[PATCH v5 4/7] treewide: use get_random_{u8,u16}() when possible, part 2
From: "Jason A. Donenfeld" <Jason@zx2c4.com>
Date: 2022-10-08 05:58:11
Also in:
dri-devel, kernel-janitors, linux-block, linux-crypto, linux-doc, linux-fsdevel, linux-media, linux-mips, linux-mm, linux-mmc, linux-nvme, linux-patches, linux-rdma, linux-s390, linux-um, linux-usb, linux-wireless, lkml, loongarch, netdev, sparclinux
Subsystem:
library code, netfilter, networking [general], networking [ipv4/ipv6], rds - reliable datagram sockets, s390 architecture, tc subsystem, the rest, vmalloc · Maintainers:
Andrew Morton, Pablo Neira Ayuso, Florian Westphal, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, David Ahern, Ido Schimmel, Allison Henderson, Heiko Carstens, Vasily Gorbik, Alexander Gordeev, Jamal Hadi Salim, Jiri Pirko, Linus Torvalds, Uladzislau Rezki
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. This was done by hand,
identifying all of the places where one of the random integer functions
was used in a non-32-bit context.
Reviewed-by: Kees Cook <redacted>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
---
arch/s390/kernel/process.c | 2 +-
lib/test_vmalloc.c | 2 +-
net/ipv4/ip_output.c | 2 +-
net/netfilter/nf_nat_core.c | 4 ++--
net/rds/bind.c | 2 +-
net/sched/sch_sfb.c | 2 +-
6 files changed, 7 insertions(+), 7 deletions(-)
diff --git a/arch/s390/kernel/process.c b/arch/s390/kernel/process.c
index 5ec78555dd2e..42af4b3aa02b 100644
--- a/arch/s390/kernel/process.c
+++ b/arch/s390/kernel/process.c@@ -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)
diff --git a/lib/test_vmalloc.c b/lib/test_vmalloc.c
index a26bbbf20e62..cf7780572f5b 100644
--- a/lib/test_vmalloc.c
+++ b/lib/test_vmalloc.c@@ -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.
diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index 04e2034f2f8e..a4fbdbff14b3 100644
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c@@ -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); }
diff --git a/net/netfilter/nf_nat_core.c b/net/netfilter/nf_nat_core.c
index 7981be526f26..57c7686ac485 100644
--- a/net/netfilter/nf_nat_core.c
+++ b/net/netfilter/nf_nat_core.c@@ -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; }
diff --git a/net/rds/bind.c b/net/rds/bind.c
index 5b5fb4ca8d3e..97a29172a8ee 100644
--- a/net/rds/bind.c
+++ b/net/rds/bind.c@@ -104,7 +104,7 @@ static int rds_add_bound(struct rds_sock *rs, const struct in6_addr *addr, return -EINVAL; last = rover; } else { - rover = max_t(u16, prandom_u32(), 2); + rover = max_t(u16, get_random_u16(), 2); last = rover - 1; }
diff --git a/net/sched/sch_sfb.c b/net/sched/sch_sfb.c
index 2829455211f8..7eb70acb4d58 100644
--- a/net/sched/sch_sfb.c
+++ b/net/sched/sch_sfb.c@@ -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)) {
--
2.37.3