nfs4-acl-tools: when who's length is very big, nfs4_getacl core dump

Commit Message

fanchaoting Jan. 11, 2013, 9:52 a.m. UTC

nfsv4 server can return a very large who's len(eg. wholen = 62343534343) 
in an FATTR4_WORD0_ACL request.It can cause nfs4_getacl core dump 
when call 'malloc((wholen + 1) * sizeof(char))'.

 This patch checked if who's len bigger than xattr_size when getfacl.

 This patch also fixed some code style.

Signed-off-by: Fan Chaoting <[e-mail]>
---
 libnfs4acl/acl_nfs4_xattr_load.c |    6 ++++++
 libnfs4acl/nfs4_acl_for_path.c   |    8 ++++----
 2 files changed, 10 insertions(+), 4 deletions(-)

-- 1.7.1 

--

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Patch

diff --git a/libnfs4acl/acl_nfs4_xattr_load.c b/libnfs4acl/acl_nfs4_xattr_load.c
index 089a139..ced1c95 100644
--- a/libnfs4acl/acl_nfs4_xattr_load.c
+++ b/libnfs4acl/acl_nfs4_xattr_load.c
@@ -139,6 +139,12 @@  struct nfs4_acl * acl_nfs4_xattr_load(char *xattr_v, int xattr_size, u32 is_dir)
 			goto err1;
 		}
 
+		/*wholen should less than xattr_size*/
+		if (wholen > xattr_size) {
+			errno = EINVAL;
+			goto err1;
+		}
+
 		who = (char *) malloc((wholen+1) * sizeof(char));
 		if (who == NULL) {
 			errno = ENOMEM;
diff --git a/libnfs4acl/nfs4_acl_for_path.c b/libnfs4acl/nfs4_acl_for_path.c
index 7461005..577dd1f 100644
--- a/libnfs4acl/nfs4_acl_for_path.c
+++ b/libnfs4acl/nfs4_acl_for_path.c
@@ -92,14 +92,14 @@  static int nfs4_getxattr(const char *path, void *value, size_t size)
 
 	res = getxattr(path, ACL_NFS4_XATTR, value, size);
 	if (res < -10000) {
-		fprintf(stderr,"An internal NFS server error code (%d) was returned; this should never happen.\n",res);
+		fprintf(stderr, "An internal NFS server error code (%d) was returned; this should never happen.\n", res);
 	} else if (res < 0) {
 		if (errno == ENOATTR)
-			fprintf(stderr,"Attribute not found on file.\n");
+			fprintf(stderr, "Attribute not found on file.\n");
 		else if (errno == EREMOTEIO)
-		    fprintf(stderr,"An NFS server error occurred.\n");
+		    fprintf(stderr, "An NFS server error occurred.\n");
 		else if (errno == EOPNOTSUPP)
-			fprintf(stderr,"Operation to request attribute not supported.\n");
+			fprintf(stderr, "Operation to request attribute not supported.\n");
 		else
 			perror("Failed getxattr operation");
 	}