[PATCH] tracing: Replace all non-returning strlcpy with strscpy
From: Azeem Shaikh
Date: Tue May 16 2023 - 00:40:34 EST
strlcpy() reads the entire source buffer first.
This read may exceed the destination size limit.
This is both inefficient and can lead to linear read
overflows if a source string is not NUL-terminated [1].
In an effort to remove strlcpy() completely [2], replace
strlcpy() here with strscpy().
No return values were used, so direct replacement with strlcpy is safe.
Occurences of strlcpy within TRACE_EVENT macros were replaced with
__string() and __assign_str() macro helpers instead.
[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy
[2] https://github.com/KSPP/linux/issues/89
Signed-off-by: Azeem Shaikh <azeemshaikh38@xxxxxxxxx>
---
include/trace/events/fib.h | 2 +-
include/trace/events/fib6.h | 2 +-
include/trace/events/kyber.h | 24 ++++++++++++------------
include/trace/events/task.h | 6 +++---
include/trace/events/wbt.h | 28 ++++++++++++----------------
kernel/trace/trace.c | 8 ++++----
kernel/trace/trace_events.c | 4 ++--
kernel/trace/trace_events_inject.c | 4 ++--
kernel/trace/trace_kprobe.c | 2 +-
kernel/trace/trace_probe.c | 2 +-
10 files changed, 39 insertions(+), 43 deletions(-)
diff --git a/include/trace/events/fib.h b/include/trace/events/fib.h
index 76297ecd4935..20b914250ce9 100644
--- a/include/trace/events/fib.h
+++ b/include/trace/events/fib.h
@@ -65,7 +65,7 @@ TRACE_EVENT(fib_table_lookup,
}
dev = nhc ? nhc->nhc_dev : NULL;
- strlcpy(__entry->name, dev ? dev->name : "-", IFNAMSIZ);
+ strscpy(__entry->name, dev ? dev->name : "-", IFNAMSIZ);
if (nhc) {
if (nhc->nhc_gw_family == AF_INET) {
diff --git a/include/trace/events/fib6.h b/include/trace/events/fib6.h
index 4d3e607b3cde..5d7ee2610728 100644
--- a/include/trace/events/fib6.h
+++ b/include/trace/events/fib6.h
@@ -63,7 +63,7 @@ TRACE_EVENT(fib6_table_lookup,
}
if (res->nh && res->nh->fib_nh_dev) {
- strlcpy(__entry->name, res->nh->fib_nh_dev->name, IFNAMSIZ);
+ strscpy(__entry->name, res->nh->fib_nh_dev->name, IFNAMSIZ);
} else {
strcpy(__entry->name, "-");
}
diff --git a/include/trace/events/kyber.h b/include/trace/events/kyber.h
index bf7533f171ff..d4db2fa60e7b 100644
--- a/include/trace/events/kyber.h
+++ b/include/trace/events/kyber.h
@@ -21,8 +21,8 @@ TRACE_EVENT(kyber_latency,
TP_STRUCT__entry(
__field( dev_t, dev )
- __array( char, domain, DOMAIN_LEN )
- __array( char, type, LATENCY_TYPE_LEN )
+ __string( domain, domain )
+ __string( type, type )
__field( u8, percentile )
__field( u8, numerator )
__field( u8, denominator )
@@ -31,8 +31,8 @@ TRACE_EVENT(kyber_latency,
TP_fast_assign(
__entry->dev = dev;
- strlcpy(__entry->domain, domain, sizeof(__entry->domain));
- strlcpy(__entry->type, type, sizeof(__entry->type));
+ __assign_str(domain, domain);
+ __assign_str(type, type);
__entry->percentile = percentile;
__entry->numerator = numerator;
__entry->denominator = denominator;
@@ -40,8 +40,8 @@ TRACE_EVENT(kyber_latency,
),
TP_printk("%d,%d %s %s p%u %u/%u samples=%u",
- MAJOR(__entry->dev), MINOR(__entry->dev), __entry->domain,
- __entry->type, __entry->percentile, __entry->numerator,
+ MAJOR(__entry->dev), MINOR(__entry->dev), __get_str(domain),
+ __get_str(type), __entry->percentile, __entry->numerator,
__entry->denominator, __entry->samples)
);
@@ -53,18 +53,18 @@ TRACE_EVENT(kyber_adjust,
TP_STRUCT__entry(
__field( dev_t, dev )
- __array( char, domain, DOMAIN_LEN )
+ __string( domain, domain )
__field( unsigned int, depth )
),
TP_fast_assign(
__entry->dev = dev;
- strlcpy(__entry->domain, domain, sizeof(__entry->domain));
+ __assign_str(domain, domain);
__entry->depth = depth;
),
TP_printk("%d,%d %s %u",
- MAJOR(__entry->dev), MINOR(__entry->dev), __entry->domain,
+ MAJOR(__entry->dev), MINOR(__entry->dev), __get_str(domain),
__entry->depth)
);
@@ -76,16 +76,16 @@ TRACE_EVENT(kyber_throttled,
TP_STRUCT__entry(
__field( dev_t, dev )
- __array( char, domain, DOMAIN_LEN )
+ __string( domain, domain )
),
TP_fast_assign(
__entry->dev = dev;
- strlcpy(__entry->domain, domain, sizeof(__entry->domain));
+ __assign_str(domain, domain);
),
TP_printk("%d,%d %s", MAJOR(__entry->dev), MINOR(__entry->dev),
- __entry->domain)
+ __get_str(domain))
);
#define _TRACE_KYBER_H
diff --git a/include/trace/events/task.h b/include/trace/events/task.h
index 64d160930b0d..48b1bb868a86 100644
--- a/include/trace/events/task.h
+++ b/include/trace/events/task.h
@@ -40,20 +40,20 @@ TRACE_EVENT(task_rename,
TP_STRUCT__entry(
__field( pid_t, pid)
__array( char, oldcomm, TASK_COMM_LEN)
- __array( char, newcomm, TASK_COMM_LEN)
+ __string( newcomm, comm)
__field( short, oom_score_adj)
),
TP_fast_assign(
__entry->pid = task->pid;
memcpy(entry->oldcomm, task->comm, TASK_COMM_LEN);
- strlcpy(entry->newcomm, comm, TASK_COMM_LEN);
+ __assign_str(newcomm, comm);
__entry->oom_score_adj = task->signal->oom_score_adj;
),
TP_printk("pid=%d oldcomm=%s newcomm=%s oom_score_adj=%hd",
__entry->pid, __entry->oldcomm,
- __entry->newcomm, __entry->oom_score_adj)
+ __get_str(newcomm), __entry->oom_score_adj)
);
#endif
diff --git a/include/trace/events/wbt.h b/include/trace/events/wbt.h
index 9c66e59d859c..874404822575 100644
--- a/include/trace/events/wbt.h
+++ b/include/trace/events/wbt.h
@@ -19,7 +19,7 @@ TRACE_EVENT(wbt_stat,
TP_ARGS(bdi, stat),
TP_STRUCT__entry(
- __array(char, name, 32)
+ __string(name, bdi_dev_name(bdi))
__field(s64, rmean)
__field(u64, rmin)
__field(u64, rmax)
@@ -33,8 +33,7 @@ TRACE_EVENT(wbt_stat,
),
TP_fast_assign(
- strlcpy(__entry->name, bdi_dev_name(bdi),
- ARRAY_SIZE(__entry->name));
+ __assign_str(name, bdi_dev_name(bdi));
__entry->rmean = stat[0].mean;
__entry->rmin = stat[0].min;
__entry->rmax = stat[0].max;
@@ -47,7 +46,7 @@ TRACE_EVENT(wbt_stat,
TP_printk("%s: rmean=%llu, rmin=%llu, rmax=%llu, rsamples=%llu, "
"wmean=%llu, wmin=%llu, wmax=%llu, wsamples=%llu",
- __entry->name, __entry->rmean, __entry->rmin, __entry->rmax,
+ __get_str(name), __entry->rmean, __entry->rmin, __entry->rmax,
__entry->rnr_samples, __entry->wmean, __entry->wmin,
__entry->wmax, __entry->wnr_samples)
);
@@ -63,17 +62,16 @@ TRACE_EVENT(wbt_lat,
TP_ARGS(bdi, lat),
TP_STRUCT__entry(
- __array(char, name, 32)
+ __string(name, bdi_dev_name(bdi))
__field(unsigned long, lat)
),
TP_fast_assign(
- strlcpy(__entry->name, bdi_dev_name(bdi),
- ARRAY_SIZE(__entry->name));
+ __assign_str(name, bdi_dev_name(bdi));
__entry->lat = div_u64(lat, 1000);
),
- TP_printk("%s: latency %lluus", __entry->name,
+ TP_printk("%s: latency %lluus", __get_str(name),
(unsigned long long) __entry->lat)
);
@@ -95,7 +93,7 @@ TRACE_EVENT(wbt_step,
TP_ARGS(bdi, msg, step, window, bg, normal, max),
TP_STRUCT__entry(
- __array(char, name, 32)
+ __string(name, bdi_dev_name(bdi))
__field(const char *, msg)
__field(int, step)
__field(unsigned long, window)
@@ -105,8 +103,7 @@ TRACE_EVENT(wbt_step,
),
TP_fast_assign(
- strlcpy(__entry->name, bdi_dev_name(bdi),
- ARRAY_SIZE(__entry->name));
+ __assign_str(name, bdi_dev_name(bdi));
__entry->msg = msg;
__entry->step = step;
__entry->window = div_u64(window, 1000);
@@ -116,7 +113,7 @@ TRACE_EVENT(wbt_step,
),
TP_printk("%s: %s: step=%d, window=%luus, background=%u, normal=%u, max=%u",
- __entry->name, __entry->msg, __entry->step, __entry->window,
+ __get_str(name), __entry->msg, __entry->step, __entry->window,
__entry->bg, __entry->normal, __entry->max)
);
@@ -134,21 +131,20 @@ TRACE_EVENT(wbt_timer,
TP_ARGS(bdi, status, step, inflight),
TP_STRUCT__entry(
- __array(char, name, 32)
+ __string(name, bdi_dev_name(bdi))
__field(unsigned int, status)
__field(int, step)
__field(unsigned int, inflight)
),
TP_fast_assign(
- strlcpy(__entry->name, bdi_dev_name(bdi),
- ARRAY_SIZE(__entry->name));
+ __assign_str(name, bdi_dev_name(bdi));
__entry->status = status;
__entry->step = step;
__entry->inflight = inflight;
),
- TP_printk("%s: status=%u, step=%d, inflight=%u", __entry->name,
+ TP_printk("%s: status=%u, step=%d, inflight=%u", __get_str(name),
__entry->status, __entry->step, __entry->inflight)
);
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index ebc59781456a..28ccd0c9bdf0 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -196,7 +196,7 @@ static int boot_snapshot_index;
static int __init set_cmdline_ftrace(char *str)
{
- strlcpy(bootup_tracer_buf, str, MAX_TRACER_SIZE);
+ strscpy(bootup_tracer_buf, str, MAX_TRACER_SIZE);
default_bootup_tracer = bootup_tracer_buf;
/* We are using ftrace early, expand it */
ring_buffer_expanded = true;
@@ -281,7 +281,7 @@ static char trace_boot_options_buf[MAX_TRACER_SIZE] __initdata;
static int __init set_trace_boot_options(char *str)
{
- strlcpy(trace_boot_options_buf, str, MAX_TRACER_SIZE);
+ strscpy(trace_boot_options_buf, str, MAX_TRACER_SIZE);
return 1;
}
__setup("trace_options=", set_trace_boot_options);
@@ -291,7 +291,7 @@ static char *trace_boot_clock __initdata;
static int __init set_trace_boot_clock(char *str)
{
- strlcpy(trace_boot_clock_buf, str, MAX_TRACER_SIZE);
+ strscpy(trace_boot_clock_buf, str, MAX_TRACER_SIZE);
trace_boot_clock = trace_boot_clock_buf;
return 1;
}
@@ -2521,7 +2521,7 @@ static void __trace_find_cmdline(int pid, char comm[])
if (map != NO_CMDLINE_MAP) {
tpid = savedcmd->map_cmdline_to_pid[map];
if (tpid == pid) {
- strlcpy(comm, get_saved_cmdlines(map), TASK_COMM_LEN);
+ strscpy(comm, get_saved_cmdlines(map), TASK_COMM_LEN);
return;
}
}
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 654ffa40457a..dc83a259915b 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -2831,7 +2831,7 @@ static __init int setup_trace_triggers(char *str)
char *buf;
int i;
- strlcpy(bootup_trigger_buf, str, COMMAND_LINE_SIZE);
+ strscpy(bootup_trigger_buf, str, COMMAND_LINE_SIZE);
ring_buffer_expanded = true;
disable_tracing_selftest("running event triggers");
@@ -3621,7 +3621,7 @@ static char bootup_event_buf[COMMAND_LINE_SIZE] __initdata;
static __init int setup_trace_event(char *str)
{
- strlcpy(bootup_event_buf, str, COMMAND_LINE_SIZE);
+ strscpy(bootup_event_buf, str, COMMAND_LINE_SIZE);
ring_buffer_expanded = true;
disable_tracing_selftest("running event tracing");
diff --git a/kernel/trace/trace_events_inject.c b/kernel/trace/trace_events_inject.c
index d6b4935a78c0..abe805d471eb 100644
--- a/kernel/trace/trace_events_inject.c
+++ b/kernel/trace/trace_events_inject.c
@@ -217,7 +217,7 @@ static int parse_entry(char *str, struct trace_event_call *call, void **pentry)
char *addr = (char *)(unsigned long) val;
if (field->filter_type == FILTER_STATIC_STRING) {
- strlcpy(entry + field->offset, addr, field->size);
+ strscpy(entry + field->offset, addr, field->size);
} else if (field->filter_type == FILTER_DYN_STRING ||
field->filter_type == FILTER_RDYN_STRING) {
int str_len = strlen(addr) + 1;
@@ -232,7 +232,7 @@ static int parse_entry(char *str, struct trace_event_call *call, void **pentry)
}
entry = *pentry;
- strlcpy(entry + (entry_size - str_len), addr, str_len);
+ strscpy(entry + (entry_size - str_len), addr, str_len);
str_item = (u32 *)(entry + field->offset);
if (field->filter_type == FILTER_RDYN_STRING)
str_loc -= field->offset + field->size;
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 59cda19a9033..1b3fa7b854aa 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -30,7 +30,7 @@ static char kprobe_boot_events_buf[COMMAND_LINE_SIZE] __initdata;
static int __init set_kprobe_boot_events(char *str)
{
- strlcpy(kprobe_boot_events_buf, str, COMMAND_LINE_SIZE);
+ strscpy(kprobe_boot_events_buf, str, COMMAND_LINE_SIZE);
disable_tracing_selftest("running kprobe events");
return 1;
diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
index 2d2616678295..73055ba8d8ef 100644
--- a/kernel/trace/trace_probe.c
+++ b/kernel/trace/trace_probe.c
@@ -254,7 +254,7 @@ int traceprobe_parse_event_name(const char **pevent, const char **pgroup,
trace_probe_log_err(offset, GROUP_TOO_LONG);
return -EINVAL;
}
- strlcpy(buf, event, slash - event + 1);
+ strscpy(buf, event, slash - event + 1);
if (!is_good_system_name(buf)) {
trace_probe_log_err(offset, BAD_GROUP_NAME);
return -EINVAL;