From: Anna Schumaker Anna.Schumaker@Netapp.com
commit a421d218603ffa822a0b8045055c03eae394a7eb upstream.
Commit de144ff4234f changes _pnfs_return_layout() to call pnfs_mark_matching_lsegs_return() passing NULL as the struct pnfs_layout_range argument. Unfortunately, pnfs_mark_matching_lsegs_return() doesn't check if we have a value here before dereferencing it, causing an oops.
I'm able to hit this crash consistently when running connectathon basic tests on NFS v4.1/v4.2 against Ontap.
Fixes: de144ff4234f ("NFSv4: Don't discard segments marked for return in _pnfs_return_layout()") Cc: stable@vger.kernel.org Signed-off-by: Anna Schumaker Anna.Schumaker@Netapp.com Signed-off-by: Trond Myklebust trond.myklebust@hammerspace.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/nfs/pnfs.c | 15 +++++++-------- 1 file changed, 7 insertions(+), 8 deletions(-)
--- a/fs/nfs/pnfs.c +++ b/fs/nfs/pnfs.c @@ -1317,6 +1317,11 @@ _pnfs_return_layout(struct inode *ino) { struct pnfs_layout_hdr *lo = NULL; struct nfs_inode *nfsi = NFS_I(ino); + struct pnfs_layout_range range = { + .iomode = IOMODE_ANY, + .offset = 0, + .length = NFS4_MAX_UINT64, + }; LIST_HEAD(tmp_list); const struct cred *cred; nfs4_stateid stateid; @@ -1344,16 +1349,10 @@ _pnfs_return_layout(struct inode *ino) } valid_layout = pnfs_layout_is_valid(lo); pnfs_clear_layoutcommit(ino, &tmp_list); - pnfs_mark_matching_lsegs_return(lo, &tmp_list, NULL, 0); + pnfs_mark_matching_lsegs_return(lo, &tmp_list, &range, 0);
- if (NFS_SERVER(ino)->pnfs_curr_ld->return_range) { - struct pnfs_layout_range range = { - .iomode = IOMODE_ANY, - .offset = 0, - .length = NFS4_MAX_UINT64, - }; + if (NFS_SERVER(ino)->pnfs_curr_ld->return_range) NFS_SERVER(ino)->pnfs_curr_ld->return_range(lo, &range); - }
/* Don't send a LAYOUTRETURN if list was initially empty */ if (!test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags) ||