From 58830e58551aef70e19c992f880e378125e5d9d9 Mon Sep 17 00:00:00 2001 From: Eric Biggers Date: Sat, 21 Jan 2023 12:32:21 -0800 Subject: misc/e4defrag: fix -Wstringop-truncation warnings Fix two -Wstringop-truncation warnings in is_ext4() by simplifying how how mnt_type is handled and by using the correct bound for mnt_fsname. Fix a -Wstringop-truncation warning in main() by replacing the fragile pattern 'strncpy(dst, src, strnlen(src, N))', which doesn't null-terminate the destination string, with a standard string copy. (It happened to work anyway because dst happens to be zero-initialized.) These warnings showed up when building with -Wall with gcc 8 or later. Signed-off-by: Eric Biggers Signed-off-by: Theodore Ts'o --- misc/e4defrag.c | 30 +++++++++--------------------- 1 file changed, 9 insertions(+), 21 deletions(-) diff --git a/misc/e4defrag.c b/misc/e4defrag.c index 9ec265f2..33bd05d2 100644 --- a/misc/e4defrag.c +++ b/misc/e4defrag.c @@ -258,12 +258,12 @@ static int get_mount_point(const char *devname, char *mount_point, * * @file: the file's name. */ -static int is_ext4(const char *file, char *devname) +static int is_ext4(const char *file, char devname[PATH_MAX + 1]) { int maxlen = 0; int len, ret; + int type_is_ext4 = 0; FILE *fp = NULL; - char *mnt_type = NULL; /* Refer to /etc/mtab */ const char *mtab = MOUNTED; char file_path[PATH_MAX + 1]; @@ -307,26 +307,16 @@ static int is_ext4(const char *file, char *devname) maxlen = len; - mnt_type = realloc(mnt_type, strlen(mnt->mnt_type) + 1); - if (mnt_type == NULL) { - endmntent(fp); - return -1; - } - memset(mnt_type, 0, strlen(mnt->mnt_type) + 1); - strncpy(mnt_type, mnt->mnt_type, strlen(mnt->mnt_type)); + type_is_ext4 = !strcmp(mnt->mnt_type, FS_EXT4); strncpy(lost_found_dir, mnt->mnt_dir, PATH_MAX); - strncpy(devname, mnt->mnt_fsname, strlen(mnt->mnt_fsname) + 1); + strncpy(devname, mnt->mnt_fsname, PATH_MAX); } endmntent(fp); - if (mnt_type && strcmp(mnt_type, FS_EXT4) == 0) { - FREE(mnt_type); + if (type_is_ext4) return 0; - } else { - FREE(mnt_type); - PRINT_ERR_MSG(NGMSG_EXT4); - return -1; - } + PRINT_ERR_MSG(NGMSG_EXT4); + return -1; } /* @@ -1865,11 +1855,9 @@ int main(int argc, char *argv[]) /* fall through */ case DEVNAME: if (arg_type == DEVNAME) { - strncpy(lost_found_dir, dir_name, - strnlen(dir_name, PATH_MAX)); + strcpy(lost_found_dir, dir_name); strncat(lost_found_dir, "/lost+found/", - PATH_MAX - strnlen(lost_found_dir, - PATH_MAX)); + PATH_MAX - strlen(lost_found_dir)); } nftw64(dir_name, calc_entry_counts, FTW_OPEN_FD, flags); -- cgit v1.2.1