1a8b3bd277
- Fix unexpected inconsistency when making directory, bsc#1203600 * tar-avoid-overflow-in-symlinks-tests.patch * tar-fix-extract-unlink.patch - Update race condition fix, bsc#1200657 * tar-fix-race-condition.patch - Refresh bsc1200657.patch OBS-URL: https://build.opensuse.org/request/show/1031561 OBS-URL: https://build.opensuse.org/package/show/Base:System/tar?expand=0&rev=116
118 lines
3.6 KiB
Diff
118 lines
3.6 KiB
Diff
From 79a442d7b0e92622794bfa41dee18a28e450a0dc Mon Sep 17 00:00:00 2001
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From: Paul Eggert <eggert@cs.ucla.edu>
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Date: Thu, 9 Jun 2022 22:09:34 -0700
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Subject: tar: fix race condition
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Problem reported by James Abbatiello in:
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https://lists.gnu.org/r/bug-tar/2022-03/msg00000.html
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* src/extract.c (make_directories): Do not assume that when
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mkdirat fails with errno == EEXIST that there is an existing file
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that can be statted. It could be a dangling symlink. Instead,
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wait until the end and stat it.
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---
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src/extract.c | 61 ++++++++++++++++++++++++++++++++++++++---------------------
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2 files changed, 43 insertions(+), 23 deletions(-)
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diff --git a/src/extract.c b/src/extract.c
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index e7be463..0753dec 100644
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--- a/src/extract.c
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+++ b/src/extract.c
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@@ -636,8 +636,7 @@ fixup_delayed_set_stat (char const *src, char const *dst)
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}
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}
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-/* After a file/link/directory creation has failed, see if
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- it's because some required directory was not present, and if so,
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+/* After a file/link/directory creation has failed due to ENOENT,
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create all required directories. Return zero if all the required
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directories were created, nonzero (issuing a diagnostic) otherwise.
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Set *INTERDIR_MADE if at least one directory was created. */
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@@ -646,6 +645,8 @@ make_directories (char *file_name, bool *interdir_made)
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{
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char *cursor0 = file_name + FILE_SYSTEM_PREFIX_LEN (file_name);
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char *cursor; /* points into the file name */
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+ char *parent_end = NULL;
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+ int parent_errno;
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for (cursor = cursor0; *cursor; cursor++)
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{
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@@ -685,31 +686,47 @@ make_directories (char *file_name, bool *interdir_made)
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print_for_mkdir (file_name, cursor - file_name, desired_mode);
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*interdir_made = true;
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+ parent_end = NULL;
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}
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- else if (errno == EEXIST)
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- status = 0;
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else
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- {
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- /* Check whether the desired file exists. Even when the
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- file exists, mkdir can fail with some errno value E other
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- than EEXIST, so long as E describes an error condition
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- that also applies. */
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- int e = errno;
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- struct stat st;
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- status = fstatat (chdir_fd, file_name, &st, 0);
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- if (status)
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- {
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- errno = e;
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- mkdir_error (file_name);
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- }
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- }
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+ switch (errno)
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+ {
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+ case ELOOP: case ENAMETOOLONG: case ENOENT: case ENOTDIR:
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+ /* FILE_NAME doesn't exist and couldn't be created; fail now. */
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+ mkdir_error (file_name);
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+ *cursor = '/';
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+ return status;
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+
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+ default:
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+ /* FILE_NAME may be an existing directory so do not fail now.
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+ Instead, arrange to check at loop exit, assuming this is
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+ the last loop iteration. */
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+ parent_end = cursor;
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+ parent_errno = errno;
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+ break;
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+ }
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*cursor = '/';
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- if (status)
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- return status;
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}
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- return 0;
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+ if (!parent_end)
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+ return 0;
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+
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+ /* Although we did not create the parent directory, some other
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+ process may have created it, so check whether it exists now. */
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+ *parent_end = '\0';
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+ struct stat st;
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+ int stat_status = fstatat (chdir_fd, file_name, &st, 0);
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+ if (!stat_status && !S_ISDIR (st.st_mode))
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+ stat_status = -1;
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+ if (stat_status)
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+ {
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+ errno = parent_errno;
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+ mkdir_error (file_name);
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+ }
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+ *parent_end = '/';
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+
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+ return stat_status;
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}
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/* Return true if FILE_NAME (with status *STP, if STP) is not a
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@@ -824,7 +841,7 @@ maybe_recoverable (char *file_name, bool regular, bool *interdir_made)
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case ENOENT:
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/* Attempt creating missing intermediate directories. */
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- if (make_directories (file_name, interdir_made) == 0 && *interdir_made)
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+ if (make_directories (file_name, interdir_made) == 0)
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return RECOVER_OK;
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break;
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--
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cgit v1.1
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