X-Git-Url: https://gerrit.automotivelinux.org/gerrit/gitweb?a=blobdiff_plain;f=meta-agl-bsp%2Fmeta-qcom%2Frecipes-kernel%2Flinux%2Ffiles%2F0003-Smack-ignore-null-signal-in-smack_task_kill.patch;fp=meta-agl-bsp%2Fmeta-qcom%2Frecipes-kernel%2Flinux%2Ffiles%2F0003-Smack-ignore-null-signal-in-smack_task_kill.patch;h=c9180bb9fcfd55bc3c4abca9ce2e1560d32cf0a8;hb=99804790f0954fc2cf0d20aa4d0a581361d3cfe6;hp=0000000000000000000000000000000000000000;hpb=8360d714b7373386f4bebeb434dbc6f0a4a49b9d;p=AGL%2Fmeta-agl.git diff --git a/meta-agl-bsp/meta-qcom/recipes-kernel/linux/files/0003-Smack-ignore-null-signal-in-smack_task_kill.patch b/meta-agl-bsp/meta-qcom/recipes-kernel/linux/files/0003-Smack-ignore-null-signal-in-smack_task_kill.patch new file mode 100644 index 000000000..c9180bb9f --- /dev/null +++ b/meta-agl-bsp/meta-qcom/recipes-kernel/linux/files/0003-Smack-ignore-null-signal-in-smack_task_kill.patch @@ -0,0 +1,39 @@ +From ec4eb03af07b0fbc330aecca6ac4ebd6accd8825 Mon Sep 17 00:00:00 2001 +From: Rafal Krypa +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 +Acked-by: Casey Schaufler +--- + 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 b2bcb14..cf8a93f 100644 +--- a/security/smack/smack_lsm.c ++++ b/security/smack/smack_lsm.c +@@ -2239,6 +2239,9 @@ 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 +