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authorNamjae Jeon2023-12-31 16:13:20 +0900
committerGreg Kroah-Hartman2024-01-05 15:18:35 +0100
commitd5651972e5c5e32c718a6c01ca57bef038dbb0a9 (patch)
tree9459cad8b4e27d30fa12d97f371d2d8e2a00b90b
parentaabc944ebf087ee91793729dc127b2378d4f66ec (diff)
ksmbd: fix possible deadlock in smb2_open
[ Upstream commit 864fb5d3716303a045c3ffb397f651bfd37bfb36 ] [ 8743.393379] ====================================================== [ 8743.393385] WARNING: possible circular locking dependency detected [ 8743.393391] 6.4.0-rc1+ #11 Tainted: G OE [ 8743.393397] ------------------------------------------------------ [ 8743.393402] kworker/0:2/12921 is trying to acquire lock: [ 8743.393408] ffff888127a14460 (sb_writers#8){.+.+}-{0:0}, at: ksmbd_vfs_setxattr+0x3d/0xd0 [ksmbd] [ 8743.393510] but task is already holding lock: [ 8743.393515] ffff8880360d97f0 (&type->i_mutex_dir_key#6/1){+.+.}-{3:3}, at: ksmbd_vfs_kern_path_locked+0x181/0x670 [ksmbd] [ 8743.393618] which lock already depends on the new lock. [ 8743.393623] the existing dependency chain (in reverse order) is: [ 8743.393628] -> #1 (&type->i_mutex_dir_key#6/1){+.+.}-{3:3}: [ 8743.393648] down_write_nested+0x9a/0x1b0 [ 8743.393660] filename_create+0x128/0x270 [ 8743.393670] do_mkdirat+0xab/0x1f0 [ 8743.393680] __x64_sys_mkdir+0x47/0x60 [ 8743.393690] do_syscall_64+0x5d/0x90 [ 8743.393701] entry_SYSCALL_64_after_hwframe+0x72/0xdc [ 8743.393711] -> #0 (sb_writers#8){.+.+}-{0:0}: [ 8743.393728] __lock_acquire+0x2201/0x3b80 [ 8743.393737] lock_acquire+0x18f/0x440 [ 8743.393746] mnt_want_write+0x5f/0x240 [ 8743.393755] ksmbd_vfs_setxattr+0x3d/0xd0 [ksmbd] [ 8743.393839] ksmbd_vfs_set_dos_attrib_xattr+0xcc/0x110 [ksmbd] [ 8743.393924] compat_ksmbd_vfs_set_dos_attrib_xattr+0x39/0x50 [ksmbd] [ 8743.394010] smb2_open+0x3432/0x3cc0 [ksmbd] [ 8743.394099] handle_ksmbd_work+0x2c9/0x7b0 [ksmbd] [ 8743.394187] process_one_work+0x65a/0xb30 [ 8743.394198] worker_thread+0x2cf/0x700 [ 8743.394209] kthread+0x1ad/0x1f0 [ 8743.394218] ret_from_fork+0x29/0x50 This patch add mnt_want_write() above parent inode lock and remove nested mnt_want_write calls in smb2_open(). Fixes: 40b268d384a2 ("ksmbd: add mnt_want_write to ksmbd vfs functions") Cc: stable@vger.kernel.org Reported-by: Marios Makassikis <mmakassikis@freebox.fr> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
-rw-r--r--fs/smb/server/smb2pdu.c47
-rw-r--r--fs/smb/server/smbacl.c7
-rw-r--r--fs/smb/server/smbacl.h2
-rw-r--r--fs/smb/server/vfs.c68
-rw-r--r--fs/smb/server/vfs.h10
5 files changed, 75 insertions, 59 deletions
diff --git a/fs/smb/server/smb2pdu.c b/fs/smb/server/smb2pdu.c
index a89a69d752a3..b8340f1382be 100644
--- a/fs/smb/server/smb2pdu.c
+++ b/fs/smb/server/smb2pdu.c
@@ -2380,7 +2380,8 @@ static int smb2_set_ea(struct smb2_ea_info *eabuf, unsigned int buf_len,
rc = 0;
} else {
rc = ksmbd_vfs_setxattr(user_ns, path, attr_name, value,
- le16_to_cpu(eabuf->EaValueLength), 0);
+ le16_to_cpu(eabuf->EaValueLength),
+ 0, true);
if (rc < 0) {
ksmbd_debug(SMB,
"ksmbd_vfs_setxattr is failed(%d)\n",
@@ -2443,7 +2444,7 @@ static noinline int smb2_set_stream_name_xattr(const struct path *path,
return -EBADF;
}
- rc = ksmbd_vfs_setxattr(user_ns, path, xattr_stream_name, NULL, 0, 0);
+ rc = ksmbd_vfs_setxattr(user_ns, path, xattr_stream_name, NULL, 0, 0, false);
if (rc < 0)
pr_err("Failed to store XATTR stream name :%d\n", rc);
return 0;
@@ -2518,7 +2519,7 @@ static void smb2_new_xattrs(struct ksmbd_tree_connect *tcon, const struct path *
da.flags = XATTR_DOSINFO_ATTRIB | XATTR_DOSINFO_CREATE_TIME |
XATTR_DOSINFO_ITIME;
- rc = ksmbd_vfs_set_dos_attrib_xattr(mnt_user_ns(path->mnt), path, &da);
+ rc = ksmbd_vfs_set_dos_attrib_xattr(mnt_user_ns(path->mnt), path, &da, false);
if (rc)
ksmbd_debug(SMB, "failed to store file attribute into xattr\n");
}
@@ -2608,7 +2609,7 @@ static int smb2_create_sd_buffer(struct ksmbd_work *work,
sizeof(struct create_sd_buf_req))
return -EINVAL;
return set_info_sec(work->conn, work->tcon, path, &sd_buf->ntsd,
- le32_to_cpu(sd_buf->ccontext.DataLength), true);
+ le32_to_cpu(sd_buf->ccontext.DataLength), true, false);
}
static void ksmbd_acls_fattr(struct smb_fattr *fattr,
@@ -3152,7 +3153,8 @@ int smb2_open(struct ksmbd_work *work)
user_ns,
&path,
pntsd,
- pntsd_size);
+ pntsd_size,
+ false);
kfree(pntsd);
if (rc)
pr_err("failed to store ntacl in xattr : %d\n",
@@ -3228,12 +3230,6 @@ int smb2_open(struct ksmbd_work *work)
if (req->CreateOptions & FILE_DELETE_ON_CLOSE_LE)
ksmbd_fd_set_delete_on_close(fp, file_info);
- if (need_truncate) {
- rc = smb2_create_truncate(&path);
- if (rc)
- goto err_out;
- }
-
if (req->CreateContextsOffset) {
struct create_alloc_size_req *az_req;
@@ -3398,11 +3394,12 @@ int smb2_open(struct ksmbd_work *work)
}
err_out:
- if (file_present || created) {
- inode_unlock(d_inode(parent_path.dentry));
- path_put(&path);
- path_put(&parent_path);
- }
+ if (file_present || created)
+ ksmbd_vfs_kern_path_unlock(&parent_path, &path);
+
+ if (fp && need_truncate)
+ rc = smb2_create_truncate(&fp->filp->f_path);
+
ksmbd_revert_fsids(work);
err_out1:
if (!rc) {
@@ -5537,7 +5534,7 @@ static int smb2_rename(struct ksmbd_work *work,
rc = ksmbd_vfs_setxattr(file_mnt_user_ns(fp->filp),
&fp->filp->f_path,
xattr_stream_name,
- NULL, 0, 0);
+ NULL, 0, 0, true);
if (rc < 0) {
pr_err("failed to store stream name in xattr: %d\n",
rc);
@@ -5630,11 +5627,9 @@ static int smb2_create_link(struct ksmbd_work *work,
if (rc)
rc = -EINVAL;
out:
- if (file_present) {
- inode_unlock(d_inode(parent_path.dentry));
- path_put(&path);
- path_put(&parent_path);
- }
+ if (file_present)
+ ksmbd_vfs_kern_path_unlock(&parent_path, &path);
+
if (!IS_ERR(link_name))
kfree(link_name);
kfree(pathname);
@@ -5701,7 +5696,8 @@ static int set_file_basic_info(struct ksmbd_file *fp,
da.flags = XATTR_DOSINFO_ATTRIB | XATTR_DOSINFO_CREATE_TIME |
XATTR_DOSINFO_ITIME;
- rc = ksmbd_vfs_set_dos_attrib_xattr(user_ns, &filp->f_path, &da);
+ rc = ksmbd_vfs_set_dos_attrib_xattr(user_ns, &filp->f_path, &da,
+ true);
if (rc)
ksmbd_debug(SMB,
"failed to restore file attribute in EA\n");
@@ -6013,7 +6009,7 @@ static int smb2_set_info_sec(struct ksmbd_file *fp, int addition_info,
fp->saccess |= FILE_SHARE_DELETE_LE;
return set_info_sec(fp->conn, fp->tcon, &fp->filp->f_path, pntsd,
- buf_len, false);
+ buf_len, false, true);
}
/**
@@ -7583,7 +7579,8 @@ static inline int fsctl_set_sparse(struct ksmbd_work *work, u64 id,
da.attr = le32_to_cpu(fp->f_ci->m_fattr);
ret = ksmbd_vfs_set_dos_attrib_xattr(user_ns,
- &fp->filp->f_path, &da);
+ &fp->filp->f_path,
+ &da, true);
if (ret)
fp->f_ci->m_fattr = old_fattr;
}
diff --git a/fs/smb/server/smbacl.c b/fs/smb/server/smbacl.c
index 7a42728d8047..d9bbd2eb89c3 100644
--- a/fs/smb/server/smbacl.c
+++ b/fs/smb/server/smbacl.c
@@ -1185,7 +1185,7 @@ pass:
pntsd_size += sizeof(struct smb_acl) + nt_size;
}
- ksmbd_vfs_set_sd_xattr(conn, user_ns, path, pntsd, pntsd_size);
+ ksmbd_vfs_set_sd_xattr(conn, user_ns, path, pntsd, pntsd_size, false);
kfree(pntsd);
}
@@ -1377,7 +1377,7 @@ err_out:
int set_info_sec(struct ksmbd_conn *conn, struct ksmbd_tree_connect *tcon,
const struct path *path, struct smb_ntsd *pntsd, int ntsd_len,
- bool type_check)
+ bool type_check, bool get_write)
{
int rc;
struct smb_fattr fattr = {{0}};
@@ -1437,7 +1437,8 @@ int set_info_sec(struct ksmbd_conn *conn, struct ksmbd_tree_connect *tcon,
if (test_share_config_flag(tcon->share_conf, KSMBD_SHARE_FLAG_ACL_XATTR)) {
/* Update WinACL in xattr */
ksmbd_vfs_remove_sd_xattrs(user_ns, path);
- ksmbd_vfs_set_sd_xattr(conn, user_ns, path, pntsd, ntsd_len);
+ ksmbd_vfs_set_sd_xattr(conn, user_ns, path, pntsd, ntsd_len,
+ get_write);
}
out:
diff --git a/fs/smb/server/smbacl.h b/fs/smb/server/smbacl.h
index 618f2e0236b3..9651a2551888 100644
--- a/fs/smb/server/smbacl.h
+++ b/fs/smb/server/smbacl.h
@@ -207,7 +207,7 @@ int smb_check_perm_dacl(struct ksmbd_conn *conn, const struct path *path,
__le32 *pdaccess, int uid);
int set_info_sec(struct ksmbd_conn *conn, struct ksmbd_tree_connect *tcon,
const struct path *path, struct smb_ntsd *pntsd, int ntsd_len,
- bool type_check);
+ bool type_check, bool get_write);
void id_to_sid(unsigned int cid, uint sidtype, struct smb_sid *ssid);
void ksmbd_init_domain(u32 *sub_auth);
diff --git a/fs/smb/server/vfs.c b/fs/smb/server/vfs.c
index d4298a751d4a..08f3f66e4b38 100644
--- a/fs/smb/server/vfs.c
+++ b/fs/smb/server/vfs.c
@@ -98,6 +98,13 @@ static int ksmbd_vfs_path_lookup_locked(struct ksmbd_share_config *share_conf,
return -ENOENT;
}
+ err = mnt_want_write(parent_path->mnt);
+ if (err) {
+ path_put(parent_path);
+ putname(filename);
+ return -ENOENT;
+ }
+
inode_lock_nested(parent_path->dentry->d_inode, I_MUTEX_PARENT);
d = lookup_one_qstr_excl(&last, parent_path->dentry, 0);
if (IS_ERR(d))
@@ -124,6 +131,7 @@ static int ksmbd_vfs_path_lookup_locked(struct ksmbd_share_config *share_conf,
err_out:
inode_unlock(d_inode(parent_path->dentry));
+ mnt_drop_write(parent_path->mnt);
path_put(parent_path);
putname(filename);
return -ENOENT;
@@ -452,7 +460,8 @@ static int ksmbd_vfs_stream_write(struct ksmbd_file *fp, char *buf, loff_t *pos,
fp->stream.name,
(void *)stream_buf,
size,
- 0);
+ 0,
+ true);
if (err < 0)
goto out;
@@ -594,10 +603,6 @@ int ksmbd_vfs_remove_file(struct ksmbd_work *work, const struct path *path)
goto out_err;
}
- err = mnt_want_write(path->mnt);
- if (err)
- goto out_err;
-
user_ns = mnt_user_ns(path->mnt);
if (S_ISDIR(d_inode(path->dentry)->i_mode)) {
err = vfs_rmdir(user_ns, d_inode(parent), path->dentry);
@@ -608,7 +613,6 @@ int ksmbd_vfs_remove_file(struct ksmbd_work *work, const struct path *path)
if (err)
ksmbd_debug(VFS, "unlink failed, err %d\n", err);
}
- mnt_drop_write(path->mnt);
out_err:
ksmbd_revert_fsids(work);
@@ -908,18 +912,22 @@ ssize_t ksmbd_vfs_getxattr(struct user_namespace *user_ns,
* @attr_value: xattr value to set
* @attr_size: size of xattr value
* @flags: destination buffer length
+ * @get_write: get write access to a mount
*
* Return: 0 on success, otherwise error
*/
int ksmbd_vfs_setxattr(struct user_namespace *user_ns,
const struct path *path, const char *attr_name,
- void *attr_value, size_t attr_size, int flags)
+ void *attr_value, size_t attr_size, int flags,
+ bool get_write)
{
int err;
- err = mnt_want_write(path->mnt);
- if (err)
- return err;
+ if (get_write == true) {
+ err = mnt_want_write(path->mnt);
+ if (err)
+ return err;
+ }
err = vfs_setxattr(user_ns,
path->dentry,
@@ -929,7 +937,8 @@ int ksmbd_vfs_setxattr(struct user_namespace *user_ns,
flags);
if (err)
ksmbd_debug(VFS, "setxattr failed, err %d\n", err);
- mnt_drop_write(path->mnt);
+ if (get_write == true)
+ mnt_drop_write(path->mnt);
return err;
}
@@ -1253,6 +1262,13 @@ out1:
}
if (!err) {
+ err = mnt_want_write(parent_path->mnt);
+ if (err) {
+ path_put(path);
+ path_put(parent_path);
+ return err;
+ }
+
err = ksmbd_vfs_lock_parent(parent_path->dentry, path->dentry);
if (err) {
path_put(path);
@@ -1262,6 +1278,14 @@ out1:
return err;
}
+void ksmbd_vfs_kern_path_unlock(struct path *parent_path, struct path *path)
+{
+ inode_unlock(d_inode(parent_path->dentry));
+ mnt_drop_write(parent_path->mnt);
+ path_put(path);
+ path_put(parent_path);
+}
+
struct dentry *ksmbd_vfs_kern_path_create(struct ksmbd_work *work,
const char *name,
unsigned int flags,
@@ -1411,7 +1435,8 @@ out:
int ksmbd_vfs_set_sd_xattr(struct ksmbd_conn *conn,
struct user_namespace *user_ns,
const struct path *path,
- struct smb_ntsd *pntsd, int len)
+ struct smb_ntsd *pntsd, int len,
+ bool get_write)
{
int rc;
struct ndr sd_ndr = {0}, acl_ndr = {0};
@@ -1471,7 +1496,7 @@ int ksmbd_vfs_set_sd_xattr(struct ksmbd_conn *conn,
rc = ksmbd_vfs_setxattr(user_ns, path,
XATTR_NAME_SD, sd_ndr.data,
- sd_ndr.offset, 0);
+ sd_ndr.offset, 0, get_write);
if (rc < 0)
pr_err("Failed to store XATTR ntacl :%d\n", rc);
@@ -1560,7 +1585,8 @@ free_n_data:
int ksmbd_vfs_set_dos_attrib_xattr(struct user_namespace *user_ns,
const struct path *path,
- struct xattr_dos_attrib *da)
+ struct xattr_dos_attrib *da,
+ bool get_write)
{
struct ndr n;
int err;
@@ -1570,7 +1596,7 @@ int ksmbd_vfs_set_dos_attrib_xattr(struct user_namespace *user_ns,
return err;
err = ksmbd_vfs_setxattr(user_ns, path, XATTR_NAME_DOS_ATTRIBUTE,
- (void *)n.data, n.offset, 0);
+ (void *)n.data, n.offset, 0, get_write);
if (err)
ksmbd_debug(SMB, "failed to store dos attribute in xattr\n");
kfree(n.data);
@@ -1840,10 +1866,6 @@ int ksmbd_vfs_set_init_posix_acl(struct user_namespace *user_ns,
}
posix_state_to_acl(&acl_state, acls->a_entries);
- rc = mnt_want_write(path->mnt);
- if (rc)
- goto out_err;
-
rc = set_posix_acl(user_ns, inode, ACL_TYPE_ACCESS, acls);
if (rc < 0)
ksmbd_debug(SMB, "Set posix acl(ACL_TYPE_ACCESS) failed, rc : %d\n",
@@ -1856,9 +1878,7 @@ int ksmbd_vfs_set_init_posix_acl(struct user_namespace *user_ns,
ksmbd_debug(SMB, "Set posix acl(ACL_TYPE_DEFAULT) failed, rc : %d\n",
rc);
}
- mnt_drop_write(path->mnt);
-out_err:
free_acl_state(&acl_state);
posix_acl_release(acls);
return rc;
@@ -1887,10 +1907,6 @@ int ksmbd_vfs_inherit_posix_acl(struct user_namespace *user_ns,
}
}
- rc = mnt_want_write(path->mnt);
- if (rc)
- goto out_err;
-
rc = set_posix_acl(user_ns, inode, ACL_TYPE_ACCESS, acls);
if (rc < 0)
ksmbd_debug(SMB, "Set posix acl(ACL_TYPE_ACCESS) failed, rc : %d\n",
@@ -1902,9 +1918,7 @@ int ksmbd_vfs_inherit_posix_acl(struct user_namespace *user_ns,
ksmbd_debug(SMB, "Set posix acl(ACL_TYPE_DEFAULT) failed, rc : %d\n",
rc);
}
- mnt_drop_write(path->mnt);
-out_err:
posix_acl_release(acls);
return rc;
}
diff --git a/fs/smb/server/vfs.h b/fs/smb/server/vfs.h
index 93799ca4cc34..e761dde2443e 100644
--- a/fs/smb/server/vfs.h
+++ b/fs/smb/server/vfs.h
@@ -109,7 +109,8 @@ ssize_t ksmbd_vfs_casexattr_len(struct user_namespace *user_ns,
int attr_name_len);
int ksmbd_vfs_setxattr(struct user_namespace *user_ns,
const struct path *path, const char *attr_name,
- void *attr_value, size_t attr_size, int flags);
+ void *attr_value, size_t attr_size, int flags,
+ bool get_write);
int ksmbd_vfs_xattr_stream_name(char *stream_name, char **xattr_stream_name,
size_t *xattr_stream_name_size, int s_type);
int ksmbd_vfs_remove_xattr(struct user_namespace *user_ns,
@@ -117,6 +118,7 @@ int ksmbd_vfs_remove_xattr(struct user_namespace *user_ns,
int ksmbd_vfs_kern_path_locked(struct ksmbd_work *work, char *name,
unsigned int flags, struct path *parent_path,
struct path *path, bool caseless);
+void ksmbd_vfs_kern_path_unlock(struct path *parent_path, struct path *path);
struct dentry *ksmbd_vfs_kern_path_create(struct ksmbd_work *work,
const char *name,
unsigned int flags,
@@ -144,14 +146,16 @@ int ksmbd_vfs_remove_sd_xattrs(struct user_namespace *user_ns, const struct path
int ksmbd_vfs_set_sd_xattr(struct ksmbd_conn *conn,
struct user_namespace *user_ns,
const struct path *path,
- struct smb_ntsd *pntsd, int len);
+ struct smb_ntsd *pntsd, int len,
+ bool get_write);
int ksmbd_vfs_get_sd_xattr(struct ksmbd_conn *conn,
struct user_namespace *user_ns,
struct dentry *dentry,
struct smb_ntsd **pntsd);
int ksmbd_vfs_set_dos_attrib_xattr(struct user_namespace *user_ns,
const struct path *path,
- struct xattr_dos_attrib *da);
+ struct xattr_dos_attrib *da,
+ bool get_write);
int ksmbd_vfs_get_dos_attrib_xattr(struct user_namespace *user_ns,
struct dentry *dentry,
struct xattr_dos_attrib *da);