diff options
| author | Mark Wielaard <[email protected]> | 2025-02-13 00:02:32 +0100 |
|---|---|---|
| committer | Mark Wielaard <[email protected]> | 2025-02-14 08:55:11 +0100 |
| commit | b16f441cca0a4841050e3215a9f120a6d8aea918 (patch) | |
| tree | a3986cd5d1d27a8ac3242843fb09d518fb01cdde | |
| parent | fbf1df9ca286de3323ae541973b08449f8d03aba (diff) | |
libelf: Handle elf_strptr on section without any data
In the unlikely situation that elf_strptr was called on a section with
sh_size already set, but that doesn't have any data yet we could crash
trying to verify the string to return.
This could happen for example when a new section was created with
elf_newscn, but no data having been added yet.
* libelf/elf_strptr.c (elf_strptr): Check strscn->rawdata_base
is not NULL.
https://sourceware.org/bugzilla/show_bug.cgi?id=32672
Signed-off-by: Mark Wielaard <[email protected]>
| -rw-r--r-- | libelf/elf_strptr.c | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/libelf/elf_strptr.c b/libelf/elf_strptr.c index c5a94f82..7be7f5e8 100644 --- a/libelf/elf_strptr.c +++ b/libelf/elf_strptr.c @@ -1,5 +1,6 @@ /* Return string pointer from string section. Copyright (C) 1998-2002, 2004, 2008, 2009, 2015 Red Hat, Inc. + Copyright (C) 2025 Mark J. Wielaard <[email protected]> This file is part of elfutils. Contributed by Ulrich Drepper <[email protected]>, 1998. @@ -183,9 +184,12 @@ elf_strptr (Elf *elf, size_t idx, size_t offset) // initialized yet (when data_read is zero). So we cannot just // look at the rawdata.d.d_size. - /* Make sure the string is NUL terminated. Start from the end, - which very likely is a NUL char. */ - if (likely (validate_str (strscn->rawdata_base, offset, sh_size))) + /* First check there actually is any data. This could be a new + section which hasn't had any data set yet. Then make sure + the string is at a valid offset and NUL terminated. */ + if (unlikely (strscn->rawdata_base == NULL)) + __libelf_seterrno (ELF_E_INVALID_SECTION); + else if (likely (validate_str (strscn->rawdata_base, offset, sh_size))) result = &strscn->rawdata_base[offset]; else __libelf_seterrno (ELF_E_INVALID_INDEX); |