diff options
Diffstat (limited to 'meta-app-framework/recipes-kernel/linux/linux/linux-yocto-4.1/0003-Smack-ignore-null-signal-in-smack_task_kill.patch')
| -rw-r--r-- | meta-app-framework/recipes-kernel/linux/linux/linux-yocto-4.1/0003-Smack-ignore-null-signal-in-smack_task_kill.patch | 39 |
1 files changed, 39 insertions, 0 deletions
diff --git a/meta-app-framework/recipes-kernel/linux/linux/linux-yocto-4.1/0003-Smack-ignore-null-signal-in-smack_task_kill.patch b/meta-app-framework/recipes-kernel/linux/linux/linux-yocto-4.1/0003-Smack-ignore-null-signal-in-smack_task_kill.patch new file mode 100644 index 000000000..67761ae46 --- /dev/null +++ b/meta-app-framework/recipes-kernel/linux/linux/linux-yocto-4.1/0003-Smack-ignore-null-signal-in-smack_task_kill.patch @@ -0,0 +1,39 @@ +From aa63c4f8ece0c54a9be735ac38667f11fcd6f44a Mon Sep 17 00:00:00 2001 +From: Rafal Krypa <r.krypa@samsung.com> +Date: Mon, 4 Apr 2016 11:14:53 +0200 +Subject: [PATCH 3/4] Smack: ignore null signal in smack_task_kill + +Kill with signal number 0 is commonly used for checking PID existence. +Smack treated such cases like any other kills, although no signal is +actually delivered when sig == 0. + +Checking permissions when sig == 0 didn't prevent an unprivileged caller +from learning whether PID exists or not. When it existed, kernel returned +EPERM, when it didn't - ESRCH. The only effect of policy check in such +case is noise in audit logs. + +This change lets Smack silently ignore kill() invocations with sig == 0. + +Signed-off-by: Rafal Krypa <r.krypa@samsung.com> +Acked-by: Casey Schaufler <casey@schaufler-ca.com> +--- + security/smack/smack_lsm.c | 3 +++ + 1 file changed, 3 insertions(+) + +diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c +index b9393e3..c916f58 100644 +--- a/security/smack/smack_lsm.c ++++ b/security/smack/smack_lsm.c +@@ -2056,6 +2056,9 @@ static int smack_task_kill(struct task_struct *p, struct siginfo *info, + struct smack_known *tkp = smk_of_task_struct(p); + int rc; + ++ if (!sig) ++ return 0; /* null signal; existence test */ ++ + smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK); + smk_ad_setfield_u_tsk(&ad, p); + /* +-- +2.7.4 + |