| Message ID | 20190726074853.4160-1-baijiaju1990@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | fs: nfs: Fix possible null-pointer dereferences in encode_attrs() | expand |
diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c index 46a8d636d151..ab07db0f07cd 100644 --- a/fs/nfs/nfs4xdr.c +++ b/fs/nfs/nfs4xdr.c @@ -1174,7 +1174,7 @@ static void encode_attrs(struct xdr_stream *xdr, const struct iattr *iap, } else *p++ = cpu_to_be32(NFS4_SET_TO_SERVER_TIME); } - if (bmval[2] & FATTR4_WORD2_SECURITY_LABEL) { + if (label && (bmval[2] & FATTR4_WORD2_SECURITY_LABEL)) { *p++ = cpu_to_be32(label->lfs); *p++ = cpu_to_be32(label->pi); *p++ = cpu_to_be32(label->len);
In encode_attrs(), there is an if statement on line 1145 to check whether label is NULL: if (label && (attrmask[2] & FATTR4_WORD2_SECURITY_LABEL)) When label is NULL, it is used on lines 1178-1181: *p++ = cpu_to_be32(label->lfs); *p++ = cpu_to_be32(label->pi); *p++ = cpu_to_be32(label->len); p = xdr_encode_opaque_fixed(p, label->label, label->len); To fix these bugs, label is checked before being used. These bugs are found by a static analysis tool STCheck written by us. Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com> --- fs/nfs/nfs4xdr.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)