[PATCH net-next 01/36] rxrpc: Fix checker warning

From: David Howells
Date: Thu Dec 01 2022 - 19:16:40 EST


Fix the following checker warning:

../net/rxrpc/key.c:692:9: error: subtraction of different types can't work (different address spaces)

Checker is wrong in this case, but cast the pointers to unsigned long to
avoid the warning.

Whilst we're at it, reduce the assertions to WARN_ON() and return an error.

Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
cc: Marc Dionne <marc.dionne@xxxxxxxxxxxx>
cc: linux-afs@xxxxxxxxxxxxxxxxxxx
---

net/rxrpc/key.c | 14 +++++++++-----
1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/net/rxrpc/key.c b/net/rxrpc/key.c
index 8d2073e0e3da..830eeffe2d5b 100644
--- a/net/rxrpc/key.c
+++ b/net/rxrpc/key.c
@@ -602,7 +602,8 @@ static long rxrpc_read(const struct key *key,
}

_debug("token[%u]: toksize=%u", ntoks, toksize);
- ASSERTCMP(toksize, <=, AFSTOKEN_LENGTH_MAX);
+ if (WARN_ON(toksize > AFSTOKEN_LENGTH_MAX))
+ return -EIO;

toksizes[ntoks++] = toksize;
size += toksize + 4; /* each token has a length word */
@@ -679,8 +680,9 @@ static long rxrpc_read(const struct key *key,
return -ENOPKG;
}

- ASSERTCMP((unsigned long)xdr - (unsigned long)oldxdr, ==,
- toksize);
+ if (WARN_ON((unsigned long)xdr - (unsigned long)oldxdr ==
+ toksize))
+ return -EIO;
}

#undef ENCODE_STR
@@ -688,8 +690,10 @@ static long rxrpc_read(const struct key *key,
#undef ENCODE64
#undef ENCODE

- ASSERTCMP(tok, ==, ntoks);
- ASSERTCMP((char __user *) xdr - buffer, ==, size);
+ if (WARN_ON(tok != ntoks))
+ return -EIO;
+ if (WARN_ON((unsigned long)xdr - (unsigned long)buffer != size))
+ return -EIO;
_leave(" = %zu", size);
return size;
}