[PATCH 1 of 3] nfsd4: fix fs locations bounds-checking

[J. Bruce Fields]

The comparison here is obviously useless as locations_count is unsigned.

Though fsloc_parse can only be handed data by root, still I'd rather have
some sanity-checking; so set a (generous) maximum number of fslocations to
keep the following kzalloc to a reasonable size.

Signed-off-by: J. Bruce Fields <bfields@xxxxxxxxxxxxxx>
---
 fs/nfsd/export.c            |    2 +-
 include/linux/nfsd/export.h |    3 +++
 2 files changed, 4 insertions(+), 1 deletions(-)

diff --git a/fs/nfsd/export.c b/fs/nfsd/export.c
index 7e429ca..71f3655 100644
--- a/fs/nfsd/export.c
+++ b/fs/nfsd/export.c
@@ -418,7 +418,7 @@ fsloc_parse(char **mesg, char *buf, stru
 	err = get_int(mesg, &fsloc->locations_count);
 	if (err)
 		return err;
-	if (fsloc->locations_count < 0)
+	if (fsloc->locations_count > MAX_FS_LOCATIONS)
 		return -EINVAL;
 	if (fsloc->locations_count == 0)
 		return 0;
diff --git a/include/linux/nfsd/export.h b/include/linux/nfsd/export.h
index 101fb4c..6e78ea9 100644
--- a/include/linux/nfsd/export.h
+++ b/include/linux/nfsd/export.h
@@ -48,6 +48,9 @@ #ifdef __KERNEL__
 /*
  * FS Locations
  */
+
+#define MAX_FS_LOCATIONS	128
+
 struct nfsd4_fs_location {
 	char *hosts; /* colon separated list of hosts */
 	char *path;  /* slash separated list of path components */
-- 
1.4.2.g55c3

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