From: Sergey Shtylyov <s.shtylyov@xxxxxx> commit f5d8a5fe77ce933f53eb8f2e22bb7a1a2019ea11 upstream. sprintf() (still used in the MMC core for the sysfs output) is vulnerable to the buffer overflow. Use the new-fangled sysfs_emit() instead. Found by Linux Verification Center (linuxtesting.org) with the SVACE static analysis tool. Signed-off-by: Sergey Shtylyov <s.shtylyov@xxxxxx> Cc: stable@xxxxxxxxxxxxxxx Link: https://lore.kernel.org/r/717729b2-d65b-c72e-9fac-471d28d00b5a@xxxxxx Signed-off-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/mmc/core/bus.c | 9 +++++---- drivers/mmc/core/bus.h | 3 ++- drivers/mmc/core/mmc.c | 16 ++++++++-------- drivers/mmc/core/sd.c | 27 +++++++++++++-------------- drivers/mmc/core/sdio.c | 5 +++-- drivers/mmc/core/sdio_bus.c | 7 ++++--- 6 files changed, 35 insertions(+), 32 deletions(-) --- a/drivers/mmc/core/bus.c +++ b/drivers/mmc/core/bus.c @@ -15,6 +15,7 @@ #include <linux/stat.h> #include <linux/of.h> #include <linux/pm_runtime.h> +#include <linux/sysfs.h> #include <linux/mmc/card.h> #include <linux/mmc/host.h> @@ -34,13 +35,13 @@ static ssize_t type_show(struct device * switch (card->type) { case MMC_TYPE_MMC: - return sprintf(buf, "MMC\n"); + return sysfs_emit(buf, "MMC\n"); case MMC_TYPE_SD: - return sprintf(buf, "SD\n"); + return sysfs_emit(buf, "SD\n"); case MMC_TYPE_SDIO: - return sprintf(buf, "SDIO\n"); + return sysfs_emit(buf, "SDIO\n"); case MMC_TYPE_SD_COMBO: - return sprintf(buf, "SDcombo\n"); + return sysfs_emit(buf, "SDcombo\n"); default: return -EFAULT; } --- a/drivers/mmc/core/bus.h +++ b/drivers/mmc/core/bus.h @@ -9,6 +9,7 @@ #define _MMC_CORE_BUS_H #include <linux/device.h> +#include <linux/sysfs.h> struct mmc_host; struct mmc_card; @@ -17,7 +18,7 @@ struct mmc_card; static ssize_t mmc_##name##_show (struct device *dev, struct device_attribute *attr, char *buf) \ { \ struct mmc_card *card = mmc_dev_to_card(dev); \ - return sprintf(buf, fmt, args); \ + return sysfs_emit(buf, fmt, args); \ } \ static DEVICE_ATTR(name, S_IRUGO, mmc_##name##_show, NULL) --- a/drivers/mmc/core/mmc.c +++ b/drivers/mmc/core/mmc.c @@ -12,6 +12,7 @@ #include <linux/slab.h> #include <linux/stat.h> #include <linux/pm_runtime.h> +#include <linux/sysfs.h> #include <linux/mmc/host.h> #include <linux/mmc/card.h> @@ -812,12 +813,11 @@ static ssize_t mmc_fwrev_show(struct dev { struct mmc_card *card = mmc_dev_to_card(dev); - if (card->ext_csd.rev < 7) { - return sprintf(buf, "0x%x\n", card->cid.fwrev); - } else { - return sprintf(buf, "0x%*phN\n", MMC_FIRMWARE_LEN, - card->ext_csd.fwrev); - } + if (card->ext_csd.rev < 7) + return sysfs_emit(buf, "0x%x\n", card->cid.fwrev); + else + return sysfs_emit(buf, "0x%*phN\n", MMC_FIRMWARE_LEN, + card->ext_csd.fwrev); } static DEVICE_ATTR(fwrev, S_IRUGO, mmc_fwrev_show, NULL); @@ -830,10 +830,10 @@ static ssize_t mmc_dsr_show(struct devic struct mmc_host *host = card->host; if (card->csd.dsr_imp && host->dsr_req) - return sprintf(buf, "0x%x\n", host->dsr); + return sysfs_emit(buf, "0x%x\n", host->dsr); else /* return default DSR value */ - return sprintf(buf, "0x%x\n", 0x404); + return sysfs_emit(buf, "0x%x\n", 0x404); } static DEVICE_ATTR(dsr, S_IRUGO, mmc_dsr_show, NULL); --- a/drivers/mmc/core/sd.c +++ b/drivers/mmc/core/sd.c @@ -13,6 +13,7 @@ #include <linux/stat.h> #include <linux/pm_runtime.h> #include <linux/scatterlist.h> +#include <linux/sysfs.h> #include <linux/mmc/host.h> #include <linux/mmc/card.h> @@ -708,18 +709,16 @@ MMC_DEV_ATTR(ocr, "0x%08x\n", card->ocr) MMC_DEV_ATTR(rca, "0x%04x\n", card->rca); -static ssize_t mmc_dsr_show(struct device *dev, - struct device_attribute *attr, - char *buf) -{ - struct mmc_card *card = mmc_dev_to_card(dev); - struct mmc_host *host = card->host; - - if (card->csd.dsr_imp && host->dsr_req) - return sprintf(buf, "0x%x\n", host->dsr); - else - /* return default DSR value */ - return sprintf(buf, "0x%x\n", 0x404); +static ssize_t mmc_dsr_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct mmc_card *card = mmc_dev_to_card(dev); + struct mmc_host *host = card->host; + + if (card->csd.dsr_imp && host->dsr_req) + return sysfs_emit(buf, "0x%x\n", host->dsr); + /* return default DSR value */ + return sysfs_emit(buf, "0x%x\n", 0x404); } static DEVICE_ATTR(dsr, S_IRUGO, mmc_dsr_show, NULL); @@ -735,9 +734,9 @@ static ssize_t info##num##_show(struct d \ if (num > card->num_info) \ return -ENODATA; \ - if (!card->info[num-1][0]) \ + if (!card->info[num - 1][0]) \ return 0; \ - return sprintf(buf, "%s\n", card->info[num-1]); \ + return sysfs_emit(buf, "%s\n", card->info[num - 1]); \ } \ static DEVICE_ATTR_RO(info##num) --- a/drivers/mmc/core/sdio.c +++ b/drivers/mmc/core/sdio.c @@ -7,6 +7,7 @@ #include <linux/err.h> #include <linux/pm_runtime.h> +#include <linux/sysfs.h> #include <linux/mmc/host.h> #include <linux/mmc/card.h> @@ -40,9 +41,9 @@ static ssize_t info##num##_show(struct d \ if (num > card->num_info) \ return -ENODATA; \ - if (!card->info[num-1][0]) \ + if (!card->info[num - 1][0]) \ return 0; \ - return sprintf(buf, "%s\n", card->info[num-1]); \ + return sysfs_emit(buf, "%s\n", card->info[num - 1]); \ } \ static DEVICE_ATTR_RO(info##num) --- a/drivers/mmc/core/sdio_bus.c +++ b/drivers/mmc/core/sdio_bus.c @@ -14,6 +14,7 @@ #include <linux/pm_runtime.h> #include <linux/pm_domain.h> #include <linux/acpi.h> +#include <linux/sysfs.h> #include <linux/mmc/card.h> #include <linux/mmc/host.h> @@ -35,7 +36,7 @@ field##_show(struct device *dev, struct struct sdio_func *func; \ \ func = dev_to_sdio_func (dev); \ - return sprintf(buf, format_string, args); \ + return sysfs_emit(buf, format_string, args); \ } \ static DEVICE_ATTR_RO(field) @@ -52,9 +53,9 @@ static ssize_t info##num##_show(struct d \ if (num > func->num_info) \ return -ENODATA; \ - if (!func->info[num-1][0]) \ + if (!func->info[num - 1][0]) \ return 0; \ - return sprintf(buf, "%s\n", func->info[num-1]); \ + return sysfs_emit(buf, "%s\n", func->info[num - 1]); \ } \ static DEVICE_ATTR_RO(info##num)
