[PATCH v2 3/5] DFU: Check the number of arguments and argument string strictly

Masami Hiramatsu
2022-01-31T02:52:54Z

When parsing the dfu_alt_info, check the number of arguments
and argument string strictly. If there is any garbage data
(which is not able to be parsed correctly) in dfu_alt_info,
that means something wrong and user may make a typo or mis-
understanding about the syntax. Since the dfu_alt_info is
used for updating the firmware, this mistake may lead to
brick the hardware.
Thus it should be checked strictly for making sure there
is no mistake.

Signed-off-by: Masami Hiramatsu <masami.hiramatsu@linaro.org>
---
drivers/dfu/dfu.c | 31 +++++++++++++++++++++------
drivers/dfu/dfu_mmc.c | 56 ++++++++++++++++++++++++++----------------------
drivers/dfu/dfu_mtd.c | 36 +++++++++++++++++++------------
drivers/dfu/dfu_nand.c | 39 ++++++++++++++++++---------------
drivers/dfu/dfu_ram.c | 25 ++++++++++-----------
drivers/dfu/dfu_sf.c | 38 +++++++++++++++++----------------
drivers/dfu/dfu_virt.c | 5 +++-
include/dfu.h | 33 ++++++++++++++++++----------
8 files changed, 154 insertions(+), 109 deletions(-)

diff --git a/drivers/dfu/dfu.c b/drivers/dfu/dfu.c
index 18154774f9..516dda6179 100644
--- a/drivers/dfu/dfu.c
+++ b/drivers/dfu/dfu.c
@@ -500,12 +500,29 @@ int dfu_read(struct dfu_entity *dfu, void *buf, int size, int blk_seq_num)
static int dfu_fill_entity(struct dfu_entity *dfu, char *s, int alt,
char *interface, char *devstr)
{
+ char *argv[DFU_MAX_ENTITY_ARGS];
+ int argc;
char *st;

debug("%s: %s interface: %s dev: %s\n", __func__, s, interface, devstr);
st = strsep(&s, " \t");
strlcpy(dfu->name, st, DFU_NAME_SIZE);
- s = skip_spaces(s);
+
+ /* Parse arguments */
+ for (argc = 0; s && argc < DFU_MAX_ENTITY_ARGS; argc++) {
+ s = skip_spaces(s);
+ if (!*s)
+ break;
+ argv[argc] = strsep(&s, " \t");
+ }
+
+ if (argc == DFU_MAX_ENTITY_ARGS && s) {
+ s = skip_spaces(s);
+ if (*s) {
+ log_err("Too many arguments for %s\n", dfu->name);
+ return -EINVAL;
+ }
+ }

dfu->alt = alt;
dfu->max_buf_size = 0;
@@ -513,22 +530,22 @@ static int dfu_fill_entity(struct dfu_entity *dfu, char *s, int alt,

/* Specific for mmc device */
if (strcmp(interface, "mmc") == 0) {
- if (dfu_fill_entity_mmc(dfu, devstr, s))
+ if (dfu_fill_entity_mmc(dfu, devstr, argv, argc))
return -1;
} else if (strcmp(interface, "mtd") == 0) {
- if (dfu_fill_entity_mtd(dfu, devstr, s))
+ if (dfu_fill_entity_mtd(dfu, devstr, argv, argc))
return -1;
} else if (strcmp(interface, "nand") == 0) {
- if (dfu_fill_entity_nand(dfu, devstr, s))
+ if (dfu_fill_entity_nand(dfu, devstr, argv, argc))
return -1;
} else if (strcmp(interface, "ram") == 0) {
- if (dfu_fill_entity_ram(dfu, devstr, s))
+ if (dfu_fill_entity_ram(dfu, devstr, argv, argc))
return -1;
} else if (strcmp(interface, "sf") == 0) {
- if (dfu_fill_entity_sf(dfu, devstr, s))
+ if (dfu_fill_entity_sf(dfu, devstr, argv, argc))
return -1;
} else if (strcmp(interface, "virt") == 0) {
- if (dfu_fill_entity_virt(dfu, devstr, s))
+ if (dfu_fill_entity_virt(dfu, devstr, argv, argc))
return -1;
} else {
printf("%s: Device %s not (yet) supported!\n",
diff --git a/drivers/dfu/dfu_mmc.c b/drivers/dfu/dfu_mmc.c
index d747ede66c..a91da972d4 100644
--- a/drivers/dfu/dfu_mmc.c
+++ b/drivers/dfu/dfu_mmc.c
@@ -337,35 +337,34 @@ void dfu_free_entity_mmc(struct dfu_entity *dfu)
* 4th (optional):
* mmcpart <num> (access to HW eMMC partitions)
*/
-int dfu_fill_entity_mmc(struct dfu_entity *dfu, char *devstr, char *s)
+int dfu_fill_entity_mmc(struct dfu_entity *dfu, char *devstr, char **argv, int argc)
{
const char *entity_type;
ssize_t second_arg;
size_t third_arg;
-
struct mmc *mmc;
+ char *s;

- const char *argv[3];
- const char **parg = argv;
-
- dfu->data.mmc.dev_num = dectoul(devstr, NULL);
-
- for (; parg < argv + sizeof(argv) / sizeof(*argv); ++parg) {
- *parg = strsep(&s, " \t");
- if (*parg == NULL) {
- pr_err("Invalid number of arguments.\n");
- return -ENODEV;
- }
- s = skip_spaces(s);
+ if (argc < 3) {
+ pr_err("The number of parameters are not enough.\n");
+ return -EINVAL;
}

+ dfu->data.mmc.dev_num = dectoul(devstr, &s);
+ if (*s)
+ return -EINVAL;
+
entity_type = argv[0];
/*
* Base 0 means we'll accept (prefixed with 0x or 0) base 16, 8,
* with default 10.
*/
- second_arg = simple_strtol(argv[1], NULL, 0);
- third_arg = simple_strtoul(argv[2], NULL, 0);
+ second_arg = simple_strtol(argv[1], &s, 0);
+ if (*s)
+ return -EINVAL;
+ third_arg = simple_strtoul(argv[2], &s, 0);
+ if (*s)
+ return -EINVAL;

mmc = find_mmc_device(dfu->data.mmc.dev_num);
if (mmc == NULL) {
@@ -390,12 +389,14 @@ int dfu_fill_entity_mmc(struct dfu_entity *dfu, char *devstr, char *s)
* Check for an extra entry at dfu_alt_info env variable
* specifying the mmc HW defined partition number
*/
- if (s)
- if (!strcmp(strsep(&s, " \t"), "mmcpart")) {
- s = skip_spaces(s);
- dfu->data.mmc.hw_partition =
- simple_strtoul(s, NULL, 0);
+ if (argc > 3) {
+ if (argc != 5 || strcmp(argv[3], "mmcpart")) {
+ pr_err("DFU mmc raw accept 'mmcpart <partnum>' option.\n");
+ return -EINVAL;
}
+ dfu->data.mmc.hw_partition =
+ simple_strtoul(argv[4], NULL, 0);
+ }

} else if (!strcmp(entity_type, "part")) {
struct disk_partition partinfo;
@@ -414,15 +415,18 @@ int dfu_fill_entity_mmc(struct dfu_entity *dfu, char *devstr, char *s)
* Check for an extra entry at dfu_alt_info env variable
* specifying the mmc HW defined partition number
*/
- if (s)
- if (!strcmp(strsep(&s, " \t"), "offset")) {
- s = skip_spaces(s);
- offset = simple_strtoul(s, NULL, 0);
+ if (argc > 3) {
+ if (argc != 5 || strcmp(argv[3], "offset")) {
+ pr_err("DFU mmc raw accept 'mmcpart <partnum>' option.\n");
+ return -EINVAL;
}
+ dfu->data.mmc.hw_partition =
+ simple_strtoul(argv[4], NULL, 0);
+ }

dfu->layout = DFU_RAW_ADDR;
dfu->data.mmc.lba_start = partinfo.start + offset;
- dfu->data.mmc.lba_size = partinfo.size-offset;
+ dfu->data.mmc.lba_size = partinfo.size - offset;
dfu->data.mmc.lba_blk_size = partinfo.blksz;
} else if (!strcmp(entity_type, "fat")) {
dfu->layout = DFU_FS_FAT;
diff --git a/drivers/dfu/dfu_mtd.c b/drivers/dfu/dfu_mtd.c
index 27c011f537..c7075f12ec 100644
--- a/drivers/dfu/dfu_mtd.c
+++ b/drivers/dfu/dfu_mtd.c
@@ -271,9 +271,9 @@ static unsigned int dfu_polltimeout_mtd(struct dfu_entity *dfu)
return DFU_DEFAULT_POLL_TIMEOUT;
}

-int dfu_fill_entity_mtd(struct dfu_entity *dfu, char *devstr, char *s)
+int dfu_fill_entity_mtd(struct dfu_entity *dfu, char *devstr, char **argv, int argc)
{
- char *st;
+ char *s;
struct mtd_info *mtd;
int ret, part;

@@ -285,25 +285,33 @@ int dfu_fill_entity_mtd(struct dfu_entity *dfu, char *devstr, char *s)
dfu->dev_type = DFU_DEV_MTD;
dfu->data.mtd.info = mtd;
dfu->max_buf_size = mtd->erasesize;
+ if (argc < 1)
+ return -EINVAL;

- st = strsep(&s, " \t");
- s = skip_spaces(s);
- if (!strcmp(st, "raw")) {
+ if (!strcmp(argv[0], "raw")) {
+ if (argc != 3)
+ return -EINVAL;
dfu->layout = DFU_RAW_ADDR;
- dfu->data.mtd.start = hextoul(s, &s);
- if (!isspace(*s))
- return -1;
- s = skip_spaces(s);
- dfu->data.mtd.size = hextoul(s, &s);
- } else if ((!strcmp(st, "part")) || (!strcmp(st, "partubi"))) {
+ dfu->data.mtd.start = hextoul(argv[1], &s);
+ if (*s)
+ return -EINVAL;
+ dfu->data.mtd.size = hextoul(argv[2], &s);
+ if (*s)
+ return -EINVAL;
+ } else if ((!strcmp(argv[0], "part")) || (!strcmp(argv[0], "partubi"))) {
char mtd_id[32];
struct mtd_device *mtd_dev;
u8 part_num;
struct part_info *pi;

+ if (argc != 2)
+ return -EINVAL;
+
dfu->layout = DFU_RAW_ADDR;

- part = dectoul(s, &s);
+ part = dectoul(argv[1], &s);
+ if (*s)
+ return -EINVAL;

sprintf(mtd_id, "%s,%d", devstr, part - 1);
printf("using id '%s'\n", mtd_id);
@@ -318,10 +326,10 @@ int dfu_fill_entity_mtd(struct dfu_entity *dfu, char *devstr, char *s)

dfu->data.mtd.start = pi->offset;
dfu->data.mtd.size = pi->size;
- if (!strcmp(st, "partubi"))
+ if (!strcmp(argv[0], "partubi"))
dfu->data.mtd.ubi = 1;
} else {
- printf("%s: Memory layout (%s) not supported!\n", __func__, st);
+ printf("%s: Memory layout (%s) not supported!\n", __func__, argv[0]);
return -1;
}

diff --git a/drivers/dfu/dfu_nand.c b/drivers/dfu/dfu_nand.c
index 76761939ab..08e8cf5cdb 100644
--- a/drivers/dfu/dfu_nand.c
+++ b/drivers/dfu/dfu_nand.c
@@ -194,23 +194,25 @@ unsigned int dfu_polltimeout_nand(struct dfu_entity *dfu)
return DFU_DEFAULT_POLL_TIMEOUT;
}

-int dfu_fill_entity_nand(struct dfu_entity *dfu, char *devstr, char *s)
+int dfu_fill_entity_nand(struct dfu_entity *dfu, char *devstr, char **argv, int argc)
{
- char *st;
+ char *s;
int ret, dev, part;

dfu->data.nand.ubi = 0;
dfu->dev_type = DFU_DEV_NAND;
- st = strsep(&s, " \t");
- s = skip_spaces(s);
- if (!strcmp(st, "raw")) {
+ if (argc != 3)
+ return -EINVAL;
+
+ if (!strcmp(argv[0], "raw")) {
dfu->layout = DFU_RAW_ADDR;
- dfu->data.nand.start = hextoul(s, &s);
- if (!isspace(*s))
- return -1;
- s = skip_spaces(s);
- dfu->data.nand.size = hextoul(s, &s);
- } else if ((!strcmp(st, "part")) || (!strcmp(st, "partubi"))) {
+ dfu->data.nand.start = hextoul(argv[1], &s);
+ if (*s)
+ return -EINVAL;
+ dfu->data.nand.size = hextoul(argv[2], &s);
+ if (*s)
+ return -EINVAL;
+ } else if ((!strcmp(argv[0], "part")) || (!strcmp(argv[0], "partubi"))) {
char mtd_id[32];
struct mtd_device *mtd_dev;
u8 part_num;
@@ -218,11 +220,12 @@ int dfu_fill_entity_nand(struct dfu_entity *dfu, char *devstr, char *s)

dfu->layout = DFU_RAW_ADDR;

- dev = dectoul(s, &s);
- if (!isspace(*s))
- return -1;
- s = skip_spaces(s);
- part = dectoul(s, &s);
+ dev = dectoul(argv[1], &s);
+ if (*s)
+ return -EINVAL;
+ part = dectoul(argv[2], &s);
+ if (*s)
+ return -EINVAL;

sprintf(mtd_id, "%s%d,%d", "nand", dev, part - 1);
debug("using id '%s'\n", mtd_id);
@@ -237,10 +240,10 @@ int dfu_fill_entity_nand(struct dfu_entity *dfu, char *devstr, char *s)

dfu->data.nand.start = pi->offset;
dfu->data.nand.size = pi->size;
- if (!strcmp(st, "partubi"))
+ if (!strcmp(argv[0], "partubi"))
dfu->data.nand.ubi = 1;
} else {
- printf("%s: Memory layout (%s) not supported!\n", __func__, st);
+ printf("%s: Memory layout (%s) not supported!\n", __func__, argv[0]);
return -1;
}

diff --git a/drivers/dfu/dfu_ram.c b/drivers/dfu/dfu_ram.c
index 361a3ff8af..9d10303164 100644
--- a/drivers/dfu/dfu_ram.c
+++ b/drivers/dfu/dfu_ram.c
@@ -54,18 +54,13 @@ static int dfu_read_medium_ram(struct dfu_entity *dfu, u64 offset,
return dfu_transfer_medium_ram(DFU_OP_READ, dfu, offset, buf, len);
}

-int dfu_fill_entity_ram(struct dfu_entity *dfu, char *devstr, char *s)
+int dfu_fill_entity_ram(struct dfu_entity *dfu, char *devstr, char **argv, int argc)
{
- const char *argv[3];
- const char **parg = argv;
-
- for (; parg < argv + sizeof(argv) / sizeof(*argv); ++parg) {
- *parg = strsep(&s, " \t");
- if (*parg == NULL) {
- pr_err("Invalid number of arguments.\n");
- return -ENODEV;
- }
- s = skip_spaces(s);
+ char *s;
+
+ if (argc != 3) {
+ pr_err("Invalid number of arguments.\n");
+ return -EINVAL;
}

dfu->dev_type = DFU_DEV_RAM;
@@ -75,8 +70,12 @@ int dfu_fill_entity_ram(struct dfu_entity *dfu, char *devstr, char *s)
}

dfu->layout = DFU_RAM_ADDR;
- dfu->data.ram.start = hextoul(argv[1], NULL);
- dfu->data.ram.size = hextoul(argv[2], NULL);
+ dfu->data.ram.start = hextoul(argv[1], &s);
+ if (*s)
+ return -EINVAL;
+ dfu->data.ram.size = hextoul(argv[2], &s);
+ if (*s)
+ return -EINVAL;

dfu->write_medium = dfu_write_medium_ram;
dfu->get_medium_size = dfu_get_medium_size_ram;
diff --git a/drivers/dfu/dfu_sf.c b/drivers/dfu/dfu_sf.c
index 993e951bc3..25a9c81850 100644
--- a/drivers/dfu/dfu_sf.c
+++ b/drivers/dfu/dfu_sf.c
@@ -166,9 +166,9 @@ static struct spi_flash *parse_dev(char *devstr)
return dev;
}

-int dfu_fill_entity_sf(struct dfu_entity *dfu, char *devstr, char *s)
+int dfu_fill_entity_sf(struct dfu_entity *dfu, char *devstr, char **argv, int argc)
{
- char *st;
+ char *s;
char *devstr_bkup = strdup(devstr);

dfu->data.sf.dev = parse_dev(devstr_bkup);
@@ -179,17 +179,18 @@ int dfu_fill_entity_sf(struct dfu_entity *dfu, char *devstr, char *s)
dfu->dev_type = DFU_DEV_SF;
dfu->max_buf_size = dfu->data.sf.dev->sector_size;

- st = strsep(&s, " \t");
- s = skip_spaces(s);
- if (!strcmp(st, "raw")) {
+ if (argc != 3)
+ return -EINVAL;
+ if (!strcmp(argv[0], "raw")) {
dfu->layout = DFU_RAW_ADDR;
- dfu->data.sf.start = hextoul(s, &s);
- if (!isspace(*s))
- return -1;
- s = skip_spaces(s);
- dfu->data.sf.size = hextoul(s, &s);
+ dfu->data.sf.start = hextoul(argv[1], &s);
+ if (*s)
+ return -EINVAL;
+ dfu->data.sf.size = hextoul(argv[2], &s);
+ if (*s)
+ return -EINVAL;
} else if (CONFIG_IS_ENABLED(DFU_SF_PART) &&
- (!strcmp(st, "part") || !strcmp(st, "partubi"))) {
+ (!strcmp(argv[0], "part") || !strcmp(argv[0], "partubi"))) {
char mtd_id[32];
struct mtd_device *mtd_dev;
u8 part_num;
@@ -198,11 +199,12 @@ int dfu_fill_entity_sf(struct dfu_entity *dfu, char *devstr, char *s)

dfu->layout = DFU_RAW_ADDR;

- dev = dectoul(s, &s);
- if (!isspace(*s))
- return -1;
- s = skip_spaces(s);
- part = dectoul(s, &s);
+ dev = dectoul(argv[1], &s);
+ if (*s)
+ return -EINVAL;
+ part = dectoul(argv[2], &s);
+ if (*s)
+ return -EINVAL;

sprintf(mtd_id, "%s%d,%d", "nor", dev, part - 1);
printf("using id '%s'\n", mtd_id);
@@ -216,10 +218,10 @@ int dfu_fill_entity_sf(struct dfu_entity *dfu, char *devstr, char *s)
}
dfu->data.sf.start = pi->offset;
dfu->data.sf.size = pi->size;
- if (!strcmp(st, "partubi"))
+ if (!strcmp(argv[0], "partubi"))
dfu->data.sf.ubi = 1;
} else {
- printf("%s: Memory layout (%s) not supported!\n", __func__, st);
+ printf("%s: Memory layout (%s) not supported!\n", __func__, argv[0]);
spi_flash_free(dfu->data.sf.dev);
return -1;
}
diff --git a/drivers/dfu/dfu_virt.c b/drivers/dfu/dfu_virt.c
index 80c99cb06e..29f7a08f67 100644
--- a/drivers/dfu/dfu_virt.c
+++ b/drivers/dfu/dfu_virt.c
@@ -32,10 +32,13 @@ int __weak dfu_read_medium_virt(struct dfu_entity *dfu, u64 offset,
return 0;
}

-int dfu_fill_entity_virt(struct dfu_entity *dfu, char *devstr, char *s)
+int dfu_fill_entity_virt(struct dfu_entity *dfu, char *devstr, char **argv, int argc)
{
debug("%s: devstr = %s\n", __func__, devstr);

+ if (argc != 0)
+ return -EINVAL;
+
dfu->dev_type = DFU_DEV_VIRT;
dfu->layout = DFU_RAW_ADDR;
dfu->data.virt.dev_num = dectoul(devstr, NULL);
diff --git a/include/dfu.h b/include/dfu.h
index f6868982df..dcb9cd9d79 100644
--- a/include/dfu.h
+++ b/include/dfu.h
@@ -432,11 +432,15 @@ static inline void dfu_set_defer_flush(struct dfu_entity *dfu)
int dfu_write_from_mem_addr(struct dfu_entity *dfu, void *buf, int size);

/* Device specific */
+/* Each entity has 5 arguments in maximum. */
+#define DFU_MAX_ENTITY_ARGS 5
+
#if CONFIG_IS_ENABLED(DFU_MMC)
-extern int dfu_fill_entity_mmc(struct dfu_entity *dfu, char *devstr, char *s);
+extern int dfu_fill_entity_mmc(struct dfu_entity *dfu, char *devstr,
+ char **argv, int argc);
#else
static inline int dfu_fill_entity_mmc(struct dfu_entity *dfu, char *devstr,
- char *s)
+ char **argv, int argc)
{
puts("MMC support not available!\n");
return -1;
@@ -444,10 +448,11 @@ static inline int dfu_fill_entity_mmc(struct dfu_entity *dfu, char *devstr,
#endif

#if CONFIG_IS_ENABLED(DFU_NAND)
-extern int dfu_fill_entity_nand(struct dfu_entity *dfu, char *devstr, char *s);
+extern int dfu_fill_entity_nand(struct dfu_entity *dfu, char *devstr,
+ char **argv, int argc);
#else
static inline int dfu_fill_entity_nand(struct dfu_entity *dfu, char *devstr,
- char *s)
+ char **argv, int argc)
{
puts("NAND support not available!\n");
return -1;
@@ -455,10 +460,11 @@ static inline int dfu_fill_entity_nand(struct dfu_entity *dfu, char *devstr,
#endif

#if CONFIG_IS_ENABLED(DFU_RAM)
-extern int dfu_fill_entity_ram(struct dfu_entity *dfu, char *devstr, char *s);
+extern int dfu_fill_entity_ram(struct dfu_entity *dfu, char *devstr,
+ char **argv, int argc);
#else
static inline int dfu_fill_entity_ram(struct dfu_entity *dfu, char *devstr,
- char *s)
+ char **argv, int argc)
{
puts("RAM support not available!\n");
return -1;
@@ -466,10 +472,11 @@ static inline int dfu_fill_entity_ram(struct dfu_entity *dfu, char *devstr,
#endif

#if CONFIG_IS_ENABLED(DFU_SF)
-extern int dfu_fill_entity_sf(struct dfu_entity *dfu, char *devstr, char *s);
+extern int dfu_fill_entity_sf(struct dfu_entity *dfu, char *devstr,
+ char **argv, int argc);
#else
static inline int dfu_fill_entity_sf(struct dfu_entity *dfu, char *devstr,
- char *s)
+ char **argv, int argc)
{
puts("SF support not available!\n");
return -1;
@@ -477,10 +484,11 @@ static inline int dfu_fill_entity_sf(struct dfu_entity *dfu, char *devstr,
#endif

#if CONFIG_IS_ENABLED(DFU_MTD)
-int dfu_fill_entity_mtd(struct dfu_entity *dfu, char *devstr, char *s);
+extern int dfu_fill_entity_mtd(struct dfu_entity *dfu, char *devstr,
+ char **argv, int argc);
#else
static inline int dfu_fill_entity_mtd(struct dfu_entity *dfu, char *devstr,
- char *s)
+ char **argv, int argc)
{
puts("MTD support not available!\n");
return -1;
@@ -488,7 +496,8 @@ static inline int dfu_fill_entity_mtd(struct dfu_entity *dfu, char *devstr,
#endif

#ifdef CONFIG_DFU_VIRT
-int dfu_fill_entity_virt(struct dfu_entity *dfu, char *devstr, char *s);
+int dfu_fill_entity_virt(struct dfu_entity *dfu, char *devstr,
+ char **argv, int argc);
int dfu_write_medium_virt(struct dfu_entity *dfu, u64 offset,
void *buf, long *len);
int dfu_get_medium_size_virt(struct dfu_entity *dfu, u64 *size);
@@ -496,7 +505,7 @@ int dfu_read_medium_virt(struct dfu_entity *dfu, u64 offset,
void *buf, long *len);
#else
static inline int dfu_fill_entity_virt(struct dfu_entity *dfu, char *devstr,
- char *s)
+ char **argv, int argc)
{
puts("VIRT support not available!\n");
return -1;