From 68641fb77c302c75ecc4ab478dc36af00b60215c Mon Sep 17 00:00:00 2001 From: Tom de Vries Date: Tue, 12 Feb 2019 14:00:59 +0000 Subject: [PATCH] [libbacktrace] Handle bsearch with NULL base in dwarf_lookup_pc The call to bsearch in dwarf_lookup_pc can have NULL as base argument when the nmemb argument is 0. The base argument is required to be pointing to the initial member of an array of nmemb objects. It is not specified what constitutes a valid pointer to an array of 0 objects, but glibc declares base with attribute non-null, so the NULL will trigger a sanitizer runtime error. Fix this by only calling bsearch if nmemb != 0. 2019-02-12 Tom de Vries PR libbacktrace/81983 * dwarf.c (dwarf_lookup_pc): Don't call bsearch if nmemb == 0. From-SVN: r268796 --- libbacktrace/ChangeLog | 5 +++++ libbacktrace/dwarf.c | 6 ++++-- 2 files changed, 9 insertions(+), 2 deletions(-) diff --git a/libbacktrace/ChangeLog b/libbacktrace/ChangeLog index 9e0da6353e3..e29c41f78ed 100644 --- a/libbacktrace/ChangeLog +++ b/libbacktrace/ChangeLog @@ -1,3 +1,8 @@ +2019-02-12 Tom de Vries + + PR libbacktrace/81983 + * dwarf.c (dwarf_lookup_pc): Don't call bsearch if nmemb == 0. + 2019-02-10 Tom de Vries * Makefile.am (BUILDTESTS): Add btest_lto. diff --git a/libbacktrace/dwarf.c b/libbacktrace/dwarf.c index d7dacf3ef32..f338489fe44 100644 --- a/libbacktrace/dwarf.c +++ b/libbacktrace/dwarf.c @@ -2821,8 +2821,10 @@ dwarf_lookup_pc (struct backtrace_state *state, struct dwarf_data *ddata, *found = 1; /* Find an address range that includes PC. */ - entry = bsearch (&pc, ddata->addrs, ddata->addrs_count, - sizeof (struct unit_addrs), unit_addrs_search); + entry = (ddata->addrs_count == 0 + ? NULL + : bsearch (&pc, ddata->addrs, ddata->addrs_count, + sizeof (struct unit_addrs), unit_addrs_search)); if (entry == NULL) { -- 2.30.2