gnu: libarchive: Fix several security issues.

* gnu/packages/backup.scm (libarchive)[replacement]: New field.
(libarchive/fixed): New variable.
* gnu/packages/patches/libarchive-7zip-heap-overflow.patch,
gnu/packages/patches/libarchive-fix-symlink-check.patch,
gnu/packages/patches/libarchive-fix-filesystem-attacks.patch,
gnu/packages/patches/libarchive-safe_fprintf-buffer-overflow.patch: New files.
* gnu/local.mk (dist_patch_DATA): Add them.

1 files changed, 44 insertions, 0 deletions

diff --git a/gnu/packages/patches/libarchive-safe_fprintf-buffer-overflow.patch b/gnu/packages/patches/libarchive-safe_fprintf-buffer-overflow.patch
new file mode 100644
index 0000000000..0e70ac90ce
--- /dev/null
+++ b/gnu/packages/patches/libarchive-safe_fprintf-buffer-overflow.patch
@@ -0,0 +1,44 @@
+Fixes this buffer overflow:
+https://github.com/libarchive/libarchive/commit/e37b620fe8f14535d737e89a4dcabaed4517bf1a
+
+Patch copied from upstream source repository:
+https://github.com/libarchive/libarchive/commit/e37b620fe8f14535d737e89a4dcabaed4517bf1a
+
+From e37b620fe8f14535d737e89a4dcabaed4517bf1a Mon Sep 17 00:00:00 2001
+From: Tim Kientzle <kientzle@acm.org>
+Date: Sun, 21 Aug 2016 10:51:43 -0700
+Subject: [PATCH] Issue #767:  Buffer overflow printing a filename
+
+The safe_fprintf function attempts to ensure clean output for an
+arbitrary sequence of bytes by doing a trial conversion of the
+multibyte characters to wide characters -- if the resulting wide
+character is printable then we pass through the corresponding bytes
+unaltered, otherwise, we convert them to C-style ASCII escapes.
+
+The stack trace in Issue #767 suggest that the 20-byte buffer
+was getting overflowed trying to format a non-printable multibyte
+character.  This should only happen if there is a valid multibyte
+character of more than 5 bytes that was unprintable.  (Each byte
+would get expanded to a four-charcter octal-style escape of the form
+"\123" resulting in >20 characters for the >5 byte multibyte character.)
+
+I've not been able to reproduce this, but have expanded the conversion
+buffer to 128 bytes on the belief that no multibyte character set
+has a single character of more than 32 bytes.
+---
+ tar/util.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/tar/util.c b/tar/util.c
+index 9ff22f2..2b4aebe 100644
+--- a/tar/util.c
++++ b/tar/util.c
+@@ -182,7 +182,7 @@ safe_fprintf(FILE *f, const char *fmt, ...)
+ 		}
+ 
+ 		/* If our output buffer is full, dump it and keep going. */
+-		if (i > (sizeof(outbuff) - 20)) {
++		if (i > (sizeof(outbuff) - 128)) {
+ 			outbuff[i] = '\0';
+ 			fprintf(f, "%s", outbuff);
+ 			i = 0;