On Thursday 30 June 2011 05:21 PM, Jim Rees wrote:
faizan husain wrote:
problem was this part of code in parse_alloc_fields() function:
if (count != 3)
goto out_free;
at this point memory is not allocated for fields leading to double
free of memory once inside parse_alloc_fields() and again inside
nfs4_ace_from_string().
instead we can change the code:
if (count != 3)
return -EINVAL; /*Invalid argument*/
This look to me as more foolproof solution.
what do you say?
That looks correct. It should return EINVAL here, and there is no need to
free. But I don't see why it fixes your segfault. fields[] should be all
NULL at this point, so free_fields shouldn't do anything.
The test in free_fields() is redundant, since free(NULL) doesn't do
anything. But it could be made more foolproof by zeroing the array so you
can't get a double free:
void
free_fields(char *fields[NUMFIELDS])
{
int i;
for (i = 0; i< NUMFIELDS; i++) {
free(fields[i]);
fields[i] = NULL;
}
}
yeah that could be done to make it more foolproof.
here is the final patch:
From 6cd5263027e3fa5cf18756aa9db108dcdb2367d5 Mon Sep 17 00:00:00 2001
From: faizan <faizan.husain@xxxxxxxxxx>
Date: Thu, 30 Jun 2011 18:55:28 +0530
Subject: [PATCH][BUILD]] FIX - 'nfs4_setfacl' failed with unexpected
messages if
the format of the input file is incorrect.
Signed-off-by: faizan <faizan.husain@xxxxxxxxxx>
---
libnfs4acl/nfs4_ace_from_string.c | 9 +++++----
1 files changed, 5 insertions(+), 4 deletions(-)
diff --git a/libnfs4acl/nfs4_ace_from_string.c
b/libnfs4acl/nfs4_ace_from_string.c
index 9d877fb..b74b1a9 100644
--- a/libnfs4acl/nfs4_ace_from_string.c
+++ b/libnfs4acl/nfs4_ace_from_string.c
@@ -86,9 +86,10 @@ free_fields(char *fields[NUMFIELDS])
{
int i;
- for (i = 0; i < NUMFIELDS; i++)
- if (fields[i] != NULL)
- free(fields[i]);
+ for (i = 0; i < NUMFIELDS; i++) {
+ free(fields[i]);
+ fields[i] = NULL;
+ }
}
int
@@ -107,7 +108,7 @@ parse_alloc_fields(char *buf, char *fields[NUMFIELDS])
count++;
}
if (count != 3)
- goto out_free;
+ return -EINVAL;
for (i = 0; i < NUMFIELDS; i++) {
field = strsep(&buf, ":");
--
1.7.1
Thanks
Faizan
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