From: Igor Lubashev <ilubashe@akamai.com> To: <linux-kernel@vger.kernel.org>, Peter Zijlstra <peterz@infradead.org>, Ingo Molnar <mingo@redhat.com>, Arnaldo Carvalho de Melo <acme@kernel.org>, Mathieu Poirier <mathieu.poirier@linaro.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>, Jiri Olsa <jolsa@redhat.com>, Namhyung Kim <namhyung@kernel.org>, Suzuki K Poulose <suzuki.poulose@arm.com>, <linux-arm-kernel@lists.infradead.org>, James Morris <jmorris@namei.org>, Igor Lubashev <ilubashe@akamai.com> Subject: [PATCH 3/3] perf: Use CAP_SYSLOG with kptr_restrict checks Date: Tue, 2 Jul 2019 20:10:05 -0400 [thread overview] Message-ID: <1562112605-6235-4-git-send-email-ilubashe@akamai.com> (raw) In-Reply-To: <1562112605-6235-1-git-send-email-ilubashe@akamai.com> Kernel is using CAP_SYSLOG capcbility instead of uid==0 and euid==0 when checking kptr_restrict. Make perf do the same. Also, the kernel is a more restrictive than "no restrictions" in case of kptr_restrict==0, so add the same logic to perf. Signed-off-by: Igor Lubashev <ilubashe@akamai.com> --- tools/perf/util/symbol.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c index 5cbad55cd99d..fd68dae3f58e 100644 --- a/tools/perf/util/symbol.c +++ b/tools/perf/util/symbol.c @@ -4,6 +4,7 @@ #include <stdlib.h> #include <stdio.h> #include <string.h> +#include <linux/capability.h> #include <linux/kernel.h> #include <linux/mman.h> #include <linux/time64.h> @@ -15,8 +16,10 @@ #include <inttypes.h> #include "annotate.h" #include "build-id.h" +#include "cap.h" #include "util.h" #include "debug.h" +#include "event.h" #include "machine.h" #include "map.h" #include "symbol.h" @@ -889,7 +892,11 @@ bool symbol__restricted_filename(const char *filename, { bool restricted = false; - if (symbol_conf.kptr_restrict) { + /* Per kernel/kallsyms.c: + * we also restrict when perf_event_paranoid > 1 w/o CAP_SYSLOG + */ + if (symbol_conf.kptr_restrict || + (perf_event_paranoid() > 1 && !perf_cap__capable(CAP_SYSLOG))) { char *r = realpath(filename, NULL); if (r != NULL) { @@ -2100,9 +2107,9 @@ static bool symbol__read_kptr_restrict(void) char line[8]; if (fgets(line, sizeof(line), fp) != NULL) - value = ((geteuid() != 0) || (getuid() != 0)) ? - (atoi(line) != 0) : - (atoi(line) == 2); + value = perf_cap__capable(CAP_SYSLOG) ? + (atoi(line) >= 2) : + (atoi(line) != 0); fclose(fp); } -- 2.7.4
WARNING: multiple messages have this Message-ID (diff)
From: Igor Lubashev <ilubashe@akamai.com> To: <linux-kernel@vger.kernel.org>, Peter Zijlstra <peterz@infradead.org>, Ingo Molnar <mingo@redhat.com>, Arnaldo Carvalho de Melo <acme@kernel.org>, Mathieu Poirier <mathieu.poirier@linaro.org> Cc: Suzuki K Poulose <suzuki.poulose@arm.com>, Alexander Shishkin <alexander.shishkin@linux.intel.com>, Igor Lubashev <ilubashe@akamai.com>, James Morris <jmorris@namei.org>, Namhyung Kim <namhyung@kernel.org>, Jiri Olsa <jolsa@redhat.com>, linux-arm-kernel@lists.infradead.org Subject: [PATCH 3/3] perf: Use CAP_SYSLOG with kptr_restrict checks Date: Tue, 2 Jul 2019 20:10:05 -0400 [thread overview] Message-ID: <1562112605-6235-4-git-send-email-ilubashe@akamai.com> (raw) In-Reply-To: <1562112605-6235-1-git-send-email-ilubashe@akamai.com> Kernel is using CAP_SYSLOG capcbility instead of uid==0 and euid==0 when checking kptr_restrict. Make perf do the same. Also, the kernel is a more restrictive than "no restrictions" in case of kptr_restrict==0, so add the same logic to perf. Signed-off-by: Igor Lubashev <ilubashe@akamai.com> --- tools/perf/util/symbol.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c index 5cbad55cd99d..fd68dae3f58e 100644 --- a/tools/perf/util/symbol.c +++ b/tools/perf/util/symbol.c @@ -4,6 +4,7 @@ #include <stdlib.h> #include <stdio.h> #include <string.h> +#include <linux/capability.h> #include <linux/kernel.h> #include <linux/mman.h> #include <linux/time64.h> @@ -15,8 +16,10 @@ #include <inttypes.h> #include "annotate.h" #include "build-id.h" +#include "cap.h" #include "util.h" #include "debug.h" +#include "event.h" #include "machine.h" #include "map.h" #include "symbol.h" @@ -889,7 +892,11 @@ bool symbol__restricted_filename(const char *filename, { bool restricted = false; - if (symbol_conf.kptr_restrict) { + /* Per kernel/kallsyms.c: + * we also restrict when perf_event_paranoid > 1 w/o CAP_SYSLOG + */ + if (symbol_conf.kptr_restrict || + (perf_event_paranoid() > 1 && !perf_cap__capable(CAP_SYSLOG))) { char *r = realpath(filename, NULL); if (r != NULL) { @@ -2100,9 +2107,9 @@ static bool symbol__read_kptr_restrict(void) char line[8]; if (fgets(line, sizeof(line), fp) != NULL) - value = ((geteuid() != 0) || (getuid() != 0)) ? - (atoi(line) != 0) : - (atoi(line) == 2); + value = perf_cap__capable(CAP_SYSLOG) ? + (atoi(line) >= 2) : + (atoi(line) != 0); fclose(fp); } -- 2.7.4 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2019-07-03 1:16 UTC|newest] Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-07-03 0:10 [PATCH 0/3] perf: Use capabilities instead of uid and euid Igor Lubashev 2019-07-03 0:10 ` Igor Lubashev 2019-07-03 0:10 ` [PATCH 1/3] perf: Add capability-related utilities Igor Lubashev 2019-07-03 0:10 ` Igor Lubashev 2019-07-16 8:46 ` Jiri Olsa 2019-07-16 8:46 ` Jiri Olsa 2019-07-17 21:05 ` Arnaldo Carvalho de Melo 2019-07-17 21:05 ` Arnaldo Carvalho de Melo 2019-07-17 23:46 ` Arnaldo Carvalho de Melo 2019-07-17 23:46 ` Arnaldo Carvalho de Melo 2019-07-17 23:48 ` Arnaldo Carvalho de Melo 2019-07-17 23:48 ` Arnaldo Carvalho de Melo 2019-07-18 21:00 ` Lubashev, Igor 2019-07-18 21:00 ` Lubashev, Igor 2019-08-07 3:58 ` Lubashev, Igor 2019-08-07 3:58 ` Lubashev, Igor 2019-07-03 0:10 ` [PATCH 2/3] perf: Use CAP_SYS_ADMIN with perf_event_paranoid checks Igor Lubashev 2019-07-03 0:10 ` Igor Lubashev 2019-07-16 8:47 ` Jiri Olsa 2019-07-16 8:47 ` Jiri Olsa 2019-07-16 17:01 ` Lubashev, Igor 2019-07-16 17:01 ` Lubashev, Igor 2019-07-17 7:10 ` Jiri Olsa 2019-07-17 7:10 ` Jiri Olsa 2019-07-17 18:33 ` Lubashev, Igor 2019-07-17 18:33 ` Lubashev, Igor 2019-07-03 0:10 ` Igor Lubashev [this message] 2019-07-03 0:10 ` [PATCH 3/3] perf: Use CAP_SYSLOG with kptr_restrict checks Igor Lubashev 2019-07-16 10:51 ` [PATCH 0/3] perf: Use capabilities instead of uid and euid Alexey Budankov 2019-07-16 10:51 ` Alexey Budankov 2019-07-17 18:15 ` [PATCH 4/3] perf: Use CAP_SYS_ADMIN instead of euid==0 with ftrace Igor Lubashev
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