diff options
| author | Jason A. Harmening <jah@FreeBSD.org> | 2024-12-22 06:36:30 +0000 |
|---|---|---|
| committer | Jason A. Harmening <jah@FreeBSD.org> | 2025-01-09 06:10:00 +0000 |
| commit | 6584e5a1c54ff24ed7c9eb80a884b4e7f54e7288 (patch) | |
| tree | 41edbc425d2dbf36d4ff0f18d2054c7bef6e4b46 | |
| parent | 96ef85cc51ba2eccc6a043227aa993180e5a0473 (diff) | |
mount(8): Avoid truncation when fstab-formatting unionfs mount info
When displaying unionfs mounts in fstab format (`mount -p`), mount(8)
currently uses strlcpy to remove the disposition prefix from the mount
name returned by getmntinfo(3). But strlcpy, like strcpy before it,
does not guarantee correct behavior if the source and destination
buffers overlap.
Just offset the buffer and avoid the destructive copy in the first
place.
PR: 283420
Reviewed by: imp (previous version), olce
Differential Revision: https://reviews.freebsd.org/D48177
(cherry picked from commit a314c60625af1829b7e12c3a4cedb74d7f69d074)
| -rw-r--r-- | sbin/mount/mount.c | 16 |
1 files changed, 8 insertions, 8 deletions
diff --git a/sbin/mount/mount.c b/sbin/mount/mount.c index 2fcc94e40818..bb84d9696d12 100644 --- a/sbin/mount/mount.c +++ b/sbin/mount/mount.c @@ -901,9 +901,11 @@ void putfsent(struct statfs *ent) { struct fstab *fst; + const char *mntfromname; char *opts, *rw; int l; + mntfromname = ent->f_mntfromname; opts = NULL; /* flags2opts() doesn't return the "rw" option. */ if ((ent->f_flags & MNT_RDONLY) != 0) @@ -914,16 +916,14 @@ putfsent(struct statfs *ent) opts = flags2opts(ent->f_flags); opts = catopt(rw, opts); - if (strncmp(ent->f_mntfromname, "<below>", 7) == 0 || - strncmp(ent->f_mntfromname, "<above>", 7) == 0) { - strlcpy(ent->f_mntfromname, - (strnstr(ent->f_mntfromname, ":", 8) +1), - sizeof(ent->f_mntfromname)); + if (strncmp(mntfromname, "<below>:", 8) == 0 || + strncmp(mntfromname, "<above>:", 8) == 0) { + mntfromname += 8; } - l = strlen(ent->f_mntfromname); + l = strlen(mntfromname); xo_emit("{:device}{P:/%s}{P:/%s}{P:/%s}", - ent->f_mntfromname, + mntfromname, l < 8 ? "\t" : "", l < 16 ? "\t" : "", l < 24 ? "\t" : " "); @@ -939,7 +939,7 @@ putfsent(struct statfs *ent) l < 8 ? "\t" : " "); free(opts); - if ((fst = getfsspec(ent->f_mntfromname))) + if ((fst = getfsspec(mntfromname))) xo_emit("{P:\t}{n:dump/%u}{P: }{n:pass/%u}\n", fst->fs_freq, fst->fs_passno); else if ((fst = getfsfile(ent->f_mntonname))) |