[PATCH 3.16 0/4] 3.16.73-rc1 review

[PATCH 3.16 0/4] 3.16.73-rc1 review

[Ben Hutchings]

This is the start of the stable review cycle for the 3.16.73 release.
There are 4 patches in this series, which will be posted as responses
to this one.  If anyone has any issues with these being applied, please
let me know.

Responses should be made by Mon Aug 19 20:00:00 UTC 2019.
Anything received after that time might be too late.

All the patches have also been committed to the linux-3.16.y-rc branch of
https://git.kernel.org/pub/scm/linux/kernel/git/bwh/linux-stable-rc.git .
A shortlog and diffstat can be found below.

Ben.

-------------

Ben Hutchings (1):
      tcp: Clear sk_send_head after purging the write queue
         [not upstream; fixes bug specific to stable]

Jason A. Donenfeld (1):
      siphash: implement HalfSipHash1-3 for hash tables
         [1ae2324f732c9c4e2fa4ebd885fa1001b70d52e1]

Zhangyi (2):
      ext4: brelse all indirect buffer in ext4_ind_remove_space()
         [674a2b27234d1b7afcb0a9162e81b2e53aeef217]
      ext4: cleanup bh release code in ext4_ind_remove_space()
         [5e86bdda41534e17621d5a071b294943cae4376e]

 Documentation/siphash.txt |  75 +++++++++++
 Makefile                  |   4 +-
 fs/ext4/indirect.c        |  43 ++++---
 include/linux/siphash.h   |  57 +++++++-
 include/net/tcp.h         |   3 +
 lib/siphash.c             | 321 +++++++++++++++++++++++++++++++++++++++++++++-
 lib/test_siphash.c        |  98 +++++++++++++-
 7 files changed, 573 insertions(+), 28 deletions(-)

-- 
Ben Hutchings
The obvious mathematical breakthrough [to break modern encryption]
would be development of an easy way to factor large prime numbers.
                                                           - Bill Gates

[PATCH 3.16 4/4] siphash: implement HalfSipHash1-3 for hash tables

[Ben Hutchings]

3.16.73-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: "Jason A. Donenfeld" <Jason@zx2c4.com>

commit 1ae2324f732c9c4e2fa4ebd885fa1001b70d52e1 upstream.

HalfSipHash, or hsiphash, is a shortened version of SipHash, which
generates 32-bit outputs using a weaker 64-bit key. It has *much* lower
security margins, and shouldn't be used for anything too sensitive, but
it could be used as a hashtable key function replacement, if the output
is never exposed, and if the security requirement is not too high.

The goal is to make this something that performance-critical jhash users
would be willing to use.

On 64-bit machines, HalfSipHash1-3 is slower than SipHash1-3, so we alias
SipHash1-3 to HalfSipHash1-3 on those systems.

64-bit x86_64:
[    0.509409] test_siphash:     SipHash2-4 cycles: 4049181
[    0.510650] test_siphash:     SipHash1-3 cycles: 2512884
[    0.512205] test_siphash: HalfSipHash1-3 cycles: 3429920
[    0.512904] test_siphash:    JenkinsHash cycles:  978267
So, we map hsiphash() -> SipHash1-3

32-bit x86:
[    0.509868] test_siphash:     SipHash2-4 cycles: 14812892
[    0.513601] test_siphash:     SipHash1-3 cycles:  9510710
[    0.515263] test_siphash: HalfSipHash1-3 cycles:  3856157
[    0.515952] test_siphash:    JenkinsHash cycles:  1148567
So, we map hsiphash() -> HalfSipHash1-3

hsiphash() is roughly 3 times slower than jhash(), but comes with a
considerable security improvement.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Reviewed-by: Jean-Philippe Aumasson <jeanphilippe.aumasson@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.16 to avoid a build regression for WireGuard with
 only part of the siphash API available]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
 Documentation/siphash.txt |  75 +++++++++
 include/linux/siphash.h   |  57 ++++++-
 lib/siphash.c             | 321 +++++++++++++++++++++++++++++++++++++-
 lib/test_siphash.c        |  98 +++++++++++-
 4 files changed, 546 insertions(+), 5 deletions(-)

--- a/Documentation/siphash.txt
+++ b/Documentation/siphash.txt
@@ -98,3 +98,78 @@ u64 h = siphash(&combined, offsetofend(t
 
 Read the SipHash paper if you're interested in learning more:
 https://131002.net/siphash/siphash.pdf
+
+
+~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~=~
+
+HalfSipHash - SipHash's insecure younger cousin
+-----------------------------------------------
+Written by Jason A. Donenfeld <jason@zx2c4.com>
+
+On the off-chance that SipHash is not fast enough for your needs, you might be
+able to justify using HalfSipHash, a terrifying but potentially useful
+possibility. HalfSipHash cuts SipHash's rounds down from "2-4" to "1-3" and,
+even scarier, uses an easily brute-forcable 64-bit key (with a 32-bit output)
+instead of SipHash's 128-bit key. However, this may appeal to some
+high-performance `jhash` users.
+
+Danger!
+
+Do not ever use HalfSipHash except for as a hashtable key function, and only
+then when you can be absolutely certain that the outputs will never be
+transmitted out of the kernel. This is only remotely useful over `jhash` as a
+means of mitigating hashtable flooding denial of service attacks.
+
+1. Generating a key
+
+Keys should always be generated from a cryptographically secure source of
+random numbers, either using get_random_bytes or get_random_once:
+
+hsiphash_key_t key;
+get_random_bytes(&key, sizeof(key));
+
+If you're not deriving your key from here, you're doing it wrong.
+
+2. Using the functions
+
+There are two variants of the function, one that takes a list of integers, and
+one that takes a buffer:
+
+u32 hsiphash(const void *data, size_t len, const hsiphash_key_t *key);
+
+And:
+
+u32 hsiphash_1u32(u32, const hsiphash_key_t *key);
+u32 hsiphash_2u32(u32, u32, const hsiphash_key_t *key);
+u32 hsiphash_3u32(u32, u32, u32, const hsiphash_key_t *key);
+u32 hsiphash_4u32(u32, u32, u32, u32, const hsiphash_key_t *key);
+
+If you pass the generic hsiphash function something of a constant length, it
+will constant fold at compile-time and automatically choose one of the
+optimized functions.
+
+3. Hashtable key function usage:
+
+struct some_hashtable {
+	DECLARE_HASHTABLE(hashtable, 8);
+	hsiphash_key_t key;
+};
+
+void init_hashtable(struct some_hashtable *table)
+{
+	get_random_bytes(&table->key, sizeof(table->key));
+}
+
+static inline hlist_head *some_hashtable_bucket(struct some_hashtable *table, struct interesting_input *input)
+{
+	return &table->hashtable[hsiphash(input, sizeof(*input), &table->key) & (HASH_SIZE(table->hashtable) - 1)];
+}
+
+You may then iterate like usual over the returned hash bucket.
+
+4. Performance
+
+HalfSipHash is roughly 3 times slower than JenkinsHash. For many replacements,
+this will not be a problem, as the hashtable lookup isn't the bottleneck. And
+in general, this is probably a good sacrifice to make for the security and DoS
+resistance of HalfSipHash.
--- a/include/linux/siphash.h
+++ b/include/linux/siphash.h
@@ -5,7 +5,9 @@
  * SipHash: a fast short-input PRF
  * https://131002.net/siphash/
  *
- * This implementation is specifically for SipHash2-4.
+ * This implementation is specifically for SipHash2-4 for a secure PRF
+ * and HalfSipHash1-3/SipHash1-3 for an insecure PRF only suitable for
+ * hashtables.
  */
 
 #ifndef _LINUX_SIPHASH_H
@@ -87,4 +89,57 @@ static inline u64 siphash(const void *da
 	return ___siphash_aligned(data, len, key);
 }
 
+#define HSIPHASH_ALIGNMENT __alignof__(unsigned long)
+typedef struct {
+	unsigned long key[2];
+} hsiphash_key_t;
+
+u32 __hsiphash_aligned(const void *data, size_t len,
+		       const hsiphash_key_t *key);
+#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
+u32 __hsiphash_unaligned(const void *data, size_t len,
+			 const hsiphash_key_t *key);
+#endif
+
+u32 hsiphash_1u32(const u32 a, const hsiphash_key_t *key);
+u32 hsiphash_2u32(const u32 a, const u32 b, const hsiphash_key_t *key);
+u32 hsiphash_3u32(const u32 a, const u32 b, const u32 c,
+		  const hsiphash_key_t *key);
+u32 hsiphash_4u32(const u32 a, const u32 b, const u32 c, const u32 d,
+		  const hsiphash_key_t *key);
+
+static inline u32 ___hsiphash_aligned(const __le32 *data, size_t len,
+				      const hsiphash_key_t *key)
+{
+	if (__builtin_constant_p(len) && len == 4)
+		return hsiphash_1u32(le32_to_cpu(data[0]), key);
+	if (__builtin_constant_p(len) && len == 8)
+		return hsiphash_2u32(le32_to_cpu(data[0]), le32_to_cpu(data[1]),
+				     key);
+	if (__builtin_constant_p(len) && len == 12)
+		return hsiphash_3u32(le32_to_cpu(data[0]), le32_to_cpu(data[1]),
+				     le32_to_cpu(data[2]), key);
+	if (__builtin_constant_p(len) && len == 16)
+		return hsiphash_4u32(le32_to_cpu(data[0]), le32_to_cpu(data[1]),
+				     le32_to_cpu(data[2]), le32_to_cpu(data[3]),
+				     key);
+	return __hsiphash_aligned(data, len, key);
+}
+
+/**
+ * hsiphash - compute 32-bit hsiphash PRF value
+ * @data: buffer to hash
+ * @size: size of @data
+ * @key: the hsiphash key
+ */
+static inline u32 hsiphash(const void *data, size_t len,
+			   const hsiphash_key_t *key)
+{
+#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
+	if (!IS_ALIGNED((unsigned long)data, HSIPHASH_ALIGNMENT))
+		return __hsiphash_unaligned(data, len, key);
+#endif
+	return ___hsiphash_aligned(data, len, key);
+}
+
 #endif /* _LINUX_SIPHASH_H */
--- a/lib/siphash.c
+++ b/lib/siphash.c
@@ -5,7 +5,9 @@
  * SipHash: a fast short-input PRF
  * https://131002.net/siphash/
  *
- * This implementation is specifically for SipHash2-4.
+ * This implementation is specifically for SipHash2-4 for a secure PRF
+ * and HalfSipHash1-3/SipHash1-3 for an insecure PRF only suitable for
+ * hashtables.
  */
 
 #include <linux/siphash.h>
@@ -230,3 +232,320 @@ u64 siphash_3u32(const u32 first, const
 	POSTAMBLE
 }
 EXPORT_SYMBOL(siphash_3u32);
+
+#if BITS_PER_LONG == 64
+/* Note that on 64-bit, we make HalfSipHash1-3 actually be SipHash1-3, for
+ * performance reasons. On 32-bit, below, we actually implement HalfSipHash1-3.
+ */
+
+#define HSIPROUND SIPROUND
+#define HPREAMBLE(len) PREAMBLE(len)
+#define HPOSTAMBLE \
+	v3 ^= b; \
+	HSIPROUND; \
+	v0 ^= b; \
+	v2 ^= 0xff; \
+	HSIPROUND; \
+	HSIPROUND; \
+	HSIPROUND; \
+	return (v0 ^ v1) ^ (v2 ^ v3);
+
+u32 __hsiphash_aligned(const void *data, size_t len, const hsiphash_key_t *key)
+{
+	const u8 *end = data + len - (len % sizeof(u64));
+	const u8 left = len & (sizeof(u64) - 1);
+	u64 m;
+	HPREAMBLE(len)
+	for (; data != end; data += sizeof(u64)) {
+		m = le64_to_cpup(data);
+		v3 ^= m;
+		HSIPROUND;
+		v0 ^= m;
+	}
+#if defined(CONFIG_DCACHE_WORD_ACCESS) && BITS_PER_LONG == 64
+	if (left)
+		b |= le64_to_cpu((__force __le64)(load_unaligned_zeropad(data) &
+						  bytemask_from_count(left)));
+#else
+	switch (left) {
+	case 7: b |= ((u64)end[6]) << 48;
+	case 6: b |= ((u64)end[5]) << 40;
+	case 5: b |= ((u64)end[4]) << 32;
+	case 4: b |= le32_to_cpup(data); break;
+	case 3: b |= ((u64)end[2]) << 16;
+	case 2: b |= le16_to_cpup(data); break;
+	case 1: b |= end[0];
+	}
+#endif
+	HPOSTAMBLE
+}
+EXPORT_SYMBOL(__hsiphash_aligned);
+
+#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
+u32 __hsiphash_unaligned(const void *data, size_t len,
+			 const hsiphash_key_t *key)
+{
+	const u8 *end = data + len - (len % sizeof(u64));
+	const u8 left = len & (sizeof(u64) - 1);
+	u64 m;
+	HPREAMBLE(len)
+	for (; data != end; data += sizeof(u64)) {
+		m = get_unaligned_le64(data);
+		v3 ^= m;
+		HSIPROUND;
+		v0 ^= m;
+	}
+#if defined(CONFIG_DCACHE_WORD_ACCESS) && BITS_PER_LONG == 64
+	if (left)
+		b |= le64_to_cpu((__force __le64)(load_unaligned_zeropad(data) &
+						  bytemask_from_count(left)));
+#else
+	switch (left) {
+	case 7: b |= ((u64)end[6]) << 48;
+	case 6: b |= ((u64)end[5]) << 40;
+	case 5: b |= ((u64)end[4]) << 32;
+	case 4: b |= get_unaligned_le32(end); break;
+	case 3: b |= ((u64)end[2]) << 16;
+	case 2: b |= get_unaligned_le16(end); break;
+	case 1: b |= end[0];
+	}
+#endif
+	HPOSTAMBLE
+}
+EXPORT_SYMBOL(__hsiphash_unaligned);
+#endif
+
+/**
+ * hsiphash_1u32 - compute 64-bit hsiphash PRF value of a u32
+ * @first: first u32
+ * @key: the hsiphash key
+ */
+u32 hsiphash_1u32(const u32 first, const hsiphash_key_t *key)
+{
+	HPREAMBLE(4)
+	b |= first;
+	HPOSTAMBLE
+}
+EXPORT_SYMBOL(hsiphash_1u32);
+
+/**
+ * hsiphash_2u32 - compute 32-bit hsiphash PRF value of 2 u32
+ * @first: first u32
+ * @second: second u32
+ * @key: the hsiphash key
+ */
+u32 hsiphash_2u32(const u32 first, const u32 second, const hsiphash_key_t *key)
+{
+	u64 combined = (u64)second << 32 | first;
+	HPREAMBLE(8)
+	v3 ^= combined;
+	HSIPROUND;
+	v0 ^= combined;
+	HPOSTAMBLE
+}
+EXPORT_SYMBOL(hsiphash_2u32);
+
+/**
+ * hsiphash_3u32 - compute 32-bit hsiphash PRF value of 3 u32
+ * @first: first u32
+ * @second: second u32
+ * @third: third u32
+ * @key: the hsiphash key
+ */
+u32 hsiphash_3u32(const u32 first, const u32 second, const u32 third,
+		  const hsiphash_key_t *key)
+{
+	u64 combined = (u64)second << 32 | first;
+	HPREAMBLE(12)
+	v3 ^= combined;
+	HSIPROUND;
+	v0 ^= combined;
+	b |= third;
+	HPOSTAMBLE
+}
+EXPORT_SYMBOL(hsiphash_3u32);
+
+/**
+ * hsiphash_4u32 - compute 32-bit hsiphash PRF value of 4 u32
+ * @first: first u32
+ * @second: second u32
+ * @third: third u32
+ * @forth: forth u32
+ * @key: the hsiphash key
+ */
+u32 hsiphash_4u32(const u32 first, const u32 second, const u32 third,
+		  const u32 forth, const hsiphash_key_t *key)
+{
+	u64 combined = (u64)second << 32 | first;
+	HPREAMBLE(16)
+	v3 ^= combined;
+	HSIPROUND;
+	v0 ^= combined;
+	combined = (u64)forth << 32 | third;
+	v3 ^= combined;
+	HSIPROUND;
+	v0 ^= combined;
+	HPOSTAMBLE
+}
+EXPORT_SYMBOL(hsiphash_4u32);
+#else
+#define HSIPROUND \
+	do { \
+	v0 += v1; v1 = rol32(v1, 5); v1 ^= v0; v0 = rol32(v0, 16); \
+	v2 += v3; v3 = rol32(v3, 8); v3 ^= v2; \
+	v0 += v3; v3 = rol32(v3, 7); v3 ^= v0; \
+	v2 += v1; v1 = rol32(v1, 13); v1 ^= v2; v2 = rol32(v2, 16); \
+	} while (0)
+
+#define HPREAMBLE(len) \
+	u32 v0 = 0; \
+	u32 v1 = 0; \
+	u32 v2 = 0x6c796765U; \
+	u32 v3 = 0x74656462U; \
+	u32 b = ((u32)(len)) << 24; \
+	v3 ^= key->key[1]; \
+	v2 ^= key->key[0]; \
+	v1 ^= key->key[1]; \
+	v0 ^= key->key[0];
+
+#define HPOSTAMBLE \
+	v3 ^= b; \
+	HSIPROUND; \
+	v0 ^= b; \
+	v2 ^= 0xff; \
+	HSIPROUND; \
+	HSIPROUND; \
+	HSIPROUND; \
+	return v1 ^ v3;
+
+u32 __hsiphash_aligned(const void *data, size_t len, const hsiphash_key_t *key)
+{
+	const u8 *end = data + len - (len % sizeof(u32));
+	const u8 left = len & (sizeof(u32) - 1);
+	u32 m;
+	HPREAMBLE(len)
+	for (; data != end; data += sizeof(u32)) {
+		m = le32_to_cpup(data);
+		v3 ^= m;
+		HSIPROUND;
+		v0 ^= m;
+	}
+	switch (left) {
+	case 3: b |= ((u32)end[2]) << 16;
+	case 2: b |= le16_to_cpup(data); break;
+	case 1: b |= end[0];
+	}
+	HPOSTAMBLE
+}
+EXPORT_SYMBOL(__hsiphash_aligned);
+
+#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
+u32 __hsiphash_unaligned(const void *data, size_t len,
+			 const hsiphash_key_t *key)
+{
+	const u8 *end = data + len - (len % sizeof(u32));
+	const u8 left = len & (sizeof(u32) - 1);
+	u32 m;
+	HPREAMBLE(len)
+	for (; data != end; data += sizeof(u32)) {
+		m = get_unaligned_le32(data);
+		v3 ^= m;
+		HSIPROUND;
+		v0 ^= m;
+	}
+	switch (left) {
+	case 3: b |= ((u32)end[2]) << 16;
+	case 2: b |= get_unaligned_le16(end); break;
+	case 1: b |= end[0];
+	}
+	HPOSTAMBLE
+}
+EXPORT_SYMBOL(__hsiphash_unaligned);
+#endif
+
+/**
+ * hsiphash_1u32 - compute 32-bit hsiphash PRF value of a u32
+ * @first: first u32
+ * @key: the hsiphash key
+ */
+u32 hsiphash_1u32(const u32 first, const hsiphash_key_t *key)
+{
+	HPREAMBLE(4)
+	v3 ^= first;
+	HSIPROUND;
+	v0 ^= first;
+	HPOSTAMBLE
+}
+EXPORT_SYMBOL(hsiphash_1u32);
+
+/**
+ * hsiphash_2u32 - compute 32-bit hsiphash PRF value of 2 u32
+ * @first: first u32
+ * @second: second u32
+ * @key: the hsiphash key
+ */
+u32 hsiphash_2u32(const u32 first, const u32 second, const hsiphash_key_t *key)
+{
+	HPREAMBLE(8)
+	v3 ^= first;
+	HSIPROUND;
+	v0 ^= first;
+	v3 ^= second;
+	HSIPROUND;
+	v0 ^= second;
+	HPOSTAMBLE
+}
+EXPORT_SYMBOL(hsiphash_2u32);
+
+/**
+ * hsiphash_3u32 - compute 32-bit hsiphash PRF value of 3 u32
+ * @first: first u32
+ * @second: second u32
+ * @third: third u32
+ * @key: the hsiphash key
+ */
+u32 hsiphash_3u32(const u32 first, const u32 second, const u32 third,
+		  const hsiphash_key_t *key)
+{
+	HPREAMBLE(12)
+	v3 ^= first;
+	HSIPROUND;
+	v0 ^= first;
+	v3 ^= second;
+	HSIPROUND;
+	v0 ^= second;
+	v3 ^= third;
+	HSIPROUND;
+	v0 ^= third;
+	HPOSTAMBLE
+}
+EXPORT_SYMBOL(hsiphash_3u32);
+
+/**
+ * hsiphash_4u32 - compute 32-bit hsiphash PRF value of 4 u32
+ * @first: first u32
+ * @second: second u32
+ * @third: third u32
+ * @forth: forth u32
+ * @key: the hsiphash key
+ */
+u32 hsiphash_4u32(const u32 first, const u32 second, const u32 third,
+		  const u32 forth, const hsiphash_key_t *key)
+{
+	HPREAMBLE(16)
+	v3 ^= first;
+	HSIPROUND;
+	v0 ^= first;
+	v3 ^= second;
+	HSIPROUND;
+	v0 ^= second;
+	v3 ^= third;
+	HSIPROUND;
+	v0 ^= third;
+	v3 ^= forth;
+	HSIPROUND;
+	v0 ^= forth;
+	HPOSTAMBLE
+}
+EXPORT_SYMBOL(hsiphash_4u32);
+#endif
--- a/lib/test_siphash.c
+++ b/lib/test_siphash.c
@@ -7,7 +7,9 @@
  * SipHash: a fast short-input PRF
  * https://131002.net/siphash/
  *
- * This implementation is specifically for SipHash2-4.
+ * This implementation is specifically for SipHash2-4 for a secure PRF
+ * and HalfSipHash1-3/SipHash1-3 for an insecure PRF only suitable for
+ * hashtables.
  */
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
@@ -18,8 +20,8 @@
 #include <linux/errno.h>
 #include <linux/module.h>
 
-/* Test vectors taken from official reference source available at:
- *     https://131002.net/siphash/siphash24.c
+/* Test vectors taken from reference source available at:
+ *     https://github.com/veorq/SipHash
  */
 
 static const siphash_key_t test_key_siphash =
@@ -50,6 +52,64 @@ static const u64 test_vectors_siphash[64
 	0x958a324ceb064572ULL
 };
 
+#if BITS_PER_LONG == 64
+static const hsiphash_key_t test_key_hsiphash =
+	{{ 0x0706050403020100ULL, 0x0f0e0d0c0b0a0908ULL }};
+
+static const u32 test_vectors_hsiphash[64] = {
+	0x050fc4dcU, 0x7d57ca93U, 0x4dc7d44dU,
+	0xe7ddf7fbU, 0x88d38328U, 0x49533b67U,
+	0xc59f22a7U, 0x9bb11140U, 0x8d299a8eU,
+	0x6c063de4U, 0x92ff097fU, 0xf94dc352U,
+	0x57b4d9a2U, 0x1229ffa7U, 0xc0f95d34U,
+	0x2a519956U, 0x7d908b66U, 0x63dbd80cU,
+	0xb473e63eU, 0x8d297d1cU, 0xa6cce040U,
+	0x2b45f844U, 0xa320872eU, 0xdae6c123U,
+	0x67349c8cU, 0x705b0979U, 0xca9913a5U,
+	0x4ade3b35U, 0xef6cd00dU, 0x4ab1e1f4U,
+	0x43c5e663U, 0x8c21d1bcU, 0x16a7b60dU,
+	0x7a8ff9bfU, 0x1f2a753eU, 0xbf186b91U,
+	0xada26206U, 0xa3c33057U, 0xae3a36a1U,
+	0x7b108392U, 0x99e41531U, 0x3f1ad944U,
+	0xc8138825U, 0xc28949a6U, 0xfaf8876bU,
+	0x9f042196U, 0x68b1d623U, 0x8b5114fdU,
+	0xdf074c46U, 0x12cc86b3U, 0x0a52098fU,
+	0x9d292f9aU, 0xa2f41f12U, 0x43a71ed0U,
+	0x73f0bce6U, 0x70a7e980U, 0x243c6d75U,
+	0xfdb71513U, 0xa67d8a08U, 0xb7e8f148U,
+	0xf7a644eeU, 0x0f1837f2U, 0x4b6694e0U,
+	0xb7bbb3a8U
+};
+#else
+static const hsiphash_key_t test_key_hsiphash =
+	{{ 0x03020100U, 0x07060504U }};
+
+static const u32 test_vectors_hsiphash[64] = {
+	0x5814c896U, 0xe7e864caU, 0xbc4b0e30U,
+	0x01539939U, 0x7e059ea6U, 0x88e3d89bU,
+	0xa0080b65U, 0x9d38d9d6U, 0x577999b1U,
+	0xc839caedU, 0xe4fa32cfU, 0x959246eeU,
+	0x6b28096cU, 0x66dd9cd6U, 0x16658a7cU,
+	0xd0257b04U, 0x8b31d501U, 0x2b1cd04bU,
+	0x06712339U, 0x522aca67U, 0x911bb605U,
+	0x90a65f0eU, 0xf826ef7bU, 0x62512debU,
+	0x57150ad7U, 0x5d473507U, 0x1ec47442U,
+	0xab64afd3U, 0x0a4100d0U, 0x6d2ce652U,
+	0x2331b6a3U, 0x08d8791aU, 0xbc6dda8dU,
+	0xe0f6c934U, 0xb0652033U, 0x9b9851ccU,
+	0x7c46fb7fU, 0x732ba8cbU, 0xf142997aU,
+	0xfcc9aa1bU, 0x05327eb2U, 0xe110131cU,
+	0xf9e5e7c0U, 0xa7d708a6U, 0x11795ab1U,
+	0x65671619U, 0x9f5fff91U, 0xd89c5267U,
+	0x007783ebU, 0x95766243U, 0xab639262U,
+	0x9c7e1390U, 0xc368dda6U, 0x38ddc455U,
+	0xfa13d379U, 0x979ea4e8U, 0x53ecd77eU,
+	0x2ee80657U, 0x33dbb66aU, 0xae3f0577U,
+	0x88b4c4ccU, 0x3e7f480bU, 0x74c1ebf8U,
+	0x87178304U
+};
+#endif
+
 static int __init siphash_test_init(void)
 {
 	u8 in[64] __aligned(SIPHASH_ALIGNMENT);
@@ -70,6 +130,16 @@ static int __init siphash_test_init(void
 			pr_info("siphash self-test unaligned %u: FAIL\n", i + 1);
 			ret = -EINVAL;
 		}
+		if (hsiphash(in, i, &test_key_hsiphash) !=
+						test_vectors_hsiphash[i]) {
+			pr_info("hsiphash self-test aligned %u: FAIL\n", i + 1);
+			ret = -EINVAL;
+		}
+		if (hsiphash(in_unaligned + 1, i, &test_key_hsiphash) !=
+						test_vectors_hsiphash[i]) {
+			pr_info("hsiphash self-test unaligned %u: FAIL\n", i + 1);
+			ret = -EINVAL;
+		}
 	}
 	if (siphash_1u64(0x0706050403020100ULL, &test_key_siphash) !=
 						test_vectors_siphash[8]) {
@@ -115,6 +185,28 @@ static int __init siphash_test_init(void
 		pr_info("siphash self-test 4u32: FAIL\n");
 		ret = -EINVAL;
 	}
+	if (hsiphash_1u32(0x03020100U, &test_key_hsiphash) !=
+						test_vectors_hsiphash[4]) {
+		pr_info("hsiphash self-test 1u32: FAIL\n");
+		ret = -EINVAL;
+	}
+	if (hsiphash_2u32(0x03020100U, 0x07060504U, &test_key_hsiphash) !=
+						test_vectors_hsiphash[8]) {
+		pr_info("hsiphash self-test 2u32: FAIL\n");
+		ret = -EINVAL;
+	}
+	if (hsiphash_3u32(0x03020100U, 0x07060504U,
+			  0x0b0a0908U, &test_key_hsiphash) !=
+						test_vectors_hsiphash[12]) {
+		pr_info("hsiphash self-test 3u32: FAIL\n");
+		ret = -EINVAL;
+	}
+	if (hsiphash_4u32(0x03020100U, 0x07060504U,
+			  0x0b0a0908U, 0x0f0e0d0cU, &test_key_hsiphash) !=
+						test_vectors_hsiphash[16]) {
+		pr_info("hsiphash self-test 4u32: FAIL\n");
+		ret = -EINVAL;
+	}
 	if (!ret)
 		pr_info("self-tests: pass\n");
 	return ret;

[PATCH 3.16 1/4] tcp: Clear sk_send_head after purging the write queue

[Ben Hutchings]

3.16.73-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Ben Hutchings <ben@decadent.org.uk>

Denis Andzakovic discovered a potential use-after-free in older kernel
versions, using syzkaller.  tcp_write_queue_purge() frees all skbs in
the TCP write queue and can leave sk->sk_send_head pointing to freed
memory.  tcp_disconnect() clears that pointer after calling
tcp_write_queue_purge(), but tcp_connect() does not.  It is
(surprisingly) possible to add to the write queue between
disconnection and reconnection, so this needs to be done in both
places.

This bug was introduced by backports of commit 7f582b248d0a ("tcp:
purge write queue in tcp_connect_init()") and does not exist upstream
because of earlier changes in commit 75c119afe14f ("tcp: implement
rb-tree based retransmit queue").  The latter is a major change that's
not suitable for stable.

Reported-by: Denis Andzakovic <denis.andzakovic@pulsesecurity.co.nz>
Bisected-by: Salvatore Bonaccorso <carnil@debian.org>
Fixes: 7f582b248d0a ("tcp: purge write queue in tcp_connect_init()")
Cc: <stable@vger.kernel.org> # before 4.15
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
 include/net/tcp.h | 3 +++
 1 file changed, 3 insertions(+)

--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -1352,6 +1352,8 @@ struct tcp_fastopen_context {
 	struct rcu_head		rcu;
 };
 
+static inline void tcp_init_send_head(struct sock *sk);
+
 /* write queue abstraction */
 static inline void tcp_write_queue_purge(struct sock *sk)
 {
@@ -1359,6 +1361,7 @@ static inline void tcp_write_queue_purge
 
 	while ((skb = __skb_dequeue(&sk->sk_write_queue)) != NULL)
 		sk_wmem_free_skb(sk, skb);
+	tcp_init_send_head(sk);
 	sk_mem_reclaim(sk);
 	tcp_clear_all_retrans_hints(tcp_sk(sk));
 }

[PATCH 3.16 2/4] ext4: brelse all indirect buffer in ext4_ind_remove_space()

[Ben Hutchings]

3.16.73-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: "zhangyi (F)" <yi.zhang@huawei.com>

commit 674a2b27234d1b7afcb0a9162e81b2e53aeef217 upstream.

All indirect buffers get by ext4_find_shared() should be released no
mater the branch should be freed or not. But now, we forget to release
the lower depth indirect buffers when removing space from the same
higher depth indirect block. It will lead to buffer leak and futher
more, it may lead to quota information corruption when using old quota,
consider the following case.

 - Create and mount an empty ext4 filesystem without extent and quota
   features,
 - quotacheck and enable the user & group quota,
 - Create some files and write some data to them, and then punch hole
   to some files of them, it may trigger the buffer leak problem
   mentioned above.
 - Disable quota and run quotacheck again, it will create two new
   aquota files and write the checked quota information to them, which
   probably may reuse the freed indirect block(the buffer and page
   cache was not freed) as data block.
 - Enable quota again, it will invoke
   vfs_load_quota_inode()->invalidate_bdev() to try to clean unused
   buffers and pagecache. Unfortunately, because of the buffer of quota
   data block is still referenced, quota code cannot read the up to date
   quota info from the device and lead to quota information corruption.

This problem can be reproduced by xfstests generic/231 on ext3 file
system or ext4 file system without extent and quota features.

This patch fix this problem by releasing the missing indirect buffers,
in ext4_ind_remove_space().

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: zhangyi (F) <yi.zhang@huawei.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
 fs/ext4/indirect.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

--- a/fs/ext4/indirect.c
+++ b/fs/ext4/indirect.c
@@ -1481,10 +1481,14 @@ end_range:
 					   partial->p + 1,
 					   partial2->p,
 					   (chain+n-1) - partial);
-			BUFFER_TRACE(partial->bh, "call brelse");
-			brelse(partial->bh);
-			BUFFER_TRACE(partial2->bh, "call brelse");
-			brelse(partial2->bh);
+			while (partial > chain) {
+				BUFFER_TRACE(partial->bh, "call brelse");
+				brelse(partial->bh);
+			}
+			while (partial2 > chain2) {
+				BUFFER_TRACE(partial2->bh, "call brelse");
+				brelse(partial2->bh);
+			}
 			return 0;
 		}
 

[PATCH 3.16 3/4] ext4: cleanup bh release code in ext4_ind_remove_space()

[Ben Hutchings]

3.16.73-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: "zhangyi (F)" <yi.zhang@huawei.com>

commit 5e86bdda41534e17621d5a071b294943cae4376e upstream.

Currently, we are releasing the indirect buffer where we are done with
it in ext4_ind_remove_space(), so we can see the brelse() and
BUFFER_TRACE() everywhere.  It seems fragile and hard to read, and we
may probably forget to release the buffer some day.  This patch cleans
up the code by putting of the code which releases the buffers to the
end of the function.

Signed-off-by: zhangyi (F) <yi.zhang@huawei.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
 fs/ext4/indirect.c | 47 ++++++++++++++++++++++------------------------
 1 file changed, 22 insertions(+), 25 deletions(-)

--- a/fs/ext4/indirect.c
+++ b/fs/ext4/indirect.c
@@ -1313,6 +1313,7 @@ int ext4_ind_remove_space(handle_t *hand
 	ext4_lblk_t offsets[4], offsets2[4];
 	Indirect chain[4], chain2[4];
 	Indirect *partial, *partial2;
+	Indirect *p = NULL, *p2 = NULL;
 	ext4_lblk_t max_block;
 	__le32 nr = 0, nr2 = 0;
 	int n = 0, n2 = 0;
@@ -1354,7 +1355,7 @@ int ext4_ind_remove_space(handle_t *hand
 		}
 
 
-		partial = ext4_find_shared(inode, n, offsets, chain, &nr);
+		partial = p = ext4_find_shared(inode, n, offsets, chain, &nr);
 		if (nr) {
 			if (partial == chain) {
 				/* Shared branch grows from the inode */
@@ -1379,13 +1380,11 @@ int ext4_ind_remove_space(handle_t *hand
 				partial->p + 1,
 				(__le32 *)partial->bh->b_data+addr_per_block,
 				(chain+n-1) - partial);
-			BUFFER_TRACE(partial->bh, "call brelse");
-			brelse(partial->bh);
 			partial--;
 		}
 
 end_range:
-		partial2 = ext4_find_shared(inode, n2, offsets2, chain2, &nr2);
+		partial2 = p2 = ext4_find_shared(inode, n2, offsets2, chain2, &nr2);
 		if (nr2) {
 			if (partial2 == chain2) {
 				/*
@@ -1415,16 +1414,14 @@ end_range:
 					   (__le32 *)partial2->bh->b_data,
 					   partial2->p,
 					   (chain2+n2-1) - partial2);
-			BUFFER_TRACE(partial2->bh, "call brelse");
-			brelse(partial2->bh);
 			partial2--;
 		}
 		goto do_indirects;
 	}
 
 	/* Punch happened within the same level (n == n2) */
-	partial = ext4_find_shared(inode, n, offsets, chain, &nr);
-	partial2 = ext4_find_shared(inode, n2, offsets2, chain2, &nr2);
+	partial = p = ext4_find_shared(inode, n, offsets, chain, &nr);
+	partial2 = p2 = ext4_find_shared(inode, n2, offsets2, chain2, &nr2);
 
 	/* Free top, but only if partial2 isn't its subtree. */
 	if (nr) {
@@ -1481,15 +1478,7 @@ end_range:
 					   partial->p + 1,
 					   partial2->p,
 					   (chain+n-1) - partial);
-			while (partial > chain) {
-				BUFFER_TRACE(partial->bh, "call brelse");
-				brelse(partial->bh);
-			}
-			while (partial2 > chain2) {
-				BUFFER_TRACE(partial2->bh, "call brelse");
-				brelse(partial2->bh);
-			}
-			return 0;
+			goto cleanup;
 		}
 
 		/*
@@ -1504,8 +1493,6 @@ end_range:
 					   partial->p + 1,
 					   (__le32 *)partial->bh->b_data+addr_per_block,
 					   (chain+n-1) - partial);
-			BUFFER_TRACE(partial->bh, "call brelse");
-			brelse(partial->bh);
 			partial--;
 		}
 		if (partial2 > chain2 && depth2 <= depth) {
@@ -1513,11 +1500,21 @@ end_range:
 					   (__le32 *)partial2->bh->b_data,
 					   partial2->p,
 					   (chain2+n2-1) - partial2);
-			BUFFER_TRACE(partial2->bh, "call brelse");
-			brelse(partial2->bh);
 			partial2--;
 		}
 	}
+
+cleanup:
+	while (p && p > chain) {
+		BUFFER_TRACE(p->bh, "call brelse");
+		brelse(p->bh);
+		p--;
+	}
+	while (p2 && p2 > chain2) {
+		BUFFER_TRACE(p2->bh, "call brelse");
+		brelse(p2->bh);
+		p2--;
+	}
 	return 0;
 
 do_indirects:
@@ -1525,7 +1522,7 @@ do_indirects:
 	switch (offsets[0]) {
 	default:
 		if (++n >= n2)
-			return 0;
+			break;
 		nr = i_data[EXT4_IND_BLOCK];
 		if (nr) {
 			ext4_free_branches(handle, inode, NULL, &nr, &nr+1, 1);
@@ -1533,7 +1530,7 @@ do_indirects:
 		}
 	case EXT4_IND_BLOCK:
 		if (++n >= n2)
-			return 0;
+			break;
 		nr = i_data[EXT4_DIND_BLOCK];
 		if (nr) {
 			ext4_free_branches(handle, inode, NULL, &nr, &nr+1, 2);
@@ -1541,7 +1538,7 @@ do_indirects:
 		}
 	case EXT4_DIND_BLOCK:
 		if (++n >= n2)
-			return 0;
+			break;
 		nr = i_data[EXT4_TIND_BLOCK];
 		if (nr) {
 			ext4_free_branches(handle, inode, NULL, &nr, &nr+1, 3);
@@ -1550,5 +1547,5 @@ do_indirects:
 	case EXT4_TIND_BLOCK:
 		;
 	}
-	return 0;
+	goto cleanup;
 }

Re: [PATCH 3.16 0/4] 3.16.73-rc1 review

[Guenter Roeck]

On 8/17/19 3:35 AM, Ben Hutchings wrote:
> This is the start of the stable review cycle for the 3.16.73 release.
> There are 4 patches in this series, which will be posted as responses
> to this one.  If anyone has any issues with these being applied, please
> let me know.
> 
> Responses should be made by Mon Aug 19 20:00:00 UTC 2019.
> Anything received after that time might be too late.
> 
Build results:
	total: 136 pass: 136 fail: 0
Qemu test results:
	total: 229 pass: 229 fail: 0

Guenter

Re: [PATCH 3.16 0/4] 3.16.73-rc1 review

[Ben Hutchings]

[-- Attachment #1: Type: text/plain, Size: 690 bytes --]

On Sat, 2019-08-17 at 04:19 -0700, Guenter Roeck wrote:
> On 8/17/19 3:35 AM, Ben Hutchings wrote:
> > This is the start of the stable review cycle for the 3.16.73 release.
> > There are 4 patches in this series, which will be posted as responses
> > to this one.  If anyone has any issues with these being applied, please
> > let me know.
> > 
> > Responses should be made by Mon Aug 19 20:00:00 UTC 2019.
> > Anything received after that time might be too late.
> > 
> Build results:
> 	total: 136 pass: 136 fail: 0
> Qemu test results:
> 	total: 229 pass: 229 fail: 0

Thanks for testing,

Ben.

-- 
Ben Hutchings
Larkinson's Law: All laws are basically false.



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