Merge branch 'akpm' (patches from Andrew)

Merge misc fixes from Andrew Morton:
 "14 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  kernel/sysctl.c: fix out-of-bounds access when setting file-max
  mm/util.c: fix strndup_user() comment
  sh: fix multiple function definition build errors
  MAINTAINERS: add maintainer and replacing reviewer ARM/NUVOTON NPCM
  MAINTAINERS: fix bad pattern in ARM/NUVOTON NPCM
  mm: writeback: use exact memcg dirty counts
  psi: clarify the units used in pressure files
  mm/huge_memory.c: fix modifying of page protection by insert_pfn_pmd()
  hugetlbfs: fix memory leak for resv_map
  mm: fix vm_fault_t cast in VM_FAULT_GET_HINDEX()
  lib/lzo: fix bugs for very short or empty input
  include/linux/bitrev.h: fix constant bitrev
  kmemleak: powerpc: skip scanning holes in the .bss section
  lib/string.c: implement a basic bcmp

1 files changed, 6 insertions, 3 deletions

diff --git a/lib/lzo/lzo1x_compress.c b/lib/lzo/lzo1x_compress.c
index 4525fb094844..a8ede77afe0d 100644
--- a/lib/lzo/lzo1x_compress.c
+++ b/lib/lzo/lzo1x_compress.c
@@ -291,13 +291,14 @@ int lzogeneric1x_1_compress(const unsigned char *in, size_t in_len,
 {
 	const unsigned char *ip = in;
 	unsigned char *op = out;
+	unsigned char *data_start;
 	size_t l = in_len;
 	size_t t = 0;
 	signed char state_offset = -2;
 	unsigned int m4_max_offset;
 
-	// LZO v0 will never write 17 as first byte,
-	// so this is used to version the bitstream
+	// LZO v0 will never write 17 as first byte (except for zero-length
+	// input), so this is used to version the bitstream
 	if (bitstream_version > 0) {
 		*op++ = 17;
 		*op++ = bitstream_version;
@@ -306,6 +307,8 @@ int lzogeneric1x_1_compress(const unsigned char *in, size_t in_len,
 		m4_max_offset = M4_MAX_OFFSET_V0;
 	}
 
+	data_start = op;
+
 	while (l > 20) {
 		size_t ll = l <= (m4_max_offset + 1) ? l : (m4_max_offset + 1);
 		uintptr_t ll_end = (uintptr_t) ip + ll;
@@ -324,7 +327,7 @@ int lzogeneric1x_1_compress(const unsigned char *in, size_t in_len,
 	if (t > 0) {
 		const unsigned char *ii = in + in_len - t;
 
-		if (op == out && t <= 238) {
+		if (op == data_start && t <= 238) {
 			*op++ = (17 + t);
 		} else if (t <= 3) {
 			op[state_offset] |= t;