This is a note to let you know that I've just added the patch titled
NFSD: Avoid calling OPDESC() with ops->opnum == OP_ILLEGAL
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
nfsd-avoid-calling-opdesc-with-ops-opnum-op_illegal.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 2f4978280f1aedb1ee37f29075670d1bb4d87abd
Author: Chuck Lever <chuck.lever@xxxxxxxxxx>
Date: Fri Mar 31 16:31:19 2023 -0400
NFSD: Avoid calling OPDESC() with ops->opnum == OP_ILLEGAL
[ Upstream commit 804d8e0a6e54427268790472781e03bc243f4ee3 ]
OPDESC() simply indexes into nfsd4_ops[] by the op's operation
number, without range checking that value. It assumes callers are
careful to avoid calling it with an out-of-bounds opnum value.
nfsd4_decode_compound() is not so careful, and can invoke OPDESC()
with opnum set to OP_ILLEGAL, which is 10044 -- well beyond the end
of nfsd4_ops[].
Reported-by: Jeff Layton <jlayton@xxxxxxxxxx>
Fixes: f4f9ef4a1b0a ("nfsd4: opdesc will be useful outside nfs4proc.c")
Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index dfd3877fdd818..0394dd60a0b47 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -2370,10 +2370,12 @@ nfsd4_decode_compound(struct nfsd4_compoundargs *argp)
for (i = 0; i < argp->opcnt; i++) {
op = &argp->ops[i];
op->replay = NULL;
+ op->opdesc = NULL;
if (xdr_stream_decode_u32(argp->xdr, &op->opnum) < 0)
return 0;
if (nfsd4_opnum_in_range(argp, op)) {
+ op->opdesc = OPDESC(op);
op->status = nfsd4_dec_ops[op->opnum](argp, &op->u);
if (op->status != nfs_ok)
trace_nfsd_compound_decode_err(argp->rqstp,
@@ -2384,7 +2386,7 @@ nfsd4_decode_compound(struct nfsd4_compoundargs *argp)
op->opnum = OP_ILLEGAL;
op->status = nfserr_op_illegal;
}
- op->opdesc = OPDESC(op);
+
/*
* We'll try to cache the result in the DRC if any one
* op in the compound wants to be cached:
