On Mon, Oct 07, 2019 at 05:50:31PM -0700, Hugh Dickins wrote: [sorry for being MIA - had been sick through the last week, just digging myself from under piles of mail; my apologies] > (tmpfs, very tiresomely, supports a NUMA "mpol" mount option which can > have commas in it e.g "mpol=bind:0,2": which makes all its comma parsing > awkward. I assume that where the new mount API commits bend over to > accommodate that peculiarity, they end up mishandling the comma in > the context string above.) Dumber than that, I'm afraid. mpol is the reason for having ->parse_monolithic() in the first place, all right, but the problem is simply the lack of security_sb_eat_lsm_opts() call in it. Could you check if the following fixes that one? diff --git a/mm/shmem.c b/mm/shmem.c index 0f7fd4a85db6..8dcc8d04cbaf 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -3482,6 +3482,12 @@ static int shmem_parse_options(struct fs_context *fc, void *data) { char *options = data; + if (options) { + int err = security_sb_eat_lsm_opts(options, &fc->security); + if (err) + return err; + } + while (options != NULL) { char *this_char = options; for (;;) {