elf_compress would compress all (new) data chunks, but didn't reset
the section data_list. This would cause extra data to be returned
after decompression or create bad compressed data. Add a new testcase
for this and explicitly zap the scn->data_list before resetting the
elf section raw data after (de)compression.
* libelf/elf_compress.c (__libelf_reset_rawdata): Cleanup
scn->data_list.
* tests/newzdata.c: New testcase.
* tests/Makefile.am (check_PROGRAMS): Add newzdata.
(TESTS): Likewise.
(newzdata_LDADD): New variable.
https://sourceware.org/bugzilla/show_bug.cgi?id=32102
Signed-off-by: Mark Wielaard <m...@klomp.org>
---
libelf/elf_compress.c | 10 +
tests/Makefile.am | 7 +-
tests/newzdata.c | 500 ++++++++++++++++++++++++++++++++++++++++++
3 files changed, 515 insertions(+), 2 deletions(-)
create mode 100644 tests/newzdata.c
diff --git a/libelf/elf_compress.c b/libelf/elf_compress.c
index 0ad6a32a7b2f..2cd32a6f345b 100644
--- a/libelf/elf_compress.c
+++ b/libelf/elf_compress.c
@@ -519,7 +519,17 @@ __libelf_reset_rawdata (Elf_Scn *scn, void *buf, size_t
size, size_t align,
scn->rawdata.d.d_align = align;
scn->rawdata.d.d_type = type;
+ /* Remove the old data. */
+ Elf_Data_List *runp = scn->data_list.next;
+ while (runp != NULL)
+ {
+ Elf_Data_List *oldp = runp;
+ runp = runp->next;
+ if ((oldp->flags & ELF_F_MALLOCED) != 0)
+ free (oldp);
+ }
/* Existing existing data is no longer valid. */
+ scn->data_list.next = NULL;
scn->data_list_rear = NULL;
if (scn->data_base != scn->rawdata_base)
free (scn->data_base);
diff --git a/tests/Makefile.am b/tests/Makefile.am
index 424c184bc200..ff07f7dc3f0b 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -52,7 +52,8 @@ check_PROGRAMS = arextract arsymtest newfile saridx scnnames
sectiondump \
backtrace-data backtrace-dwarf debuglink debugaltlink \
buildid deleted deleted-lib.so aggregate_size peel_type \
vdsosyms \
- getsrc_die strptr newdata elfstrtab dwfl-proc-attach \
+ getsrc_die strptr newdata newzdata \
+ elfstrtab dwfl-proc-attach \
elfshphehdr elfstrmerge dwelfgnucompressed elfgetchdr \
elfgetzdata elfputzdata zstrptr emptyfile vendorelf \
fillfile dwarf_default_lower_bound dwarf-die-addr-die \
@@ -183,7 +184,8 @@ TESTS = run-arextract.sh run-arsymtest.sh run-ar.sh newfile
test-nlist \
run-readelf-dwz-multi.sh run-allfcts-multi.sh run-deleted.sh \
run-linkmap-cut.sh run-aggregate-size.sh run-peel-type.sh \
vdsosyms run-readelf-A.sh \
- run-getsrc-die.sh run-strptr.sh newdata elfstrtab dwfl-proc-attach \
+ run-getsrc-die.sh run-strptr.sh newdata newzdata \
+ elfstrtab dwfl-proc-attach \
elfshphehdr run-lfs-symbols.sh run-dwelfgnucompressed.sh \
run-elfgetchdr.sh \
run-elfgetzdata.sh run-elfputzdata.sh run-zstrptr.sh \
@@ -824,6 +826,7 @@ vdsosyms_LDADD = $(libeu) $(libdw) $(libelf)
getsrc_die_LDADD = $(libeu) $(libdw) $(libelf)
strptr_LDADD = $(libelf)
newdata_LDADD = $(libelf)
+newzdata_LDADD = $(libelf)
elfstrtab_LDADD = $(libelf)
dwfl_proc_attach_LDADD = $(libeu) $(libdw)
dwfl_proc_attach_LDFLAGS = -pthread -rdynamic $(AM_LDFLAGS)
diff --git a/tests/newzdata.c b/tests/newzdata.c
new file mode 100644
index 000000000000..7e6abed2fd04
--- /dev/null
+++ b/tests/newzdata.c
@@ -0,0 +1,500 @@
+/* Test program for elf_newdata function with compressed elf sections.
+ Copyright (C) 2015 Red Hat, Inc.
+ Copyright (C) 2024 Mark J. Wielaard <m...@klomp.org>
+ This file is part of elfutils.
+
+ This file is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
+
+ elfutils is distributed in the hope that it will be useful, but
+ WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <errno.h>
+#include <fcntl.h>
+#include <inttypes.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include "system.h"
+
+#include ELFUTILS_HEADER(elf)
+#include <gelf.h>
+
+// Random data string (16 bytes, 15 chars plus zero-terminator).
+static char *DATA = "123456789ABCDEF";
+static size_t DATA_LEN = 16;
+
+static void
+add_section_data (Elf *elf, char *buf, size_t len)
+{
+ printf ("Adding %zd bytes.\n", len);
+
+ Elf_Scn *scn = elf_getscn (elf, 1);
+ if (scn == NULL)
+ {
+ printf ("couldn't get data section: %s\n", elf_errmsg (-1));
+ exit (1);
+ }
+
+ Elf_Data *data = elf_newdata (scn);
+ if (data == NULL)
+ {
+ printf ("cannot create newdata for section: %s\n", elf_errmsg (-1));
+ exit (1);
+ }
+
+ data->d_buf = buf;
+ data->d_type = ELF_T_BYTE;
+ data->d_size = len;
+ data->d_align = 1;
+ data->d_version = EV_CURRENT;
+
+ // Let the library compute the internal structure information.
+ if (elf_update (elf, ELF_C_NULL) < 0)
+ {
+ printf ("failure in elf_update(NULL): %s\n", elf_errmsg (-1));
+ exit (1);
+ }
+
+}
+
+static Elf *
+create_elf (int fd, int class, int use_mmap)
+{
+ Elf *elf = elf_begin (fd, use_mmap ? ELF_C_WRITE_MMAP : ELF_C_WRITE, NULL);
+ if (elf == NULL)
+ {
+ printf ("cannot create ELF descriptor: %s\n", elf_errmsg (-1));
+ exit (1);
+ }
+
+ // Create an ELF header.
+ if (gelf_newehdr (elf, class) == 0)
+ {
+ printf ("cannot create ELF header: %s\n", elf_errmsg (-1));
+ exit (1);
+ }
+
+ GElf_Ehdr ehdr_mem;
+ GElf_Ehdr *ehdr = gelf_getehdr (elf, &ehdr_mem);
+ if (ehdr == NULL)
+ {
+ printf ("cannot get ELF header: %s\n", elf_errmsg (-1));
+ exit (1);
+ }
+
+ // Initialize header.
+ ehdr->e_ident[EI_DATA] = class == ELFCLASS32 ? ELFDATA2LSB : ELFDATA2MSB;
+ ehdr->e_ident[EI_OSABI] = ELFOSABI_GNU;
+ ehdr->e_type = ET_NONE;
+ ehdr->e_machine = class == ELFCLASS32 ? EM_PPC : EM_X86_64;
+ ehdr->e_version = EV_CURRENT;
+
+ // Update the ELF header.
+ if (gelf_update_ehdr (elf, ehdr) == 0)
+ {
+ printf ("cannot update ELF header: %s\n", elf_errmsg (-1));
+ exit (1);
+ }
+
+ // Create a section.
+ Elf_Scn *scn = elf_newscn (elf);
+ if (scn == NULL)
+ {
+ printf ("cannot create new section: %s\n", elf_errmsg (-1));
+ exit (1);
+ }
+
+ GElf_Shdr shdr_mem;
+ GElf_Shdr *shdr = gelf_getshdr (scn, &shdr_mem);
+ if (shdr == NULL)
+ {
+ printf ("cannot get header for data section: %s\n", elf_errmsg (-1));
+ exit (1);
+ }
+
+ shdr->sh_type = SHT_PROGBITS;
+ shdr->sh_flags = 0;
+ shdr->sh_addr = 0;
+ shdr->sh_link = SHN_UNDEF;
+ shdr->sh_info = SHN_UNDEF;
+ shdr->sh_addralign = 1;
+ shdr->sh_entsize = 1;
+ shdr->sh_name = 0;
+
+ // Finish section, update the header.
+ if (gelf_update_shdr (scn, shdr) == 0)
+ {
+ printf ("cannot update header for DATA section: %s\n", elf_errmsg (-1));
+ exit (1);
+ }
+
+ // Add some data to the section. 3x 16 bytes.
+ add_section_data (elf, DATA, DATA_LEN);
+ add_section_data (elf, DATA, DATA_LEN);
+ add_section_data (elf, DATA, DATA_LEN);
+
+ // Compress the section.
+ if (elf_compress (scn, ELFCOMPRESS_ZLIB, ELF_CHF_FORCE) < 0)
+ {
+ printf ("failure in elf_compress(ELFCOMPRESS_ZLIB): %s\n",
+ elf_errmsg (-1));
+ exit (1);
+ }
+
+ // Mark it dirty so it gets written to disk compressed.
+ elf_flagshdr (scn, ELF_C_SET, ELF_F_DIRTY);
+
+ // Create layout
+ if (elf_update (elf, ELF_C_NULL) < 0)
+ {
+ printf ("failure in elf_update(NULL): %s\n", elf_errmsg (-1));
+ exit (1);
+ }
+
+ // We want to keep this exact layout
+ elf_flagelf (elf, ELF_C_SET, ELF_F_LAYOUT);
+
+ // Write everything to disk.
+ if (elf_update (elf, ELF_C_WRITE) < 0)
+ {
+ printf ("failure in elf_update(WRITE): %s\n", elf_errmsg (-1));
+ exit (1);
+ }
+
+ return elf;
+}
+
+static Elf *
+read_elf (int fd, int use_mmap)
+{
+ printf ("Reading ELF file\n");
+ Elf *elf = elf_begin (fd, use_mmap ? ELF_C_RDWR_MMAP : ELF_C_RDWR, NULL);
+ if (elf == NULL)
+ {
+ printf ("cannot create ELF descriptor read-again: %s\n", elf_errmsg
(-1));
+ exit (1);
+ }
+
+ return elf;
+}
+
+static void
+check_section_size (Elf *elf, size_t size)
+{
+ Elf_Scn *scn = elf_getscn (elf, 1);
+ if (scn == NULL)
+ {
+ printf ("couldn't get data section: %s\n", elf_errmsg (-1));
+ exit (1);
+ }
+
+ GElf_Shdr shdr_mem;
+ GElf_Shdr *shdr = gelf_getshdr (scn, &shdr_mem);
+ if (shdr == NULL)
+ {
+ printf ("cannot get header for DATA section: %s\n", elf_errmsg (-1));
+ exit (1);
+ }
+
+ // Make sure section is uncompressed
+ if (shdr->sh_flags & SHF_COMPRESSED)
+ {
+ if (elf_compress (scn, 0, 0) < 0)
+ {
+ printf ("failure in elf_compress(0): %s\n",
+ elf_errmsg (-1));
+ exit (1);
+ }
+
+ // Re-get the header to get the uncompressed meta-data
+ shdr = gelf_getshdr (scn, &shdr_mem);
+ if (shdr == NULL)
+ {
+ printf ("cannot get header for uncompressed DATA section: %s\n",
+ elf_errmsg (-1));
+ exit (1);
+ }
+ }
+
+ if (shdr->sh_size == size)
+ printf ("OK %zd bytes.\n", size);
+ else
+ {
+ printf ("BAD size, expected %zd, got %" PRIu64 "\n",
+ size, shdr->sh_size);
+ exit (-1);
+ }
+}
+
+static void
+check_section_data (Elf *elf, char *data, size_t len, size_t times)
+{
+ Elf_Scn *scn = elf_getscn (elf, 1);
+ if (scn == NULL)
+ {
+ printf ("couldn't get data section: %s\n", elf_errmsg (-1));
+ exit (1);
+ }
+
+ // Make sure section is uncompressed
+ GElf_Shdr shdr_mem;
+ GElf_Shdr *shdr = gelf_getshdr (scn, &shdr_mem);
+ if (shdr->sh_flags & SHF_COMPRESSED)
+ {
+ if (elf_compress (scn, 0, 0) < 0)
+ {
+ printf ("failure in elf_compress(0): %s\n",
+ elf_errmsg (-1));
+ exit (1);
+ }
+
+ shdr = gelf_getshdr (scn, &shdr_mem);
+ if (shdr == NULL)
+ {
+ printf ("cannot get header for uncompressed DATA section: %s\n",
+ elf_errmsg (-1));
+ exit (1);
+ }
+ }
+
+ // What we expect.
+ char *e_data = (char *) malloc (len * times);
+ if (e_data == NULL)
+ {
+ printf ("Cannot allocate expected data\n");
+ exit (1);
+ }
+
+ for (size_t i = 0; i < times; i++)
+ memcpy (e_data + i * len, data, len);
+
+ // What we get.
+ char *d_data = (char *) malloc (len * times);
+ if (e_data == NULL)
+ {
+ printf ("Cannot allocate d_data\n");
+ exit (1);
+ }
+
+ Elf_Data *d = NULL;
+ size_t dp = 0;
+ while ((d = elf_getdata (scn, d)) != NULL)
+ {
+ printf ("section data item (d_off: %" PRId64 ", d_size: %zd)\n",
+ d->d_off, d->d_size);
+ if (dp + d->d_size > len * times)
+ {
+ printf ("d_size too big: %zd > %zd\n", dp + d->d_size, len * times);
+ exit (1);
+ }
+ memcpy (d_data + dp, d->d_buf, d->d_size);
+ dp += d->d_size;
+ }
+
+ if (dp != len * times)
+ {
+ printf ("not enough data in section data\n");
+ exit (1);
+ }
+
+ if (memcmp (e_data, d_data, times * len) != 0)
+ {
+ printf ("Got bad data in section\n");
+ exit (1);
+ }
+
+ free (e_data);
+ free (d_data);
+}
+
+static void
+check_elf (int class, int use_mmap)
+{
+ static const char *fname;
+ if (class == ELFCLASS32)
+ fname = use_mmap ? "newzdata.elf32.mmap" : "newzdata.elf32";
+ else
+ fname = use_mmap ? "newzdata.elf64.mmap" : "newzdata.elf64";
+
+ printf ("\ncheck_elf: %s\n", fname);
+
+ int fd = open (fname, O_RDWR|O_CREAT|O_TRUNC, DEFFILEMODE);
+ if (fd == -1)
+ {
+ printf ("cannot create `%s': %s\n", fname, strerror (errno));
+ exit (1);
+ }
+
+ Elf *elf = create_elf (fd, class, use_mmap);
+
+ // create_elf adds three hunks of data.
+ // Note that this decompresses the data again.
+ // But after it was written to disk.
+ check_section_size (elf, DATA_LEN * 3);
+ check_section_data (elf, DATA, DATA_LEN, 3);
+
+ if (elf_end (elf) != 0)
+ {
+ printf ("failure in elf_end: %s\n", elf_errmsg (-1));
+ exit (1);
+ }
+
+ close (fd);
+
+ // Read the ELF from disk now. And add new data directly.
+ fd = open (fname, O_RDONLY);
+ if (fd == -1)
+ {
+ printf ("cannot open `%s' read-only: %s\n", fname, strerror (errno));
+ exit (1);
+ }
+
+ elf = read_elf (fd, use_mmap);
+ check_section_size (elf, DATA_LEN * 3);
+ // But don't check contents, that would read the data...
+ // We just need it to be decompressed first.
+
+ // Add some more data.
+ add_section_data (elf, DATA, DATA_LEN);
+ // And check that there is now 4 times the data.
+ check_section_size (elf, DATA_LEN * 4);
+ check_section_data (elf, DATA, DATA_LEN, 4);
+
+ if (elf_end (elf) != 0)
+ {
+ printf ("failure in elf_end: %s\n", elf_errmsg (-1));
+ exit (1);
+ }
+
+ close (fd);
+
+ // Read the ELF from disk now. And add new data after raw reading.
+ fd = open (fname, O_RDONLY);
+ if (fd == -1)
+ {
+ printf ("cannot open `%s' read-only: %s\n", fname, strerror (errno));
+ exit (1);
+ }
+
+ elf = read_elf (fd, use_mmap);
+ check_section_size (elf, DATA_LEN * 3);
+ // But don't check contents, that would read the data...
+ // We just need it decompressed.
+
+ // Get raw data before adding new data.
+ Elf_Scn *scn = elf_getscn (elf, 1);
+ if (scn == NULL)
+ {
+ printf ("couldn't get data section: %s\n", elf_errmsg (-1));
+ exit (1);
+ }
+
+ // Make sure section is uncompressed
+ GElf_Shdr shdr_mem;
+ GElf_Shdr *shdr = gelf_getshdr (scn, &shdr_mem);
+ if (shdr->sh_flags & SHF_COMPRESSED)
+ {
+ if (elf_compress (scn, 0, 0) < 0)
+ {
+ printf ("failure in elf_compress(0): %s\n",
+ elf_errmsg (-1));
+ exit (1);
+ }
+
+ shdr = gelf_getshdr (scn, &shdr_mem);
+ if (shdr == NULL)
+ {
+ printf ("cannot get header for uncompressed DATA section: %s\n",
+ elf_errmsg (-1));
+ exit (1);
+ }
+ }
+
+ printf ("elf_rawdata\n");
+ Elf_Data *data = elf_rawdata (scn, NULL);
+ if (data == NULL)
+ {
+ printf ("couldn't get raw data from section: %s\n", elf_errmsg (-1));
+ exit (1);
+ }
+
+ if (data->d_size != DATA_LEN * 3)
+ {
+ printf ("Unexpected Elf_Data: %zd\n", data->d_size);
+ exit (1);
+ }
+
+ // Now add more data.
+ add_section_data (elf, DATA, DATA_LEN);
+ check_section_size (elf, 4 * DATA_LEN);
+ check_section_data (elf, DATA, DATA_LEN, 4);
+
+ if (elf_end (elf) != 0)
+ {
+ printf ("failure in elf_end: %s\n", elf_errmsg (-1));
+ exit (1);
+ }
+
+ close (fd);
+
+ // Read the ELF from disk now. And add new data after data reading.
+ fd = open (fname, O_RDONLY);
+ if (fd == -1)
+ {
+ printf ("cannot open `%s' read-only: %s\n", fname, strerror (errno));
+ exit (1);
+ }
+
+ elf = read_elf (fd, use_mmap);
+ check_section_size (elf, DATA_LEN * 3);
+ // Get (converted) data before adding new data.
+ check_section_data (elf, DATA, DATA_LEN, 3);
+
+ printf ("elf_getdata\n");
+
+ // Now add more data.
+ add_section_data (elf, DATA, DATA_LEN);
+ add_section_data (elf, DATA, DATA_LEN);
+ check_section_size (elf, 5 * DATA_LEN);
+ check_section_data (elf, DATA, DATA_LEN, 5);
+
+ if (elf_end (elf) != 0)
+ {
+ printf ("failure in elf_end: %s\n", elf_errmsg (-1));
+ exit (1);
+ }
+
+ close (fd);
+
+ unlink (fname);
+}
+
+int
+main (int argc __attribute__ ((unused)), char *argv[] __attribute__ ((unused)))
+{
+ // Initialize libelf.
+ elf_version (EV_CURRENT);
+
+ // Fill holes with something non-zero to more easily spot bad data.
+ elf_fill ('X');
+
+ check_elf (ELFCLASS32, 0);
+ check_elf (ELFCLASS32, 1);
+ check_elf (ELFCLASS64, 0);
+ check_elf (ELFCLASS64, 1);
+
+ return 0;
+}
--
2.47.0
