From 5e0977fd08aac7174519c0f4b8eb9bc6ca4353f0 Mon Sep 17 00:00:00 2001 From: KP Singh Date: Wed, 20 May 2020 14:56:16 +0200 Subject: [PATCH] security: Fix hook iteration for secid_to_secctx [upstream commit 0550cfe8c2c6f8e7a4c348b6603a794576db12dd] secid_to_secctx is not stackable, and since the BPF LSM registers this hook by default, the call_int_hook logic is not suitable which "bails-on-fail" and casues issues when other LSMs register this hook and eventually breaks Audit. In order to fix this, directly iterate over the security hooks instead of using call_int_hook as suggested in: https: //lore.kernel.org/bpf/9d0eb6c6-803a-ff3a-5603-9ad6d9edfc00@schaufler-ca.com/#t Fixes: 98e828a0650f ("security: Refactor declaration of LSM hooks") Fixes: 625236ba3832 ("security: Fix the default value of secid_to_secctx hook") Reported-by: Alexei Starovoitov Signed-off-by: KP Singh Signed-off-by: Alexei Starovoitov Acked-by: James Morris Link: https://lore.kernel.org/bpf/20200520125616.193765-1-kpsingh@chromium.org Signed-off-by: Menglong Dong --- security/security.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) diff --git a/security/security.c b/security/security.c index c6272872154d..ae266a9c5181 100644 --- a/security/security.c +++ b/security/security.c @@ -1933,8 +1933,20 @@ EXPORT_SYMBOL(security_ismaclabel); int security_secid_to_secctx(u32 secid, char **secdata, u32 *seclen) { - return call_int_hook(secid_to_secctx, -EOPNOTSUPP, secid, secdata, - seclen); + struct security_hook_list *hp; + int rc; + + /* + * Currently, only one LSM can implement secid_to_secctx (i.e this + * LSM hook is not "stackable"). + */ + hlist_for_each_entry(hp, &security_hook_heads.secid_to_secctx, list) { + rc = hp->hook.secid_to_secctx(secid, secdata, seclen); + if (rc != LSM_RET_DEFAULT(secid_to_secctx)) + return rc; + } + + return LSM_RET_DEFAULT(secid_to_secctx); } EXPORT_SYMBOL(security_secid_to_secctx);