6.1-stable review patch. If anyone has any objections, please let me know.
------------------
From: Paulo Alcantara <pc@xxxxxxxxxxxxx>
commit a8f68b11158f09754418de62e6b3e7b9b7a50cc9 upstream.
Validate next header's offset in ->next_header() so that it isn't
smaller than MID_HEADER_SIZE(server) and then standard_receive3() or
->receive() ends up writing off the end of the buffer because
'pdu_length - MID_HEADER_SIZE(server)' wraps up to a huge length:
BUG: KASAN: slab-out-of-bounds in _copy_to_iter+0x4fc/0x840
Write of size 701 at addr ffff88800caf407f by task cifsd/1090
CPU: 0 PID: 1090 Comm: cifsd Not tainted 6.7.0-rc4 #5
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS
rel-1.16.2-3-gd478f380-rebuilt.opensuse.org 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0x4a/0x80
print_report+0xcf/0x650
? srso_alias_return_thunk+0x5/0xfbef5
? srso_alias_return_thunk+0x5/0xfbef5
? __phys_addr+0x46/0x90
kasan_report+0xd8/0x110
? _copy_to_iter+0x4fc/0x840
? _copy_to_iter+0x4fc/0x840
kasan_check_range+0x105/0x1b0
__asan_memcpy+0x3c/0x60
_copy_to_iter+0x4fc/0x840
? srso_alias_return_thunk+0x5/0xfbef5
? hlock_class+0x32/0xc0
? srso_alias_return_thunk+0x5/0xfbef5
? __pfx__copy_to_iter+0x10/0x10
? srso_alias_return_thunk+0x5/0xfbef5
? lock_is_held_type+0x90/0x100
? srso_alias_return_thunk+0x5/0xfbef5
? __might_resched+0x278/0x360
? __pfx___might_resched+0x10/0x10
? srso_alias_return_thunk+0x5/0xfbef5
__skb_datagram_iter+0x2c2/0x460
? __pfx_simple_copy_to_iter+0x10/0x10
skb_copy_datagram_iter+0x6c/0x110
tcp_recvmsg_locked+0x9be/0xf40
? __pfx_tcp_recvmsg_locked+0x10/0x10
? mark_held_locks+0x5d/0x90
? srso_alias_return_thunk+0x5/0xfbef5
tcp_recvmsg+0xe2/0x310
? __pfx_tcp_recvmsg+0x10/0x10
? srso_alias_return_thunk+0x5/0xfbef5
? srso_alias_return_thunk+0x5/0xfbef5
? lock_acquire+0x14a/0x3a0
? srso_alias_return_thunk+0x5/0xfbef5
inet_recvmsg+0xd0/0x370
? __pfx_inet_recvmsg+0x10/0x10
? __pfx_lock_release+0x10/0x10
? do_raw_spin_trylock+0xd1/0x120
sock_recvmsg+0x10d/0x150
cifs_readv_from_socket+0x25a/0x490 [cifs]
? __pfx_cifs_readv_from_socket+0x10/0x10 [cifs]
? srso_alias_return_thunk+0x5/0xfbef5
cifs_read_from_socket+0xb5/0x100 [cifs]
? __pfx_cifs_read_from_socket+0x10/0x10 [cifs]
? __pfx_lock_release+0x10/0x10
? do_raw_spin_trylock+0xd1/0x120
? _raw_spin_unlock+0x23/0x40
? srso_alias_return_thunk+0x5/0xfbef5
? __smb2_find_mid+0x126/0x230 [cifs]
cifs_demultiplex_thread+0xd39/0x1270 [cifs]
? __pfx_cifs_demultiplex_thread+0x10/0x10 [cifs]
? __pfx_lock_release+0x10/0x10
? srso_alias_return_thunk+0x5/0xfbef5
? mark_held_locks+0x1a/0x90
? lockdep_hardirqs_on_prepare+0x136/0x210
? srso_alias_return_thunk+0x5/0xfbef5
? srso_alias_return_thunk+0x5/0xfbef5
? __kthread_parkme+0xce/0xf0
? __pfx_cifs_demultiplex_thread+0x10/0x10 [cifs]
kthread+0x18d/0x1d0
? kthread+0xdb/0x1d0
? __pfx_kthread+0x10/0x10
ret_from_fork+0x34/0x60
? __pfx_kthread+0x10/0x10
ret_from_fork_asm+0x1b/0x30
</TASK>
Fixes: 8ce79ec359ad ("cifs: update multiplex loop to handle compounded responses")
Cc: stable@xxxxxxxxxxxxxxx
Reported-by: Robert Morris <rtm@xxxxxxxxxxxxx>
Signed-off-by: Paulo Alcantara (SUSE) <pc@xxxxxxxxxxxxx>
Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/smb/client/cifsglob.h | 3 ++-
fs/smb/client/connect.c | 7 ++++++-
fs/smb/client/smb2ops.c | 19 ++++++++++++-------
3 files changed, 20 insertions(+), 9 deletions(-)
--- a/fs/smb/client/cifsglob.h
+++ b/fs/smb/client/cifsglob.h
@@ -513,7 +513,8 @@ struct smb_version_operations {
struct mid_q_entry **, char **, int *);
enum securityEnum (*select_sectype)(struct TCP_Server_Info *,
enum securityEnum);
- int (*next_header)(char *);
+ int (*next_header)(struct TCP_Server_Info *server, char *buf,
+ unsigned int *noff);
/* ioctl passthrough for query_info */
int (*ioctl_query_info)(const unsigned int xid,
struct cifs_tcon *tcon,
--- a/fs/smb/client/connect.c
+++ b/fs/smb/client/connect.c
@@ -1225,7 +1225,12 @@ next_pdu:
server->total_read += length;
if (server->ops->next_header) {
- next_offset = server->ops->next_header(buf);
+ if (server->ops->next_header(server, buf, &next_offset)) {
+ cifs_dbg(VFS, "%s: malformed response (next_offset=%u)\n",
+ __func__, next_offset);
+ cifs_reconnect(server, true);
+ continue;
+ }
if (next_offset)
server->pdu_size = next_offset;
}
--- a/fs/smb/client/smb2ops.c
+++ b/fs/smb/client/smb2ops.c
@@ -5196,17 +5196,22 @@ smb3_handle_read_data(struct TCP_Server_
NULL, 0, 0, false);
}
-static int
-smb2_next_header(char *buf)
+static int smb2_next_header(struct TCP_Server_Info *server, char *buf,
+ unsigned int *noff)
{
struct smb2_hdr *hdr = (struct smb2_hdr *)buf;
struct smb2_transform_hdr *t_hdr = (struct smb2_transform_hdr *)buf;
- if (hdr->ProtocolId == SMB2_TRANSFORM_PROTO_NUM)
- return sizeof(struct smb2_transform_hdr) +
- le32_to_cpu(t_hdr->OriginalMessageSize);
-
- return le32_to_cpu(hdr->NextCommand);
+ if (hdr->ProtocolId == SMB2_TRANSFORM_PROTO_NUM) {
+ *noff = le32_to_cpu(t_hdr->OriginalMessageSize);
+ if (unlikely(check_add_overflow(*noff, sizeof(*t_hdr), noff)))
+ return -EINVAL;
+ } else {
+ *noff = le32_to_cpu(hdr->NextCommand);
+ }
+ if (unlikely(*noff && *noff < MID_HEADER_SIZE(server)))
+ return -EINVAL;
+ return 0;
}
static int
