From ce5eb07339b9162812458ee611b6e7af7604a3e4 Mon Sep 17 00:00:00 2001 From: "David E. Box" Date: Tue, 8 Jul 2014 10:06:17 +0800 Subject: [PATCH] ACPICA: Utilities: Validate full RSDP header Implement proper RSDP validation in acpi_ut_read_table(). Prevents a segmentation fault that can occur if a user passes the wrong file to iasl. This patch is only useful for iasl, which is not shipped in the Linux kernel. After the new table reading utility functions are well tested, acpidump can also switch to use the generic acpi_ut_read_table_xxx() APIs. Currently this patch is no-op as acpidump does not link to the new APIs. Signed-off-by: David E. Box Signed-off-by: Bob Moore Signed-off-by: Lv Zheng Signed-off-by: Rafael J. Wysocki --- drivers/acpi/acpica/utfileio.c | 19 +++++++------------ 1 file changed, 7 insertions(+), 12 deletions(-) diff --git a/drivers/acpi/acpica/utfileio.c b/drivers/acpi/acpica/utfileio.c index c8f63594b198..bdf9914733cb 100644 --- a/drivers/acpi/acpica/utfileio.c +++ b/drivers/acpi/acpica/utfileio.c @@ -150,6 +150,7 @@ acpi_ut_read_table(FILE * fp, acpi_status status; u32 file_size; u8 standard_header = TRUE; + s32 count; /* Get the file size */ @@ -164,27 +165,21 @@ acpi_ut_read_table(FILE * fp, /* Read the signature */ - if (fread(&table_header, 1, 4, fp) != 4) { - acpi_os_printf("Could not read the table signature\n"); + fseek(fp, 0, SEEK_SET); + + count = fread(&table_header, 1, sizeof(struct acpi_table_header), fp); + if (count != sizeof(struct acpi_table_header)) { + acpi_os_printf("Could not read the table header\n"); return (AE_BAD_HEADER); } - fseek(fp, 0, SEEK_SET); - /* The RSDP table does not have standard ACPI header */ - if (ACPI_COMPARE_NAME(table_header.signature, "RSD ")) { + if (ACPI_VALIDATE_RSDP_SIG(table_header.signature)) { *table_length = file_size; standard_header = FALSE; } else { - /* Read the table header */ - if (fread - (&table_header, 1, sizeof(struct acpi_table_header), - fp) != sizeof(struct acpi_table_header)) { - acpi_os_printf("Could not read the table header\n"); - return (AE_BAD_HEADER); - } #if 0 /* Validate the table header/length */ -- 2.20.1