| Message ID | 20230722081646.4136-3-jgross@suse.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | tools/xenstore: fix get_spec_node() | expand |
Hi Juergen, On 22/07/2023 09:16, 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 <jgross@suse.com> Reviewed-by: Julien Grall <jgrall@amazon.com> Cheers,
diff --git a/tools/xenstore/xenstored_core.c b/tools/xenstore/xenstored_core.c index 3d3c39bd70..749717ec25 100644 --- a/tools/xenstore/xenstored_core.c +++ b/tools/xenstore/xenstored_core.c @@ -1253,8 +1253,11 @@ static struct node *get_spec_node(struct connection *conn, const void *ctx, const char *name, const char **canonical_name, unsigned int perm) { - if (name[0] == '@') + if (name[0] == '@') { + if (canonical_name) + *canonical_name = name; return get_node(conn, ctx, name, perm); + } return get_node_canonicalized(conn, ctx, name, canonical_name, perm); }
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 <jgross@suse.com> --- tools/xenstore/xenstored_core.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)