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authorAri Kauppi <ari@synopsys.com>2017-05-05 16:07:55 -0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-05-25 15:44:48 +0200
commitea465551af30146efea215da58786ff732da70fb (patch)
tree81f87c44ebeeff8a142625cd4f79a9399ee5226c /fs
parentf2b6f508c5417bc5f2a5a30268b5b75ae3b4a754 (diff)
nfsd: fix undefined behavior in nfsd4_layout_verify
commit b550a32e60a4941994b437a8d662432a486235a5 upstream. UBSAN: Undefined behaviour in fs/nfsd/nfs4proc.c:1262:34 shift exponent 128 is too large for 32-bit type 'int' Depending on compiler+architecture, this may cause the check for layout_type to succeed for overly large values (which seems to be the case with amd64). The large value will be later used in de-referencing nfsd4_layout_ops for function pointers. Reported-by: Jani Tuovila <tuovila@synopsys.com> Signed-off-by: Ari Kauppi <ari@synopsys.com> [colin.king@canonical.com: use LAYOUT_TYPE_MAX instead of 32] Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: J. Bruce Fields <bfields@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs')
-rw-r--r--fs/nfsd/nfs4proc.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index abb09b580389..650226f33298 100644
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -1273,7 +1273,8 @@ nfsd4_layout_verify(struct svc_export *exp, unsigned int layout_type)
return NULL;
}
- if (!(exp->ex_layout_types & (1 << layout_type))) {
+ if (layout_type >= LAYOUT_TYPE_MAX ||
+ !(exp->ex_layout_types & (1 << layout_type))) {
dprintk("%s: layout type %d not supported\n",
__func__, layout_type);
return NULL;