git: 6bddcd7682b1 - releng/12.2 - Ensure that dirent's d_off field is initialized
Ed Maste
emaste at FreeBSD.org
Fri Jan 29 01:19:50 UTC 2021
The branch releng/12.2 has been updated by emaste:
URL: https://cgit.FreeBSD.org/src/commit/?id=6bddcd7682b1ac90f01134c7ffa3f9ed023b1338
commit 6bddcd7682b1ac90f01134c7ffa3f9ed023b1338
Author: Mark Johnston <markj at FreeBSD.org>
AuthorDate: 2021-01-03 16:32:30 +0000
Commit: Ed Maste <emaste at FreeBSD.org>
CommitDate: 2021-01-29 01:14:58 +0000
Ensure that dirent's d_off field is initialized
We have the d_off field in struct dirent for providing the seek offset
of the next directory entry. Several filesystems were not initializing
the field, which ends up being copied out to userland.
Reported by: Syed Faraz Abrar <faraz at elttam.com>
Reviewed by: kib
(cherry picked from commit 90f580b954090e669da234f6c8e8d0379ff9d8bc)
(cherry picked from commit acaac0eefa1f2675dfc49faa077e3fb10949d540)
Approved by: so
Security: CVE-2020-25578
---
sys/fs/autofs/autofs_vnops.c | 1 +
sys/fs/smbfs/smbfs_io.c | 2 ++
sys/fs/tmpfs/tmpfs_subr.c | 50 ++++++++++++++++++++++++++++----------------
sys/kern/uipc_mqueue.c | 1 +
4 files changed, 36 insertions(+), 18 deletions(-)
diff --git a/sys/fs/autofs/autofs_vnops.c b/sys/fs/autofs/autofs_vnops.c
index 09d77b9fccf8..ac5886f96054 100644
--- a/sys/fs/autofs/autofs_vnops.c
+++ b/sys/fs/autofs/autofs_vnops.c
@@ -369,6 +369,7 @@ autofs_readdir_one(struct uio *uio, const char *name, int fileno,
return (EINVAL);
dirent.d_fileno = fileno;
+ dirent.d_off = uio->uio_offset + reclen;
dirent.d_reclen = reclen;
dirent.d_type = DT_DIR;
dirent.d_namlen = namlen;
diff --git a/sys/fs/smbfs/smbfs_io.c b/sys/fs/smbfs/smbfs_io.c
index 790538d7ce8b..78a11309edc3 100644
--- a/sys/fs/smbfs/smbfs_io.c
+++ b/sys/fs/smbfs/smbfs_io.c
@@ -103,6 +103,7 @@ smbfs_readvdir(struct vnode *vp, struct uio *uio, struct ucred *cred)
(np->n_parent ? np->n_parentino : 2);
if (de.d_fileno == 0)
de.d_fileno = 0x7ffffffd + offset;
+ de.d_off = offset + 1;
de.d_namlen = offset + 1;
de.d_name[0] = '.';
de.d_name[1] = '.';
@@ -153,6 +154,7 @@ smbfs_readvdir(struct vnode *vp, struct uio *uio, struct ucred *cred)
bzero((caddr_t)&de, DE_SIZE);
de.d_reclen = DE_SIZE;
de.d_fileno = ctx->f_attr.fa_ino;
+ de.d_off = offset + 1;
de.d_type = (ctx->f_attr.fa_attr & SMB_FA_DIR) ? DT_DIR : DT_REG;
de.d_namlen = ctx->f_nmlen;
bcopy(ctx->f_name, de.d_name, de.d_namlen);
diff --git a/sys/fs/tmpfs/tmpfs_subr.c b/sys/fs/tmpfs/tmpfs_subr.c
index f03537640e32..2e035ed8d7f1 100644
--- a/sys/fs/tmpfs/tmpfs_subr.c
+++ b/sys/fs/tmpfs/tmpfs_subr.c
@@ -1188,6 +1188,7 @@ tmpfs_dir_getdotdent(struct tmpfs_mount *tm, struct tmpfs_node *node,
MPASS(uio->uio_offset == TMPFS_DIRCOOKIE_DOT);
dent.d_fileno = node->tn_id;
+ dent.d_off = TMPFS_DIRCOOKIE_DOTDOT;
dent.d_type = DT_DIR;
dent.d_namlen = 1;
dent.d_name[0] = '.';
@@ -1213,7 +1214,7 @@ tmpfs_dir_getdotdent(struct tmpfs_mount *tm, struct tmpfs_node *node,
*/
static int
tmpfs_dir_getdotdotdent(struct tmpfs_mount *tm, struct tmpfs_node *node,
- struct uio *uio)
+ struct uio *uio, off_t next)
{
struct tmpfs_node *parent;
struct dirent dent;
@@ -1234,6 +1235,7 @@ tmpfs_dir_getdotdotdent(struct tmpfs_mount *tm, struct tmpfs_node *node,
dent.d_fileno = parent->tn_id;
TMPFS_NODE_UNLOCK(parent);
+ dent.d_off = next;
dent.d_type = DT_DIR;
dent.d_namlen = 2;
dent.d_name[0] = '.';
@@ -1263,7 +1265,7 @@ tmpfs_dir_getdents(struct tmpfs_mount *tm, struct tmpfs_node *node,
struct uio *uio, int maxcookies, u_long *cookies, int *ncookies)
{
struct tmpfs_dir_cursor dc;
- struct tmpfs_dirent *de;
+ struct tmpfs_dirent *de, *nde;
off_t off;
int error;
@@ -1284,18 +1286,19 @@ tmpfs_dir_getdents(struct tmpfs_mount *tm, struct tmpfs_node *node,
error = tmpfs_dir_getdotdent(tm, node, uio);
if (error != 0)
return (error);
- uio->uio_offset = TMPFS_DIRCOOKIE_DOTDOT;
+ uio->uio_offset = off = TMPFS_DIRCOOKIE_DOTDOT;
if (cookies != NULL)
- cookies[(*ncookies)++] = off = uio->uio_offset;
+ cookies[(*ncookies)++] = off;
/* FALLTHROUGH */
case TMPFS_DIRCOOKIE_DOTDOT:
- error = tmpfs_dir_getdotdotdent(tm, node, uio);
+ de = tmpfs_dir_first(node, &dc);
+ off = tmpfs_dirent_cookie(de);
+ error = tmpfs_dir_getdotdotdent(tm, node, uio, off);
if (error != 0)
return (error);
- de = tmpfs_dir_first(node, &dc);
- uio->uio_offset = tmpfs_dirent_cookie(de);
+ uio->uio_offset = off;
if (cookies != NULL)
- cookies[(*ncookies)++] = off = uio->uio_offset;
+ cookies[(*ncookies)++] = off;
/* EOF. */
if (de == NULL)
return (0);
@@ -1310,13 +1313,17 @@ tmpfs_dir_getdents(struct tmpfs_mount *tm, struct tmpfs_node *node,
off = tmpfs_dirent_cookie(de);
}
- /* Read as much entries as possible; i.e., until we reach the end of
- * the directory or we exhaust uio space. */
+ /*
+ * Read as much entries as possible; i.e., until we reach the end of the
+ * directory or we exhaust uio space.
+ */
do {
struct dirent d;
- /* Create a dirent structure representing the current
- * tmpfs_node and fill it. */
+ /*
+ * Create a dirent structure representing the current tmpfs_node
+ * and fill it.
+ */
if (de->td_node == NULL) {
d.d_fileno = 1;
d.d_type = DT_WHT;
@@ -1360,20 +1367,27 @@ tmpfs_dir_getdents(struct tmpfs_mount *tm, struct tmpfs_node *node,
MPASS(de->td_namelen < sizeof(d.d_name));
(void)memcpy(d.d_name, de->ud.td_name, de->td_namelen);
d.d_reclen = GENERIC_DIRSIZ(&d);
- dirent_terminate(&d);
- /* Stop reading if the directory entry we are treating is
- * bigger than the amount of data that can be returned. */
+ /*
+ * Stop reading if the directory entry we are treating is bigger
+ * than the amount of data that can be returned.
+ */
if (d.d_reclen > uio->uio_resid) {
error = EJUSTRETURN;
break;
}
- /* Copy the new dirent structure into the output buffer and
- * advance pointers. */
+ nde = tmpfs_dir_next(node, &dc);
+ d.d_off = tmpfs_dirent_cookie(nde);
+ dirent_terminate(&d);
+
+ /*
+ * Copy the new dirent structure into the output buffer and
+ * advance pointers.
+ */
error = uiomove(&d, d.d_reclen, uio);
if (error == 0) {
- de = tmpfs_dir_next(node, &dc);
+ de = nde;
if (cookies != NULL) {
off = tmpfs_dirent_cookie(de);
MPASS(*ncookies < maxcookies);
diff --git a/sys/kern/uipc_mqueue.c b/sys/kern/uipc_mqueue.c
index 67c828cae222..84f51fafb636 100644
--- a/sys/kern/uipc_mqueue.c
+++ b/sys/kern/uipc_mqueue.c
@@ -1426,6 +1426,7 @@ mqfs_readdir(struct vop_readdir_args *ap)
if (!pn->mn_fileno)
mqfs_fileno_alloc(mi, pn);
entry.d_fileno = pn->mn_fileno;
+ entry.d_off = offset + entry.d_reclen;
for (i = 0; i < MQFS_NAMELEN - 1 && pn->mn_name[i] != '\0'; ++i)
entry.d_name[i] = pn->mn_name[i];
entry.d_namlen = i;
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