From: Mark Wielaard Date: Fri, 21 Oct 2016 13:24:34 +0000 (+0200) Subject: libelf: Sanity check offset and size before trying to malloc and read data. X-Git-Tag: elfutils-0.168~6 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=09ec02ec7f7e6913d10943148e2a898264345b07;p=platform%2Fupstream%2Felfutils.git libelf: Sanity check offset and size before trying to malloc and read data. Bad sh_off or sh_size could trigger a bad malloc or read. Sanity check the header values first before trying to malloc a huge buffer or reading any data that will certainly fail. https://bugzilla.redhat.com/show_bug.cgi?id=1387584 Signed-off-by: Mark Wielaard --- diff --git a/libelf/ChangeLog b/libelf/ChangeLog index 39fbccf..6414128 100644 --- a/libelf/ChangeLog +++ b/libelf/ChangeLog @@ -1,3 +1,8 @@ +2016-10-21 Mark Wielaard + + * elf_getdata.c (__libelf_set_rawdata_wrlock): Sanity check + offset and size before trying to malloc and read data. + 2016-10-26 Mark Wielaard * elf_begin.c (read_file): Always set maxsize when parent == NULL. diff --git a/libelf/elf_getdata.c b/libelf/elf_getdata.c index d1fafbf..97c503b 100644 --- a/libelf/elf_getdata.c +++ b/libelf/elf_getdata.c @@ -312,6 +312,17 @@ __libelf_set_rawdata_wrlock (Elf_Scn *scn) } else if (likely (elf->fildes != -1)) { + /* First see whether the information in the section header is + valid and it does not ask for too much. Check for unsigned + overflow. */ + if (unlikely (offset > elf->maximum_size + || elf->maximum_size - offset < size)) + { + /* Something is wrong. */ + __libelf_seterrno (ELF_E_INVALID_SECTION_HEADER); + return 1; + } + /* We have to read the data from the file. Allocate the needed memory. */ scn->rawdata_base = scn->rawdata.d.d_buf