From: Punit Agrawal Date: Fri, 24 Oct 2025 12:31:25 +0000 (+0100) Subject: ACPI: SPCR: Check for table version when using precise baudrate X-Git-Tag: v6.12.58~4 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=3f916a93fc59895a5b18a604cf06ffb9ad96c3c7;p=thirdparty%2Fkernel%2Fstable.git ACPI: SPCR: Check for table version when using precise baudrate commit 543d35004007a06ef247acf2fc55efa8388aa741 upstream. Commit 4d330fe54145 ("ACPI: SPCR: Support Precise Baud Rate field") added support to use the precise baud rate available since SPCR 1.09 (revision 4) but failed to check the version of the table provided by the firmware. Accessing an older version of SPCR table causes accesses beyond the end of the table and can lead to garbage data to be used for the baud rate. Check the version of the firmware provided SPCR to ensure that the precise baudrate is vaild before using it. Fixes: 4d330fe54145 ("ACPI: SPCR: Support Precise Baud Rate field") Signed-off-by: Punit Agrawal Link: https://patch.msgid.link/20251024123125.1081612-1-punit.agrawal@oss.qualcomm.com Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/acpi/spcr.c b/drivers/acpi/spcr.c index fa12e740386de..52bd7e800b1d8 100644 --- a/drivers/acpi/spcr.c +++ b/drivers/acpi/spcr.c @@ -152,7 +152,7 @@ int __init acpi_parse_spcr(bool enable_earlycon, bool enable_console) * Baud Rate field. If this field is zero or not present, Configured * Baud Rate is used. */ - if (table->precise_baudrate) + if (table->header.revision >= 4 && table->precise_baudrate) baud_rate = table->precise_baudrate; else switch (table->baud_rate) { case 0: