From 52e0b20c8c5751d90ef1f02f9270ac561d37a079 Mon Sep 17 00:00:00 2001 From: David Howells Date: Tue, 12 Jan 2021 15:23:51 +0000 Subject: [PATCH] rxrpc: Fix handling of an unsupported token type in rxrpc_read() [ Upstream commit d52e419ac8b50c8bef41b398ed13528e75d7ad48 ] Clang static analysis reports the following: net/rxrpc/key.c:657:11: warning: Assigned value is garbage or undefined toksize = toksizes[tok++]; ^ ~~~~~~~~~~~~~~~ rxrpc_read() contains two consecutive loops. The first loop calculates the token sizes and stores the results in toksizes[] and the second one uses the array. When there is an error in identifying the token in the first loop, the token is skipped, no change is made to the toksizes[] array. When the same error happens in the second loop, the token is not skipped. This will cause the toksizes[] array to be out of step and will overrun past the calculated sizes. Fix this by making both loops log a message and return an error in this case. This should only happen if a new token type is incompletely implemented, so it should normally be impossible to trigger this. Fixes: 9a059cd5ca7d ("rxrpc: Downgrade the BUG() for unsupported token type in rxrpc_read()") Reported-by: Tom Rix Signed-off-by: David Howells Reviewed-by: Tom Rix Link: https://lore.kernel.org/r/161046503122.2445787.16714129930607546635.stgit@warthog.procyon.org.uk Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman --- net/rxrpc/key.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/net/rxrpc/key.c b/net/rxrpc/key.c index 85a9ff8cd236..2b26c4d229a5 100644 --- a/net/rxrpc/key.c +++ b/net/rxrpc/key.c @@ -1110,7 +1110,7 @@ static long rxrpc_read(const struct key *key, default: /* we have a ticket we can't encode */ pr_err("Unsupported key token type (%u)\n", token->security_index); - continue; + return -ENOPKG; } _debug("token[%u]: toksize=%u", ntoks, toksize); @@ -1225,7 +1225,9 @@ static long rxrpc_read(const struct key *key, break; default: - break; + pr_err("Unsupported key token type (%u)\n", + token->security_index); + return -ENOPKG; } ASSERTCMP((unsigned long)xdr - (unsigned long)oldxdr, ==,