From 9ace4692b2fa96c1c92177bb51e5e36680de25ad Mon Sep 17 00:00:00 2001 From: "Dmitry V. Levin" Date: Wed, 16 Nov 2016 22:49:25 +0000 Subject: Check for __mprotect failure in _dl_map_segments [BZ #20831] * elf/dl-map-segments.h (_dl_map_segments): Check for failure of __mprotect to change protection on the excess portion to disallow all access. --- elf/dl-map-segments.h | 20 ++++++++++++-------- 1 file changed, 12 insertions(+), 8 deletions(-) (limited to 'elf') diff --git a/elf/dl-map-segments.h b/elf/dl-map-segments.h index 31d6861c8e..d36f9bd2f6 100644 --- a/elf/dl-map-segments.h +++ b/elf/dl-map-segments.h @@ -64,14 +64,18 @@ _dl_map_segments (struct link_map *l, int fd, l->l_addr = l->l_map_start - c->mapstart; if (has_holes) - /* Change protection on the excess portion to disallow all access; - the portions we do not remap later will be inaccessible as if - unallocated. Then jump into the normal segment-mapping loop to - handle the portion of the segment past the end of the file - mapping. */ - __mprotect ((caddr_t) (l->l_addr + c->mapend), - loadcmds[nloadcmds - 1].mapstart - c->mapend, - PROT_NONE); + { + /* Change protection on the excess portion to disallow all access; + the portions we do not remap later will be inaccessible as if + unallocated. Then jump into the normal segment-mapping loop to + handle the portion of the segment past the end of the file + mapping. */ + if (__glibc_unlikely + (__mprotect ((caddr_t) (l->l_addr + c->mapend), + loadcmds[nloadcmds - 1].mapstart - c->mapend, + PROT_NONE) < 0)) + return DL_MAP_SEGMENTS_ERROR_MPROTECT; + } l->l_contiguous = 1; -- cgit 1.4.1