From 89857df2d1233f60ca7702b387d8e2a17e125d23 Mon Sep 17 00:00:00 2001 From: Fabrice Fontaine Date: Thu, 19 Aug 2021 23:46:09 +0200 Subject: [PATCH] package/cpio: fix CVE-2021-38185 GNU cpio through 2.13 allows attackers to execute arbitrary code via a crafted pattern file, because of a dstring.c ds_fgetstr integer overflow that triggers an out-of-bounds heap write. NOTE: it is unclear whether there are common cases where the pattern file, associated with the -E option, is untrusted data. Signed-off-by: Fabrice Fontaine Signed-off-by: Yann E. MORIN --- .../0002-Rewrite-dynamic-string-support.patch | 461 ++++++++++++++++++ package/cpio/0003-Fix-previous-commit.patch | 40 ++ package/cpio/cpio.mk | 4 + 3 files changed, 505 insertions(+) create mode 100644 package/cpio/0002-Rewrite-dynamic-string-support.patch create mode 100644 package/cpio/0003-Fix-previous-commit.patch diff --git a/package/cpio/0002-Rewrite-dynamic-string-support.patch b/package/cpio/0002-Rewrite-dynamic-string-support.patch new file mode 100644 index 0000000000..44282ae3f1 --- /dev/null +++ b/package/cpio/0002-Rewrite-dynamic-string-support.patch @@ -0,0 +1,461 @@ +From dd96882877721703e19272fe25034560b794061b Mon Sep 17 00:00:00 2001 +From: Sergey Poznyakoff +Date: Sat, 7 Aug 2021 12:52:21 +0300 +Subject: Rewrite dynamic string support. + +* src/dstring.c (ds_init): Take a single argument. +(ds_free): New function. +(ds_resize): Take a single argument. Use x2nrealloc to expand +the storage. +(ds_reset,ds_append,ds_concat,ds_endswith): New function. +(ds_fgetstr): Rewrite. In particular, this fixes integer overflow. +* src/dstring.h (dynamic_string): Keep both the allocated length +(ds_size) and index of the next free byte in the string (ds_idx). +(ds_init,ds_resize): Change signature. +(ds_len): New macro. +(ds_free,ds_reset,ds_append,ds_concat,ds_endswith): New protos. +* src/copyin.c: Use new ds_ functions. +* src/copyout.c: Likewise. +* src/copypass.c: Likewise. +* src/util.c: Likewise. + +[Retrieved from: +https://git.savannah.gnu.org/cgit/cpio.git/commit/?id=dd96882877721703e19272fe25034560b794061b] +Signed-off-by: Fabrice Fontaine +--- + src/copyin.c | 40 +++++++++++++------------- + src/copyout.c | 16 ++++------- + src/copypass.c | 34 +++++++++++------------ + src/dstring.c | 88 ++++++++++++++++++++++++++++++++++++++++++---------------- + src/dstring.h | 31 ++++++++++----------- + src/util.c | 6 ++-- + 6 files changed, 123 insertions(+), 92 deletions(-) + +diff --git a/src/copyin.c b/src/copyin.c +index a096048..4fb14af 100644 +--- a/src/copyin.c ++++ b/src/copyin.c +@@ -55,11 +55,12 @@ query_rename(struct cpio_file_stat* file_hdr, FILE *tty_in, FILE *tty_out, + char *str_res; /* Result for string function. */ + static dynamic_string new_name; /* New file name for rename option. */ + static int initialized_new_name = false; ++ + if (!initialized_new_name) +- { +- ds_init (&new_name, 128); +- initialized_new_name = true; +- } ++ { ++ ds_init (&new_name); ++ initialized_new_name = true; ++ } + + if (rename_flag) + { +@@ -780,37 +781,36 @@ long_format (struct cpio_file_stat *file_hdr, char const *link_name) + already in `save_patterns' (from the command line) are preserved. */ + + static void +-read_pattern_file () ++read_pattern_file (void) + { +- int max_new_patterns; +- char **new_save_patterns; +- int new_num_patterns; ++ char **new_save_patterns = NULL; ++ size_t max_new_patterns; ++ size_t new_num_patterns; + int i; +- dynamic_string pattern_name; ++ dynamic_string pattern_name = DYNAMIC_STRING_INITIALIZER; + FILE *pattern_fp; + + if (num_patterns < 0) + num_patterns = 0; +- max_new_patterns = 1 + num_patterns; +- new_save_patterns = (char **) xmalloc (max_new_patterns * sizeof (char *)); + new_num_patterns = num_patterns; +- ds_init (&pattern_name, 128); ++ max_new_patterns = num_patterns; ++ new_save_patterns = xcalloc (max_new_patterns, sizeof (new_save_patterns[0])); + + pattern_fp = fopen (pattern_file_name, "r"); + if (pattern_fp == NULL) + open_fatal (pattern_file_name); + while (ds_fgetstr (pattern_fp, &pattern_name, '\n') != NULL) + { +- if (new_num_patterns >= max_new_patterns) +- { +- max_new_patterns += 1; +- new_save_patterns = (char **) +- xrealloc ((char *) new_save_patterns, +- max_new_patterns * sizeof (char *)); +- } ++ if (new_num_patterns == max_new_patterns) ++ new_save_patterns = x2nrealloc (new_save_patterns, ++ &max_new_patterns, ++ sizeof (new_save_patterns[0])); + new_save_patterns[new_num_patterns] = xstrdup (pattern_name.ds_string); + ++new_num_patterns; + } ++ ++ ds_free (&pattern_name); ++ + if (ferror (pattern_fp) || fclose (pattern_fp) == EOF) + close_error (pattern_file_name); + +@@ -1210,7 +1210,7 @@ swab_array (char *ptr, int count) + in the file system. */ + + void +-process_copy_in () ++process_copy_in (void) + { + FILE *tty_in = NULL; /* Interactive file for rename option. */ + FILE *tty_out = NULL; /* Interactive file for rename option. */ +diff --git a/src/copyout.c b/src/copyout.c +index 5ca587f..ca6798c 100644 +--- a/src/copyout.c ++++ b/src/copyout.c +@@ -594,9 +594,10 @@ assign_string (char **pvar, char *value) + The format of the header depends on the compatibility (-c) flag. */ + + void +-process_copy_out () ++process_copy_out (void) + { +- dynamic_string input_name; /* Name of file read from stdin. */ ++ dynamic_string input_name = DYNAMIC_STRING_INITIALIZER; ++ /* Name of file read from stdin. */ + struct stat file_stat; /* Stat record for file. */ + struct cpio_file_stat file_hdr = CPIO_FILE_STAT_INITIALIZER; + /* Output header information. */ +@@ -605,7 +606,6 @@ process_copy_out () + char *orig_file_name = NULL; + + /* Initialize the copy out. */ +- ds_init (&input_name, 128); + file_hdr.c_magic = 070707; + + /* Check whether the output file might be a tape. */ +@@ -657,14 +657,9 @@ process_copy_out () + { + if (file_hdr.c_mode & CP_IFDIR) + { +- int len = strlen (input_name.ds_string); + /* Make sure the name ends with a slash */ +- if (input_name.ds_string[len-1] != '/') +- { +- ds_resize (&input_name, len + 2); +- input_name.ds_string[len] = '/'; +- input_name.ds_string[len+1] = 0; +- } ++ if (!ds_endswith (&input_name, '/')) ++ ds_append (&input_name, '/'); + } + } + +@@ -875,6 +870,7 @@ process_copy_out () + (unsigned long) blocks), (unsigned long) blocks); + } + cpio_file_stat_free (&file_hdr); ++ ds_free (&input_name); + } + + +diff --git a/src/copypass.c b/src/copypass.c +index 5d5e939..23ee687 100644 +--- a/src/copypass.c ++++ b/src/copypass.c +@@ -48,10 +48,12 @@ set_copypass_perms (int fd, const char *name, struct stat *st) + If `link_flag', link instead of copying. */ + + void +-process_copy_pass () ++process_copy_pass (void) + { +- dynamic_string input_name; /* Name of file from stdin. */ +- dynamic_string output_name; /* Name of new file. */ ++ dynamic_string input_name = DYNAMIC_STRING_INITIALIZER; ++ /* Name of file from stdin. */ ++ dynamic_string output_name = DYNAMIC_STRING_INITIALIZER; ++ /* Name of new file. */ + size_t dirname_len; /* Length of `directory_name'. */ + int res; /* Result of functions. */ + char *slash; /* For moving past slashes in input name. */ +@@ -65,25 +67,18 @@ process_copy_pass () + created files */ + + /* Initialize the copy pass. */ +- ds_init (&input_name, 128); + + dirname_len = strlen (directory_name); + if (change_directory_option && !ISSLASH (directory_name[0])) + { + char *pwd = xgetcwd (); +- +- dirname_len += strlen (pwd) + 1; +- ds_init (&output_name, dirname_len + 2); +- strcpy (output_name.ds_string, pwd); +- strcat (output_name.ds_string, "/"); +- strcat (output_name.ds_string, directory_name); ++ ++ ds_concat (&output_name, pwd); ++ ds_append (&output_name, '/'); + } +- else +- { +- ds_init (&output_name, dirname_len + 2); +- strcpy (output_name.ds_string, directory_name); +- } +- output_name.ds_string[dirname_len] = '/'; ++ ds_concat (&output_name, directory_name); ++ ds_append (&output_name, '/'); ++ dirname_len = ds_len (&output_name); + output_is_seekable = true; + + change_dir (); +@@ -116,8 +111,8 @@ process_copy_pass () + /* Make the name of the new file. */ + for (slash = input_name.ds_string; *slash == '/'; ++slash) + ; +- ds_resize (&output_name, dirname_len + strlen (slash) + 2); +- strcpy (output_name.ds_string + dirname_len + 1, slash); ++ ds_reset (&output_name, dirname_len); ++ ds_concat (&output_name, slash); + + existing_dir = false; + if (lstat (output_name.ds_string, &out_file_stat) == 0) +@@ -333,6 +328,9 @@ process_copy_pass () + (unsigned long) blocks), + (unsigned long) blocks); + } ++ ++ ds_free (&input_name); ++ ds_free (&output_name); + } + + /* Try and create a hard link from FILE_NAME to another file +diff --git a/src/dstring.c b/src/dstring.c +index b261d5a..692d3e7 100644 +--- a/src/dstring.c ++++ b/src/dstring.c +@@ -20,8 +20,8 @@ + #if defined(HAVE_CONFIG_H) + # include + #endif +- + #include ++#include + #if defined(HAVE_STRING_H) || defined(STDC_HEADERS) + #include + #else +@@ -33,24 +33,41 @@ + /* Initialiaze dynamic string STRING with space for SIZE characters. */ + + void +-ds_init (dynamic_string *string, int size) ++ds_init (dynamic_string *string) ++{ ++ memset (string, 0, sizeof *string); ++} ++ ++/* Free the dynamic string storage. */ ++ ++void ++ds_free (dynamic_string *string) + { +- string->ds_length = size; +- string->ds_string = (char *) xmalloc (size); ++ free (string->ds_string); + } + +-/* Expand dynamic string STRING, if necessary, to hold SIZE characters. */ ++/* Expand dynamic string STRING, if necessary. */ + + void +-ds_resize (dynamic_string *string, int size) ++ds_resize (dynamic_string *string) + { +- if (size > string->ds_length) ++ if (string->ds_idx == string->ds_size) + { +- string->ds_length = size; +- string->ds_string = (char *) xrealloc ((char *) string->ds_string, size); ++ string->ds_string = x2nrealloc (string->ds_string, &string->ds_size, ++ 1); + } + } + ++/* Reset the index of the dynamic string S to LEN. */ ++ ++void ++ds_reset (dynamic_string *s, size_t len) ++{ ++ while (len > s->ds_size) ++ ds_resize (s); ++ s->ds_idx = len; ++} ++ + /* Dynamic string S gets a string terminated by the EOS character + (which is removed) from file F. S will increase + in size during the function if the string from F is longer than +@@ -61,34 +78,50 @@ ds_resize (dynamic_string *string, int size) + char * + ds_fgetstr (FILE *f, dynamic_string *s, char eos) + { +- int insize; /* Amount needed for line. */ +- int strsize; /* Amount allocated for S. */ + int next_ch; + + /* Initialize. */ +- insize = 0; +- strsize = s->ds_length; ++ s->ds_idx = 0; + + /* Read the input string. */ +- next_ch = getc (f); +- while (next_ch != eos && next_ch != EOF) ++ while ((next_ch = getc (f)) != eos && next_ch != EOF) + { +- if (insize >= strsize - 1) +- { +- ds_resize (s, strsize * 2 + 2); +- strsize = s->ds_length; +- } +- s->ds_string[insize++] = next_ch; +- next_ch = getc (f); ++ ds_resize (s); ++ s->ds_string[s->ds_idx++] = next_ch; + } +- s->ds_string[insize++] = '\0'; ++ ds_resize (s); ++ s->ds_string[s->ds_idx] = '\0'; + +- if (insize == 1 && next_ch == EOF) ++ if (s->ds_idx == 0 && next_ch == EOF) + return NULL; + else + return s->ds_string; + } + ++void ++ds_append (dynamic_string *s, int c) ++{ ++ ds_resize (s); ++ s->ds_string[s->ds_idx] = c; ++ if (c) ++ { ++ s->ds_idx++; ++ ds_resize (s); ++ s->ds_string[s->ds_idx] = 0; ++ } ++} ++ ++void ++ds_concat (dynamic_string *s, char const *str) ++{ ++ size_t len = strlen (str); ++ while (len + 1 > s->ds_size) ++ ds_resize (s); ++ memcpy (s->ds_string + s->ds_idx, str, len); ++ s->ds_idx += len; ++ s->ds_string[s->ds_idx] = 0; ++} ++ + char * + ds_fgets (FILE *f, dynamic_string *s) + { +@@ -100,3 +133,10 @@ ds_fgetname (FILE *f, dynamic_string *s) + { + return ds_fgetstr (f, s, '\0'); + } ++ ++/* Return true if the dynamic string S ends with character C. */ ++int ++ds_endswith (dynamic_string *s, int c) ++{ ++ return (s->ds_idx > 0 && s->ds_string[s->ds_idx - 1] == c); ++} +diff --git a/src/dstring.h b/src/dstring.h +index 5d24181..ca7a5f1 100644 +--- a/src/dstring.h ++++ b/src/dstring.h +@@ -17,10 +17,6 @@ + Software Foundation, Inc., 51 Franklin Street, Fifth Floor, + Boston, MA 02110-1301 USA. */ + +-#ifndef NULL +-#define NULL 0 +-#endif +- + /* A dynamic string consists of record that records the size of an + allocated string and the pointer to that string. The actual string + is a normal zero byte terminated string that can be used with the +@@ -30,22 +26,25 @@ + + typedef struct + { +- int ds_length; /* Actual amount of storage allocated. */ +- char *ds_string; /* String. */ ++ size_t ds_size; /* Actual amount of storage allocated. */ ++ size_t ds_idx; /* Index of the next free byte in the string. */ ++ char *ds_string; /* String storage. */ + } dynamic_string; + ++#define DYNAMIC_STRING_INITIALIZER { 0, 0, NULL } + +-/* Macros that look similar to the original string functions. +- WARNING: These macros work only on pointers to dynamic string records. +- If used with a real record, an "&" must be used to get the pointer. */ +-#define ds_strlen(s) strlen ((s)->ds_string) +-#define ds_strcmp(s1, s2) strcmp ((s1)->ds_string, (s2)->ds_string) +-#define ds_strncmp(s1, s2, n) strncmp ((s1)->ds_string, (s2)->ds_string, n) +-#define ds_index(s, c) index ((s)->ds_string, c) +-#define ds_rindex(s, c) rindex ((s)->ds_string, c) ++void ds_init (dynamic_string *string); ++void ds_free (dynamic_string *string); ++void ds_reset (dynamic_string *s, size_t len); + +-void ds_init (dynamic_string *string, int size); +-void ds_resize (dynamic_string *string, int size); ++/* All functions below guarantee that s->ds_string[s->ds_idx] == '\0' */ + char *ds_fgetname (FILE *f, dynamic_string *s); + char *ds_fgets (FILE *f, dynamic_string *s); + char *ds_fgetstr (FILE *f, dynamic_string *s, char eos); ++void ds_append (dynamic_string *s, int c); ++void ds_concat (dynamic_string *s, char const *str); ++ ++#define ds_len(s) ((s)->ds_idx) ++ ++int ds_endswith (dynamic_string *s, int c); ++ +diff --git a/src/util.c b/src/util.c +index 996d4fa..ff2746d 100644 +--- a/src/util.c ++++ b/src/util.c +@@ -846,11 +846,9 @@ get_next_reel (int tape_des) + FILE *tty_out; /* File for interacting with user. */ + int old_tape_des; + char *next_archive_name; +- dynamic_string new_name; ++ dynamic_string new_name = DYNAMIC_STRING_INITIALIZER; + char *str_res; + +- ds_init (&new_name, 128); +- + /* Open files for interactive communication. */ + tty_in = fopen (TTY_NAME, "r"); + if (tty_in == NULL) +@@ -925,7 +923,7 @@ get_next_reel (int tape_des) + error (PAXEXIT_FAILURE, 0, _("internal error: tape descriptor changed from %d to %d"), + old_tape_des, tape_des); + +- free (new_name.ds_string); ++ ds_free (&new_name); + fclose (tty_in); + fclose (tty_out); + } +-- +cgit v1.2.1 + diff --git a/package/cpio/0003-Fix-previous-commit.patch b/package/cpio/0003-Fix-previous-commit.patch new file mode 100644 index 0000000000..e33a8523d8 --- /dev/null +++ b/package/cpio/0003-Fix-previous-commit.patch @@ -0,0 +1,40 @@ +From dfc801c44a93bed7b3951905b188823d6a0432c8 Mon Sep 17 00:00:00 2001 +From: Sergey Poznyakoff +Date: Wed, 11 Aug 2021 18:10:38 +0300 +Subject: Fix previous commit + +* src/dstring.c (ds_reset,ds_concat): Don't call ds_resize in a +loop. + +[Retrieved from: +https://git.savannah.gnu.org/cgit/cpio.git/commit/?id=dfc801c44a93bed7b3951905b188823d6a0432c8] +Signed-off-by: Fabrice Fontaine +--- + src/dstring.c | 4 ++-- + 1 file changed, 2 insertions(+), 2 deletions(-) + +diff --git a/src/dstring.c b/src/dstring.c +index 692d3e7..b7e0bb5 100644 +--- a/src/dstring.c ++++ b/src/dstring.c +@@ -64,7 +64,7 @@ void + ds_reset (dynamic_string *s, size_t len) + { + while (len > s->ds_size) +- ds_resize (s); ++ s->ds_string = x2nrealloc (s->ds_string, &s->ds_size, 1); + s->ds_idx = len; + } + +@@ -116,7 +116,7 @@ ds_concat (dynamic_string *s, char const *str) + { + size_t len = strlen (str); + while (len + 1 > s->ds_size) +- ds_resize (s); ++ s->ds_string = x2nrealloc (s->ds_string, &s->ds_size, 1); + memcpy (s->ds_string + s->ds_idx, str, len); + s->ds_idx += len; + s->ds_string[s->ds_idx] = 0; +-- +cgit v1.2.1 + diff --git a/package/cpio/cpio.mk b/package/cpio/cpio.mk index 9ce281dd1c..e95ea742b3 100644 --- a/package/cpio/cpio.mk +++ b/package/cpio/cpio.mk @@ -12,6 +12,10 @@ CPIO_LICENSE = GPL-3.0+ CPIO_LICENSE_FILES = COPYING CPIO_CPE_ID_VENDOR = gnu +# 0002-Rewrite-dynamic-string-support.patch +# 0003-Fix-previous-commit.patch +CPIO_IGNORE_CVES += CVE-2021-38185 + # cpio uses argp.h which is not provided by uclibc or musl by default. # Use the argp-standalone package to provide this. ifeq ($(BR2_PACKAGE_ARGP_STANDALONE),y) -- 2.30.2