This is a note to let you know that I've just added the patch titled nfsd: memory corruption in nfsd4_lock() to the 5.6-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-memory-corruption-in-nfsd4_lock.patch and it can be found in the queue-5.6 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 2b36581ddd6f5ed73a88f5a48ff22d927b61fc9b Author: Vasily Averin <vvs@xxxxxxxxxxxxx> Date: Fri Mar 27 07:50:40 2020 +0300 nfsd: memory corruption in nfsd4_lock() commit e1e8399eee72e9d5246d4d1bcacd793debe34dd3 upstream. 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: 76d348fadff5 ("nfsd: have nfsd4_lock use blocking locks for v4.1+ lock") Signed-off-by: Vasily Averin <vvs@xxxxxxxxxxxxx> Reviewed-by: Jeff Layton <jlayton@xxxxxxxxxx> Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index 65cfe9ab47be0..de9fbe7ed06ce 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -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,