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| author | Mark Johnston <markj@FreeBSD.org> | 2021-10-13 00:11:02 +0000 |
|---|---|---|
| committer | Mark Johnston <markj@FreeBSD.org> | 2021-10-13 13:33:35 +0000 |
| commit | 03d5820f738de130b2feb66833f18741b7f92a14 (patch) | |
| tree | 5f1fd4160afa2758b6cf2463032506a65566f7fd | |
| parent | d0f0e0bd741af867582ceede8ac1b0aec90eae2d (diff) | |
| download | src-03d5820f738de130b2feb66833f18741b7f92a14.tar.gz src-03d5820f738de130b2feb66833f18741b7f92a14.zip | |
mount: Check for !VDIR mount points before handling -o emptydir
To implement -o emptydir, vfs_emptydir() checks that the passed
directory is empty. This should be done after checking whether the
vnode is of type VDIR, though, or vfs_emptydir() may end up calling
VOP_READDIR on a non-directory.
Reported by: syzbot+4006732c69fb0f792b2c@syzkaller.appspotmail.com
Reviewed by: kib, imp
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D32475
| -rw-r--r-- | sys/kern/vfs_mount.c | 10 | ||||
| -rw-r--r-- | sys/kern/vfs_subr.c | 1 |
2 files changed, 3 insertions, 8 deletions
diff --git a/sys/kern/vfs_mount.c b/sys/kern/vfs_mount.c index 55c62b7fe491..2fc98d3cc6c8 100644 --- a/sys/kern/vfs_mount.c +++ b/sys/kern/vfs_mount.c @@ -1095,14 +1095,6 @@ vfs_domount_first( ASSERT_VOP_ELOCKED(vp, __func__); KASSERT((fsflags & MNT_UPDATE) == 0, ("MNT_UPDATE shouldn't be here")); - if ((fsflags & MNT_EMPTYDIR) != 0) { - error = vfs_emptydir(vp); - if (error != 0) { - vput(vp); - return (error); - } - } - /* * If the jail of the calling thread lacks permission for this type of * file system, or is trying to cover its own root, deny immediately. @@ -1124,6 +1116,8 @@ vfs_domount_first( error = vinvalbuf(vp, V_SAVE, 0, 0); if (error == 0 && vp->v_type != VDIR) error = ENOTDIR; + if (error == 0 && (fsflags & MNT_EMPTYDIR) != 0) + error = vfs_emptydir(vp); if (error == 0) { VI_LOCK(vp); if ((vp->v_iflag & VI_MOUNT) == 0 && vp->v_mountedhere == NULL) diff --git a/sys/kern/vfs_subr.c b/sys/kern/vfs_subr.c index d4b7ac71eb97..181d0004e940 100644 --- a/sys/kern/vfs_subr.c +++ b/sys/kern/vfs_subr.c @@ -6300,6 +6300,7 @@ vfs_emptydir(struct vnode *vp) eof = 0; ASSERT_VOP_LOCKED(vp, "vfs_emptydir"); + VNASSERT(vp->v_type == VDIR, vp, ("vp is not a directory")); dirent = malloc(sizeof(struct dirent), M_TEMP, M_WAITOK); iov.iov_base = dirent; |