There are several places to perform subtraction to calculate buffer size such as: si->si_ofs.cydata_size = si->si_ofs.test_ofs - si->si_ofs.cydata_ofs; ... p = krealloc(si->si_ptrs.cydata, si->si_ofs.cydata_size, GFP_KERNEL); Actually, data types of above variables during subtraction are size_t, so it is unsigned. That means if second operand(si->si_ofs.cydata_ofs) is greater than the first operand(si->si_ofs.test_ofs), then resulting si->si_ofs.cydata_size could result in an unsigned integer wrap which is not desiarable. The properway to correct this problem is to perform a test of both operands to avoid having unsigned wrap. --- drivers/input/touchscreen/cyttsp4_core.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/drivers/input/touchscreen/cyttsp4_core.c b/drivers/input/touchscreen/cyttsp4_core.c index beaf61c..eecc7f1 100644 --- a/drivers/input/touchscreen/cyttsp4_core.c +++ b/drivers/input/touchscreen/cyttsp4_core.c @@ -201,6 +201,11 @@ static int cyttsp4_si_get_cydata(struct cyttsp4 *cd) void *p; int rc; + if (si->si_ofs.test_ofs <= si->si_ofs.cydata_ofs) + dev_err(cd->dev, "%s: invalid offset test_ofs:%zd, cydata_ofs:%zd \n", __func__, si->si_ofs.test_ofs, si->si_ofs.cydata_ofs); + return -EINVAL; + } + si->si_ofs.cydata_size = si->si_ofs.test_ofs - si->si_ofs.cydata_ofs; dev_dbg(cd->dev, "%s: cydata size: %zd\n", __func__, si->si_ofs.cydata_size); @@ -270,6 +275,11 @@ static int cyttsp4_si_get_test_data(struct cyttsp4 *cd) void *p; int rc; + if (si->si_ofs.pcfg_ofs <= si->si_ofs.test_ofs) + dev_err(cd->dev, "%s: invalid offset pcfg_ofs:%zd, test_ofs:%zd \n", __func__, si->si_ofs.pcfg_ofs, si->si_ofs.test_ofs); + return -EINVAL; + } + si->si_ofs.test_size = si->si_ofs.pcfg_ofs - si->si_ofs.test_ofs; p = krealloc(si->si_ptrs.test, si->si_ofs.test_size, GFP_KERNEL); @@ -321,6 +331,11 @@ static int cyttsp4_si_get_pcfg_data(struct cyttsp4 *cd) void *p; int rc; + if (si->si_ofs.opcfg_ofs <= si->si_ofs.pcfg_ofs) + dev_err(cd->dev, "%s: invalid offset opcfg_ofs:%zd, pcfg_ofs:%zd \n", __func__, si->si_ofs.opcfg_ofs, si->si_ofs.pcfg_ofs); + return -EINVAL; + } + si->si_ofs.pcfg_size = si->si_ofs.opcfg_ofs - si->si_ofs.pcfg_ofs; p = krealloc(si->si_ptrs.pcfg, si->si_ofs.pcfg_size, GFP_KERNEL); @@ -367,6 +382,11 @@ static int cyttsp4_si_get_opcfg_data(struct cyttsp4 *cd) void *p; int rc; + if (si->si_ofs.ddata_ofs <= si->si_ofs.opcfg_ofs) + dev_err(cd->dev, "%s: invalid offset ddata_ofs:%zd, opcfg_ofs:%zd \n", __func__, si->si_ofs.ddata_ofs, si->si_ofs.opcfg_ofs); + return -EINVAL; + } + si->si_ofs.opcfg_size = si->si_ofs.ddata_ofs - si->si_ofs.opcfg_ofs; p = krealloc(si->si_ptrs.opcfg, si->si_ofs.opcfg_size, GFP_KERNEL); -- 2.7.4 -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
