[Patch v9 01/10] perf dwarf-regs: Fix DWARF register index bounds check

[Dapeng Mi]

Tighten bounds validation in __get_dwarf_regnum_for_perf_regnum_xxx()
helpers by changing perf_regnum > ARRAY_SIZE() to
perf_regnum >= ARRAY_SIZE().

This fixes an off-by-one condition where perf_regnum == ARRAY_SIZE()
could pass validation and cause out-of-bounds access for
dwarf_xxx_regnums[].

Signed-off-by: Dapeng Mi <dapeng1.mi@xxxxxxxxxxxxxxx>
---
 tools/perf/util/dwarf-regs-arch/dwarf-regs-csky.c    | 2 +-
 tools/perf/util/dwarf-regs-arch/dwarf-regs-powerpc.c | 2 +-
 tools/perf/util/dwarf-regs-arch/dwarf-regs-s390.c    | 2 +-
 tools/perf/util/dwarf-regs-arch/dwarf-regs-x86.c     | 4 ++--
 4 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/tools/perf/util/dwarf-regs-arch/dwarf-regs-csky.c b/tools/perf/util/dwarf-regs-arch/dwarf-regs-csky.c
index cb44b774f8d9..7f976aa3cfa2 100644
--- a/tools/perf/util/dwarf-regs-arch/dwarf-regs-csky.c
+++ b/tools/perf/util/dwarf-regs-arch/dwarf-regs-csky.c
@@ -118,7 +118,7 @@ int __get_dwarf_regnum_for_perf_regnum_csky(int perf_regnum, unsigned int flags)
 	if (flags & EF_CSKY_ABIV2)
 		idx++;
 
-	if (perf_regnum <  0 || perf_regnum > (int)ARRAY_SIZE(dwarf_csky_regnums) ||
+	if (perf_regnum < 0 || perf_regnum >= (int)ARRAY_SIZE(dwarf_csky_regnums) ||
 	    dwarf_csky_regnums[perf_regnum][idx] == 0)
 		return -ENOENT;
 
diff --git a/tools/perf/util/dwarf-regs-arch/dwarf-regs-powerpc.c b/tools/perf/util/dwarf-regs-arch/dwarf-regs-powerpc.c
index 51892a09725b..98e7f2b2791c 100644
--- a/tools/perf/util/dwarf-regs-arch/dwarf-regs-powerpc.c
+++ b/tools/perf/util/dwarf-regs-arch/dwarf-regs-powerpc.c
@@ -128,7 +128,7 @@ int __get_dwarf_regnum_for_perf_regnum_powerpc(int perf_regnum)
 	if (perf_regnum == 0)
 		return 0;
 
-	if (perf_regnum <  0 || perf_regnum > (int)ARRAY_SIZE(dwarf_powerpc_regnums) ||
+	if (perf_regnum < 0 || perf_regnum >= (int)ARRAY_SIZE(dwarf_powerpc_regnums) ||
 	    dwarf_powerpc_regnums[perf_regnum] == 0)
 		return -ENOENT;
 
diff --git a/tools/perf/util/dwarf-regs-arch/dwarf-regs-s390.c b/tools/perf/util/dwarf-regs-arch/dwarf-regs-s390.c
index 310a37451bdc..9cef846ef9c0 100644
--- a/tools/perf/util/dwarf-regs-arch/dwarf-regs-s390.c
+++ b/tools/perf/util/dwarf-regs-arch/dwarf-regs-s390.c
@@ -45,7 +45,7 @@ int __get_dwarf_regnum_for_perf_regnum_s390(int perf_regnum)
 	if (perf_regnum == 0)
 		return 0;
 
-	if (perf_regnum <  0 || perf_regnum > (int)ARRAY_SIZE(dwarf_s390_regnums) ||
+	if (perf_regnum < 0 || perf_regnum >= (int)ARRAY_SIZE(dwarf_s390_regnums) ||
 	    dwarf_s390_regnums[perf_regnum] == 0)
 		return -ENOENT;
 
diff --git a/tools/perf/util/dwarf-regs-arch/dwarf-regs-x86.c b/tools/perf/util/dwarf-regs-arch/dwarf-regs-x86.c
index cadef120aeb4..c2a70e03b1a9 100644
--- a/tools/perf/util/dwarf-regs-arch/dwarf-regs-x86.c
+++ b/tools/perf/util/dwarf-regs-arch/dwarf-regs-x86.c
@@ -197,7 +197,7 @@ int __get_dwarf_regnum_for_perf_regnum_i386(int perf_regnum)
 	if (perf_regnum == 0)
 		return 0;
 
-	if (perf_regnum <  0 || perf_regnum > (int)ARRAY_SIZE(dwarf_i386_regnums) ||
+	if (perf_regnum < 0 || perf_regnum >= (int)ARRAY_SIZE(dwarf_i386_regnums) ||
 	    dwarf_i386_regnums[perf_regnum] == 0)
 		return -ENOENT;
 
@@ -252,7 +252,7 @@ int __get_dwarf_regnum_for_perf_regnum_x86_64(int perf_regnum)
 	if (perf_regnum == 0)
 		return 0;
 
-	if (perf_regnum <  0 || perf_regnum > (int)ARRAY_SIZE(dwarf_x86_64_regnums) ||
+	if (perf_regnum < 0 || perf_regnum >= (int)ARRAY_SIZE(dwarf_x86_64_regnums) ||
 	    dwarf_x86_64_regnums[perf_regnum] == 0)
 		return -ENOENT;
 
-- 
2.34.1