diff options
Diffstat (limited to 'builtin/apply.c')
| -rw-r--r-- | builtin/apply.c | 142 |
1 files changed, 141 insertions, 1 deletions
diff --git a/builtin/apply.c b/builtin/apply.c index c484b53f55..0ca687fa6b 100644 --- a/builtin/apply.c +++ b/builtin/apply.c @@ -51,6 +51,7 @@ static int apply_verbosely; static int allow_overlap; static int no_add; static int threeway; +static int unsafe_paths; static const char *fake_ancestor; static int line_termination = '\n'; static unsigned int p_context = UINT_MAX; @@ -3221,7 +3222,7 @@ static int load_patch_target(struct strbuf *buf, const char *name, unsigned expected_mode) { - if (cached) { + if (cached || check_index) { if (read_file_or_gitlink(ce, buf)) return error(_("read of %s failed"), name); } else if (name) { @@ -3230,6 +3231,8 @@ static int load_patch_target(struct strbuf *buf, return read_file_or_gitlink(ce, buf); else return SUBMODULE_PATCH_WITHOUT_INDEX; + } else if (has_symlink_leading_path(name, strlen(name))) { + return error(_("reading from '%s' beyond a symbolic link"), name); } else { if (read_old_data(st, name, buf)) return error(_("read of %s failed"), name); @@ -3570,6 +3573,121 @@ static int check_to_create(const char *new_name, int ok_if_exists) } /* + * We need to keep track of how symlinks in the preimage are + * manipulated by the patches. A patch to add a/b/c where a/b + * is a symlink should not be allowed to affect the directory + * the symlink points at, but if the same patch removes a/b, + * it is perfectly fine, as the patch removes a/b to make room + * to create a directory a/b so that a/b/c can be created. + */ +static struct string_list symlink_changes; +#define SYMLINK_GOES_AWAY 01 +#define SYMLINK_IN_RESULT 02 + +static uintptr_t register_symlink_changes(const char *path, uintptr_t what) +{ + struct string_list_item *ent; + + ent = string_list_lookup(&symlink_changes, path); + if (!ent) { + ent = string_list_insert(&symlink_changes, path); + ent->util = (void *)0; + } + ent->util = (void *)(what | ((uintptr_t)ent->util)); + return (uintptr_t)ent->util; +} + +static uintptr_t check_symlink_changes(const char *path) +{ + struct string_list_item *ent; + + ent = string_list_lookup(&symlink_changes, path); + if (!ent) + return 0; + return (uintptr_t)ent->util; +} + +static void prepare_symlink_changes(struct patch *patch) +{ + for ( ; patch; patch = patch->next) { + if ((patch->old_name && S_ISLNK(patch->old_mode)) && + (patch->is_rename || patch->is_delete)) + /* the symlink at patch->old_name is removed */ + register_symlink_changes(patch->old_name, SYMLINK_GOES_AWAY); + + if (patch->new_name && S_ISLNK(patch->new_mode)) + /* the symlink at patch->new_name is created or remains */ + register_symlink_changes(patch->new_name, SYMLINK_IN_RESULT); + } +} + +static int path_is_beyond_symlink_1(struct strbuf *name) +{ + do { + unsigned int change; + + while (--name->len && name->buf[name->len] != '/') + ; /* scan backwards */ + if (!name->len) + break; + name->buf[name->len] = '\0'; + change = check_symlink_changes(name->buf); + if (change & SYMLINK_IN_RESULT) + return 1; + if (change & SYMLINK_GOES_AWAY) + /* + * This cannot be "return 0", because we may + * see a new one created at a higher level. + */ + continue; + + /* otherwise, check the preimage */ + if (check_index) { + struct cache_entry *ce; + + ce = cache_file_exists(name->buf, name->len, ignore_case); + if (ce && S_ISLNK(ce->ce_mode)) + return 1; + } else { + struct stat st; + if (!lstat(name->buf, &st) && S_ISLNK(st.st_mode)) + return 1; + } + } while (1); + return 0; +} + +static int path_is_beyond_symlink(const char *name_) +{ + int ret; + struct strbuf name = STRBUF_INIT; + + assert(*name_ != '\0'); + strbuf_addstr(&name, name_); + ret = path_is_beyond_symlink_1(&name); + strbuf_release(&name); + + return ret; +} + +static void die_on_unsafe_path(struct patch *patch) +{ + const char *old_name = NULL; + const char *new_name = NULL; + if (patch->is_delete) + old_name = patch->old_name; + else if (!patch->is_new && !patch->is_copy) + old_name = patch->old_name; + if (!patch->is_delete) + new_name = patch->new_name; + + if (old_name && !verify_path(old_name)) + die(_("invalid path '%s'"), old_name); + if (new_name && !verify_path(new_name)) + die(_("invalid path '%s'"), new_name); +} + +/* * Check and apply the patch in-core; leave the result in patch->result * for the caller to write it out to the final destination. */ @@ -3656,6 +3774,22 @@ static int check_patch(struct patch *patch) } } + if (!unsafe_paths) + die_on_unsafe_path(patch); + + /* + * An attempt to read from or delete a path that is beyond a + * symbolic link will be prevented by load_patch_target() that + * is called at the beginning of apply_data() so we do not + * have to worry about a patch marked with "is_delete" bit + * here. We however need to make sure that the patch result + * is not deposited to a path that is beyond a symbolic link + * here. + */ + if (!patch->is_delete && path_is_beyond_symlink(patch->new_name)) + return error(_("affected file '%s' is beyond a symbolic link"), + patch->new_name); + if (apply_data(patch, &st, ce) < 0) return error(_("%s: patch does not apply"), name); patch->rejected = 0; @@ -3666,6 +3800,7 @@ static int check_patch_list(struct patch *patch) { int err = 0; + prepare_symlink_changes(patch); prepare_fn_table(patch); while (patch) { if (apply_verbosely) @@ -4404,6 +4539,8 @@ int cmd_apply(int argc, const char **argv, const char *prefix_) N_("make sure the patch is applicable to the current index")), OPT_BOOL(0, "cached", &cached, N_("apply a patch without touching the working tree")), + OPT_BOOL(0, "unsafe-paths", &unsafe_paths, + N_("accept a patch that touches outside the working area")), OPT_BOOL(0, "apply", &force_apply, N_("also apply the patch (use with --stat/--summary/--check)")), OPT_BOOL('3', "3way", &threeway, @@ -4476,6 +4613,9 @@ int cmd_apply(int argc, const char **argv, const char *prefix_) die(_("--cached outside a repository")); check_index = 1; } + if (check_index) + unsafe_paths = 0; + for (i = 0; i < argc; i++) { const char *arg = argv[i]; int fd; |