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Commit 553d603c8fce8cf727eb26e4bf6b9549cd4623f1

Authored by David Howells
Committed by James Morris
1 parent 0ffbe2699c
Exists in master and in 7 other branches imx_3.0.35_4.1.0, imx_3.10.17_1.0.1_ga, imx_3.10.53_1.1.0_ga, imx_3.14.28_1.0.0_ga, smarc-imx_3.10.53_1.1.0_ga, smarc-imx_3.14.28_1.0.0_ga, smarc-l5.0.0_1.0.0-ga

KEYS: keyring_serialise_link_sem is only needed for keyring->keyring links 

keyring_serialise_link_sem is only needed for keyring->keyring links as it's
used to prevent cycle detection from being avoided by parallel keyring
additions.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>

Showing 1 changed file with 9 additions and 7 deletions Side-by-side Diff

security/keys/keyring.c
Diff comments   View file @ 553d603
... ... @@ -705,13 +705,14 @@
705 705 if (keyring->type != &key_type_keyring)
706 706 goto error;
707 707  
708   - /* serialise link/link calls to prevent parallel calls causing a
709   - * cycle when applied to two keyring in opposite orders */
710   - down_write(&keyring_serialise_link_sem);
711   -
712   - /* check that we aren't going to create a cycle adding one keyring to
713   - * another */
  708 + /* do some special keyring->keyring link checks */
714 709 if (key->type == &key_type_keyring) {
  710 + /* serialise link/link calls to prevent parallel calls causing
  711 + * a cycle when applied to two keyring in opposite orders */
  712 + down_write(&keyring_serialise_link_sem);
  713 +
  714 + /* check that we aren't going to create a cycle adding one
  715 + * keyring to another */
715 716 ret = keyring_detect_cycle(keyring, key);
716 717 if (ret < 0)
717 718 goto error2;
... ... @@ -814,7 +815,8 @@
814 815 done:
815 816 ret = 0;
816 817 error2:
817   - up_write(&keyring_serialise_link_sem);
  818 + if (key->type == &key_type_keyring)
  819 + up_write(&keyring_serialise_link_sem);
818 820 error:
819 821 return ret;
820 822