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author | Ben Hutchings <ben@decadent.org.uk> | 2017-04-01 04:55:18 +0100 |
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committer | Ben Hutchings <ben@decadent.org.uk> | 2017-04-04 22:21:57 +0100 |
commit | c53ee259ad3da891e191dee7af119af340f9c01b (patch) | |
tree | 61ff73b22ff531699e4edd3110133fef9393149e | |
parent | 880366a6e2ef182c37b7c7317dc6d449f625b97d (diff) | |
download | linux-stable-c53ee259ad3da891e191dee7af119af340f9c01b.tar.gz linux-stable-c53ee259ad3da891e191dee7af119af340f9c01b.tar.bz2 linux-stable-c53ee259ad3da891e191dee7af119af340f9c01b.zip |
keys: Guard against null match function in keyring_search_aux()
The "dead" key type has no match operation, and a search for keys of
this type can cause a null dereference in keyring_search_iterator().
keyring_search() has a check for this, but request_keyring_and_link()
does not. Move the check into keyring_search_aux(), covering both of
them.
This was fixed upstream by commit c06cfb08b88d ("KEYS: Remove
key_type::match in favour of overriding default by match_preparse"),
part of a series of large changes that are not suitable for
backporting.
CVE-2017-2647 / CVE-2017-6951
Reported-by: Igor Redko <redkoi@virtuozzo.com>
Reported-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
References: https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2017-2647
Reported-by: idl3r <idler1984@gmail.com>
References: https://www.spinics.net/lists/keyrings/msg01845.html
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Cc: David Howells <dhowells@redhat.com>
-rw-r--r-- | security/keys/keyring.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/security/keys/keyring.c b/security/keys/keyring.c index 860345cb05f1..796256db1004 100644 --- a/security/keys/keyring.c +++ b/security/keys/keyring.c @@ -848,6 +848,9 @@ key_ref_t keyring_search_aux(key_ref_t keyring_ref, return ERR_PTR(err); } + if (!ctx->match) + return ERR_PTR(-ENOKEY); + rcu_read_lock(); ctx->now = current_kernel_time(); if (search_nested_keyrings(keyring, ctx)) @@ -879,9 +882,6 @@ key_ref_t keyring_search(key_ref_t keyring, KEYRING_SEARCH_DO_STATE_CHECK), }; - if (!ctx.match) - return ERR_PTR(-ENOKEY); - return keyring_search_aux(keyring, &ctx); } EXPORT_SYMBOL(keyring_search); |