From a27991791bf7d0bc8210c595703e970f894b932e Mon Sep 17 00:00:00 2001 From: Lin Ma Date: Mon, 5 Feb 2024 22:58:34 +0900 Subject: [PATCH] ksmbd: fix global oob in ksmbd_nl_policy 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: __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 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. Cc: stable@vger.kernel.org Fixes: 0626e6641f6b ("cifsd: add server handler for central processing and tranport layers") Signed-off-by: Lin Ma Signed-off-by: Namjae Jeon --- ksmbd_netlink.h | 3 ++- transport_ipc.c | 4 ++-- 2 files changed, 4 insertions(+), 3 deletions(-) diff --git a/ksmbd_netlink.h b/ksmbd_netlink.h index 821ed8e3c..ecffcb8a1 100644 --- a/ksmbd_netlink.h +++ b/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/transport_ipc.c b/transport_ipc.c index fb8e191e8..5289d63cd 100644 --- a/transport_ipc.c +++ b/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, }, @@ -405,7 +405,7 @@ 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; }