perf dwarf: Fix potential array out of bounds access

There is a problem in the dwarf-regs.c files for sh, sparc and x86 where
it is possible to make an out-of-bounds array access when searching for
register names.

This patch fixes it by replacing '<=' to '<', so when register (number
== XXX_MAX_REGS), get_arch_regstr() will return NULL.

Signed-off-by: Wang Nan <wangnan0@huawei.com>
Reviewed-by: Matt Fleming <matt@console-pimps.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@huawei.com
Link: http://lkml.kernel.org/r/1441078184-105038-1-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/arch/sh/util/dwarf-regs.c b/tools/perf/arch/sh/util/dwarf-regs.c
index 0d0897f57a1027eeb88a8c34a3acd2a9974014cf..f8dfa89696f42e536042c7150b2f970b2502f4cf 100644 (file)
--- 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 92eda412fed34348c09b8471085cc8d88e8d4c2d..b704fdb9237a95263810b07a041f9c45a7daba17 100644 (file)
--- 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 be22dd463232ed734e7a880838035db5e8f86574..a08de0a35b8384ffd4cad3d6c8e08522c0276f59 100644 (file)
--- 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;
 }