| From: Colin Ian King <colin.king@canonical.com> |
| Date: Thu, 25 Oct 2018 14:52:31 +0100 |
| Subject: x86/PCI: Fix Broadcom CNB20LE unintended sign extension (redux) |
| |
| commit 53bb565fc5439f2c8c57a786feea5946804aa3e9 upstream. |
| |
| In the expression "word1 << 16", word1 starts as u16, but is promoted to a |
| signed int, then sign-extended to resource_size_t, which is probably not |
| what was intended. Cast to resource_size_t to avoid the sign extension. |
| |
| This fixes an identical issue as fixed by commit 0b2d70764bb3 ("x86/PCI: |
| Fix Broadcom CNB20LE unintended sign extension") back in 2014. |
| |
| Detected by CoverityScan, CID#138749, 138750 ("Unintended sign extension") |
| |
| Fixes: 3f6ea84a3035 ("PCI: read memory ranges out of Broadcom CNB20LE host bridge") |
| Signed-off-by: Colin Ian King <colin.king@canonical.com> |
| Signed-off-by: Bjorn Helgaas <helgaas@kernel.org> |
| Signed-off-by: Ben Hutchings <ben@decadent.org.uk> |
| --- |
| arch/x86/pci/broadcom_bus.c | 4 ++-- |
| 1 file changed, 2 insertions(+), 2 deletions(-) |
| |
| --- a/arch/x86/pci/broadcom_bus.c |
| +++ b/arch/x86/pci/broadcom_bus.c |
| @@ -50,8 +50,8 @@ static void __init cnb20le_res(u8 bus, u |
| word1 = read_pci_config_16(bus, slot, func, 0xc0); |
| word2 = read_pci_config_16(bus, slot, func, 0xc2); |
| if (word1 != word2) { |
| - res.start = (word1 << 16) | 0x0000; |
| - res.end = (word2 << 16) | 0xffff; |
| + res.start = ((resource_size_t) word1 << 16) | 0x0000; |
| + res.end = ((resource_size_t) word2 << 16) | 0xffff; |
| res.flags = IORESOURCE_MEM; |
| update_res(info, res.start, res.end, res.flags, 0); |
| } |
