERS)];
if (wg_allowedips_insert_v6(&t,
@@ -1594,7 +1594,7 @@ static int cw1200_get_prio_queue(struct cw1200_common *priv,
edca = &priv->edca.params[i];
score = ((edca->aifns + edca->cwmin) << 16) +
((edca->cwmax - edca->cwmin) *
- (get_random_int() & 0xFFFF));
+ get_random_u16());
if (score < best && (winner < 0 || i != 3)) {
best = score;
winner = i;
@@ -2150,8 +2150,8 @@ lpfc_check_pending_fcoe_event(struct lpfc_hba *phba, uint8_t unreg_fcf)
* This function makes an running random selection decision on FCF record to
* use through a sequence of @fcf_cnt eligible FCF records with equal
* probability. To perform integer manunipulation of random numbers with
- * size unit32_t, the lower 16 bits of the 32-bit random number returned
- * from prandom_u32() are taken as the random random number generated.
+ * size unit32_t, a 16-bit random number returned from get_random_u16() is
+ * taken as the random random number generated.
*
* Returns true when outcome is for the newly read FCF record should be
* chosen; otherwise, return false when outcome is for keeping the previously
@@ -2163,7 +2163,7 @@ lpfc_sli4_new_fcf_random_select(struct lpfc_hba *phba, uint32_t fcf_cnt)
uint32_t rand_num;
/* Get 16-bit uniform random number */
- rand_num = 0xFFFF & prandom_u32();
+ rand_num = get_random_u16();
/* Decision with probability 1/fcf_cnt */
if ((fcf_cnt * rand_num) < 0xFFFF)
@@ -76,7 +76,7 @@ static void cmdline_test_lead_int(struct kunit *test)
int rc = cmdline_test_values[i];
int offset;
- sprintf(in, "%u%s", get_random_int() % 256, str);
+ sprintf(in, "%u%s", get_random_u8(), str);
/* Only first '-' after the number will advance the pointer */
offset = strlen(in) - strlen(str) + !!(rc == 2);
cmdline_do_one_test(test, in, rc, offset);
@@ -94,7 +94,7 @@ static void cmdline_test_tail_int(struct kunit *test)
int rc = strcmp(str, "") ? (strcmp(str, "-") ? 0 : 1) : 1;
int offset;
- sprintf(in, "%s%u", str, get_random_int() % 256);
+ sprintf(in, "%s%u", str, get_random_u8());
/*
* Only first and leading '-' not followed by integer
* will advance the pointer.
@@ -80,7 +80,7 @@ static int random_size_align_alloc_test(void)
int i;
for (i = 0; i < test_loop_count; i++) {
- rnd = prandom_u32();
+ rnd = get_random_u8();
/*
* Maximum 1024 pages, if PAGE_SIZE is 4096.
@@ -123,7 +123,7 @@ int dccp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
inet->inet_daddr,
inet->inet_sport,
inet->inet_dport);
- inet->inet_id = prandom_u32();
+ inet->inet_id = get_random_u16();
err = dccp_connect(sk);
rt = NULL;
@@ -422,7 +422,7 @@ struct sock *dccp_v4_request_recv_sock(const struct sock *sk,
RCU_INIT_POINTER(newinet->inet_opt, rcu_dereference(ireq->ireq_opt));
newinet->mc_index = inet_iif(skb);
newinet->mc_ttl = ip_hdr(skb)->ttl;
- newinet->inet_id = prandom_u32();
+ newinet->inet_id = get_random_u16();
if (dst == NULL && (dst = inet_csk_route_child_sock(sk, newsk, req)) == NULL)
goto put_and_exit;
@@ -71,7 +71,7 @@ int __ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len
reuseport_has_conns(sk, true);
sk->sk_state = TCP_ESTABLISHED;
sk_set_txhash(sk);
- inet->inet_id = prandom_u32();
+ inet->inet_id = get_random_u16();
sk_dst_set(sk, &rt->dst);
err = 0;
@@ -172,7 +172,7 @@ int ip_build_and_send_pkt(struct sk_buff *skb, const struct sock *sk,
* Avoid using the hashed IP ident generator.
*/
if (sk->sk_protocol == IPPROTO_TCP)
- iph->id = (__force __be16)prandom_u32();
+ iph->id = (__force __be16)get_random_u16();
else
__ip_select_ident(net, iph, 1);
}
@@ -303,7 +303,7 @@ int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
inet->inet_daddr);
}
- inet->inet_id = prandom_u32();
+ inet->inet_id = get_random_u16();
if (tcp_fastopen_defer_connect(sk, &err))
return err;
@@ -1523,7 +1523,7 @@ struct sock *tcp_v4_syn_recv_sock(const struct sock *sk, struct sk_buff *skb,
inet_csk(newsk)->icsk_ext_hdr_len = 0;
if (inet_opt)
inet_csk(newsk)->icsk_ext_hdr_len = inet_opt->opt.optlen;
- newinet->inet_id = prandom_u32();
+ newinet->inet_id = get_random_u16();
/* Set ToS of the new socket based upon the value of incoming SYN.
* ECT bits are set later in tcp_init_transfer().
@@ -641,7 +641,7 @@ static void ieee80211_send_scan_probe_req(struct ieee80211_sub_if_data *sdata,
if (flags & IEEE80211_PROBE_FLAG_RANDOM_SN) {
struct ieee80211_hdr *hdr = (void *)skb->data;
struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
- u16 sn = get_random_u32();
+ u16 sn = get_random_u16();
info->control.flags |= IEEE80211_TX_CTRL_NO_SEQNO;
hdr->seq_ctrl =
@@ -468,7 +468,7 @@ static void nf_nat_l4proto_unique_tuple(struct nf_conntrack_tuple *tuple,
if (range->flags & NF_NAT_RANGE_PROTO_OFFSET)
off = (ntohs(*keyptr) - ntohs(range->base_proto.all));
else
- off = prandom_u32();
+ off = get_random_u16();
attempts = range_size;
if (attempts > max_attempts)
@@ -490,7 +490,7 @@ static void nf_nat_l4proto_unique_tuple(struct nf_conntrack_tuple *tuple,
if (attempts >= range_size || attempts < 16)
return;
attempts /= 2;
- off = prandom_u32();
+ off = get_random_u16();
goto another_round;
}
@@ -2092,11 +2092,11 @@ static struct sk_buff *cake_dequeue(struct Qdisc *sch)
WARN_ON(host_load > CAKE_QUEUES);
- /* The shifted prandom_u32() is a way to apply dithering to
- * avoid accumulating roundoff errors
+ /* The get_random_u16() is a way to apply dithering to avoid
+ * accumulating roundoff errors
*/
flow->deficit += (b->flow_quantum * quantum_div[host_load] +
- (prandom_u32() >> 16)) >> 16;
+ get_random_u16()) >> 16;
list_move_tail(&flow->flowchain, &b->old_flows);
goto retry;
@@ -379,7 +379,7 @@ static int sfb_enqueue(struct sk_buff *skb, struct Qdisc *sch,
goto enqueue;
}
- r = prandom_u32() & SFB_MAX_PROB;
+ r = get_random_u16() & SFB_MAX_PROB;
if (unlikely(r < p_min)) {
if (unlikely(p_min > SFB_MAX_PROB / 2)) {
@@ -9448,7 +9448,7 @@ void sctp_copy_sock(struct sock *newsk, struct sock *sk,
newinet->inet_rcv_saddr = inet->inet_rcv_saddr;
newinet->inet_dport = htons(asoc->peer.port);
newinet->pmtudisc = inet->pmtudisc;
- newinet->inet_id = prandom_u32();
+ newinet->inet_id = get_random_u16();
newinet->uc_ttl = inet->uc_ttl;
newinet->mc_loop = 1;
Rather than truncate a 32-bit value to a 16-bit value or an 8-bit value, simply use the get_random_{u8,u16}() functions, which are faster than wasting the additional bytes from a 32-bit value. Reviewed-by: Kees Cook <keescook@chromium.org> Acked-by: Toke Høiland-Jørgensen <toke@toke.dk> # for sch_cake Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> --- arch/arm/kernel/signal.c | 2 +- arch/arm64/kernel/syscall.c | 2 +- arch/s390/kernel/process.c | 2 +- arch/sparc/vdso/vma.c | 2 +- crypto/testmgr.c | 8 ++++---- drivers/media/common/v4l2-tpg/v4l2-tpg-core.c | 2 +- drivers/media/test-drivers/vivid/vivid-radio-rx.c | 4 ++-- .../net/ethernet/chelsio/inline_crypto/chtls/chtls_cm.c | 2 +- drivers/net/hamradio/baycom_epp.c | 2 +- drivers/net/hamradio/hdlcdrv.c | 2 +- drivers/net/hamradio/yam.c | 2 +- drivers/net/wireguard/selftest/allowedips.c | 4 ++-- drivers/net/wireless/st/cw1200/wsm.c | 2 +- drivers/scsi/lpfc/lpfc_hbadisc.c | 6 +++--- lib/cmdline_kunit.c | 4 ++-- lib/test_vmalloc.c | 2 +- net/dccp/ipv4.c | 4 ++-- net/ipv4/datagram.c | 2 +- net/ipv4/ip_output.c | 2 +- net/ipv4/tcp_ipv4.c | 4 ++-- net/mac80211/scan.c | 2 +- net/netfilter/nf_nat_core.c | 4 ++-- net/sched/sch_cake.c | 6 +++--- net/sched/sch_sfb.c | 2 +- net/sctp/socket.c | 2 +- 25 files changed, 38 insertions(+), 38 deletions(-)