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| author | Paul Eggert <eggert@cs.ucla.edu> | 2022-08-26 15:23:23 -0500 |
|---|---|---|
| committer | Paul Eggert <eggert@cs.ucla.edu> | 2022-08-26 16:39:16 -0500 |
| commit | 0b74885e81b90d6ab4890b195dce99ca9109fe59 (patch) | |
| tree | 6d4b3df349fa35a26b8c3bab24d469584791204a /src | |
| parent | 258d1c44e5ee7c58b28bf0000e9d737df6081885 (diff) | |
| download | tar-0b74885e81b90d6ab4890b195dce99ca9109fe59.tar.gz | |
Fix bug with -x --xattr read-only files
Problem reported by Kevin Raymond in:
https://bugzilla.redhat.com/show_bug.cgi?id=1886540
* src/extract.c (open_output_file): If we already created the
empty file, do not open with O_EXCL, or with O_CREAT or O_TRUNC
for that matter. Instead, use only O_NOFOLLOW to avoid some
races. When estimating current mode, use openflag & O_EXCL rather
than overwriting_old_files.
(extract_file): Also invert S_IWUSR if it’s not set.
* tests/xattr08.at: New test.
* tests/Makefile.am, tests/testsuite.at: Add it.
Diffstat (limited to 'src')
| -rw-r--r-- | src/extract.c | 31 |
1 files changed, 15 insertions, 16 deletions
diff --git a/src/extract.c b/src/extract.c index 2813c961..c1f5731b 100644 --- a/src/extract.c +++ b/src/extract.c @@ -1189,14 +1189,12 @@ open_output_file (char const *file_name, int typeflag, mode_t mode, int fd; bool overwriting_old_files = old_files_option == OVERWRITE_OLD_FILES; int openflag = (O_WRONLY | O_BINARY | O_CLOEXEC | O_NOCTTY | O_NONBLOCK - | O_CREAT - | (overwriting_old_files - ? O_TRUNC | (dereference_option ? 0 : O_NOFOLLOW) - : O_EXCL)); - - /* File might be created in set_xattr. So clear O_EXCL to avoid open() fail */ - if (file_created) - openflag = openflag & ~O_EXCL; + | (file_created + ? O_NOFOLLOW + : (O_CREAT + | (overwriting_old_files + ? O_TRUNC | (dereference_option ? 0 : O_NOFOLLOW) + : O_EXCL)))); if (typeflag == CONTTYPE) { @@ -1227,7 +1225,12 @@ open_output_file (char const *file_name, int typeflag, mode_t mode, fd = openat (chdir_fd, file_name, openflag, mode); if (0 <= fd) { - if (overwriting_old_files) + if (openflag & O_EXCL) + { + *current_mode = mode & ~ current_umask; + *current_mode_mask = MODE_RWX; + } + else { struct stat st; if (fstat (fd, &st) != 0) @@ -1246,11 +1249,6 @@ open_output_file (char const *file_name, int typeflag, mode_t mode, *current_mode = st.st_mode; *current_mode_mask = ALL_MODE_BITS; } - else - { - *current_mode = mode & ~ current_umask; - *current_mode_mask = MODE_RWX; - } } return fd; @@ -1268,8 +1266,9 @@ extract_file (char *file_name, int typeflag) bool interdir_made = false; mode_t mode = (current_stat_info.stat.st_mode & MODE_RWX & ~ (0 < same_owner_option ? S_IRWXG | S_IRWXO : 0)); - mode_t invert_permissions = 0 < same_owner_option ? mode & (S_IRWXG | S_IRWXO) - : 0; + mode_t invert_permissions + = ((0 < same_owner_option ? mode & (S_IRWXG | S_IRWXO) : 0) + | ((mode & S_IWUSR) ^ S_IWUSR)); mode_t current_mode = 0; mode_t current_mode_mask = 0; |