Commit e1e8399e authored Mar 27, 2020 by Vasily Averin Committed by Chuck Lever Apr 13, 2020

nfsd: memory corruption in nfsd4_lock()



New struct nfsd4_blocked_lock allocated in find_or_allocate_block()
does not initialized nbl_list and nbl_lru.
If conflock allocation fails rollback can call list_del_init()
access uninitialized fields and corrupt memory.

v2: just initialize nbl_list and nbl_lru right after nbl allocation.

Fixes: 76d348fa ("nfsd: have nfsd4_lock use blocking locks for v4.1+ lock")
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

parent 8f3d9f35

fs/nfsd/nfs4state.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -267,6 +267,8 @@ find_or_allocate_block(struct nfs4_lockowner lo, struct knfsd_fh fh,
		if (!nbl) {
		nbl= kmalloc(sizeof(*nbl), GFP_KERNEL);
		if (nbl) {
		INIT_LIST_HEAD(&nbl->nbl_list);
		INIT_LIST_HEAD(&nbl->nbl_lru);
		fh_copy_shallow(&nbl->nbl_fh, fh);
		locks_init_lock(&nbl->nbl_lock);
		nfsd4_init_cb(&nbl->nbl_cb, lo->lo_owner.so_client,

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