466 lines
15 KiB
Diff
466 lines
15 KiB
Diff
From fd555fc06bfb4eae3eb48fbc150d20a4dda0d150 Mon Sep 17 00:00:00 2001
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From: Sergey Poznyakoff <gray@gnu.org>
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Date: Thu, 27 Dec 2018 17:48:57 +0200
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Subject: [PATCH] Fixed a denial of service when the '--sparse' option
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mishandles file shrinkage during read access(CVE-2018-20482)
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https://github.com/praiskup/tar/commit/c15c42ccd1e2377945fd0414eca1a49294bff454
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Signed-off-by: fangyufa1 <fangyufa1@huawei.com>
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---
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NEWS | 32 +++++++++++++++++-
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src/sparse.c | 82 +++++++++++++++++++++++++++++----------------
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tests/Makefile.am | 5 ++-
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tests/sptrcreat.at | 62 ++++++++++++++++++++++++++++++++++
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tests/sptrdiff00.at | 55 ++++++++++++++++++++++++++++++
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tests/sptrdiff01.at | 55 ++++++++++++++++++++++++++++++
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tests/testsuite.at | 5 ++-
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7 files changed, 264 insertions(+), 32 deletions(-)
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create mode 100644 tests/sptrcreat.at
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create mode 100644 tests/sptrdiff00.at
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create mode 100644 tests/sptrdiff01.at
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diff --git a/NEWS b/NEWS
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index cd15fa1..283c376 100644
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--- a/NEWS
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+++ b/NEWS
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@@ -1,7 +1,37 @@
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-GNU tar NEWS - User visible changes. 2017-12-17
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+GNU tar NEWS - User visible changes. 2018-12-27
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Please send GNU tar bug reports to <bug-tar@gnu.org>
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+version 1.30.90 (Git)
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+
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+* Fix heap-buffer-overrun with --one-top-level.
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+Bug introduced with the addition of that option in 1.28.
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+
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+* Support for zstd compression
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+
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+New option '--zstd' instructs tar to use zstd as compression program.
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+When listing, extractng and comparing, zstd compressed archives are
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+recognized automatically.
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+When '-a' option is in effect, zstd compression is selected if the
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+destination archive name ends in '.zst' or '.tzst'.
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+
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+* The -K option interacts properly with member names given in the command line
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+
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+Names of members to extract can be specified along with the "-K NAME"
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+option. In this case, tar will extract NAME and those of named members
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+that appear in the archive after it, which is consistent with the
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+semantics of the option.
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+
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+Previous versions of tar extracted NAME, those of named members that
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+appeared before it, and everything after it.
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+
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+* Fix CVE-2018-20482
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+
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+When creating archives with the --sparse option, previous versions of
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+tar would loop endlessly if a sparse file had been truncated while
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+being archived.
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+
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+
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version 1.30 - Sergey Poznyakoff, 2017-12-17
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* Member names containing '..' components are now skipped when extracting.
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diff --git a/src/sparse.c b/src/sparse.c
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index 6ec069d..726facd 100644
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--- a/src/sparse.c
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+++ b/src/sparse.c
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@@ -1,6 +1,6 @@
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/* Functions for dealing with sparse files
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- Copyright 2003-2007, 2010, 2013-2017 Free Software Foundation, Inc.
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+ Copyright 2003-2007, 2010, 2013-2018 Free Software Foundation, Inc.
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This program is free software; you can redistribute it and/or modify it
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under the terms of the GNU General Public License as published by the
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@@ -428,16 +428,30 @@ sparse_dump_region (struct tar_sparse_file *file, size_t i)
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bufsize);
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return false;
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}
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- if (bytes_read == 0)
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- {
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- char buf[UINTMAX_STRSIZE_BOUND];
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- FATAL_ERROR ((0, 0,
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- ngettext ("%s: File shrank by %s byte",
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- "%s: File shrank by %s bytes",
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- bytes_left),
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- quotearg_colon (file_name),
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- offtostr (bytes_left, buf)));
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- }
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+ else if (bytes_read == 0)
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+ {
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+ char buf[UINTMAX_STRSIZE_BOUND];
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+ struct stat st;
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+ size_t n;
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+ if (fstat (file->fd, &st) == 0)
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+ n = file->stat_info->stat.st_size - st.st_size;
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+ else
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+ n = file->stat_info->stat.st_size
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+ - (file->stat_info->sparse_map[i].offset
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+ + file->stat_info->sparse_map[i].numbytes
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+ - bytes_left);
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+
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+ WARNOPT (WARN_FILE_SHRANK,
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+ (0, 0,
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+ ngettext ("%s: File shrank by %s byte; padding with zeros",
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+ "%s: File shrank by %s bytes; padding with zeros",
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+ n),
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+ quotearg_colon (file_name),
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+ STRINGIFY_BIGINT (n, buf)));
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+ if (! ignore_failed_read_option)
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+ set_exit_status (TAREXIT_DIFFERS);
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+ return false;
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+ }
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memset (blk->buffer + bytes_read, 0, BLOCKSIZE - bytes_read);
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bytes_left -= bytes_read;
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@@ -475,9 +489,9 @@ sparse_extract_region (struct tar_sparse_file *file, size_t i)
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return false;
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}
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set_next_block_after (blk);
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+ file->dumped_size += BLOCKSIZE;
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count = blocking_write (file->fd, blk->buffer, wrbytes);
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write_size -= count;
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- file->dumped_size += count;
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mv_size_left (file->stat_info->archive_file_size - file->dumped_size);
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file->offset += count;
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if (count != wrbytes)
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@@ -610,20 +624,24 @@ check_sparse_region (struct tar_sparse_file *file, off_t beg, off_t end)
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offset, rdsize);
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return false;
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}
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-
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- if (bytes_read == 0
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- || !zero_block_p (diff_buffer, bytes_read))
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- {
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- char begbuf[INT_BUFSIZE_BOUND (off_t)];
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- const char *msg = bytes_read ? _("File fragment at %s is not a hole")
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- : _("Hole starting at %s is truncated");
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-
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- report_difference (file->stat_info, msg, offtostr (beg, begbuf));
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- return false;
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- }
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+ else if (bytes_read == 0)
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+ {
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+ report_difference (file->stat_info, _("Size differs"));
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+ return false;
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+ }
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+
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+ if (!zero_block_p (diff_buffer, bytes_read))
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+ {
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+ char begbuf[INT_BUFSIZE_BOUND (off_t)];
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+ report_difference (file->stat_info,
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+ _("File fragment at %s is not a hole"),
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+ offtostr (offset, begbuf));
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+ return false;
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+ }
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offset += bytes_read;
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}
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+
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return true;
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}
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@@ -650,6 +668,7 @@ check_data_region (struct tar_sparse_file *file, size_t i)
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return false;
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}
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set_next_block_after (blk);
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+ file->dumped_size += BLOCKSIZE;
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bytes_read = safe_read (file->fd, diff_buffer, rdsize);
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if (bytes_read == SAFE_READ_ERROR)
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{
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@@ -660,11 +679,14 @@ check_data_region (struct tar_sparse_file *file, size_t i)
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rdsize);
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return false;
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}
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- file->dumped_size += bytes_read;
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+ else if (bytes_read == 0)
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+ {
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+ report_difference (¤t_stat_info, _("Size differs"));
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+ return false;
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+ }
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size_left -= bytes_read;
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mv_size_left (file->stat_info->archive_file_size - file->dumped_size);
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- if (bytes_read == 0
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- || memcmp (blk->buffer, diff_buffer, bytes_read))
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+ if (memcmp (blk->buffer, diff_buffer, bytes_read))
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{
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report_difference (file->stat_info, _("Contents differ"));
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return false;
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@@ -1229,7 +1251,8 @@ pax_decode_header (struct tar_sparse_file *file)
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union block *blk;
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char *p;
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size_t i;
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-
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+ off_t start;
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+
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#define COPY_BUF(b,buf,src) do \
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{ \
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char *endp = b->buffer + BLOCKSIZE; \
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@@ -1245,7 +1268,6 @@ pax_decode_header (struct tar_sparse_file *file)
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if (src == endp) \
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{ \
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set_next_block_after (b); \
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- file->dumped_size += BLOCKSIZE; \
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b = find_next_block (); \
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if (!b) \
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FATAL_ERROR ((0, 0, _("Unexpected EOF in archive"))); \
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@@ -1258,8 +1280,8 @@ pax_decode_header (struct tar_sparse_file *file)
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dst[-1] = 0; \
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} while (0)
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+ start = current_block_ordinal ();
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set_next_block_after (current_header);
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- file->dumped_size += BLOCKSIZE;
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blk = find_next_block ();
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if (!blk)
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FATAL_ERROR ((0, 0, _("Unexpected EOF in archive")));
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@@ -1298,6 +1320,8 @@ pax_decode_header (struct tar_sparse_file *file)
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sparse_add_map (file->stat_info, &sp);
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}
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set_next_block_after (blk);
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+
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+ file->dumped_size += BLOCKSIZE * (current_block_ordinal () - start);
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}
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return true;
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diff --git a/tests/Makefile.am b/tests/Makefile.am
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index 2d7939d..ac3b6e7 100644
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--- a/tests/Makefile.am
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+++ b/tests/Makefile.am
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@@ -1,6 +1,6 @@
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# Makefile for GNU tar regression tests.
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-# Copyright 1996-1997, 1999-2001, 2003-2007, 2009, 2012-2015 Free Software
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+# Copyright 1996-1997, 1999-2001, 2003-2007, 2009, 2012-2018 Free Software
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# This file is part of GNU tar.
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@@ -228,6 +228,9 @@ TESTSUITE_AT = \
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spmvp00.at\
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spmvp01.at\
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spmvp10.at\
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+ sptrcreat.at\
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+ sptrdiff00.at\
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+ sptrdiff01.at\
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time01.at\
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time02.at\
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truncate.at\
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diff --git a/tests/sptrcreat.at b/tests/sptrcreat.at
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new file mode 100644
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index 0000000..8e28f0e
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--- /dev/null
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+++ b/tests/sptrcreat.at
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@@ -0,0 +1,62 @@
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+# Process this file with autom4te to create testsuite. -*- Autotest -*-
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+
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+# Test suite for GNU tar.
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+# Copyright 2018 Free Software Foundation, Inc.
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+
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+# This file is part of GNU tar.
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+
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+# GNU tar is free software; you can redistribute it and/or modify
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+# it under the terms of the GNU General Public License as published by
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+# the Free Software Foundation; either version 3 of the License, or
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+# (at your option) any later version.
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+
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+# GNU tar is distributed in the hope that it will be useful,
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+# but WITHOUT ANY WARRANTY; without even the implied warranty of
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+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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+# GNU General Public License for more details.
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+
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+# You should have received a copy of the GNU General Public License
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+# along with this program. If not, see <http://www.gnu.org/licenses/>.
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+
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+# Tar up to 1.30 would loop endlessly if a sparse file had been truncated
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+# while being archived (with --sparse flag).
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+#
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+# The bug has been assigned id CVE-2018-20482 (on the grounds that it is a
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+# denial of service possibility).
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+#
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+# Reported by: Chris Siebenmann <cks.gnutar-01@cs.toronto.edu>
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+# References: <20181226223948.781EB32008E@apps1.cs.toronto.edu>,
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+# <http://lists.gnu.org/archive/html/bug-tar/2018-12/msg00023.html>
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+# <https://utcc.utoronto.ca/~cks/space/blog/sysadmin/TarFindingTruncateBug>
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+# <https://nvd.nist.gov/vuln/detail/CVE-2018-20482>
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+
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+AT_SETUP([sparse file truncated while archiving])
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+AT_KEYWORDS([truncate filechange sparse sptr sptrcreat])
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+
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+AT_TAR_CHECK([
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+genfile --sparse --block-size=1024 --file foo \
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+ 0 ABCDEFGHIJ 1M ABCDEFGHIJ 10M ABCDEFGHIJ 200M ABCDEFGHIJ
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+genfile --file baz
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+genfile --run --checkpoint 3 --length 200m --truncate foo -- \
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+ tar --checkpoint=1 \
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+ --checkpoint-action=echo \
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+ --checkpoint-action=sleep=1 \
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+ --sparse -vcf bar foo baz
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+echo Exit status: $?
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+echo separator
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+genfile --file foo --seek 200m --length 11575296 --pattern=zeros
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+tar dvf bar],
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+[1],
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+[foo
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+baz
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+Exit status: 1
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+separator
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+foo
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+foo: Mod time differs
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+baz
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+],
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+[tar: foo: File shrank by 11575296 bytes; padding with zeros
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+],
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+[],[],[posix, gnu, oldgnu])
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+
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+AT_CLEANUP
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diff --git a/tests/sptrdiff00.at b/tests/sptrdiff00.at
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new file mode 100644
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index 0000000..c410561
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--- /dev/null
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+++ b/tests/sptrdiff00.at
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@@ -0,0 +1,55 @@
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+# Process this file with autom4te to create testsuite. -*- Autotest -*-
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+#
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+# Test suite for GNU tar.
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+# Copyright 2018 Free Software Foundation, Inc.
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+#
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+# This file is part of GNU tar.
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+#
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+# GNU tar is free software; you can redistribute it and/or modify
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+# it under the terms of the GNU General Public License as published by
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+# the Free Software Foundation; either version 3 of the License, or
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+# (at your option) any later version.
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+#
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+# GNU tar is distributed in the hope that it will be useful,
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+# but WITHOUT ANY WARRANTY; without even the implied warranty of
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+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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+# GNU General Public License for more details.
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+#
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+# You should have received a copy of the GNU General Public License
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+# along with this program. If not, see <http://www.gnu.org/licenses/>.
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+
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+# While fixing CVE-2018-20482 (see sptrcreat.at) it has been discovered
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+# that similar bug exists in file checking code (tar d).
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+# This test case checks if tar correctly handles a short read condition
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+# appearing in check_sparse_region.
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+
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+AT_SETUP([file truncated in sparse region while comparing])
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+AT_KEYWORDS([truncate filechange sparse sptr sptrdiff diff])
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+
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+# This triggers short read in check_sparse_region.
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+AT_TAR_CHECK([
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+genfile --sparse --block-size=1024 --file foo \
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+ 0 ABCDEFGHIJ 1M ABCDEFGHIJ 10M ABCDEFGHIJ 200M ABCDEFGHIJ
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+genfile --file baz
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+echo creating
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+tar --sparse -vcf bar foo baz
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+echo comparing
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+genfile --run --checkpoint 3 --length 200m --truncate foo -- \
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+ tar --checkpoint=1 \
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+ --checkpoint-action=echo='Write checkpoint %u' \
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+ --checkpoint-action=sleep=1 \
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+ --sparse -vdf bar
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+],
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+[1],
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+[creating
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+foo
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+baz
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+comparing
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+foo
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+foo: Size differs
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+baz
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+],
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+[],
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+[],[],[posix, gnu, oldgnu])
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+
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+AT_CLEANUP
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diff --git a/tests/sptrdiff01.at b/tests/sptrdiff01.at
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new file mode 100644
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index 0000000..2da2267
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--- /dev/null
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+++ b/tests/sptrdiff01.at
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@@ -0,0 +1,55 @@
|
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+# Process this file with autom4te to create testsuite. -*- Autotest -*-
|
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+#
|
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+# Test suite for GNU tar.
|
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+# Copyright 2018 Free Software Foundation, Inc.
|
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+#
|
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+# This file is part of GNU tar.
|
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+#
|
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+# GNU tar is free software; you can redistribute it and/or modify
|
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+# it under the terms of the GNU General Public License as published by
|
||
+# the Free Software Foundation; either version 3 of the License, or
|
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+# (at your option) any later version.
|
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+#
|
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+# GNU tar is distributed in the hope that it will be useful,
|
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+# but WITHOUT ANY WARRANTY; without even the implied warranty of
|
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+# 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/>.
|
||
+
|
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+# While fixing CVE-2018-20482 (see sptrcreat.at) it has been discovered
|
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+# that similar bug exists in file checking code (tar d).
|
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+# This test case checks if tar correctly handles a short read condition
|
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+# appearing in check_data_region.
|
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+
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+AT_SETUP([file truncated in data region while comparing])
|
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+AT_KEYWORDS([truncate filechange sparse sptr sptrdiff diff])
|
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+
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+# This triggers short read in check_data_region.
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+AT_TAR_CHECK([
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+genfile --sparse --block-size=1024 --file foo \
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+ 0 ABCDEFGHIJ 1M ABCDEFGHIJ 10M ABCDEFGHIJ 200M ABCDEFGHIJ
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+genfile --file baz
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+echo creating
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+tar --sparse -vcf bar foo baz
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+echo comparing
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+genfile --run --checkpoint 5 --length 221278210 --truncate foo -- \
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+ tar --checkpoint=1 \
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+ --checkpoint-action=echo='Write checkpoint %u' \
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+ --checkpoint-action=sleep=1 \
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+ --sparse -vdf bar
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+],
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+[1],
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+[creating
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+foo
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+baz
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+comparing
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+foo
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+foo: Size differs
|
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+baz
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+],
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+[],
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+[],[],[posix, gnu, oldgnu])
|
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+
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+AT_CLEANUP
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diff --git a/tests/testsuite.at b/tests/testsuite.at
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index 2a83757..23386f7 100644
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--- a/tests/testsuite.at
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+++ b/tests/testsuite.at
|
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@@ -1,7 +1,7 @@
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# Process this file with autom4te to create testsuite. -*- Autotest -*-
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|
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# Test suite for GNU tar.
|
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-# Copyright 2004-2008, 2010-2017 Free Software Foundation, Inc.
|
||
+# Copyright 2004-2008, 2010-2018 Free Software Foundation, Inc.
|
||
|
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# This file is part of GNU tar.
|
||
|
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@@ -405,6 +405,9 @@ m4_include([sparsemv.at])
|
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m4_include([spmvp00.at])
|
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m4_include([spmvp01.at])
|
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m4_include([spmvp10.at])
|
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+m4_include([sptrcreat.at])
|
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+m4_include([sptrdiff00.at])
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+m4_include([sptrdiff01.at])
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AT_BANNER([Updates])
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m4_include([update.at])
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--
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2.19.1
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