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| author | NeilBrown <neilb@suse.de> | 2012-09-17 08:46:34 +0200 |
|---|---|---|
| committer | Trond Myklebust <Trond.Myklebust@netapp.com> | 2012-09-25 16:38:54 +0200 |
| commit | 62d98c935456ee121b03d6a68aa3091a04085b7e (patch) | |
| tree | 09f58145bc10308f4672ee156a0ed23ea87c4f7b /fs/nfs/nfs4namespace.c | |
| parent | NFS: fix the return value check by using IS_ERR (diff) | |
| download | linux-62d98c935456ee121b03d6a68aa3091a04085b7e.tar.xz linux-62d98c935456ee121b03d6a68aa3091a04085b7e.zip | |
NFS4: avoid underflow when converting error to pointer.
In nfs4_create_sec_client, 'flavor' can hold a negative error
code (returned from nfs4_negotiate_security), even though it
is an 'enum' and hence unsigned.
The code is careful to cast it to an (int) before testing if it
is negative, however it doesn't cast to an (int) before calling
ERR_PTR.
On a machine where "void*" is larger than "int", this results in
the unsigned equivalent of -1 (e.g. 0xffffffff) being converted
to a pointer. Subsequent code determines that this is not
negative, and so dereferences it with predictable results.
So: cast 'flavor' to a (signed) int before passing to ERR_PTR.
cc: Benny Halevy <bhalevy@tonian.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Diffstat (limited to 'fs/nfs/nfs4namespace.c')
| -rw-r--r-- | fs/nfs/nfs4namespace.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/nfs/nfs4namespace.c b/fs/nfs/nfs4namespace.c index 398d5fd74157..4fdeb1b7042e 100644 --- a/fs/nfs/nfs4namespace.c +++ b/fs/nfs/nfs4namespace.c @@ -198,7 +198,7 @@ struct rpc_clnt *nfs4_create_sec_client(struct rpc_clnt *clnt, struct inode *ino flavor = nfs4_negotiate_security(inode, name); if ((int)flavor < 0) - return ERR_PTR(flavor); + return ERR_PTR((int)flavor); clone = rpc_clone_client(clnt); if (IS_ERR(clone)) |