| Message ID | 20220105174714.15723-1-mlangsdo@redhat.com (mailing list archive) |
|---|---|
| State | Mainlined, archived |
| Headers | show |
| Series | ACPI: SPCR: check if table->serial_port.access_width is too wide | expand |
On Wed, Jan 5, 2022 at 6:47 PM Mark Langsdorf <mlangsdo@redhat.com> wrote: > > 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> > --- > drivers/acpi/spcr.c | 9 +++++++-- > 1 file 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; > -- Applied as 5.17-rc material, thanks!
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;
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> --- drivers/acpi/spcr.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-)