4.20-stable review patch. If anyone has any objections, please let me know.
------------------
[ Upstream commit 53bb565fc5439f2c8c57a786feea5946804aa3e9 ]
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: Sasha Levin sashal@kernel.org --- arch/x86/pci/broadcom_bus.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
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); }