From 3bd8bf9bca97bbfb7b4b408f9fccd0cf6f742d4c Mon Sep 17 00:00:00 2001
From: Kamil Konieczny <kamil.konieczny@linux.intel.com>
Date: Mon, 27 Feb 2023 15:27:48 +0100
Subject: [PATCH] runner: check disk limit at dumping kmsg
It was reported that kernel dumps can grow beyond disk limit size
so add checks for it and report error if that happen.
v2: return number of written bytes (Petri)
Reported-by: Karol Krol <karol.krol@intel.com>
Ref: https://gitlab.freedesktop.org/drm/igt-gpu-tools/-/issues/129
Cc: Petri Latvala <adrinael@adrinael.net>
Cc: Arkadiusz Hiler <arkadiusz.hiler@intel.com>
Cc: Juha-Pekka Heikkila <juhapekka.heikkila@gmail.com>
Signed-off-by: Kamil Konieczny <kamil.konieczny@linux.intel.com>
Reviewed-by: Petri Latvala <adrinael@adrinael.net>
Reviewed-by: Andrzej Hajda <andrzej.hajda@intel.com>
---
runner/executor.c | 24 +++++++++++++++++++-----
1 file changed, 19 insertions(+), 5 deletions(-)
diff --git a/runner/executor.c b/runner/executor.c
index 597cd7f58..ae6cf1bba 100644
--- a/runner/executor.c
+++ b/runner/executor.c
@@ -584,7 +584,7 @@ void close_outputs(int *fds)
}
/* Returns the number of bytes written to disk, or a negative number on error */
-static long dump_dmesg(int kmsgfd, int outfd)
+static long dump_dmesg(int kmsgfd, int outfd, size_t disk_limit)
{
/*
* Write kernel messages to the log file until we reach
@@ -599,12 +599,18 @@ static long dump_dmesg(int kmsgfd, int outfd)
bool underflow_once = false;
char cont;
char buf[2048];
- ssize_t r;
+ ssize_t r, disk_written;
long written = 0;
if (kmsgfd < 0)
return 0;
+ disk_written = lseek(outfd, 0, SEEK_SET);
+ if (disk_written > disk_limit) {
+ errf("Error dumping kmsg: disk limit already exceeded\n");
+ return 0; /* number of written bytes */
+ }
+
comparefd = open("/dev/kmsg", O_RDONLY | O_NONBLOCK);
if (comparefd < 0) {
errf("Error opening another fd for /dev/kmsg\n");
@@ -655,6 +661,13 @@ static long dump_dmesg(int kmsgfd, int outfd)
write(outfd, buf, r);
written += r;
+ disk_written += r;
+
+ if (disk_written > disk_limit) {
+ close(comparefd);
+ errf("Error dumping kmsg: disk limit exceeded\n");
+ return written;
+ }
if (comparefd < 0 && sscanf(buf, "%u,%llu,%llu,%c;",
&flags, &seq, &usec, &cont) == 4) {
@@ -890,6 +903,7 @@ static int monitor_output(pid_t child,
unsigned long taints = 0;
bool aborting = false;
size_t disk_usage = 0;
+ const size_t mon_disk_limit = settings->disk_usage_limit ? : (~(size_t)0);
bool socket_comms_used = false; /* whether the test actually uses comms */
bool results_received = false; /* whether we already have test results that might need overriding if we detect an abort condition */
@@ -1219,7 +1233,7 @@ static int monitor_output(pid_t child,
time_last_activity = time_now;
- dmesgwritten = dump_dmesg(kmsgfd, outputs[_F_DMESG]);
+ dmesgwritten = dump_dmesg(kmsgfd, outputs[_F_DMESG], mon_disk_limit);
if (settings->sync)
fdatasync(outputs[_F_DMESG]);
@@ -1457,7 +1471,7 @@ static int monitor_output(pid_t child,
asprintf(abortreason, "Child refuses to die, tainted 0x%lx.", taints);
}
- dump_dmesg(kmsgfd, outputs[_F_DMESG]);
+ dump_dmesg(kmsgfd, outputs[_F_DMESG], mon_disk_limit);
if (settings->sync)
fdatasync(outputs[_F_DMESG]);
@@ -1483,7 +1497,7 @@ static int monitor_output(pid_t child,
}
}
- dump_dmesg(kmsgfd, outputs[_F_DMESG]);
+ dump_dmesg(kmsgfd, outputs[_F_DMESG], mon_disk_limit);
if (settings->sync)
fdatasync(outputs[_F_DMESG]);
--
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