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debuggerd_handler: raise ambient capset before execing.

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Raise the ambient capability set to match CapEff so that crash_dump can
inherit all of the capabilities of the dumped process to be able to
ptrace. Note that selinux will prevent crash_dump from actually use
any of the capabilities.

Bug: http://b/34853272
Test: debuggerd -b `pidof system_server`
Test: debuggerd -b `pidof zygote`
Change-Id: I1fe69eff54c1c0a5b3ec63f6fa504b2681c47a88
This commit is contained in:
Josh Gao 2017-02-01 15:33:18 -08:00
parent ac91b0c452
commit 7ae426c731
1 changed files with 6 additions and 0 deletions
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6
debuggerd/handler/debuggerd_handler.cpp
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@ -39,6 +39,7 @@
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/capability.h>
#include <sys/mman.h>
#include <sys/prctl.h>
#include <sys/socket.h>
@ -205,6 +206,11 @@ static int debuggerd_dispatch_pseudothread(void* arg) {
close(pipefds[0]);
close(pipefds[1]);
// Set all of the ambient capability bits we can, so that crash_dump can ptrace us.
for (unsigned long i = 0; prctl(PR_CAPBSET_READ, i, 0, 0, 0); ++i) {
prctl(PR_CAP_AMBIENT, PR_CAP_AMBIENT_RAISE, i, 0, 0);
}
char buf[10];
snprintf(buf, sizeof(buf), "%d", thread_info->crashing_tid);
execl(CRASH_DUMP_PATH, CRASH_DUMP_NAME, buf, nullptr);