From: Colin Ian King Date: Thu, 25 Oct 2018 13:52:31 +0000 (+0100) Subject: x86/PCI: Fix Broadcom CNB20LE unintended sign extension (redux) X-Git-Tag: v5.0-rc1~17^2~11^2 X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=53bb565fc5439f2c8c57a786feea5946804aa3e9;p=linux.git x86/PCI: Fix Broadcom CNB20LE unintended sign extension (redux) 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 Signed-off-by: Bjorn Helgaas --- diff --git a/arch/x86/pci/broadcom_bus.c b/arch/x86/pci/broadcom_bus.c index 526536c81ddc..ca1e8e6dccc8 100644 --- 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, u8 slot, u8 func) 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); }