On 21.07.23 00:45, Julien Grall wrote:
Hi Juergen,On 20/07/2023 16:08, Juergen Gross wrote:In case get_spec_node() is being called for a special node starting with '@' it won't set *canonical_name. This can result in a crash of xenstored due to dereferencing the uninitialized name in fire_watches(). This is no security issue as it requires either a privileged caller or ownership of the special node in question by an unprivileged caller (which is questionable, as this would make the owner privileged in some way).Fixes: d6bb63924fc2 ("tools/xenstore: introduce dummy nodes for special watch paths")Signed-off-by: Juergen Gross <jgr...@suse.com> --- tools/xenstore/xenstored_core.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/tools/xenstore/xenstored_core.c b/tools/xenstore/xenstored_core.c index a1d3047e48..790c403904 100644 --- a/tools/xenstore/xenstored_core.c +++ b/tools/xenstore/xenstored_core.c@@ -1252,8 +1252,11 @@ static struct node *get_spec_node(struct connection *conn, const void *ctx,const char *name, char **canonical_name, unsigned int perm) { - if (name[0] == '@') + if (name[0] == '@') { + if (canonical_name) + *canonical_name = (char *)name;eww. Let's not continue the bad practice in Xenstored to cast away the const. I will have a look to remove the const and you can rebase your patch on top.
I think it should be possible to make canonical_name const. I'll look into that. Juergen
OpenPGP_0xB0DE9DD628BF132F.asc
Description: OpenPGP public key
OpenPGP_signature
Description: OpenPGP digital signature
