diff options
| author | Mark Langsdorf <mlangsdo@redhat.com> | 2022-01-05 11:47:14 -0600 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2022-01-11 16:39:14 +0100 |
| commit | ee3fe99ff0a27108ac38d9766ac0e92f5ec35692 (patch) | |
| tree | 04191cd3135a5fc1aee346d98e9f94c5d2890c89 /drivers | |
| parent | bca21755b9fc00dbe371994b53389eb5d70b8e72 (diff) | |
ACPI: SPCR: check if table->serial_port.access_width is too wide
If table->serial_port.access_width is more than 29, it causes
undefined behavior when ACPI_ACCESS_BIT_WIDTH shifts it to
(1 << ((size) + 2)):
[ 0.000000] UBSAN: Undefined behaviour in drivers/acpi/spcr.c:114:11
[ 0.000000] shift exponent 102 is too large for 32-bit type 'int'
Use the new ACPI_ACCESS_ defines to test that serial_port.access_width
is less than 30 and set it to 6 if it is not.
Signed-off-by: Mark Langsdorf <mlangsdo@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/acpi/spcr.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/drivers/acpi/spcr.c b/drivers/acpi/spcr.c index 25c2d0be953e..d589543875b8 100644 --- a/drivers/acpi/spcr.c +++ b/drivers/acpi/spcr.c @@ -107,8 +107,13 @@ int __init acpi_parse_spcr(bool enable_earlycon, bool enable_console) pr_info("SPCR table version %d\n", table->header.revision); if (table->serial_port.space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) { - switch (ACPI_ACCESS_BIT_WIDTH(( - table->serial_port.access_width))) { + u32 bit_width = table->serial_port.access_width; + + if (bit_width > ACPI_ACCESS_BIT_MAX) { + pr_err("Unacceptable wide SPCR Access Width. Defaulting to byte size\n"); + bit_width = ACPI_ACCESS_BIT_DEFAULT; + } + switch (ACPI_ACCESS_BIT_WIDTH((bit_width))) { default: pr_err("Unexpected SPCR Access Width. Defaulting to byte size\n"); fallthrough; |