Checking the result of a stat() to avoid referencing unitialized data.

The original patch was by Kamil Dudka.


git-svn-id: svn://svn.savannah.gnu.org/nano/trunk/nano@5621 35c25a1d-7b9e-4130-9fde-d3aeb78583b8
master
Benno Schulenberg 2016-02-09 20:53:11 +00:00
parent e853c1ee7c
commit cdeb90515b
2 changed files with 25 additions and 14 deletions

View File

@ -1,3 +1,8 @@
2016-02-09 Benno Schulenberg <bensberg@justemail.net>
* src/files.c (stat_with_alloc, open_buffer, write_file): Check the
result of a stat() to avoid referencing unitialized data. Original
patch was by Kamil Dudka.
2016-02-07 Benno Schulenberg <bensberg@justemail.net>
* src/files.c (update_poshistory): Don't put files in the history list
when they have the default cursor position (line 1, column 1).

View File

@ -383,6 +383,20 @@ int do_lockfile(const char *filename)
return retval;
}
/* Perform a stat call on the given filename, allocating a stat struct
* if necessary. On success, *pstat points to the stat's result. On
* failure, *pstat is freed and made NULL. */
void stat_with_alloc(const char *filename, struct stat **pstat)
{
if (*pstat == NULL)
*pstat = (struct stat *)nmalloc(sizeof(struct stat));
if (stat(filename, *pstat) != 0) {
free(*pstat);
*pstat = NULL;
}
}
#endif /* !NANO_TINY */
/* If it's not "", filename is a file to open. We make a new buffer, if
@ -466,11 +480,8 @@ bool open_buffer(const char *filename, bool undoable)
if (rc > 0) {
read_file(f, rc, filename, undoable, new_buffer);
#ifndef NANO_TINY
if (openfile->current_stat == NULL) {
openfile->current_stat =
(struct stat *)nmalloc(sizeof(struct stat));
stat(filename, openfile->current_stat);
}
if (openfile->current_stat == NULL)
stat_with_alloc(filename, &openfile->current_stat);
#endif
}
@ -1801,10 +1812,8 @@ bool write_file(const char *name, FILE *f_open, bool tmp, append_type
* specified it interactively), stat and save the value now,
* or else we will chase null pointers when we do modtime checks,
* preserve file times, and so on, during backup. */
if (openfile->current_stat == NULL && !tmp && realexists) {
openfile->current_stat = (struct stat *)nmalloc(sizeof(struct stat));
stat(realname, openfile->current_stat);
}
if (openfile->current_stat == NULL && !tmp && realexists)
stat_with_alloc(realname, &openfile->current_stat);
/* We backup only if the backup toggle is set, the file isn't
* temporary, and the file already exists. Furthermore, if we
@ -2181,12 +2190,9 @@ bool write_file(const char *name, FILE *f_open, bool tmp, append_type
}
#ifndef NANO_TINY
/* Update current_stat to reference the file as it is now. */
if (openfile->current_stat == NULL)
openfile->current_stat =
(struct stat *)nmalloc(sizeof(struct stat));
if (!openfile->mark_set)
stat(realname, openfile->current_stat);
/* Get or update the stat info to reflect the current state. */
stat_with_alloc(realname, &openfile->current_stat);
#endif
statusbar(P_("Wrote %lu line", "Wrote %lu lines",