The function alloca() like VLA's has problems if the caller
passes a large value. Instead use a fixed size buffer (2K)
which will be more than sufficient for the info related blocks
in the file. Add bounds checks as well.
Signed-off-by: Stephen Hemminger <step...@networkplumber.org>
Acked-by: Morten Brørup <m...@smartsharesystems.com>
---
lib/pcapng/rte_pcapng.c | 37 ++++++++++++++++---------------------
1 file changed, 16 insertions(+), 21 deletions(-)
diff --git a/lib/pcapng/rte_pcapng.c b/lib/pcapng/rte_pcapng.c
index 13fd2b97fb80..f74ec939a9f8 100644
--- a/lib/pcapng/rte_pcapng.c
+++ b/lib/pcapng/rte_pcapng.c
@@ -33,6 +33,9 @@
/* conversion from DPDK speed to PCAPNG */
#define PCAPNG_MBPS_SPEED 1000000ull
+/* upper bound for section, stats and interface blocks */
+#define PCAPNG_BLKSIZ 2048
+
/* Format of the capture file handle */
struct rte_pcapng {
int outfd; /* output file */
@@ -140,9 +143,8 @@ pcapng_section_block(rte_pcapng_t *self,
{
struct pcapng_section_header *hdr;
struct pcapng_option *opt;
- void *buf;
+ uint8_t buf[PCAPNG_BLKSIZ];
uint32_t len;
- ssize_t cc;
len = sizeof(*hdr);
if (hw)
@@ -158,8 +160,7 @@ pcapng_section_block(rte_pcapng_t *self,
len += pcapng_optlen(0);
len += sizeof(uint32_t);
- buf = calloc(1, len);
- if (!buf)
+ if (len > sizeof(buf))
return -1;
hdr = (struct pcapng_section_header *)buf;
@@ -193,10 +194,7 @@ pcapng_section_block(rte_pcapng_t *self,
/* clone block_length after option */
memcpy(opt, &hdr->block_length, sizeof(uint32_t));
- cc = write(self->outfd, buf, len);
- free(buf);
-
- return cc;
+ return write(self->outfd, buf, len);
}
/* Write an interface block for a DPDK port */
@@ -213,7 +211,7 @@ rte_pcapng_add_interface(rte_pcapng_t *self, uint16_t port,
struct pcapng_option *opt;
const uint8_t tsresol = 9; /* nanosecond resolution */
uint32_t len;
- void *buf;
+ uint8_t buf[PCAPNG_BLKSIZ];
char ifname_buf[IF_NAMESIZE];
char ifhw[256];
uint64_t speed = 0;
@@ -267,8 +265,7 @@ rte_pcapng_add_interface(rte_pcapng_t *self, uint16_t port,
len += pcapng_optlen(0);
len += sizeof(uint32_t);
- buf = alloca(len);
- if (!buf)
+ if (len > sizeof(buf))
return -1;
hdr = (struct pcapng_interface_block *)buf;
@@ -296,17 +293,16 @@ rte_pcapng_add_interface(rte_pcapng_t *self, uint16_t
port,
opt = pcapng_add_option(opt, PCAPNG_IFB_HARDWARE,
ifhw, strlen(ifhw));
if (filter) {
- /* Encoding is that the first octet indicates string vs BPF */
size_t len;
- char *buf;
len = strlen(filter) + 1;
- buf = alloca(len);
- *buf = '\0';
- memcpy(buf + 1, filter, len);
+ opt->code = PCAPNG_IFB_FILTER;
+ opt->length = len;
+ /* Encoding is that the first octet indicates string vs BPF */
+ opt->data[0] = 0;
+ memcpy(opt->data + 1, filter, strlen(filter));
- opt = pcapng_add_option(opt, PCAPNG_IFB_FILTER,
- buf, len);
+ opt = (struct pcapng_option *)((uint8_t *)opt +
pcapng_optlen(len));
}
opt = pcapng_add_option(opt, PCAPNG_OPT_END, NULL, 0);
@@ -333,7 +329,7 @@ rte_pcapng_write_stats(rte_pcapng_t *self, uint16_t port_id,
uint64_t start_time = self->offset_ns;
uint64_t sample_time;
uint32_t optlen, len;
- uint8_t *buf;
+ uint8_t buf[PCAPNG_BLKSIZ];
RTE_ETH_VALID_PORTID_OR_ERR_RET(port_id, -EINVAL);
@@ -353,8 +349,7 @@ rte_pcapng_write_stats(rte_pcapng_t *self, uint16_t port_id,
optlen += pcapng_optlen(0);
len = sizeof(*hdr) + optlen + sizeof(uint32_t);
- buf = alloca(len);
- if (buf == NULL)
+ if (len > sizeof(buf))
return -1;
hdr = (struct pcapng_statistics *)buf;
--
2.39.2
