From 0545e3b69ab57af1c21d199611c56b7f7593c8c5 Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Tue, 19 Nov 2013 17:17:48 +0100 Subject: [PATCH] tar: prevent empty file to be treated as valid tarball function old new delta tar_main 879 895 +16 Signed-off-by: Denys Vlasenko --- archival/tar.c | 13 ++++++++++--- testsuite/tar.tests | 25 +++++++++++++++++++++++++ 2 files changed, 35 insertions(+), 3 deletions(-) diff --git a/archival/tar.c b/archival/tar.c index 3877ea4..bd61abd 100644 --- a/archival/tar.c +++ b/archival/tar.c @@ -1196,8 +1196,14 @@ int tar_main(int argc UNUSED_PARAM, char **argv) /*tar_handle->offset = 0; - already is */ } + /* Zero processed headers (== empty file) is not a valid tarball. + * We (ab)use bb_got_signal as exitcode here, + * because check_errors_in_children() uses _it_ as error indicator. + */ + bb_got_signal = EXIT_FAILURE; + while (get_header_tar(tar_handle) == EXIT_SUCCESS) - continue; + bb_got_signal = EXIT_SUCCESS; /* saw at least one header, good */ /* Check that every file that should have been extracted was */ while (tar_handle->accept) { @@ -1213,8 +1219,9 @@ int tar_main(int argc UNUSED_PARAM, char **argv) close(tar_handle->src_fd); if (SEAMLESS_COMPRESSION || OPT_COMPRESS) { + /* Set bb_got_signal to 1 if a child died with !0 exitcode */ check_errors_in_children(0); - return bb_got_signal; } - return EXIT_SUCCESS; + + return bb_got_signal; } diff --git a/testsuite/tar.tests b/testsuite/tar.tests index c947d33..93ba5f0 100755 --- a/testsuite/tar.tests +++ b/testsuite/tar.tests @@ -15,6 +15,15 @@ mkdir tar.tempdir && cd tar.tempdir || exit 1 # testing "test name" "script" "expected result" "file input" "stdin" +testing "Empty file is not a tarball" '\ +tar xvf - 2>&1; echo $? +' "\ +tar: short read +1 +" \ +"" "" +SKIP= + optional FEATURE_SEAMLESS_GZ testing "Empty file is not a tarball.tar.gz" '\ tar xvzf - 2>&1; echo $? @@ -26,6 +35,22 @@ tar: short read "" "" SKIP= +testing "Two zeroed blocks is a ('truncated') empty tarball" '\ +dd if=/dev/zero bs=512 count=2 2>/dev/null | strace -o /tmp/zzz -tt -s99 tar xvf - 2>&1; echo $? +' "\ +0 +" \ +"" "" +SKIP= + +testing "Twenty zeroed blocks is an empty tarball" '\ +dd if=/dev/zero bs=512 count=20 2>/dev/null | tar xvf - 2>&1; echo $? +' "\ +0 +" \ +"" "" +SKIP= + optional FEATURE_TAR_CREATE FEATURE_LS_SORTFILES testing "tar hardlinks and repeated files" '\ rm -rf input_* test.tar 2>/dev/null -- 2.7.4