From 2b5c1b4b133a97a46354142aa8ab0d9e79bc70a4 Mon Sep 17 00:00:00 2001 From: Tomasz Kramkowski Date: Thu, 29 Dec 2016 19:42:41 +0100 Subject: [PATCH] Replace all uses of sprintf with snprintf In all the cases where sprintf was being used within htop, snprintf could have been used. This patch replaces all uses of sprintf with snprintf which makes sure that if a buffer is too small to hold the resulting string, the string is simply cut short instead of causing a buffer overflow which leads to undefined behaviour. `sizeof(variable)` was used in these cases, as opposed to `sizeof variable` which is my personal preference because `sizeof(variable)` was already used in one way or another in other parts of the code. --- CPUMeter.c | 24 ++++++++++++------------ LoadAverageMeter.c | 8 ++++---- Process.c | 2 +- TasksMeter.c | 8 ++++---- TraceScreen.c | 2 +- UptimeMeter.c | 6 +++--- 6 files changed, 25 insertions(+), 25 deletions(-) diff --git a/CPUMeter.c b/CPUMeter.c index 32bad04..6b9b83d 100644 --- a/CPUMeter.c +++ b/CPUMeter.c @@ -48,7 +48,7 @@ static void CPUMeter_init(Meter* this) { int cpu = this->param; if (this->pl->cpuCount > 1) { char caption[10]; - sprintf(caption, "%-3d", Settings_cpuId(this->pl->settings, cpu - 1)); + snprintf(caption, sizeof(caption), "%-3d", Settings_cpuId(this->pl->settings, cpu - 1)); Meter_setCaption(this, caption); } if (this->param == 0) @@ -74,44 +74,44 @@ static void CPUMeter_display(Object* cast, RichString* out) { RichString_append(out, CRT_colors[METER_TEXT], "absent"); return; } - sprintf(buffer, "%5.1f%% ", this->values[CPU_METER_NORMAL]); + snprintf(buffer, sizeof(buffer), "%5.1f%% ", this->values[CPU_METER_NORMAL]); RichString_append(out, CRT_colors[METER_TEXT], ":"); RichString_append(out, CRT_colors[CPU_NORMAL], buffer); if (this->pl->settings->detailedCPUTime) { - sprintf(buffer, "%5.1f%% ", this->values[CPU_METER_KERNEL]); + snprintf(buffer, sizeof(buffer), "%5.1f%% ", this->values[CPU_METER_KERNEL]); RichString_append(out, CRT_colors[METER_TEXT], "sy:"); RichString_append(out, CRT_colors[CPU_KERNEL], buffer); - sprintf(buffer, "%5.1f%% ", this->values[CPU_METER_NICE]); + snprintf(buffer, sizeof(buffer), "%5.1f%% ", this->values[CPU_METER_NICE]); RichString_append(out, CRT_colors[METER_TEXT], "ni:"); RichString_append(out, CRT_colors[CPU_NICE_TEXT], buffer); - sprintf(buffer, "%5.1f%% ", this->values[CPU_METER_IRQ]); + snprintf(buffer, sizeof(buffer), "%5.1f%% ", this->values[CPU_METER_IRQ]); RichString_append(out, CRT_colors[METER_TEXT], "hi:"); RichString_append(out, CRT_colors[CPU_IRQ], buffer); - sprintf(buffer, "%5.1f%% ", this->values[CPU_METER_SOFTIRQ]); + snprintf(buffer, sizeof(buffer), "%5.1f%% ", this->values[CPU_METER_SOFTIRQ]); RichString_append(out, CRT_colors[METER_TEXT], "si:"); RichString_append(out, CRT_colors[CPU_SOFTIRQ], buffer); if (this->values[CPU_METER_STEAL]) { - sprintf(buffer, "%5.1f%% ", this->values[CPU_METER_STEAL]); + snprintf(buffer, sizeof(buffer), "%5.1f%% ", this->values[CPU_METER_STEAL]); RichString_append(out, CRT_colors[METER_TEXT], "st:"); RichString_append(out, CRT_colors[CPU_STEAL], buffer); } if (this->values[CPU_METER_GUEST]) { - sprintf(buffer, "%5.1f%% ", this->values[CPU_METER_GUEST]); + snprintf(buffer, sizeof(buffer), "%5.1f%% ", this->values[CPU_METER_GUEST]); RichString_append(out, CRT_colors[METER_TEXT], "gu:"); RichString_append(out, CRT_colors[CPU_GUEST], buffer); } - sprintf(buffer, "%5.1f%% ", this->values[CPU_METER_IOWAIT]); + snprintf(buffer, sizeof(buffer), "%5.1f%% ", this->values[CPU_METER_IOWAIT]); RichString_append(out, CRT_colors[METER_TEXT], "wa:"); RichString_append(out, CRT_colors[CPU_IOWAIT], buffer); } else { - sprintf(buffer, "%5.1f%% ", this->values[CPU_METER_KERNEL]); + snprintf(buffer, sizeof(buffer), "%5.1f%% ", this->values[CPU_METER_KERNEL]); RichString_append(out, CRT_colors[METER_TEXT], "sys:"); RichString_append(out, CRT_colors[CPU_KERNEL], buffer); - sprintf(buffer, "%5.1f%% ", this->values[CPU_METER_NICE]); + snprintf(buffer, sizeof(buffer), "%5.1f%% ", this->values[CPU_METER_NICE]); RichString_append(out, CRT_colors[METER_TEXT], "low:"); RichString_append(out, CRT_colors[CPU_NICE_TEXT], buffer); if (this->values[CPU_METER_IRQ]) { - sprintf(buffer, "%5.1f%% ", this->values[CPU_METER_IRQ]); + snprintf(buffer, sizeof(buffer), "%5.1f%% ", this->values[CPU_METER_IRQ]); RichString_append(out, CRT_colors[METER_TEXT], "vir:"); RichString_append(out, CRT_colors[CPU_GUEST], buffer); } diff --git a/LoadAverageMeter.c b/LoadAverageMeter.c index 54e517a..517031d 100644 --- a/LoadAverageMeter.c +++ b/LoadAverageMeter.c @@ -28,11 +28,11 @@ static void LoadAverageMeter_updateValues(Meter* this, char* buffer, int size) { static void LoadAverageMeter_display(Object* cast, RichString* out) { Meter* this = (Meter*)cast; char buffer[20]; - sprintf(buffer, "%.2f ", this->values[0]); + snprintf(buffer, sizeof(buffer), "%.2f ", this->values[0]); RichString_write(out, CRT_colors[LOAD_AVERAGE_ONE], buffer); - sprintf(buffer, "%.2f ", this->values[1]); + snprintf(buffer, sizeof(buffer), "%.2f ", this->values[1]); RichString_append(out, CRT_colors[LOAD_AVERAGE_FIVE], buffer); - sprintf(buffer, "%.2f ", this->values[2]); + snprintf(buffer, sizeof(buffer), "%.2f ", this->values[2]); RichString_append(out, CRT_colors[LOAD_AVERAGE_FIFTEEN], buffer); } @@ -48,7 +48,7 @@ static void LoadMeter_updateValues(Meter* this, char* buffer, int size) { static void LoadMeter_display(Object* cast, RichString* out) { Meter* this = (Meter*)cast; char buffer[20]; - sprintf(buffer, "%.2f ", ((Meter*)this)->values[0]); + snprintf(buffer, sizeof(buffer), "%.2f ", ((Meter*)this)->values[0]); RichString_write(out, CRT_colors[LOAD], buffer); } diff --git a/Process.c b/Process.c index a1ffcf0..fea5533 100644 --- a/Process.c +++ b/Process.c @@ -198,7 +198,7 @@ void Process_setupColumnWidths() { snprintf(Process_titleBuffer[i], 20, "%*s ", digits, Process_pidColumns[i].label); Process_fields[Process_pidColumns[i].id].title = Process_titleBuffer[i]; } - sprintf(Process_pidFormat, "%%%dd ", digits); + snprintf(Process_pidFormat, sizeof(Process_pidFormat), "%%%dd ", digits); } void Process_humanNumber(RichString* str, unsigned long number, bool coloring) { diff --git a/TasksMeter.c b/TasksMeter.c index 78a1468..3e69531 100644 --- a/TasksMeter.c +++ b/TasksMeter.c @@ -40,7 +40,7 @@ static void TasksMeter_display(Object* cast, RichString* out) { int processes = (int) this->values[2]; - sprintf(buffer, "%d", processes); + snprintf(buffer, sizeof(buffer), "%d", processes); RichString_write(out, CRT_colors[METER_VALUE], buffer); int threadValueColor = CRT_colors[METER_VALUE]; int threadCaptionColor = CRT_colors[METER_TEXT]; @@ -50,18 +50,18 @@ static void TasksMeter_display(Object* cast, RichString* out) { } if (!settings->hideUserlandThreads) { RichString_append(out, CRT_colors[METER_TEXT], ", "); - sprintf(buffer, "%d", (int)this->values[1]); + snprintf(buffer, sizeof(buffer), "%d", (int)this->values[1]); RichString_append(out, threadValueColor, buffer); RichString_append(out, threadCaptionColor, " thr"); } if (!settings->hideKernelThreads) { RichString_append(out, CRT_colors[METER_TEXT], ", "); - sprintf(buffer, "%d", (int)this->values[0]); + snprintf(buffer, sizeof(buffer), "%d", (int)this->values[0]); RichString_append(out, threadValueColor, buffer); RichString_append(out, threadCaptionColor, " kthr"); } RichString_append(out, CRT_colors[METER_TEXT], "; "); - sprintf(buffer, "%d", (int)this->values[3]); + snprintf(buffer, sizeof(buffer), "%d", (int)this->values[3]); RichString_append(out, CRT_colors[TASKS_RUNNING], buffer); RichString_append(out, CRT_colors[METER_TEXT], " running"); } diff --git a/TraceScreen.c b/TraceScreen.c index 2d6eb33..bd77118 100644 --- a/TraceScreen.c +++ b/TraceScreen.c @@ -99,7 +99,7 @@ bool TraceScreen_forkTracer(TraceScreen* this) { dup2(this->fdpair[1], STDERR_FILENO); int ok = fcntl(this->fdpair[1], F_SETFL, O_NONBLOCK); if (ok != -1) { - sprintf(buffer, "%d", this->super.process->pid); + snprintf(buffer, sizeof(buffer), "%d", this->super.process->pid); execlp("strace", "strace", "-p", buffer, NULL); } const char* message = "Could not execute 'strace'. Please make sure it is available in your $PATH."; diff --git a/UptimeMeter.c b/UptimeMeter.c index d20c479..2fe603a 100644 --- a/UptimeMeter.c +++ b/UptimeMeter.c @@ -33,11 +33,11 @@ static void UptimeMeter_updateValues(Meter* this, char* buffer, int len) { } char daysbuf[15]; if (days > 100) { - sprintf(daysbuf, "%d days(!), ", days); + snprintf(daysbuf, sizeof(daysbuf), "%d days(!), ", days); } else if (days > 1) { - sprintf(daysbuf, "%d days, ", days); + snprintf(daysbuf, sizeof(daysbuf), "%d days, ", days); } else if (days == 1) { - sprintf(daysbuf, "1 day, "); + snprintf(daysbuf, sizeof(daysbuf), "1 day, "); } else { daysbuf[0] = '\0'; } -- GitLab