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-rw-r--r--NEWS5
-rw-r--r--src/extent-scan.c12
-rwxr-xr-xtests/cp/fiemap-FMR.sh31
-rw-r--r--tests/local.mk1
4 files changed, 46 insertions, 3 deletions
diff --git a/NEWS b/NEWS
index aff5bf18e..0fc2a94d1 100644
--- a/NEWS
+++ b/NEWS
@@ -12,6 +12,11 @@ GNU coreutils NEWS -*- outline -*-
** Bug fixes
+ cp could read from freed memory and could even make corrupt copies.
+ This could happen with a very fragmented and sparse input file,
+ on GNU/Linux file systems supporting fiemap extent scanning.
+ [bug introduced in coreutils-8.11]
+
cp --no-preserve=mode now no longer preserves the original file's
permissions but correctly sets mode specified by 0666 & ~umask
diff --git a/src/extent-scan.c b/src/extent-scan.c
index 0c25c5705..f96229855 100644
--- a/src/extent-scan.c
+++ b/src/extent-scan.c
@@ -89,7 +89,7 @@ extern bool
extent_scan_read (struct extent_scan *scan)
{
unsigned int si = 0;
- struct extent_info *last_ei IF_LINT ( = scan->ext_info);
+ struct extent_info *last_ei = scan->ext_info;
while (true)
{
@@ -127,8 +127,14 @@ extent_scan_read (struct extent_scan *scan)
assert (scan->ei_count <= SIZE_MAX - fiemap->fm_mapped_extents);
scan->ei_count += fiemap->fm_mapped_extents;
- scan->ext_info = xnrealloc (scan->ext_info, scan->ei_count,
- sizeof (struct extent_info));
+ {
+ /* last_ei points into a buffer that may be freed via xnrealloc.
+ Record its offset and adjust after allocation. */
+ size_t prev_idx = last_ei - scan->ext_info;
+ scan->ext_info = xnrealloc (scan->ext_info, scan->ei_count,
+ sizeof (struct extent_info));
+ last_ei = scan->ext_info + prev_idx;
+ }
unsigned int i = 0;
for (i = 0; i < fiemap->fm_mapped_extents; i++)
diff --git a/tests/cp/fiemap-FMR.sh b/tests/cp/fiemap-FMR.sh
new file mode 100755
index 000000000..10c9e0571
--- /dev/null
+++ b/tests/cp/fiemap-FMR.sh
@@ -0,0 +1,31 @@
+#!/bin/sh
+# Trigger a free-memory read bug in cp from coreutils-[8.11..8.19]
+
+# Copyright (C) 2012 Free Software Foundation, Inc.
+
+# This program 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.
+
+# This program 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/>.
+
+. "${srcdir=.}/tests/init.sh"; path_prepend_ ./src
+print_ver_ cp
+
+require_valgrind_
+require_perl_
+: ${PERL=perl}
+
+$PERL -e 'for (1..600) { sysseek (*STDOUT, 4096, 1)' \
+ -e '&& syswrite (*STDOUT, "a" x 1024) or die "$!"}' > j || fail=1
+valgrind --quiet --error-exitcode=3 cp j j2 || fail=1
+cmp j j2 || fail=1
+
+Exit $fail
diff --git a/tests/local.mk b/tests/local.mk
index 486bf312b..5a237fa71 100644
--- a/tests/local.mk
+++ b/tests/local.mk
@@ -418,6 +418,7 @@ all_tests = \
tests/cp/existing-perm-race.sh \
tests/cp/fail-perm.sh \
tests/cp/fiemap-empty.sh \
+ tests/cp/fiemap-FMR.sh \
tests/cp/fiemap-perf.sh \
tests/cp/fiemap-2.sh \
tests/cp/file-perm-race.sh \