fix: harmless 'dmesg: write error' that could happen on some systems

Fixes #519.
This commit is contained in:
Stéphane Lesimple
2026-01-25 11:49:17 +01:00
parent 8e33a1dbf2
commit d550ea8c85

View File

@@ -1889,11 +1889,11 @@ dmesg_grep()
# grep for something in dmesg, ensuring that the dmesg buffer
# has not been truncated
dmesg_grepped=''
if ! dmesg | grep -qE -e '(^|\] )Linux version [0-9]' -e '^FreeBSD is a registered' ; then
if ! dmesg 2>/dev/null | grep -qE -e '(^|\] )Linux version [0-9]' -e '^FreeBSD is a registered' ; then
# dmesg truncated
return 2
fi
dmesg_grepped=$(dmesg | grep -E "$1" | head -n1)
dmesg_grepped=$(dmesg 2>/dev/null | grep -E "$1" | head -n1)
# not found:
[ -z "$dmesg_grepped" ] && return 1
# found, output is in $dmesg_grepped
@@ -2020,13 +2020,13 @@ write_msr_one_core()
msr_locked_down=1
write_msr_msg="your kernel is configured to deny writes to MSRs from user space"
return $WRITE_MSR_RET_LOCKDOWN
elif dmesg | grep -qF "msr: Direct access to MSR"; then
elif dmesg 2>/dev/null | grep -qF "msr: Direct access to MSR"; then
_debug "write_msr: locked down kernel detected (Red Hat / Fedora)"
mockme=$(printf "%b\n%b" "$mockme" "SMC_MOCK_WRMSR_${_msr}_RET=$WRITE_MSR_RET_LOCKDOWN")
msr_locked_down=1
write_msr_msg="your kernel is locked down (Fedora/Red Hat), please reboot without secure boot and retry"
return $WRITE_MSR_RET_LOCKDOWN
elif dmesg | grep -qF "raw MSR access is restricted"; then
elif dmesg 2>/dev/null | grep -qF "raw MSR access is restricted"; then
_debug "write_msr: locked down kernel detected (vanilla)"
mockme=$(printf "%b\n%b" "$mockme" "SMC_MOCK_WRMSR_${_msr}_RET=$WRITE_MSR_RET_LOCKDOWN")
msr_locked_down=1
@@ -2217,12 +2217,12 @@ parse_cpu_details()
cpu_stepping=$(grep '^stepping' "$procfs/cpuinfo" | awk '{print $3}' | grep -E '^[0-9]+$' | head -n1)
cpu_ucode=$( grep '^microcode' "$procfs/cpuinfo" | awk '{print $3}' | head -n1)
else
cpu_vendor=$( dmesg | grep -i -m1 'Origin=' | cut -f2 -w | cut -f2 -d= | cut -f2 -d\" )
cpu_family=$( dmesg | grep -i -m1 'Family=' | cut -f4 -w | cut -f2 -d= )
cpu_vendor=$( dmesg 2>/dev/null | grep -i -m1 'Origin=' | cut -f2 -w | cut -f2 -d= | cut -f2 -d\" )
cpu_family=$( dmesg 2>/dev/null | grep -i -m1 'Family=' | cut -f4 -w | cut -f2 -d= )
cpu_family=$(( cpu_family ))
cpu_model=$( dmesg | grep -i -m1 'Model=' | cut -f5 -w | cut -f2 -d= )
cpu_model=$( dmesg 2>/dev/null | grep -i -m1 'Model=' | cut -f5 -w | cut -f2 -d= )
cpu_model=$(( cpu_model ))
cpu_stepping=$( dmesg | grep -i -m1 'Stepping=' | cut -f6 -w | cut -f2 -d= )
cpu_stepping=$( dmesg 2>/dev/null | grep -i -m1 'Stepping=' | cut -f6 -w | cut -f2 -d= )
cpu_friendly_name=$(sysctl -n hw.model 2>/dev/null)
fi
@@ -4863,7 +4863,7 @@ check_CVE_2017_5754_linux()
kpti_enabled=$(cat /sys/kernel/debug/x86/pti_enabled 2>/dev/null)
_debug "kpti_enabled: file /sys/kernel/debug/x86/pti_enabled exists and says: $kpti_enabled"
elif is_xen_dom0; then
pti_xen_pv_domU=$(xl dmesg | grep 'XPTI' | grep 'DomU enabled' | head -n1)
pti_xen_pv_domU=$(xl dmesg 2>/dev/null | grep 'XPTI' | grep 'DomU enabled' | head -n1)
[ -n "$pti_xen_pv_domU" ] && kpti_enabled=1
fi
@@ -5481,9 +5481,9 @@ check_CVE_2018_3646_linux()
pstatus green YES "unconditional flushes"
else
if is_xen_dom0; then
l1d_xen_hardware=$(xl dmesg | grep 'Hardware features:' | grep 'L1D_FLUSH' | head -n1)
l1d_xen_hypervisor=$(xl dmesg | grep 'Xen settings:' | grep 'L1D_FLUSH' | head -n1)
l1d_xen_pv_domU=$(xl dmesg | grep 'PV L1TF shadowing:' | grep 'DomU enabled' | head -n1)
l1d_xen_hardware=$(xl dmesg 2>/dev/null | grep 'Hardware features:' | grep 'L1D_FLUSH' | head -n1)
l1d_xen_hypervisor=$(xl dmesg 2>/dev/null | grep 'Xen settings:' | grep 'L1D_FLUSH' | head -n1)
l1d_xen_pv_domU=$(xl dmesg 2>/dev/null | grep 'PV L1TF shadowing:' | grep 'DomU enabled' | head -n1)
if [ -n "$l1d_xen_hardware" ] && [ -n "$l1d_xen_hypervisor" ] && [ -n "$l1d_xen_pv_domU" ]; then
l1d_mode=5