The branch main has been updated by fsu:
URL:
https://cgit.FreeBSD.org/src/commit/?id=bb9f1ba4b55c1f566d59cc7c7d1d28dd37715984
commit bb9f1ba4b55c1f566d59cc7c7d1d28dd37715984
Author: Fedor Uporov <f...@freebsd.org>
AuthorDate: 2021-10-29 12:45:50 +0000
Commit: Fedor Uporov <f...@freebsd.org>
CommitDate: 2021-12-30 06:14:44 +0000
Add more accurate directory entries check
Rename ext2_dirbadentry() to ext2_check_direntry(). Add directory
entry inode value check, and call ext2_check_direntry() in all cases.
The dirchk sysctl is removed.
PR: 259024,259041
Reported by: Robert Morris
Reviewed by: pfg
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D33374
---
sys/fs/ext2fs/ext2_lookup.c | 39 ++++++++++-----------------------------
1 file changed, 10 insertions(+), 29 deletions(-)
diff --git a/sys/fs/ext2fs/ext2_lookup.c b/sys/fs/ext2fs/ext2_lookup.c
index 3294ad3401ff..a8e28e24f9e2 100644
--- a/sys/fs/ext2fs/ext2_lookup.c
+++ b/sys/fs/ext2fs/ext2_lookup.c
@@ -79,15 +79,8 @@ SDT_PROBE_DEFINE4(ext2fs, , trace, ext2_dirbad_error,
SDT_PROBE_DEFINE5(ext2fs, , trace, ext2_dirbadentry_error,
"char*", "int", "uint32_t", "uint16_t", "uint8_t");
-#ifdef INVARIANTS
-static int dirchk = 1;
-#else
-static int dirchk = 0;
-#endif
-
static SYSCTL_NODE(_vfs, OID_AUTO, e2fs, CTLFLAG_RD | CTLFLAG_MPSAFE, 0,
"EXT2FS filesystem");
-SYSCTL_INT(_vfs_e2fs, OID_AUTO, dircheck, CTLFLAG_RW, &dirchk, 0, "");
/*
DIRBLKSIZE in ffs is DEV_BSIZE (in most cases 512)
@@ -129,8 +122,8 @@ static u_char dt_to_ext2_ft[] = {
#define DTTOFT(dt) \
((dt) < nitems(dt_to_ext2_ft) ? dt_to_ext2_ft[(dt)] : EXT2_FT_UNKNOWN)
-static int ext2_dirbadentry(struct vnode *dp, struct ext2fs_direct_2 *de,
- int entryoffsetinblock);
+static int ext2_check_direntry(struct vnode *dp,
+ struct ext2fs_direct_2 *de, int entryoffsetinblock);
static int ext2_is_dot_entry(struct componentname *cnp);
static int ext2_lookup_ino(struct vnode *vdp, struct vnode **vpp,
struct componentname *cnp, ino_t *dd_ino);
@@ -734,20 +727,14 @@ ext2_search_dirblock(struct inode *ip, void *data, int
*foundp,
ep = (struct ext2fs_direct_2 *)((char *)data + offset);
top = (struct ext2fs_direct_2 *)((char *)data + bsize);
while (ep < top) {
- /*
- * Full validation checks are slow, so we only check
- * enough to insure forward progress through the
- * directory. Complete checks can be run by setting
- * "vfs.e2fs.dirchk" to be true.
- */
- if (le16toh(ep->e2d_reclen) == 0 ||
- (dirchk && ext2_dirbadentry(vdp, ep, offset))) {
+ if (ext2_check_direntry(vdp, ep, offset)) {
int i;
ext2_dirbad(ip, *offp, "mangled entry");
i = bsize - (offset & (bsize - 1));
*offp += i;
offset += i;
+ ep = (struct ext2fs_direct_2 *)((char *)data + offset);
continue;
}
@@ -836,15 +823,11 @@ ext2_dirbad(struct inode *ip, doff_t offset, char *how)
* name is not longer than MAXNAMLEN
* name must be as long as advertised, and null terminated
*/
-/*
- * changed so that it confirms to ext2_check_dir_entry
- */
static int
-ext2_dirbadentry(struct vnode *dp, struct ext2fs_direct_2 *de,
+ext2_check_direntry(struct vnode *dp, struct ext2fs_direct_2 *de,
int entryoffsetinblock)
{
- int DIRBLKSIZ = VTOI(dp)->i_e2fs->e2fs_bsize;
-
+ struct m_ext2fs *fs = VTOI(dp)->i_e2fs;
char *error_msg = NULL;
if (le16toh(de->e2d_reclen) < EXT2_DIR_REC_LEN(1))
@@ -853,12 +836,10 @@ ext2_dirbadentry(struct vnode *dp, struct ext2fs_direct_2
*de,
error_msg = "rec_len % 4 != 0";
else if (le16toh(de->e2d_reclen) < EXT2_DIR_REC_LEN(de->e2d_namlen))
error_msg = "reclen is too small for name_len";
- else if (entryoffsetinblock + le16toh(de->e2d_reclen)> DIRBLKSIZ)
+ else if (entryoffsetinblock + le16toh(de->e2d_reclen)> fs->e2fs_bsize)
error_msg = "directory entry across blocks";
- /* else LATER
- if (de->inode > dir->i_sb->u.ext2_sb.s_es->s_inodes_count)
- error_msg = "inode out of bounds";
- */
+ else if (le32toh(de->e2d_ino) > fs->e2fs->e2fs_icount)
+ error_msg = "directory entry inode out of bounds";
if (error_msg != NULL) {
SDT_PROBE5(ext2fs, , trace, ext2_dirbadentry_error,
@@ -866,7 +847,7 @@ ext2_dirbadentry(struct vnode *dp, struct ext2fs_direct_2
*de,
le32toh(de->e2d_ino), le16toh(de->e2d_reclen),
de->e2d_namlen);
}
- return (error_msg == NULL ? 0 : 1);
+ return (error_msg == NULL ? 0 : EINVAL);
}
/*
