* [PATCH 3/4] ksmbd: add validation for ndr read/write functions
2021-09-01 0:45 [PATCH 1/4] ksmbd: Reduce error log 'speed is unknown' to debug Namjae Jeon
2021-09-01 0:45 ` [PATCH 2/4] ksmbd: smbd: fix dma mapping error in smb_direct_post_send_data Namjae Jeon
@ 2021-09-01 0:45 ` Namjae Jeon
2021-09-01 10:22 ` Dan Carpenter
2021-09-01 0:45 ` [PATCH 4/4] ksmbd: remove unused ksmbd_file_table_flush function Namjae Jeon
2 siblings, 1 reply; 6+ messages in thread
From: Namjae Jeon @ 2021-09-01 0:45 UTC (permalink / raw)
To: linux-cifs; +Cc: Namjae Jeon, Dan Carpenter
If ndr->length is smaller than expected size, ksmbd can access invalid
access in ndr->data. This patch add validation to check ndr->offset is
over ndr->length. and added exception handling to check return value of
ndr read/write function.
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
---
fs/ksmbd/ndr.c | 382 +++++++++++++++++++++++++++++++++++--------------
1 file changed, 273 insertions(+), 109 deletions(-)
diff --git a/fs/ksmbd/ndr.c b/fs/ksmbd/ndr.c
index e6a574fa7709..aefdea744f73 100644
--- a/fs/ksmbd/ndr.c
+++ b/fs/ksmbd/ndr.c
@@ -28,37 +28,60 @@ static int try_to_realloc_ndr_blob(struct ndr *n, size_t sz)
return 0;
}
-static void ndr_write_int16(struct ndr *n, __u16 value)
+static int ndr_write_int16(struct ndr *n, __u16 value)
{
- if (n->length <= n->offset + sizeof(value))
- try_to_realloc_ndr_blob(n, sizeof(value));
+ if (n->length <= n->offset + sizeof(value)) {
+ int ret;
+
+ ret = try_to_realloc_ndr_blob(n, sizeof(value));
+ if (ret)
+ return ret;
+ }
*(__le16 *)ndr_get_field(n) = cpu_to_le16(value);
n->offset += sizeof(value);
+ return 0;
}
-static void ndr_write_int32(struct ndr *n, __u32 value)
+static int ndr_write_int32(struct ndr *n, __u32 value)
{
- if (n->length <= n->offset + sizeof(value))
- try_to_realloc_ndr_blob(n, sizeof(value));
+ if (n->length <= n->offset + sizeof(value)) {
+ int ret;
+
+ ret = try_to_realloc_ndr_blob(n, sizeof(value));
+ if (ret)
+ return ret;
+ }
*(__le32 *)ndr_get_field(n) = cpu_to_le32(value);
n->offset += sizeof(value);
+ return 0;
}
-static void ndr_write_int64(struct ndr *n, __u64 value)
+static int ndr_write_int64(struct ndr *n, __u64 value)
{
- if (n->length <= n->offset + sizeof(value))
- try_to_realloc_ndr_blob(n, sizeof(value));
+ if (n->length <= n->offset + sizeof(value)) {
+ int ret;
+
+ ret = try_to_realloc_ndr_blob(n, sizeof(value));
+ if (ret)
+ return ret;
+ }
*(__le64 *)ndr_get_field(n) = cpu_to_le64(value);
n->offset += sizeof(value);
+ return 0;
}
static int ndr_write_bytes(struct ndr *n, void *value, size_t sz)
{
- if (n->length <= n->offset + sz)
- try_to_realloc_ndr_blob(n, sz);
+ if (n->length <= n->offset + sz) {
+ int ret;
+
+ ret = try_to_realloc_ndr_blob(n, sz);
+ if (ret)
+ return ret;
+ }
memcpy(ndr_get_field(n), value, sz);
n->offset += sz;
@@ -70,8 +93,13 @@ static int ndr_write_string(struct ndr *n, char *value)
size_t sz;
sz = strlen(value) + 1;
- if (n->length <= n->offset + sz)
- try_to_realloc_ndr_blob(n, sz);
+ if (n->length <= n->offset + sz) {
+ int ret;
+
+ ret = try_to_realloc_ndr_blob(n, sz);
+ if (ret)
+ return ret;
+ }
memcpy(ndr_get_field(n), value, sz);
n->offset += sz;
@@ -81,9 +109,14 @@ static int ndr_write_string(struct ndr *n, char *value)
static int ndr_read_string(struct ndr *n, void *value, size_t sz)
{
- int len = strnlen(ndr_get_field(n), sz);
+ int len;
- memcpy(value, ndr_get_field(n), len);
+ if (n->offset + sz > n->length)
+ return -EINVAL;
+
+ len = strnlen(ndr_get_field(n), sz);
+ if (value)
+ memcpy(value, ndr_get_field(n), len);
len++;
n->offset += len;
n->offset = ALIGN(n->offset, 2);
@@ -92,41 +125,52 @@ static int ndr_read_string(struct ndr *n, void *value, size_t sz)
static int ndr_read_bytes(struct ndr *n, void *value, size_t sz)
{
- memcpy(value, ndr_get_field(n), sz);
+ if (n->offset + sz > n->length)
+ return -EINVAL;
+
+ if (value)
+ memcpy(value, ndr_get_field(n), sz);
n->offset += sz;
return 0;
}
-static __u16 ndr_read_int16(struct ndr *n)
+static int ndr_read_int16(struct ndr *n, __u16 *value)
{
- __u16 ret;
+ if (n->offset + sizeof(__u16) > n->length)
+ return -EINVAL;
- ret = le16_to_cpu(*(__le16 *)ndr_get_field(n));
+ if (value)
+ *value = le16_to_cpu(*(__le16 *)ndr_get_field(n));
n->offset += sizeof(__u16);
- return ret;
+ return 0;
}
-static __u32 ndr_read_int32(struct ndr *n)
+static int ndr_read_int32(struct ndr *n, __u32 *value)
{
- __u32 ret;
+ if (n->offset + sizeof(__u32) > n->length)
+ return 0;
- ret = le32_to_cpu(*(__le32 *)ndr_get_field(n));
+ if (value)
+ *value = le32_to_cpu(*(__le32 *)ndr_get_field(n));
n->offset += sizeof(__u32);
- return ret;
+ return 0;
}
-static __u64 ndr_read_int64(struct ndr *n)
+static int ndr_read_int64(struct ndr *n, __u64 *value)
{
- __u64 ret;
+ if (n->offset + sizeof(__u64) > n->length)
+ return -EINVAL;
- ret = le64_to_cpu(*(__le64 *)ndr_get_field(n));
+ if (value)
+ *value = le64_to_cpu(*(__le64 *)ndr_get_field(n));
n->offset += sizeof(__u64);
- return ret;
+ return 0;
}
int ndr_encode_dos_attr(struct ndr *n, struct xattr_dos_attrib *da)
{
char hex_attr[12] = {0};
+ int ret;
n->offset = 0;
n->length = 1024;
@@ -136,97 +180,160 @@ int ndr_encode_dos_attr(struct ndr *n, struct xattr_dos_attrib *da)
if (da->version == 3) {
snprintf(hex_attr, 10, "0x%x", da->attr);
- ndr_write_string(n, hex_attr);
+ ret = ndr_write_string(n, hex_attr);
} else {
- ndr_write_string(n, "");
+ ret = ndr_write_string(n, "");
}
- ndr_write_int16(n, da->version);
- ndr_write_int32(n, da->version);
+ if (ret)
+ return ret;
+
+ ret = ndr_write_int16(n, da->version);
+ if (ret)
+ return ret;
+
+ ret = ndr_write_int32(n, da->version);
+ if (ret)
+ return ret;
+
+ ret = ndr_write_int32(n, da->flags);
+ if (ret)
+ return ret;
+
+ ret = ndr_write_int32(n, da->attr);
+ if (ret)
+ return ret;
- ndr_write_int32(n, da->flags);
- ndr_write_int32(n, da->attr);
if (da->version == 3) {
- ndr_write_int32(n, da->ea_size);
- ndr_write_int64(n, da->size);
- ndr_write_int64(n, da->alloc_size);
+ ret = ndr_write_int32(n, da->ea_size);
+ if (ret)
+ return ret;
+ ret = ndr_write_int64(n, da->size);
+ if (ret)
+ return ret;
+ ret = ndr_write_int64(n, da->alloc_size);
} else {
- ndr_write_int64(n, da->itime);
+ ret = ndr_write_int64(n, da->itime);
}
- ndr_write_int64(n, da->create_time);
+ if (ret)
+ return ret;
+
+ ret = ndr_write_int64(n, da->create_time);
+ if (ret)
+ return ret;
+
if (da->version == 3)
- ndr_write_int64(n, da->change_time);
- return 0;
+ ret = ndr_write_int64(n, da->change_time);
+ return ret;
}
int ndr_decode_dos_attr(struct ndr *n, struct xattr_dos_attrib *da)
{
- char *hex_attr;
- int version2;
-
- hex_attr = kzalloc(n->length, GFP_KERNEL);
- if (!hex_attr)
- return -ENOMEM;
+ char hex_attr[12];
+ unsigned int version2, ret;
n->offset = 0;
- ndr_read_string(n, hex_attr, n->length);
- kfree(hex_attr);
- da->version = ndr_read_int16(n);
+ ret = ndr_read_string(n, hex_attr, sizeof(hex_attr));
+ if (ret)
+ return ret;
+
+ ret = ndr_read_int16(n, &da->version);
+ if (ret)
+ return ret;
if (da->version != 3 && da->version != 4) {
pr_err("v%d version is not supported\n", da->version);
return -EINVAL;
}
- version2 = ndr_read_int32(n);
+ ret = ndr_read_int32(n, &version2);
+ if (ret)
+ return ret;
+
if (da->version != version2) {
pr_err("ndr version mismatched(version: %d, version2: %d)\n",
da->version, version2);
return -EINVAL;
}
- ndr_read_int32(n);
- da->attr = ndr_read_int32(n);
+ ret = ndr_read_int32(n, NULL);
+ if (ret)
+ return ret;
+
+ ret = ndr_read_int32(n, &da->attr);
+ if (ret)
+ return ret;
+
if (da->version == 4) {
- da->itime = ndr_read_int64(n);
- da->create_time = ndr_read_int64(n);
+ ret = ndr_read_int64(n, &da->itime);
+ if (ret)
+ return ret;
+
+ ret = ndr_read_int64(n, &da->create_time);
} else {
- ndr_read_int32(n);
- ndr_read_int64(n);
- ndr_read_int64(n);
- da->create_time = ndr_read_int64(n);
- ndr_read_int64(n);
+ ret = ndr_read_int32(n, NULL);
+ if (ret)
+ return ret;
+
+ ndr_read_int64(n, NULL);
+ if (ret)
+ return ret;
+
+ ndr_read_int64(n, NULL);
+ if (ret)
+ return ret;
+
+ ret = ndr_read_int64(n, &da->create_time);
+ if (ret)
+ return ret;
+
+ ret = ndr_read_int64(n, NULL);
}
- return 0;
+ return ret;
}
static int ndr_encode_posix_acl_entry(struct ndr *n, struct xattr_smb_acl *acl)
{
- int i;
+ int i, ret;
+
+ ret = ndr_write_int32(n, acl->count);
+ if (ret)
+ return ret;
- ndr_write_int32(n, acl->count);
n->offset = ALIGN(n->offset, 8);
- ndr_write_int32(n, acl->count);
- ndr_write_int32(n, 0);
+ ret = ndr_write_int32(n, acl->count);
+ if (ret)
+ return ret;
+
+ ret = ndr_write_int32(n, 0);
+ if (ret)
+ return ret;
for (i = 0; i < acl->count; i++) {
n->offset = ALIGN(n->offset, 8);
- ndr_write_int16(n, acl->entries[i].type);
- ndr_write_int16(n, acl->entries[i].type);
+ ret = ndr_write_int16(n, acl->entries[i].type);
+ if (ret)
+ return ret;
+
+ ret = ndr_write_int16(n, acl->entries[i].type);
+ if (ret)
+ return ret;
if (acl->entries[i].type == SMB_ACL_USER) {
n->offset = ALIGN(n->offset, 8);
- ndr_write_int64(n, acl->entries[i].uid);
+ ret = ndr_write_int64(n, acl->entries[i].uid);
} else if (acl->entries[i].type == SMB_ACL_GROUP) {
n->offset = ALIGN(n->offset, 8);
- ndr_write_int64(n, acl->entries[i].gid);
+ ret = ndr_write_int64(n, acl->entries[i].gid);
}
+ if (ret)
+ return ret;
/* push permission */
- ndr_write_int32(n, acl->entries[i].perm);
+ ret = ndr_write_int32(n, acl->entries[i].perm);
}
- return 0;
+ return ret;
}
int ndr_encode_posix_acl(struct ndr *n,
@@ -235,7 +342,8 @@ int ndr_encode_posix_acl(struct ndr *n,
struct xattr_smb_acl *acl,
struct xattr_smb_acl *def_acl)
{
- int ref_id = 0x00020000;
+ unsigned int ref_id = 0x00020000;
+ int ret;
n->offset = 0;
n->length = 1024;
@@ -245,35 +353,46 @@ int ndr_encode_posix_acl(struct ndr *n,
if (acl) {
/* ACL ACCESS */
- ndr_write_int32(n, ref_id);
+ ret = ndr_write_int32(n, ref_id);
ref_id += 4;
} else {
- ndr_write_int32(n, 0);
+ ret = ndr_write_int32(n, 0);
}
+ if (ret)
+ return ret;
if (def_acl) {
/* DEFAULT ACL ACCESS */
- ndr_write_int32(n, ref_id);
+ ret = ndr_write_int32(n, ref_id);
ref_id += 4;
} else {
- ndr_write_int32(n, 0);
+ ret = ndr_write_int32(n, 0);
}
-
- ndr_write_int64(n, from_kuid(&init_user_ns, i_uid_into_mnt(user_ns, inode)));
- ndr_write_int64(n, from_kgid(&init_user_ns, i_gid_into_mnt(user_ns, inode)));
- ndr_write_int32(n, inode->i_mode);
+ if (ret)
+ return ret;
+
+ ret = ndr_write_int64(n, from_kuid(&init_user_ns, i_uid_into_mnt(user_ns, inode)));
+ if (ret)
+ return ret;
+ ret = ndr_write_int64(n, from_kgid(&init_user_ns, i_gid_into_mnt(user_ns, inode)));
+ if (ret)
+ return ret;
+ ret = ndr_write_int32(n, inode->i_mode);
+ if (ret)
+ return ret;
if (acl) {
- ndr_encode_posix_acl_entry(n, acl);
- if (def_acl)
- ndr_encode_posix_acl_entry(n, def_acl);
+ ret = ndr_encode_posix_acl_entry(n, acl);
+ if (def_acl && !ret)
+ ret = ndr_encode_posix_acl_entry(n, def_acl);
}
- return 0;
+ return ret;
}
int ndr_encode_v4_ntacl(struct ndr *n, struct xattr_ntacl *acl)
{
- int ref_id = 0x00020004;
+ unsigned int ref_id = 0x00020004;
+ int ret;
n->offset = 0;
n->length = 2048;
@@ -281,36 +400,65 @@ int ndr_encode_v4_ntacl(struct ndr *n, struct xattr_ntacl *acl)
if (!n->data)
return -ENOMEM;
- ndr_write_int16(n, acl->version);
- ndr_write_int32(n, acl->version);
- ndr_write_int16(n, 2);
- ndr_write_int32(n, ref_id);
+ ret = ndr_write_int16(n, acl->version);
+ if (ret)
+ return ret;
+
+ ret = ndr_write_int32(n, acl->version);
+ if (ret)
+ return ret;
+
+ ret = ndr_write_int16(n, 2);
+ if (ret)
+ return ret;
+
+ ret = ndr_write_int32(n, ref_id);
+ if (ret)
+ return ret;
/* push hash type and hash 64bytes */
- ndr_write_int16(n, acl->hash_type);
- ndr_write_bytes(n, acl->hash, XATTR_SD_HASH_SIZE);
- ndr_write_bytes(n, acl->desc, acl->desc_len);
- ndr_write_int64(n, acl->current_time);
- ndr_write_bytes(n, acl->posix_acl_hash, XATTR_SD_HASH_SIZE);
+ ret = ndr_write_int16(n, acl->hash_type);
+ if (ret)
+ return ret;
- /* push ndr for security descriptor */
- ndr_write_bytes(n, acl->sd_buf, acl->sd_size);
+ ret = ndr_write_bytes(n, acl->hash, XATTR_SD_HASH_SIZE);
+ if (ret)
+ return ret;
- return 0;
+ ret = ndr_write_bytes(n, acl->desc, acl->desc_len);
+ if (ret)
+ return ret;
+
+ ret = ndr_write_int64(n, acl->current_time);
+ if (ret)
+ return ret;
+
+ ret = ndr_write_bytes(n, acl->posix_acl_hash, XATTR_SD_HASH_SIZE);
+ if (ret)
+ return ret;
+
+ /* push ndr for security descriptor */
+ ret = ndr_write_bytes(n, acl->sd_buf, acl->sd_size);
+ return ret;
}
int ndr_decode_v4_ntacl(struct ndr *n, struct xattr_ntacl *acl)
{
- int version2;
+ unsigned int version2;
+ int ret;
n->offset = 0;
- acl->version = ndr_read_int16(n);
+ ret = ndr_read_int16(n, &acl->version);
+ if (ret)
+ return ret;
if (acl->version != 4) {
pr_err("v%d version is not supported\n", acl->version);
return -EINVAL;
}
- version2 = ndr_read_int32(n);
+ ret = ndr_read_int32(n, &version2);
+ if (ret)
+ return ret;
if (acl->version != version2) {
pr_err("ndr version mismatched(version: %d, version2: %d)\n",
acl->version, version2);
@@ -318,11 +466,22 @@ int ndr_decode_v4_ntacl(struct ndr *n, struct xattr_ntacl *acl)
}
/* Read Level */
- ndr_read_int16(n);
+ ret = ndr_read_int16(n, NULL);
+ if (ret)
+ return ret;
+
/* Read Ref Id */
- ndr_read_int32(n);
- acl->hash_type = ndr_read_int16(n);
- ndr_read_bytes(n, acl->hash, XATTR_SD_HASH_SIZE);
+ ret = ndr_read_int32(n, NULL);
+ if (ret)
+ return ret;
+
+ ret = ndr_read_int16(n, &acl->hash_type);
+ if (ret)
+ return ret;
+
+ ret = ndr_read_bytes(n, acl->hash, XATTR_SD_HASH_SIZE);
+ if (ret)
+ return ret;
ndr_read_bytes(n, acl->desc, 10);
if (strncmp(acl->desc, "posix_acl", 9)) {
@@ -331,15 +490,20 @@ int ndr_decode_v4_ntacl(struct ndr *n, struct xattr_ntacl *acl)
}
/* Read Time */
- ndr_read_int64(n);
+ ret = ndr_read_int64(n, NULL);
+ if (ret)
+ return ret;
+
/* Read Posix ACL hash */
- ndr_read_bytes(n, acl->posix_acl_hash, XATTR_SD_HASH_SIZE);
+ ret = ndr_read_bytes(n, acl->posix_acl_hash, XATTR_SD_HASH_SIZE);
+ if (ret)
+ return ret;
+
acl->sd_size = n->length - n->offset;
acl->sd_buf = kzalloc(acl->sd_size, GFP_KERNEL);
if (!acl->sd_buf)
return -ENOMEM;
- ndr_read_bytes(n, acl->sd_buf, acl->sd_size);
-
- return 0;
+ ret = ndr_read_bytes(n, acl->sd_buf, acl->sd_size);
+ return ret;
}
--
2.25.1
^ permalink raw reply related [flat|nested] 6+ messages in thread