From 04d2c0bc4dc1b10c5824fa54ceee7ee3547ca880 Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Fri, 10 May 2019 15:12:04 +0900 Subject: [PATCH] kconfig: do not accept a directory for configuration output Currently, conf_write() can be called with a directory name instead of a file name. As far as I see, this can happen for menuconfig, nconfig, gconfig. If it is given with a directory path, conf_write() kindly appends getenv("KCONFIG_CONFIG"), but this ends up with hacky dir/basename handling, and screwed up in corner-cases like "what if KCONFIG_CONFIG is an absolute path?" as discussed before: https://patchwork.kernel.org/patch/9910037/ Since conf_write() is already messed up, I'd say "do not do it". Please pass a file path all the time. If a directory path is specified for the configuration output, conf_write() will simply error out. Now that the tmp file is created in the same directory as the .config, the previously reported "what if KCONFIG_CONFIG points to a different file system?" has been solved. Signed-off-by: Masahiro Yamada Cc: Nicolas Porcel Signed-off-by: Christian Lamparter --- config/confdata.c | 58 ++++++++++++++++++++--------------------------- 1 file changed, 24 insertions(+), 34 deletions(-) diff --git a/config/confdata.c b/config/confdata.c index d67695d..da98566 100644 --- a/config/confdata.c +++ b/config/confdata.c @@ -863,40 +863,31 @@ int conf_write(const char *name) FILE *out; struct symbol *sym; struct menu *menu; - const char *basename; const char *str; - char dirname[PATH_MAX+1], tmpname[PATH_MAX+22], newname[PATH_MAX+8]; + char tmpname[PATH_MAX + 1], oldname[PATH_MAX + 1]; char *env; - dirname[0] = 0; - if (name && name[0]) { - char *slash; - - if (is_dir(name)) { - strcpy(dirname, name); - strcat(dirname, "/"); - basename = conf_get_configname(); - } else if ((slash = strrchr(name, '/'))) { - int size = slash - name + 1; - memcpy(dirname, name, size); - dirname[size] = 0; - if (slash[1]) - basename = slash + 1; - else - basename = conf_get_configname(); - } else - basename = name; - } else - basename = conf_get_configname(); - - sprintf(newname, "%s%s", dirname, basename); + if (!name) + name = conf_get_configname(); + + if (!*name) { + fprintf(stderr, "config name is empty\n"); + return -1; + } + + if (is_dir(name)) { + fprintf(stderr, "%s: Is a directory\n", name); + return -1; + } + env = getenv("KCONFIG_OVERWRITECONFIG"); - if (!env || !*env) { - sprintf(tmpname, "%s.tmpconfig.%d", dirname, (int)getpid()); - out = fopen(tmpname, "w"); - } else { + if (env && *env) { *tmpname = 0; - out = fopen(newname, "w"); + out = fopen(name, "w"); + } else { + snprintf(tmpname, sizeof(tmpname), "%s.%d.tmp", + name, (int)getpid()); + out = fopen(tmpname, "w"); } if (!out) return 1; @@ -943,14 +934,13 @@ next: fclose(out); if (*tmpname) { - strcat(dirname, basename); - strcat(dirname, ".old"); - rename(newname, dirname); - if (rename(tmpname, newname)) + snprintf(oldname, sizeof(oldname), "%s.old", name); + rename(name, oldname); + if (rename(tmpname, name)) return 1; } - conf_message("configuration written to %s", newname); + conf_message("configuration written to %s", name); sym_set_change_count(0); -- 2.31.1