From 8ea90b7a5c030321d70bea246c989fc18c404a14 Mon Sep 17 00:00:00 2001 From: Mark Wielaard Date: Sun, 16 Nov 2014 11:30:51 +0100 Subject: [PATCH] gelf_getnote: Check padding overflow. Since ELF notes need to be properly aligned they can include padding. Make sure the padding itself and the padding calculation doesn't overflow. Signed-off-by: Mark Wielaard --- libelf/ChangeLog | 4 ++++ libelf/gelf_getnote.c | 9 +++++++-- 2 files changed, 11 insertions(+), 2 deletions(-) diff --git a/libelf/ChangeLog b/libelf/ChangeLog index 488609392..beb431fda 100644 --- a/libelf/ChangeLog +++ b/libelf/ChangeLog @@ -1,3 +1,7 @@ +2014-11-16 Mark Wielaard + + * gelf_getnote.c (gelf_getnote): Check padding overflow. + 2014-11-16 Mark Wielaard * elf_getdata.c (__libelf_set_rawdata_wrlock): Declare offset, size diff --git a/libelf/gelf_getnote.c b/libelf/gelf_getnote.c index 8bb78c166..7dc821567 100644 --- a/libelf/gelf_getnote.c +++ b/libelf/gelf_getnote.c @@ -73,16 +73,21 @@ gelf_getnote (data, offset, result, name_offset, desc_offset) const GElf_Nhdr *n = data->d_buf + offset; offset += sizeof *n; + /* Include padding. Check below for overflow. */ GElf_Word namesz = NOTE_ALIGN (n->n_namesz); GElf_Word descsz = NOTE_ALIGN (n->n_descsz); - if (unlikely (data->d_size - offset < namesz)) + if (unlikely (offset > data->d_size + || data->d_size - offset < namesz + || (namesz == 0 && n->n_namesz != 0))) offset = 0; else { *name_offset = offset; offset += namesz; - if (unlikely (data->d_size - offset < descsz)) + if (unlikely (offset > data->d_size + || data->d_size - offset < descsz + || (descsz == 0 && n->n_descsz != 0))) offset = 0; else { -- 2.47.2