From 6668ed271eaefaa63e686bdfbedaeb7b8e492722 Mon Sep 17 00:00:00 2001 From: Kumar Kartikeya Dwivedi Date: Fri, 4 Sep 2026 10:43:19 +0200 Subject: selftests/bpf: Reject graph kptr use after RCU unlock Add a sleepable verifier test that loads a graph-node local kptr in an explicit RCU read-side critical section, then passes its node to bpf_rbtree_remove() after the section ends. Before the verifier fix, the stale NON_OWN_REF flag makes the node look like a live borrowed reference and the program is accepted. After the fix, the pointer is demoted without NON_OWN_REF and the graph kfunc argument is rejected. Also exercise a graph kptr loaded while a spin lock provides implicit RCU protection. The pointer must be invalidated when the lock is released, which guards the required ordering between non-owning-reference invalidation and RCU demotion. Update the existing fault-protected load test state description. The post-unlock pointer no longer carries NON_OWN_REF, but remains readable because the load is rewritten to use BPF_PROBE_MEM. Signed-off-by: Kumar Kartikeya Dwivedi Link: https://lore.kernel.org/r/20260904084325.52250-7-memxor@gmail.com Signed-off-by: Alexei Starovoitov --- fs/ufs/Kconfig | 45 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 45 insertions(+) create mode 100644 fs/ufs/Kconfig (limited to 'fs/ufs/Kconfig') diff --git a/fs/ufs/Kconfig b/fs/ufs/Kconfig new file mode 100644 index 000000000..9301e7ecd --- /dev/null +++ b/fs/ufs/Kconfig @@ -0,0 +1,45 @@ +# SPDX-License-Identifier: GPL-2.0-only +config UFS_FS + tristate "UFS file system support (read only)" + depends on BLOCK + select BUFFER_HEAD + help + BSD and derivate versions of Unix (such as SunOS, FreeBSD, NetBSD, + OpenBSD and NeXTstep) use a file system called UFS. Some System V + Unixes can create and mount hard disk partitions and diskettes using + this file system as well. Saying Y here will allow you to read from + these partitions; if you also want to write to them, say Y to the + experimental "UFS file system write support", below. Please read the + file for more information. + + The recently released UFS2 variant (used in FreeBSD 5.x) is + READ-ONLY supported. + + Note that this option is generally not needed for floppies, since a + good portable way to transport files and directories between unixes + (and even other operating systems) is given by the tar program ("man + tar" or preferably "info tar"). + + When accessing NeXTstep files, you may need to convert them from the + NeXT character set to the Latin1 character set; use the program + recode ("info recode") for this purpose. + + To compile the UFS file system support as a module, choose M here: the + module will be called ufs. + + If you haven't heard about all of this before, it's safe to say N. + +config UFS_FS_WRITE + bool "UFS file system write support (DANGEROUS)" + depends on UFS_FS + help + Say Y here if you want to try writing to UFS partitions. This is + experimental, so you should back up your UFS partitions beforehand. + +config UFS_DEBUG + bool "UFS debugging" + depends on UFS_FS + help + If you are experiencing any problems with the UFS filesystem, say + Y here. This will result in _many_ additional debugging messages to be + written to the system log. -- cgit v1.3.1