From: Numfor Mbiziwo-Tiapo <n...@google.com> If insn_init is given a NULL kaddr and 0 buflen then validate_next will perform arithmetic on NULL, add a guard to avoid this.
Don't perform unaligned loads in __get_next and __peek_nbyte_next as these are forms of undefined behavior. These problems were identified using the undefined behavior sanitizer (ubsan) with perf test. Part of this patch was previously posted here: https://lore.kernel.org/lkml/20190724184512.162887-4-n...@google.com/ Signed-off-by: Ian Rogers <irog...@google.com> Signed-off-by: Numfor Mbiziwo-Tiapo <n...@google.com> --- tools/arch/x86/lib/insn.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/tools/arch/x86/lib/insn.c b/tools/arch/x86/lib/insn.c index 0151dfc6da61..e8874a8cac2c 100644 --- a/tools/arch/x86/lib/insn.c +++ b/tools/arch/x86/lib/insn.c @@ -17,13 +17,13 @@ /* Verify next sizeof(t) bytes can be on the same instruction */ #define validate_next(t, insn, n) \ - ((insn)->next_byte + sizeof(t) + n <= (insn)->end_kaddr) + ((insn)->end_kaddr != 0 && (insn)->next_byte + sizeof(t) + n <= (insn)->end_kaddr) #define __get_next(t, insn) \ - ({ t r = *(t*)insn->next_byte; insn->next_byte += sizeof(t); r; }) + ({ t r; memcpy(&r, insn->next_byte, sizeof(t)); insn->next_byte += sizeof(t); r; }) #define __peek_nbyte_next(t, insn, n) \ - ({ t r = *(t*)((insn)->next_byte + n); r; }) + ({ t r; memcpy(&r, (insn)->next_byte + n, sizeof(t)); r; }) #define get_next(t, insn) \ ({ if (unlikely(!validate_next(t, insn, 0))) goto err_out; __get_next(t, insn); }) -- 2.28.0.1011.ga647a8990f-goog
