[PATCH] tipc: fix TLV out-of-bounds read in tipc_nl_compat_net_set() and depth mask

[Hui Peng]

Fix two validation flaws in `net/tipc/netlink_compat.c`:

1. `tipc_nl_compat_net_set()` (`TIPC_CMD_SET_NETID` /
   `TIPC_CMD_SET_NODE_ADDR`) unconditionally dereferences `*(__be32
   *)TLV_DATA(msg->req)` without verifying that
   `TLV_GET_DATA_LEN(msg->req) >= sizeof(__be32)` (4 bytes), reading 4
   bytes past the end of a 0-byte TLV payload (`tlv_len == 4`).
2. In `tipc_nl_compat_name_table_dump_header()` and
   `tipc_nl_compat_name_table_dump()`, `ntq->depth` can contain the high
   flag bit `TIPC_NTQ_ALLTYPES` (`0x80000000`).
   `tipc_nl_compat_name_table_dump_header()` compares `depth > 4`
   without masking off `TIPC_NTQ_ALLTYPES` first (always clamping
   `depth` to 4 whenever `TIPC_NTQ_ALLTYPES` is set, even if the low
   depth bits are `1`), and `tipc_nl_compat_name_table_dump()` checks
   `depth > 1` and `depth > 2` with `TIPC_NTQ_ALLTYPES` still set in
   `depth`. Mask off `TIPC_NTQ_ALLTYPES` after testing it.

Fixes: d7cc75d3cb6b ("tipc: convert legacy nl node addr set to nl compat")
Fixes: 44a8ae94fd55 ("tipc: convert legacy nl name table dump to nl compat")
Assisted-by: LLM
Signed-off-by: Hui Peng <benquike@xxxxxxxxx>

---
 net/tipc/netlink_compat.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/net/tipc/netlink_compat.c b/net/tipc/netlink_compat.c
index d9a4f94ea2d4..9b2d93704e23 100644
--- a/net/tipc/netlink_compat.c
+++ b/net/tipc/netlink_compat.c
@@ -881,7 +881,7 @@ static int tipc_nl_compat_name_table_dump_header(struct tipc_nl_compat_msg *msg)
 	if (TLV_GET_DATA_LEN(msg->req) < (int)sizeof(struct tipc_name_table_query))
 		return -EINVAL;
 
-	depth = ntohl(ntq->depth);
+	depth = ntohl(ntq->depth) & ~TIPC_NTQ_ALLTYPES;
 
 	if (depth > 4)
 		depth = 4;
@@ -932,6 +932,7 @@ static int tipc_nl_compat_name_table_dump(struct tipc_nl_compat_msg *msg,
 	if (!(depth & TIPC_NTQ_ALLTYPES) &&
 	    (type != nla_get_u32(publ[TIPC_NLA_PUBL_TYPE])))
 		return 0;
+	depth &= ~TIPC_NTQ_ALLTYPES;
 	if (lowbound && (lowbound > nla_get_u32(publ[TIPC_NLA_PUBL_UPPER])))
 		return 0;
 	if (upbound && (upbound < nla_get_u32(publ[TIPC_NLA_PUBL_LOWER])))
@@ -1139,6 +1140,9 @@ static int tipc_nl_compat_net_set(struct tipc_nl_compat_cmd_doit *cmd,
 	u32 val;
 	struct nlattr *net;
 
+	if (TLV_GET_DATA_LEN(msg->req) < (int)sizeof(__be32))
+		return -EINVAL;
+
 	val = ntohl(*(__be32 *)TLV_DATA(msg->req));
 
 	net = nla_nest_start_noflag(skb, TIPC_NLA_NET);
-- 
2.55.0.1082.g2b9226bbc0-goog