2015-09-01 03:33:44

by Wang Nan

[permalink] [raw]
Subject: [PATCH] perf tools: Fix potential array out of bounce accessing

There is a problem in dwarf-regs.c of sh, sparc and x86 that it is
possible to make an out-of-bound array accessing when searching
register names. This patch fixes it by replacing '<=' to '<', so when
register (number == XXX_MAX_REGS), get_arch_regstr() returns NULL.

Signed-off-by: Wang Nan <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Masami Hiramatsu <[email protected]>
Cc: David S. Miller <[email protected]>
Cc: Matt Fleming <[email protected]>
Cc: Jiri Olsa <[email protected]>
---
tools/perf/arch/sh/util/dwarf-regs.c | 2 +-
tools/perf/arch/sparc/util/dwarf-regs.c | 2 +-
tools/perf/arch/x86/util/dwarf-regs.c | 2 +-
3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/tools/perf/arch/sh/util/dwarf-regs.c b/tools/perf/arch/sh/util/dwarf-regs.c
index 0d0897f..f8dfa89 100644
--- a/tools/perf/arch/sh/util/dwarf-regs.c
+++ b/tools/perf/arch/sh/util/dwarf-regs.c
@@ -51,5 +51,5 @@ const char *sh_regs_table[SH_MAX_REGS] = {
/* Return architecture dependent register string (for kprobe-tracer) */
const char *get_arch_regstr(unsigned int n)
{
- return (n <= SH_MAX_REGS) ? sh_regs_table[n] : NULL;
+ return (n < SH_MAX_REGS) ? sh_regs_table[n] : NULL;
}
diff --git a/tools/perf/arch/sparc/util/dwarf-regs.c b/tools/perf/arch/sparc/util/dwarf-regs.c
index 92eda41..b704fdb 100644
--- a/tools/perf/arch/sparc/util/dwarf-regs.c
+++ b/tools/perf/arch/sparc/util/dwarf-regs.c
@@ -39,5 +39,5 @@ const char *sparc_regs_table[SPARC_MAX_REGS] = {
*/
const char *get_arch_regstr(unsigned int n)
{
- return (n <= SPARC_MAX_REGS) ? sparc_regs_table[n] : NULL;
+ return (n < SPARC_MAX_REGS) ? sparc_regs_table[n] : NULL;
}
diff --git a/tools/perf/arch/x86/util/dwarf-regs.c b/tools/perf/arch/x86/util/dwarf-regs.c
index be22dd4..a08de0a 100644
--- a/tools/perf/arch/x86/util/dwarf-regs.c
+++ b/tools/perf/arch/x86/util/dwarf-regs.c
@@ -71,5 +71,5 @@ const char *x86_64_regs_table[X86_64_MAX_REGS] = {
/* Return architecture dependent register string (for kprobe-tracer) */
const char *get_arch_regstr(unsigned int n)
{
- return (n <= ARCH_MAX_REGS) ? arch_regs_table[n] : NULL;
+ return (n < ARCH_MAX_REGS) ? arch_regs_table[n] : NULL;
}
--
1.8.3.4