svn commit: r309300 - in head: contrib/libarchive contrib/libarchive/libarchive contrib/libarchive/libarchive/test contrib/libarchive/tar/test lib/libarchive/tests

Cy Schubert Cy.Schubert at komquats.com
Fri Dec 2 02:25:29 UTC 2016


In message <201611292214.uATMEgQH079904 at repo.freebsd.org>, Martin Matuska 
write
s:
> Author: mm
> Date: Tue Nov 29 22:14:42 2016
> New Revision: 309300
> URL: https://svnweb.freebsd.org/changeset/base/309300
> 
> Log:
>   MFV r309299:
>   Sync libarchive with vendor.
>   
>   Important vendor bugfixes (relevant to FreeBSD):
>   #821: tar -P cannot extract hardlinks through symlinks
>   #825: Add sanity check of tar "uid, "gid" and "mtime" fields
>   
>   PR:		213255
>   Reported by:	Tijl Coosemans <tilj at FreeBSD.org>
>   MFC after:	1 week
> 
> Added:
>   head/contrib/libarchive/libarchive/test/test_compat_gtar_2.tar.uu
>      - copied unchanged from r309299, vendor/libarchive/dist/libarchive/test/
> test_compat_gtar_2.tar.uu
>   head/contrib/libarchive/libarchive/test/test_compat_star_acl_posix1e.c
>      - copied unchanged from r309299, vendor/libarchive/dist/libarchive/test/
> test_compat_star_acl_posix1e.c
>   head/contrib/libarchive/libarchive/test/test_compat_star_acl_posix1e.tar.uu
>      - copied unchanged from r309299, vendor/libarchive/dist/libarchive/test/
> test_compat_star_acl_posix1e.tar.uu
>   head/contrib/libarchive/libarchive/test/test_read_format_raw.bufr.uu
>      - copied unchanged from r309299, vendor/libarchive/dist/libarchive/test/
> test_read_format_raw.bufr.uu
> Modified:
>   head/contrib/libarchive/NEWS
>   head/contrib/libarchive/libarchive/archive_acl.c
>   head/contrib/libarchive/libarchive/archive_entry.c
>   head/contrib/libarchive/libarchive/archive_entry.h
>   head/contrib/libarchive/libarchive/archive_entry_acl.3
>   head/contrib/libarchive/libarchive/archive_read_disk_entry_from_file.c
>   head/contrib/libarchive/libarchive/archive_read_support_filter_xz.c
>   head/contrib/libarchive/libarchive/archive_read_support_format_tar.c
>   head/contrib/libarchive/libarchive/archive_read_support_format_xar.c
>   head/contrib/libarchive/libarchive/archive_write_disk_posix.c
>   head/contrib/libarchive/libarchive/test/test_compat_gtar.c
>   head/contrib/libarchive/libarchive/test/test_read_format_raw.c
>   head/contrib/libarchive/libarchive/test/test_sparse_basic.c
>   head/contrib/libarchive/tar/test/test_symlink_dir.c
>   head/lib/libarchive/tests/Makefile
> Directory Properties:
>   head/contrib/libarchive/   (props changed)
> 
[...]
> Modified: head/contrib/libarchive/libarchive/archive_read_support_format_tar.
> c
> =============================================================================
> =
> --- head/contrib/libarchive/libarchive/archive_read_support_format_tar.c
> 	Tue Nov 29 21:53:16 2016	(r309299)
> +++ head/contrib/libarchive/libarchive/archive_read_support_format_tar.c
> 	Tue Nov 29 22:14:42 2016	(r309300)
> @@ -294,6 +294,46 @@ archive_read_format_tar_cleanup(struct a
>  	return (ARCHIVE_OK);
>  }
>  
> +static int
> +validate_number_field(const char* p_field, size_t i_size)
> +{
> +	unsigned char marker = (unsigned char)p_field[0];
> +	/* octal? */
> +	if ((marker >= '0' && marker <= '7') || marker == ' ') {
> +		size_t i = 0;
> +		int octal_found = 0;
> +		for (i = 0; i < i_size; ++i) {
> +			switch (p_field[i])
> +			{
> +			case ' ': /* skip any leading spaces and trailing space
> */
> +				if (octal_found == 0 || i == i_size - 1) {
> +					continue;
> +				}
> +				break;
> +			case '\0': /* null is allowed only at the end */
> +				if (i != i_size - 1) {
> +					return 0;
> +				}
> +				break;
> +			/* rest must be octal digits */
> +			case '0': case '1': case '2': case '3':
> +			case '4': case '5': case '6': case '7':
> +				++octal_found;
> +				break;
> +			}
> +		}
> +		return octal_found > 0;
> +	}
> +	/* base 256 (i.e. binary number) */
> +	else if (marker == 128 || marker == 255 || marker == 0) {
> +		/* nothing to check */
> +		return 1;
> +	}
> +	/* not a number field */
> +	else {
> +		return 0;
> +	}
> +}
>  
>  static int
>  archive_read_format_tar_bid(struct archive_read *a, int best_bid)
> @@ -346,23 +386,23 @@ archive_read_format_tar_bid(struct archi
>  		return (0);
>  	bid += 2;  /* 6 bits of variation in an 8-bit field leaves 2 bits. */
>  
> -	/* Sanity check: Look at first byte of mode field. */
> -	switch (255 & (unsigned)header->mode[0]) {
> -	case 0: case 255:
> -		/* Base-256 value: No further verification possible! */
> -		break;
> -	case ' ': /* Not recommended, but not illegal, either. */
> -		break;
> -	case '0': case '1': case '2': case '3':
> -	case '4': case '5': case '6': case '7':
> -		/* Octal Value. */
> -		/* TODO: Check format of remainder of this field. */
> -		break;
> -	default:
> -		/* Not a valid mode; bail out here. */
> -		return (0);
> +	/*
> +	 * Check format of mode/uid/gid/mtime/size/rdevmajor/rdevminor fields.
> +	 * These are usually octal numbers but GNU tar encodes "big" values as
> +	 * base256 and leading zeroes are sometimes replaced by spaces.
> +	 * Even the null terminator is sometimes omitted. Anyway, must be check
> ed
> +	 * to avoid false positives.
> +	 */
> +	if (bid > 0 &&
> +		(validate_number_field(header->mode, sizeof(header->mode)) == 0
>  ||
> +		 validate_number_field(header->uid, sizeof(header->uid)) == 0 |
> |
> +		 validate_number_field(header->gid, sizeof(header->gid)) == 0 |
> |
> +		 validate_number_field(header->mtime, sizeof(header->mtime)) ==
>  0 ||
> +		 validate_number_field(header->size, sizeof(header->size)) == 0
>  ||
> +		 validate_number_field(header->rdevmajor, sizeof(header->rdevma
> jor)) == 0 ||
> +		 validate_number_field(header->rdevminor, sizeof(header->rdevmi
> nor)) == 0)) {
> +			bid = 0;
>  	}
> -	/* TODO: Sanity test uid/gid/size/mtime/rdevmajor/rdevminor fields. */
>  
>  	return (bid);
>  }
> 

Hi,

This broke extract of older tarballs and compatibility with Perl
Archive::Tar. You can test this by trying to extract ports/net/tcpview.

The following patch fixes it:

https://github.com/libarchive/libarchive/commit/2d2b3e928605f795515b03f060fd638c265b0778#diff-845deb76aa98ded5cb2860ded3e19dfb

The relevant part of the patch follows:

diff --git a/libarchive/archive_read_support_format_tar.c b/libarchive/archive_read_support_format_tar.c
index 0ee511e..b977cb7 100644
--- libarchive/archive_read_support_format_tar.c
+++ libarchive/archive_read_support_format_tar.c
@@ -294,8 +294,14 @@ archive_read_format_tar_cleanup(struct archive_read *a)
 	return (ARCHIVE_OK);
 }
 
+/*
+ * Validate number field
+ *
+ * Flags:
+ * 1 - allow double \0 at field end
+ */
 static int
-validate_number_field(const char* p_field, size_t i_size)
+validate_number_field(const char* p_field, size_t i_size, int flags)
 {
 	unsigned char marker = (unsigned char)p_field[0];
 	/* octal? */
@@ -305,14 +311,24 @@ validate_number_field(const char* p_field, size_t i_size)
 		for (i = 0; i < i_size; ++i) {
 			switch (p_field[i])
 			{
-			case ' ': /* skip any leading spaces and trailing space*/
+			case ' ':
+				/* skip any leading spaces and trailing space */
 				if (octal_found == 0 || i == i_size - 1) {
 					continue;
 				}
 				break;
-			case '\0': /* null is allowed only at the end */
+			case '\0':
+				/*
+				 * null should be allowed only at the end
+				 *
+				 * Perl Archive::Tar terminates some fields
+				 * with two nulls. We must allow this to stay
+				 * compatible.
+				 */
 				if (i != i_size - 1) {
-					return 0;
+					if (((flags & 1) == 0)
+					    || i != i_size - 2)
+						return 0;
 				}
 				break;
 			/* rest must be octal digits */
@@ -390,18 +406,25 @@ archive_read_format_tar_bid(struct archive_read *a, int best_bid)
 	 * Check format of mode/uid/gid/mtime/size/rdevmajor/rdevminor fields.
 	 * These are usually octal numbers but GNU tar encodes "big" values as
 	 * base256 and leading zeroes are sometimes replaced by spaces.
-	 * Even the null terminator is sometimes omitted. Anyway, must be checked
-	 * to avoid false positives.
+	 * Even the null terminator is sometimes omitted. Anyway, must be
+	 * checked to avoid false positives.
+	 *
+	 * Perl Archive::Tar does not follow the spec and terminates mode, uid,
+	 * gid, rdevmajor and rdevminor with a double \0. For compatibility
+	 * reasons we allow this deviation.
 	 */
-	if (bid > 0 &&
-		(validate_number_field(header->mode, sizeof(header->mode)) == 0 ||
-		 validate_number_field(header->uid, sizeof(header->uid)) == 0 ||
-		 validate_number_field(header->gid, sizeof(header->gid)) == 0 ||
-		 validate_number_field(header->mtime, sizeof(header->mtime)) == 0 ||
-		 validate_number_field(header->size, sizeof(header->size)) == 0 ||
-		 validate_number_field(header->rdevmajor, sizeof(header->rdevmajor)) == 0 ||
-		 validate_number_field(header->rdevminor, sizeof(header->rdevminor)) == 0)) {
-			bid = 0;
+	if (bid > 0 && (
+	    validate_number_field(header->mode, sizeof(header->mode), 1) == 0
+	    || validate_number_field(header->uid, sizeof(header->uid), 1) == 0
+	    || validate_number_field(header->gid, sizeof(header->gid), 1) == 0 
+	    || validate_number_field(header->mtime, sizeof(header->mtime),
+	    0) == 0
+	    || validate_number_field(header->size, sizeof(header->size), 0) == 0
+	    || validate_number_field(header->rdevmajor,
+	    sizeof(header->rdevmajor), 1) == 0
+	    || validate_number_field(header->rdevminor,
+	    sizeof(header->rdevminor), 1) == 0)) {
+		bid = 0;
 	}
 
 	return (bid);

Updating to git 2d2b3e928605f795515b03f060fd638c265b0778 or later probably
makes the most sense.

 

-- 
Cheers,
Cy Schubert <Cy.Schubert at cschubert.com>
FreeBSD UNIX:  <cy at FreeBSD.org>   Web:  http://www.FreeBSD.org

	The need of the many outweighs the greed of the few.



More information about the svn-src-head mailing list