From: Scott Mayhew Date: Wed, 11 Oct 2023 14:43:26 +0000 (-0400) Subject: NFS: Fix potential oops in nfs_inode_remove_request() X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=6a6d4644ce935ddec4f76223ac0ca68da56bd2d3;p=linux.git NFS: Fix potential oops in nfs_inode_remove_request() Once a folio's private data has been cleared, it's possible for another process to clear the folio->mapping (e.g. via invalidate_complete_folio2 or evict_mapping_folio), so it wouldn't be safe to call nfs_page_to_inode() after that. Fixes: 0c493b5cf16e ("NFS: Convert buffered writes to use folios") Signed-off-by: Scott Mayhew Reviewed-by: Benjamin Coddington Tested-by: Benjamin Coddington Reviewed-by: Jeff Layton Signed-off-by: Anna Schumaker --- diff --git a/fs/nfs/write.c b/fs/nfs/write.c index 7720b5e43014b..9d82d50ce0b12 100644 --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -788,6 +788,8 @@ static void nfs_inode_add_request(struct nfs_page *req) */ static void nfs_inode_remove_request(struct nfs_page *req) { + struct nfs_inode *nfsi = NFS_I(nfs_page_to_inode(req)); + if (nfs_page_group_sync_on_bit(req, PG_REMOVE)) { struct folio *folio = nfs_page_to_folio(req->wb_head); struct address_space *mapping = folio_file_mapping(folio); @@ -802,7 +804,7 @@ static void nfs_inode_remove_request(struct nfs_page *req) } if (test_and_clear_bit(PG_INODE_REF, &req->wb_flags)) { - atomic_long_dec(&NFS_I(nfs_page_to_inode(req))->nrequests); + atomic_long_dec(&nfsi->nrequests); nfs_release_request(req); } }