From: Mark Wielaard Date: Sun, 1 Nov 2020 17:51:02 +0000 (+0100) Subject: libelf: Set dst to zero on failure in __elf_getphdrnum_rdlock X-Git-Tag: elfutils-0.183~99 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=86cedebad363184ef5e4e4f51e1ee2f701e32ad3;p=thirdparty%2Felfutils.git libelf: Set dst to zero on failure in __elf_getphdrnum_rdlock GCC with -flto finds some (very) unlikely error paths. It flags callers of __elf_getphdrnum_chk_rdlock with *dst not yet set because an internal call to __elf_getphdrnum_rdlock might not initialize *dst either in one particular failure path. The sanity check that __elf_getphdrnum_chk_rdlock then performs might happen against uninitialized data. So just set *dst to zero on failure in __elf_getphdrnum_rdlock so any caller can simply check either the result/error code or whether *dst is zero or not. Signed-off-by: Mark Wielaard --- diff --git a/libelf/ChangeLog b/libelf/ChangeLog index 7bd15a284..aee1ffff5 100644 --- a/libelf/ChangeLog +++ b/libelf/ChangeLog @@ -1,3 +1,8 @@ +2020-11-01 Mark Wielaard + + * elf_getphdrnum.c (__elf_getphdrnum_rdlock): Set *dst to zero on + error. + 2020-11-01 Mark Wielaard * libelfP.h (__libelf_data_type): Take an GElf_Ehdr instead of an diff --git a/libelf/elf_getphdrnum.c b/libelf/elf_getphdrnum.c index 53617dfc7..60ebec58c 100644 --- a/libelf/elf_getphdrnum.c +++ b/libelf/elf_getphdrnum.c @@ -44,6 +44,7 @@ __elf_getphdrnum_rdlock (Elf *elf, size_t *dst) if (unlikely (elf->state.elf64.ehdr == NULL)) { /* Maybe no ELF header was created yet. */ + *dst = 0; __libelf_seterrno (ELF_E_WRONG_ORDER_EHDR); return -1; }