[dpdk-dev,v2] librte_cmdline: FreeBSD Fix oveflow when size of command result structure is greater than BUFSIZ
Commit Message
When using test-pmd with flow director in FreeBSD, the application will
segfault/Bus error while parsing the command-line. This is due to how
each commands result structure is represented during parsing, where the offsets
for each tokens value is stored in a character array(char result_buf[BUFSIZ])
in cmdline_parse()(./lib/librte_cmdline/cmdline_parse.c).
The overflow occurs where BUFSIZ is less than the size of a commands result
structure, in this case "struct cmd_pkt_filter_result"
(app/test-pmd/cmdline.c) is 1088 bytes and BUFSIZ on FreeBSD is 1024 bytes as
opposed to 8192 bytes on Linux.
The problem can be reproduced by running test-pmd on FreeBSD:
./testpmd -c 0x3 -n 4 -- -i --portmask=0x3 --pkt-filter-mode=perfect
And adding a filter:
add_perfect_filter 0 udp src 192.168.0.0 1024 dst 192.168.0.0 1024 flexbytes
0x800 vlan 0 queue 0 soft 0x17
This patch removes the OS dependency on BUFSIZ and defines and uses a
library #define CMDLINE_PARSE_RESULT_BUFSIZE 8192
Added boundary checking to ensure this buffer size cannot overflow, with
an error message being produced.
Suggested-by: Olivier MATZ <olivier.matz@6wind.com>
http://git.droids-corp.org/?p=libcmdline.git;a=commitdiff;h=b1d5b169352e57df3fc14c51ffad4b83f3e5613f
Signed-off-by: Alan Carew <alan.carew@intel.com>
---
lib/librte_cmdline/cmdline_parse.c | 22 +++++++++++++++-------
lib/librte_cmdline/cmdline_parse.h | 3 +++
2 files changed, 18 insertions(+), 7 deletions(-)
Comments
Hi Alan,
On 11/10/2014 10:19 AM, Alan Carew wrote:
> When using test-pmd with flow director in FreeBSD, the application will
> segfault/Bus error while parsing the command-line. This is due to how
> each commands result structure is represented during parsing, where the offsets
> for each tokens value is stored in a character array(char result_buf[BUFSIZ])
> in cmdline_parse()(./lib/librte_cmdline/cmdline_parse.c).
>
> The overflow occurs where BUFSIZ is less than the size of a commands result
> structure, in this case "struct cmd_pkt_filter_result"
> (app/test-pmd/cmdline.c) is 1088 bytes and BUFSIZ on FreeBSD is 1024 bytes as
> opposed to 8192 bytes on Linux.
>
> The problem can be reproduced by running test-pmd on FreeBSD:
> ./testpmd -c 0x3 -n 4 -- -i --portmask=0x3 --pkt-filter-mode=perfect
> And adding a filter:
> add_perfect_filter 0 udp src 192.168.0.0 1024 dst 192.168.0.0 1024 flexbytes
> 0x800 vlan 0 queue 0 soft 0x17
>
> This patch removes the OS dependency on BUFSIZ and defines and uses a
> library #define CMDLINE_PARSE_RESULT_BUFSIZE 8192
>
> Added boundary checking to ensure this buffer size cannot overflow, with
> an error message being produced.
>
> Suggested-by: Olivier MATZ <olivier.matz@6wind.com>
> http://git.droids-corp.org/?p=libcmdline.git;a=commitdiff;h=b1d5b169352e57df3fc14c51ffad4b83f3e5613f
>
> Signed-off-by: Alan Carew <alan.carew@intel.com>
I think some checks are missing compared to the original patch. The
cmdline_parse_xxx() functions should be modified too. Please see a
v3 in my next email.
Regards,
Olivier
@@ -138,7 +138,7 @@ nb_common_chars(const char * s1, const char * s2)
*/
static int
match_inst(cmdline_parse_inst_t *inst, const char *buf,
- unsigned int nb_match_token, void * result_buf)
+ unsigned int nb_match_token, void *result_buf, unsigned result_buf_size)
{
unsigned int token_num=0;
cmdline_parse_token_hdr_t * token_p;
@@ -162,10 +162,18 @@ match_inst(cmdline_parse_inst_t *inst, const char *buf,
if ( isendofline(*buf) || iscomment(*buf) )
break;
- if (result_buf)
+ if (result_buf) {
+ if (token_hdr.offset > result_buf_size) {
+ printf("Parse error(%s:%d): Token offset(%u) exceeds maximum "
+ "size(%u)\n", __FILE__, __LINE__, token_hdr.offset,
+ result_buf_size);
+ return -ENOBUFS;
+ }
+
n = token_hdr.ops->parse(token_p, buf,
(char *)result_buf +
token_hdr.offset);
+ }
else
n = token_hdr.ops->parse(token_p, buf, NULL);
@@ -219,7 +227,7 @@ cmdline_parse(struct cmdline *cl, const char * buf)
unsigned int inst_num=0;
cmdline_parse_inst_t *inst;
const char *curbuf;
- char result_buf[BUFSIZ];
+ char result_buf[CMDLINE_PARSE_RESULT_BUFSIZE];
void (*f)(void *, struct cmdline *, void *) = NULL;
void *data = NULL;
int comment = 0;
@@ -280,7 +288,7 @@ cmdline_parse(struct cmdline *cl, const char * buf)
debug_printf("INST %d\n", inst_num);
/* fully parsed */
- tok = match_inst(inst, buf, 0, result_buf);
+ tok = match_inst(inst, buf, 0, result_buf, sizeof(result_buf));
if (tok > 0) /* we matched at least one token */
err = CMDLINE_PARSE_BAD_ARGS;
@@ -377,10 +385,10 @@ cmdline_complete(struct cmdline *cl, const char *buf, int *state,
inst = ctx[inst_num];
while (inst) {
/* parse the first tokens of the inst */
- if (nb_token && match_inst(inst, buf, nb_token, NULL))
+ if (nb_token && match_inst(inst, buf, nb_token, NULL, 0))
goto next;
- debug_printf("instruction match \n");
+ debug_printf("instruction match\n");
token_p = inst->tokens[nb_token];
if (token_p)
memcpy(&token_hdr, token_p, sizeof(token_hdr));
@@ -471,7 +479,7 @@ cmdline_complete(struct cmdline *cl, const char *buf, int *state,
/* we need to redo it */
inst = ctx[inst_num];
- if (nb_token && match_inst(inst, buf, nb_token, NULL))
+ if (nb_token && match_inst(inst, buf, nb_token, NULL, 0))
goto next2;
token_p = inst->tokens[nb_token];
@@ -80,6 +80,9 @@ extern "C" {
#define CMDLINE_PARSE_COMPLETE_AGAIN 1
#define CMDLINE_PARSE_COMPLETED_BUFFER 2
+/* maximum buffer size for parsed result */
+#define CMDLINE_PARSE_RESULT_BUFSIZE 8192
+
/**
* Stores a pointer to the ops struct, and the offset: the place to
* write the parsed result in the destination structure.