From 16b91f798faf6413f9b043543c5c0c3467b6fdbf Mon Sep 17 00:00:00 2001 From: Andrew Gregory Date: Sun, 9 Apr 2017 19:49:17 -0400 Subject: unlink_file: strip trailing slashes If the user replaces a directory with a symlink, libalpm would get confused because the trailing slash causes system calls to resolve the symlink. This leads to errors and a misleading message during upgrades. Even though libalpm does not support this, it should not be giving misleading errors. Also adds an overflow check. Fixes FS#51377 Signed-off-by: Andrew Gregory --- lib/libalpm/remove.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) (limited to 'lib') diff --git a/lib/libalpm/remove.c b/lib/libalpm/remove.c index 8ce10f84..ffe92518 100644 --- a/lib/libalpm/remove.c +++ b/lib/libalpm/remove.c @@ -440,8 +440,19 @@ static int unlink_file(alpm_handle_t *handle, alpm_pkg_t *oldpkg, { struct stat buf; char file[PATH_MAX]; + int file_len; - snprintf(file, PATH_MAX, "%s%s", handle->root, fileobj->name); + file_len = snprintf(file, PATH_MAX, "%s%s", handle->root, fileobj->name); + if(file_len <= 0 || file_len >= PATH_MAX) { + /* 0 is a valid value from snprintf, but should be impossible here */ + _alpm_log(handle, ALPM_LOG_DEBUG, "path too long to unlink %s%s\n", + handle->root, fileobj->name); + return -1; + } else if(file[file_len-1] == '/') { + /* trailing slashes cause errors and confusing messages if the user has + * replaced a directory with a symlink */ + file[--file_len] = '\0'; + } if(llstat(file, &buf)) { _alpm_log(handle, ALPM_LOG_DEBUG, "file %s does not exist\n", file); -- cgit v1.2.3-24-g4f1b