diff mbox series

[v1] ksmbd: fix global oob in ksmbd_nl_policy

Message ID 20240121073506.84528-1-linma@zju.edu.cn
State New
Headers
Series [v1] ksmbd: fix global oob in ksmbd_nl_policy |

Commit Message

Lin Ma Jan. 21, 2024, 7:35 a.m. UTC 
  Similar to a reported issue (check the commit b33fb5b801c6 ("net:
qualcomm: rmnet: fix global oob in rmnet_policy"), my local fuzzer finds
another global out-of-bounds read for policy ksmbd_nl_policy. See bug
trace below:

==================================================================
BUG: KASAN: global-out-of-bounds in validate_nla lib/nlattr.c:386 [inline]
BUG: KASAN: global-out-of-bounds in __nla_validate_parse+0x24af/0x2750 lib/nlattr.c:600
Read of size 1 at addr ffffffff8f24b100 by task syz-executor.1/62810

CPU: 0 PID: 62810 Comm: syz-executor.1 Tainted: G                 N 6.1.0 #3
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x8b/0xb3 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:284 [inline]
 print_report+0x172/0x475 mm/kasan/report.c:395
 kasan_report+0xbb/0x1c0 mm/kasan/report.c:495
 validate_nla lib/nlattr.c:386 [inline]
 __nla_validate_parse+0x24af/0x2750 lib/nlattr.c:600
 __nla_parse+0x3e/0x50 lib/nlattr.c:697
 __nlmsg_parse include/net/netlink.h:748 [inline]
 genl_family_rcv_msg_attrs_parse.constprop.0+0x1b0/0x290 net/netlink/genetlink.c:565
 genl_family_rcv_msg_doit+0xda/0x330 net/netlink/genetlink.c:734
 genl_family_rcv_msg net/netlink/genetlink.c:833 [inline]
 genl_rcv_msg+0x441/0x780 net/netlink/genetlink.c:850
 netlink_rcv_skb+0x14f/0x410 net/netlink/af_netlink.c:2540
 genl_rcv+0x24/0x40 net/netlink/genetlink.c:861
 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
 netlink_unicast+0x54e/0x800 net/netlink/af_netlink.c:1345
 netlink_sendmsg+0x930/0xe50 net/netlink/af_netlink.c:1921
 sock_sendmsg_nosec net/socket.c:714 [inline]
 sock_sendmsg+0x154/0x190 net/socket.c:734
 ____sys_sendmsg+0x6df/0x840 net/socket.c:2482
 ___sys_sendmsg+0x110/0x1b0 net/socket.c:2536
 __sys_sendmsg+0xf3/0x1c0 net/socket.c:2565
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0x90 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fdd66a8f359
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fdd65e00168 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fdd66bbcf80 RCX: 00007fdd66a8f359
RDX: 0000000000000000 RSI: 0000000020000500 RDI: 0000000000000003
RBP: 00007fdd66ada493 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffc84b81aff R14: 00007fdd65e00300 R15: 0000000000022000
 </TASK>

The buggy address belongs to the variable:
 ksmbd_nl_policy+0x100/0xa80

The buggy address belongs to the physical page:
page:0000000034f47940 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1ccc4b
flags: 0x200000000001000(reserved|node=0|zone=2)
raw: 0200000000001000 ffffea00073312c8 ffffea00073312c8 0000000000000000
raw: 0000000000000000 0000000000000000 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffffffff8f24b000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffffffff8f24b080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffffffff8f24b100: f9 f9 f9 f9 00 00 f9 f9 f9 f9 f9 f9 00 00 07 f9
                   ^
 ffffffff8f24b180: f9 f9 f9 f9 00 05 f9 f9 f9 f9 f9 f9 00 00 00 05
 ffffffff8f24b200: f9 f9 f9 f9 00 00 03 f9 f9 f9 f9 f9 00 00 04 f9
==================================================================

To fix it, add a placeholder named __KSMBD_EVENT_MAX and let
KSMBD_EVENT_MAX to be its original value - 1 according to what other
netlink families do. Also change two sites that refer the
KSMBD_EVENT_MAX to correct value.

Fixes: 0626e6641f6b ("cifsd: add server handler for central processing and tranport layers")
Signed-off-by: Lin Ma <linma@zju.edu.cn>
---
 fs/smb/server/ksmbd_netlink.h | 3 ++-
 fs/smb/server/transport_ipc.c | 4 ++--
 2 files changed, 4 insertions(+), 3 deletions(-)

Comments

Namjae Jeon Jan. 21, 2024, 8:24 a.m. UTC | #1 
2024-01-21 16:35 GMT+09:00, Lin Ma <linma@zju.edu.cn>:
> Similar to a reported issue (check the commit b33fb5b801c6 ("net:
> qualcomm: rmnet: fix global oob in rmnet_policy"), my local fuzzer finds
> another global out-of-bounds read for policy ksmbd_nl_policy. See bug
> trace below:
>
> ==================================================================
> BUG: KASAN: global-out-of-bounds in validate_nla lib/nlattr.c:386 [inline]
> BUG: KASAN: global-out-of-bounds in __nla_validate_parse+0x24af/0x2750
> lib/nlattr.c:600
> Read of size 1 at addr ffffffff8f24b100 by task syz-executor.1/62810
>
> CPU: 0 PID: 62810 Comm: syz-executor.1 Tainted: G                 N 6.1.0
> #3
> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
> 1.13.0-1ubuntu1.1 04/01/2014
> Call Trace:
>  <TASK>
>  __dump_stack lib/dump_stack.c:88 [inline]
>  dump_stack_lvl+0x8b/0xb3 lib/dump_stack.c:106
>  print_address_description mm/kasan/report.c:284 [inline]
>  print_report+0x172/0x475 mm/kasan/report.c:395
>  kasan_report+0xbb/0x1c0 mm/kasan/report.c:495
>  validate_nla lib/nlattr.c:386 [inline]
>  __nla_validate_parse+0x24af/0x2750 lib/nlattr.c:600
>  __nla_parse+0x3e/0x50 lib/nlattr.c:697
>  __nlmsg_parse include/net/netlink.h:748 [inline]
>  genl_family_rcv_msg_attrs_parse.constprop.0+0x1b0/0x290
> net/netlink/genetlink.c:565
>  genl_family_rcv_msg_doit+0xda/0x330 net/netlink/genetlink.c:734
>  genl_family_rcv_msg net/netlink/genetlink.c:833 [inline]
>  genl_rcv_msg+0x441/0x780 net/netlink/genetlink.c:850
>  netlink_rcv_skb+0x14f/0x410 net/netlink/af_netlink.c:2540
>  genl_rcv+0x24/0x40 net/netlink/genetlink.c:861
>  netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
>  netlink_unicast+0x54e/0x800 net/netlink/af_netlink.c:1345
>  netlink_sendmsg+0x930/0xe50 net/netlink/af_netlink.c:1921
>  sock_sendmsg_nosec net/socket.c:714 [inline]
>  sock_sendmsg+0x154/0x190 net/socket.c:734
>  ____sys_sendmsg+0x6df/0x840 net/socket.c:2482
>  ___sys_sendmsg+0x110/0x1b0 net/socket.c:2536
>  __sys_sendmsg+0xf3/0x1c0 net/socket.c:2565
>  do_syscall_x64 arch/x86/entry/common.c:50 [inline]
>  do_syscall_64+0x3b/0x90 arch/x86/entry/common.c:80
>  entry_SYSCALL_64_after_hwframe+0x63/0xcd
> RIP: 0033:0x7fdd66a8f359
> Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 00 00 90 48 89 f8 48 89 f7
> 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff
> 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
> RSP: 002b:00007fdd65e00168 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
> RAX: ffffffffffffffda RBX: 00007fdd66bbcf80 RCX: 00007fdd66a8f359
> RDX: 0000000000000000 RSI: 0000000020000500 RDI: 0000000000000003
> RBP: 00007fdd66ada493 R08: 0000000000000000 R09: 0000000000000000
> R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
> R13: 00007ffc84b81aff R14: 00007fdd65e00300 R15: 0000000000022000
>  </TASK>
>
> The buggy address belongs to the variable:
>  ksmbd_nl_policy+0x100/0xa80
>
> The buggy address belongs to the physical page:
> page:0000000034f47940 refcount:1 mapcount:0 mapping:0000000000000000
> index:0x0 pfn:0x1ccc4b
> flags: 0x200000000001000(reserved|node=0|zone=2)
> raw: 0200000000001000 ffffea00073312c8 ffffea00073312c8 0000000000000000
> raw: 0000000000000000 0000000000000000 00000001ffffffff 0000000000000000
> page dumped because: kasan: bad access detected
>
> Memory state around the buggy address:
>  ffffffff8f24b000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>  ffffffff8f24b080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>>ffffffff8f24b100: f9 f9 f9 f9 00 00 f9 f9 f9 f9 f9 f9 00 00 07 f9
>                    ^
>  ffffffff8f24b180: f9 f9 f9 f9 00 05 f9 f9 f9 f9 f9 f9 00 00 00 05
>  ffffffff8f24b200: f9 f9 f9 f9 00 00 03 f9 f9 f9 f9 f9 00 00 04 f9
> ==================================================================
>
> To fix it, add a placeholder named __KSMBD_EVENT_MAX and let
> KSMBD_EVENT_MAX to be its original value - 1 according to what other
> netlink families do. Also change two sites that refer the
> KSMBD_EVENT_MAX to correct value.
>
> Fixes: 0626e6641f6b ("cifsd: add server handler for central processing and
> tranport layers")
> Signed-off-by: Lin Ma <linma@zju.edu.cn>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Applied it to #ksmbd-for-next-next, Thanks for your patch!
diff mbox series

Patch

diff --git a/fs/smb/server/ksmbd_netlink.h b/fs/smb/server/ksmbd_netlink.h
index b7521e41402e..0ebf91ffa236 100644
--- a/fs/smb/server/ksmbd_netlink.h
+++ b/fs/smb/server/ksmbd_netlink.h
@@ -304,7 +304,8 @@  enum ksmbd_event {
 	KSMBD_EVENT_SPNEGO_AUTHEN_REQUEST,
 	KSMBD_EVENT_SPNEGO_AUTHEN_RESPONSE	= 15,
 
-	KSMBD_EVENT_MAX
+	__KSMBD_EVENT_MAX,
+	KSMBD_EVENT_MAX = __KSMBD_EVENT_MAX - 1
 };
 
 /*
diff --git a/fs/smb/server/transport_ipc.c b/fs/smb/server/transport_ipc.c
index b49d47bdafc9..f29bb03f0dc4 100644
--- a/fs/smb/server/transport_ipc.c
+++ b/fs/smb/server/transport_ipc.c
@@ -74,7 +74,7 @@  static int handle_unsupported_event(struct sk_buff *skb, struct genl_info *info)
 static int handle_generic_event(struct sk_buff *skb, struct genl_info *info);
 static int ksmbd_ipc_heartbeat_request(void);
 
-static const struct nla_policy ksmbd_nl_policy[KSMBD_EVENT_MAX] = {
+static const struct nla_policy ksmbd_nl_policy[KSMBD_EVENT_MAX + 1] = {
 	[KSMBD_EVENT_UNSPEC] = {
 		.len = 0,
 	},
@@ -403,7 +403,7 @@  static int handle_generic_event(struct sk_buff *skb, struct genl_info *info)
 		return -EPERM;
 #endif
 
-	if (type >= KSMBD_EVENT_MAX) {
+	if (type > KSMBD_EVENT_MAX) {
 		WARN_ON(1);
 		return -EINVAL;
 	}