File cpio-2.12-CVE-2019-14866.patch of Package cpio.20895
From 7554e3e42cd72f6f8304410c47fe6f8918e9bfd7 Mon Sep 17 00:00:00 2001
From: Sergey Poznyakoff <gray@gnu.org>
Date: Sun, 3 Nov 2019 23:59:39 +0200
Subject: Fix CVE-2019-14866
* src/copyout.c (to_ascii): Additional argument nul controls whether
to add the terminating nul character.
(field_width_error): Improve diagnostics: print the actual and the
maximum allowed field value.
* src/extern.h (to_ascii, field_width_error): New prototypes.
* src/tar.c (to_oct): Remove.
(to_oct_or_error): New function.
(TO_OCT): New macro.
(write_out_tar_header): Use TO_OCT and to_ascii. Return 0 on
success, 1 on error.
---
src/copyout.c | 49 ++++++++++++++++++++++++----------------
src/extern.h | 15 +++++++++++--
src/tar.c | 72 +++++++++++++++++++++++++++--------------------------------
3 files changed, 76 insertions(+), 60 deletions(-)
Index: cpio-2.12/src/copyout.c
===================================================================
--- cpio-2.12.orig/src/copyout.c
+++ cpio-2.12/src/copyout.c
@@ -269,26 +269,32 @@ writeout_final_defers (int out_des)
so it should be moved to paxutils too.
Allowed values for logbase are: 1 (binary), 2, 3 (octal), 4 (hex) */
int
-to_ascii (char *where, uintmax_t v, size_t digits, unsigned logbase)
+to_ascii (char *where, uintmax_t v, size_t digits, unsigned logbase, bool nul)
{
static char codetab[] = "0123456789ABCDEF";
- int i = digits;
-
- do
+
+ if (nul)
+ where[--digits] = 0;
+ while (digits > 0)
{
- where[--i] = codetab[(v & ((1 << logbase) - 1))];
+ where[--digits] = codetab[(v & ((1 << logbase) - 1))];
v >>= logbase;
}
- while (i);
return v != 0;
}
-static void
-field_width_error (const char *filename, const char *fieldname)
+void
+field_width_error (const char *filename, const char *fieldname,
+ uintmax_t value, size_t width, bool nul)
{
- error (0, 0, _("%s: field width not sufficient for storing %s"),
- filename, fieldname);
+ char valbuf[UINTMAX_STRSIZE_BOUND + 1];
+ char maxbuf[UINTMAX_STRSIZE_BOUND + 1];
+ error (0, 0, _("%s: value %s %s out of allowed range 0..%s"),
+ filename, fieldname,
+ STRINGIFY_BIGINT (value, valbuf),
+ STRINGIFY_BIGINT (MAX_VAL_WITH_DIGITS (width - nul, LG_8),
+ maxbuf));
}
static void
@@ -303,7 +309,7 @@ to_ascii_or_warn (char *where, uintmax_t
unsigned logbase,
const char *filename, const char *fieldname)
{
- if (to_ascii (where, n, digits, logbase))
+ if (to_ascii (where, n, digits, logbase, false))
field_width_warning (filename, fieldname);
}
@@ -312,9 +318,9 @@ to_ascii_or_error (char *where, uintmax_
unsigned logbase,
const char *filename, const char *fieldname)
{
- if (to_ascii (where, n, digits, logbase))
+ if (to_ascii (where, n, digits, logbase, false))
{
- field_width_error (filename, fieldname);
+ field_width_error (filename, fieldname, n, digits, false);
return 1;
}
return 0;
@@ -371,7 +377,7 @@ write_out_new_ascii_header (const char *
_("name size")))
return 1;
p += 8;
- to_ascii (p, file_hdr->c_chksum & 0xffffffff, 8, LG_16);
+ to_ascii (p, file_hdr->c_chksum & 0xffffffff, 8, LG_16, false);
tape_buffered_write (ascii_header, out_des, sizeof ascii_header);
@@ -388,7 +394,7 @@ write_out_old_ascii_header (dev_t dev, d
char ascii_header[76];
char *p = ascii_header;
- to_ascii (p, file_hdr->c_magic, 6, LG_8);
+ to_ascii (p, file_hdr->c_magic, 6, LG_8, false);
p += 6;
to_ascii_or_warn (p, dev, 6, LG_8, file_hdr->c_name, _("device number"));
p += 6;
@@ -492,7 +498,10 @@ write_out_binary_header (dev_t rdev,
short_hdr.c_namesize = file_hdr->c_namesize & 0xFFFF;
if (short_hdr.c_namesize != file_hdr->c_namesize)
{
- field_width_error (file_hdr->c_name, _("name size"));
+ char maxbuf[UINTMAX_STRSIZE_BOUND + 1];
+ error (0, 0, _("%s: value %s %s out of allowed range 0..%u"),
+ file_hdr->c_name, _("name size"),
+ STRINGIFY_BIGINT (file_hdr->c_namesize, maxbuf), 0xFFFFu);
return 1;
}
@@ -502,7 +511,10 @@ write_out_binary_header (dev_t rdev,
if (((off_t)short_hdr.c_filesizes[0] << 16) + short_hdr.c_filesizes[1]
!= file_hdr->c_filesize)
{
- field_width_error (file_hdr->c_name, _("file size"));
+ char maxbuf[UINTMAX_STRSIZE_BOUND + 1];
+ error (0, 0, _("%s: value %s %s out of allowed range 0..%lu"),
+ file_hdr->c_name, _("file size"),
+ STRINGIFY_BIGINT (file_hdr->c_namesize, maxbuf), 0xFFFFFFFFlu);
return 1;
}
@@ -552,8 +564,7 @@ write_out_header (struct cpio_file_stat
error (0, 0, _("%s: file name too long"), file_hdr->c_name);
return 1;
}
- write_out_tar_header (file_hdr, out_des); /* FIXME: No error checking */
- return 0;
+ return write_out_tar_header (file_hdr, out_des);
case arf_binary:
return write_out_binary_header (makedev (file_hdr->c_rdev_maj,
Index: cpio-2.12/src/extern.h
===================================================================
--- cpio-2.12.orig/src/extern.h
+++ cpio-2.12/src/extern.h
@@ -118,6 +118,10 @@ void print_name_with_quoting (char *p);
/* copyout.c */
int write_out_header (struct cpio_file_stat *file_hdr, int out_des);
void process_copy_out (void);
+int to_ascii (char *where, uintmax_t v, size_t digits, unsigned logbase,
+ bool nul);
+void field_width_error (const char *filename, const char *fieldname,
+ uintmax_t value, size_t width, bool nul);
/* copypass.c */
void process_copy_pass (void);
@@ -146,7 +150,7 @@ int make_path (char *argpath, uid_t owne
const char *verbose_fmt_string);
/* tar.c */
-void write_out_tar_header (struct cpio_file_stat *file_hdr, int out_des);
+int write_out_tar_header (struct cpio_file_stat *file_hdr, int out_des);
int null_block (long *block, int size);
void read_in_tar_header (struct cpio_file_stat *file_hdr, int in_des);
int otoa (char *s, unsigned long *n);
@@ -205,9 +209,16 @@ void cpio_safer_name_suffix (char *name,
int cpio_create_dir (struct cpio_file_stat *file_hdr, int existing_dir);
void change_dir (void);
-/* FIXME: These two defines should be defined in paxutils */
+/* FIXME: The following three should be defined in paxutils */
#define LG_8 3
#define LG_16 4
+/* The maximum uintmax_t value that can be represented with DIGITS digits,
+ assuming that each digit is BITS_PER_DIGIT wide. */
+#define MAX_VAL_WITH_DIGITS(digits, bits_per_digit) \
+ ((digits) * (bits_per_digit) < sizeof (uintmax_t) * CHAR_BIT \
+ ? ((uintmax_t) 1 << ((digits) * (bits_per_digit))) - 1 \
+ : (uintmax_t) -1)
+
uintmax_t from_ascii (char const *where, size_t digs, unsigned logbase);
Index: cpio-2.12/src/tar.c
===================================================================
--- cpio-2.12.orig/src/tar.c
+++ cpio-2.12/src/tar.c
@@ -1,6 +1,5 @@
/* tar.c - read in write tar headers for cpio
- Copyright (C) 1992, 2001, 2004, 2006-2007, 2010, 2014-2015 Free
- Software Foundation, Inc.
+ Copyright (C) 1992-2019 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
@@ -79,36 +78,17 @@ stash_tar_filename (char *prefix, char *
return hold_tar_filename;
}
-/* Convert a number into a string of octal digits.
- Convert long VALUE into a DIGITS-digit field at WHERE,
- including a trailing space and room for a NUL. DIGITS==3 means
- 1 digit, a space, and room for a NUL.
-
- We assume the trailing NUL is already there and don't fill it in.
- This fact is used by start_header and finish_header, so don't change it!
-
- This is be equivalent to:
- sprintf (where, "%*lo ", digits - 2, value);
- except that sprintf fills in the trailing NUL and we don't. */
-
-static void
-to_oct (register long value, register int digits, register char *where)
+static int
+to_oct_or_error (uintmax_t value, size_t digits, char *where, char const *field,
+ char const *file)
{
- --digits; /* Leave the trailing NUL slot alone. */
-
- /* Produce the digits -- at least one. */
- do
+ if (to_ascii (where, value, digits, LG_8, true))
{
- where[--digits] = '0' + (char) (value & 7); /* One octal digit. */
- value >>= 3;
+ field_width_error (file, field, value, digits, true);
+ return 1;
}
- while (digits > 0 && value != 0);
-
- /* Add leading zeroes, if necessary. */
- while (digits > 0)
- where[--digits] = '0';
+ return 0;
}
-
/* Compute and return a checksum for TAR_HDR,
@@ -134,10 +114,22 @@ tar_checksum (struct tar_header *tar_hdr
return sum;
}
+#define TO_OCT(file_hdr, c_fld, digits, tar_hdr, tar_field) \
+ do \
+ { \
+ if (to_oct_or_error (file_hdr -> c_fld, \
+ digits, \
+ tar_hdr -> tar_field, \
+ #tar_field, \
+ file_hdr->c_name)) \
+ return 1; \
+ } \
+ while (0)
+
/* Write out header FILE_HDR, including the file name, to file
descriptor OUT_DES. */
-void
+int
write_out_tar_header (struct cpio_file_stat *file_hdr, int out_des)
{
int name_len;
@@ -166,11 +158,11 @@ write_out_tar_header (struct cpio_file_s
/* Ustar standard (POSIX.1-1988) requires the mode to contain only 3 octal
digits */
- to_oct (file_hdr->c_mode & MODE_ALL, 8, tar_hdr->mode);
- to_oct (file_hdr->c_uid, 8, tar_hdr->uid);
- to_oct (file_hdr->c_gid, 8, tar_hdr->gid);
- to_oct (file_hdr->c_filesize, 12, tar_hdr->size);
- to_oct (file_hdr->c_mtime, 12, tar_hdr->mtime);
+ TO_OCT (file_hdr, c_mode & MODE_ALL, 8, tar_hdr, mode);
+ TO_OCT (file_hdr, c_uid, 8, tar_hdr, uid);
+ TO_OCT (file_hdr, c_gid, 8, tar_hdr, gid);
+ TO_OCT (file_hdr, c_filesize, 12, tar_hdr, size);
+ TO_OCT (file_hdr, c_mtime, 12, tar_hdr, mtime);
switch (file_hdr->c_mode & CP_IFMT)
{
@@ -182,7 +174,7 @@ write_out_tar_header (struct cpio_file_s
strncpy (tar_hdr->linkname, file_hdr->c_tar_linkname,
TARLINKNAMESIZE);
tar_hdr->typeflag = LNKTYPE;
- to_oct (0, 12, tar_hdr->size);
+ to_ascii (tar_hdr->size, 0, 12, LG_8, true);
}
else
tar_hdr->typeflag = REGTYPE;
@@ -208,7 +200,7 @@ write_out_tar_header (struct cpio_file_s
than TARLINKNAMESIZE. */
strncpy (tar_hdr->linkname, file_hdr->c_tar_linkname,
TARLINKNAMESIZE);
- to_oct (0, 12, tar_hdr->size);
+ to_ascii (tar_hdr->size, 0, 12, LG_8, true);
break;
#endif /* CP_IFLNK */
}
@@ -227,13 +219,15 @@ write_out_tar_header (struct cpio_file_s
if (name)
strcpy (tar_hdr->gname, name);
- to_oct (file_hdr->c_rdev_maj, 8, tar_hdr->devmajor);
- to_oct (file_hdr->c_rdev_min, 8, tar_hdr->devminor);
+ TO_OCT (file_hdr, c_rdev_maj, 8, tar_hdr, devmajor);
+ TO_OCT (file_hdr, c_rdev_min, 8, tar_hdr, devminor);
}
- to_oct (tar_checksum (tar_hdr), 8, tar_hdr->chksum);
+ to_ascii (tar_hdr->chksum, tar_checksum (tar_hdr), 8, LG_8, true);
tape_buffered_write ((char *) &tar_rec, out_des, TARRECORDSIZE);
+
+ return 0;
}
/* Return nonzero iff all the bytes in BLOCK are NUL.
