cpio: fix unpacking of names with leading slashes

function                                             old     new   delta
get_header_cpio                                      968     990     +22
cpio_main                                            533     526      -7

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

3 files changed, 13 insertions, 2 deletions

diff --git a/archival/cpio.c b/archival/cpio.c
index 5c16678e4..067d6e88d 100644
--- a/archival/cpio.c
+++ b/archival/cpio.c
@@ -364,7 +364,7 @@ int cpio_main(int argc UNUSED_PARAM, char **argv)
 #endif
 
         archive_handle = init_handle();
-        archive_handle->src_fd = STDIN_FILENO;
+        /* archive_handle->src_fd = STDIN_FILENO; - done by init_handle */
         archive_handle->seek = seek_by_read;
         archive_handle->ah_flags = ARCHIVE_EXTRACT_NEWER;
 
diff --git a/archival/libunarchive/get_header_cpio.c b/archival/libunarchive/get_header_cpio.c
index 302f12233..52854dff9 100644
--- a/archival/libunarchive/get_header_cpio.c
+++ b/archival/libunarchive/get_header_cpio.c
@@ -70,6 +70,15 @@ char FAST_FUNC get_header_cpio(archive_handle_t *archive_handle)
         file_header->name = xzalloc(namesize + 1);
         /* Read in filename */
         xread(archive_handle->src_fd, file_header->name, namesize);
+        if (file_header->name[0] == '/') {
+                /* Testcase: echo /etc/hosts | cpio -pvd /tmp
+                 * Without this code, it tries to unpack /etc/hosts
+                 * into "/etc/hosts", not "etc/hosts".
+                 */
+                char *p = file_header->name;
+                do p++; while (*p == '/');
+                overlapping_strcpy(file_header->name, p);
+        }
         archive_handle->offset += namesize;
 
         /* Update offset amount and skip padding before file contents */
diff --git a/testsuite/cpio.tests b/testsuite/cpio.tests
index f21ba18d1..56f1885ac 100755
--- a/testsuite/cpio.tests
+++ b/testsuite/cpio.tests
@@ -36,6 +36,7 @@ ls -ln cpio.testdir | $FILTER_LS" \
 "\
 1 blocks
 0
+total 0
 -rw-r--r-- 2 $user $group 0 x
 -rw-r--r-- 2 $user $group 0 y
 " \
@@ -47,10 +48,10 @@ test x"$SKIP_KNOWN_BUGS" = x"" && {
 testing "cpio lists hardlinks" \
 "$ECHO -ne '$hexdump' | bzcat | cpio -t 2>&1; echo \$?" \
 "\
-1 block
 cpio.testdir
 cpio.testdir/x
 cpio.testdir/y
+1 blocks
 0
 " \
         "" ""
@@ -72,6 +73,7 @@ ls -ln cpio.testdir2/cpio.testdir | $FILTER_LS" \
 "\
 2 blocks
 0
+total 8
 -rw-r--r-- 2 $user $group 0 empty
 -rw-r--r-- 2 $user $group 0 empty1
 -rw-r--r-- 2 $user $group 2 nonempty