From: Takashi Iwai Date: Wed, 6 Apr 2022 10:48:35 +0200 Subject: Pass the correct stat to backup files Patch-mainline: Yes Git-commit: c835ecc67b7e37c0d0b7dd7e032209fdaa285808 References: boo#1198106 savananh#62364 The last case to call output_file() in the main loop is output_file (outname, NULL, &tmpoutst, NULL, NULL, file_type | 0, backup); and this essentially means to create a backup file (where to=NULL) only if backup=true, and does nothing else. And, in the current code, the passed file stat (&tmpoutst) is a file stat of the temporary file that has been processed, not the original file (outname) to be backed up. When the backup is performed immediately, this is no big problem. However, output_file() may schedule the deferred handling, and the given file may be backed up at a later point. The problem is that create_backup() tries to avoid the backup of the same file twice, and it checks the given stat i-node number in the hash list. Since it's a stat of a temporary file, the same i-node number may be reused once a temp file is deleted and another is created. This results in a false-positive detection of the already existing file, eventually missing a backup file. This patch attempts to address the issue: - Modify the condition for better understanding, clearly indicating that the code there is for creating a backup file - Pass the stat of the original file instead of a temporary file BugLink: https://bugzilla.opensuse.org/show_bug.cgi?id=1198106 Signed-off-by: Takashi Iwai Signed-off-by: Jean Delvare --- src/patch.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) --- a/src/patch.c +++ b/src/patch.c @@ -611,9 +611,16 @@ main (int argc, char **argv) output_file (NULL, NULL, NULL, inname, &instat, mode, backup); } - else - output_file (outname, NULL, &tmpoutst, NULL, NULL, - file_type | 0, backup); + else if (backup) + { + struct stat outstat; + + if (stat_file (outname, &outstat) != 0) + say ("Cannot stat file %s, skipping backup\n", outname); + else + output_file (outname, NULL, &outstat, NULL, NULL, + file_type | 0, true); + } } } }