4.9-stable review patch. If anyone has any objections, please let me know.
------------------ From: Ari Kauppi <[email protected]> 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 <[email protected]> Signed-off-by: Ari Kauppi <[email protected]> [[email protected]: use LAYOUT_TYPE_MAX instead of 32] Reviewed-by: Dan Carpenter <[email protected]> Reviewed-by: Christoph Hellwig <[email protected]> Signed-off-by: J. Bruce Fields <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- fs/nfsd/nfs4proc.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/fs/nfsd/nfs4proc.c +++ b/fs/nfsd/nfs4proc.c @@ -1273,7 +1273,8 @@ nfsd4_layout_verify(struct svc_export *e 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;
