From 2c0915cbf570cb9c8a65f1d20a55c5a7238e5b63 Mon Sep 17 00:00:00 2001 From: "H.J. Lu" Date: Tue, 15 Feb 2022 06:57:11 -0800 Subject: [PATCH] elf: Check invalid hole in PT_LOAD segments [BZ #28838] Changes in v2: 1. Update commit log. commit 163f625cf9becbb82dfec63a29e566324129c0cd Author: H.J. Lu Date: Tue Dec 21 12:35:47 2021 -0800 elf: Remove excessive p_align check on PT_LOAD segments [BZ #28688] removed the p_align check against the page size. It caused the loader error or crash on elf/tst-p_align3 when loading elf/tst-p_alignmod3.so, which has the invalid p_align in PT_LOAD segments, added by commit d8d94863ef125a392b929732b37e07dc927fbcd1 Author: H.J. Lu Date: Tue Dec 21 13:42:28 2021 -0800 The loader failure caused by a negative length passed to __mprotect is random, depending on architecture and toolchain. Update _dl_map_segments to detect invalid holes. This fixes BZ #28838. Reviewed-by: Florian Weimer --- elf/dl-map-segments.h | 3 +++ 1 file changed, 3 insertions(+) diff --git a/elf/dl-map-segments.h b/elf/dl-map-segments.h index b3513e7909..024175b2d5 100644 --- a/elf/dl-map-segments.h +++ b/elf/dl-map-segments.h @@ -112,6 +112,9 @@ _dl_map_segments (struct link_map *l, int fd, 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 (loadcmds[nloadcmds - 1].mapstart < + c->mapend)) + return N_("ELF load command address/offset not page-aligned"); if (__glibc_unlikely (__mprotect ((caddr_t) (l->l_addr + c->mapend), loadcmds[nloadcmds - 1].mapstart - c->mapend,