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/xfs/Kconfig | 243 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 243 insertions(+) create mode 100644 fs/xfs/Kconfig (limited to 'fs/xfs/Kconfig') diff --git a/fs/xfs/Kconfig b/fs/xfs/Kconfig new file mode 100644 index 000000000..b99da294e --- /dev/null +++ b/fs/xfs/Kconfig @@ -0,0 +1,243 @@ +# SPDX-License-Identifier: GPL-2.0-only +config XFS_FS + tristate "XFS filesystem support" + depends on BLOCK + select EXPORTFS + select CRC32 + select FS_IOMAP + help + XFS is a high performance journaling filesystem which originated + on the SGI IRIX platform. It is completely multi-threaded, can + support large files and large filesystems, extended attributes, + variable block sizes, is extent based, and makes extensive use of + Btrees (directories, extents, free space) to aid both performance + and scalability. + + Refer to the documentation at + for complete details. This implementation is on-disk compatible + with the IRIX version of XFS. + + To compile this file system support as a module, choose M here: the + module will be called xfs. Be aware, however, that if the file + system of your root partition is compiled as a module, you'll need + to use an initial ramdisk (initrd) to boot. + +config XFS_SUPPORT_V4 + bool "Support deprecated V4 (crc=0) format" + depends on XFS_FS + default n + help + The V4 filesystem format lacks certain features that are supported + by the V5 format, such as metadata checksumming, strengthened + metadata verification, and the ability to store timestamps past the + year 2038. Because of this, the V4 format is deprecated. All users + should upgrade by backing up their files, reformatting, and restoring + from the backup. + + Administrators and users can detect a V4 filesystem by running + xfs_info against a filesystem mountpoint and checking for a string + beginning with "crc=". If the string "crc=0" is found, the + filesystem is a V4 filesystem. If no such string is found, please + upgrade xfsprogs to the latest version and try again. + + This option became default N in September 2025. Support for the + V4 format will be removed entirely in September 2030. Distributors + can say N here to withdraw support earlier. + + To continue supporting the old V4 format (crc=0), say Y. + To close off an attack surface, say N. + +config XFS_SUPPORT_ASCII_CI + bool "Support deprecated case-insensitive ascii (ascii-ci=1) format" + depends on XFS_FS + default n + help + The ASCII case insensitivity filesystem feature only works correctly + on systems that have been coerced into using ISO 8859-1, and it does + not work on extended attributes. The kernel has no visibility into + the locale settings in userspace, so it corrupts UTF-8 names. + Enabling this feature makes XFS vulnerable to mixed case sensitivity + attacks. Because of this, the feature is deprecated. All users + should upgrade by backing up their files, reformatting, and restoring + from the backup. + + Administrators and users can detect such a filesystem by running + xfs_info against a filesystem mountpoint and checking for a string + beginning with "ascii-ci=". If the string "ascii-ci=1" is found, the + filesystem is a case-insensitive filesystem. If no such string is + found, please upgrade xfsprogs to the latest version and try again. + + This option became default N in September 2025. Support for the + feature will be removed entirely in September 2030. Distributors + can say N here to withdraw support earlier. + + To continue supporting case-insensitivity (ascii-ci=1), say Y. + To close off an attack surface, say N. + +config XFS_QUOTA + bool "XFS Quota support" + depends on XFS_FS + select QUOTACTL + help + If you say Y here, you will be able to set limits for disk usage on + a per user and/or a per group basis under XFS. XFS considers quota + information as filesystem metadata and uses journaling to provide a + higher level guarantee of consistency. The on-disk data format for + quota is also compatible with the IRIX version of XFS, allowing a + filesystem to be migrated between Linux and IRIX without any need + for conversion. + + If unsure, say N. More comprehensive documentation can be found in + README.quota in the xfsprogs package. XFS quota can be used either + with or without the generic quota support enabled (CONFIG_QUOTA) - + they are completely independent subsystems. + +config XFS_POSIX_ACL + bool "XFS POSIX ACL support" + depends on XFS_FS + select FS_POSIX_ACL + help + POSIX Access Control Lists (ACLs) support permissions for users and + groups beyond the owner/group/world scheme. + + If you don't know what Access Control Lists are, say N. + +config XFS_RT + bool "XFS Realtime subvolume support" + depends on XFS_FS + default BLK_DEV_ZONED + help + If you say Y here you will be able to mount and use XFS filesystems + which contain a realtime subvolume. The realtime subvolume is a + separate area of disk space where only file data is stored. It was + originally designed to provide deterministic data rates suitable + for media streaming applications, but is also useful as a generic + mechanism for ensuring data and metadata/log I/Os are completely + separated. Regular file I/Os are isolated to a separate device + from all other requests, and this can be done quite transparently + to applications via the inherit-realtime directory inode flag. + + See the xfs man page in section 5 for additional information. + + This option is mandatory to support zoned block devices. For these + devices, the realtime subvolume must be backed by a zoned block + device and a regular block device used as the main device (for + metadata). If the zoned block device is a host-managed SMR hard-disk + containing conventional zones at the beginning of its address space, + XFS will use the disk conventional zones as the main device and the + remaining sequential write required zones as the backing storage for + the realtime subvolume. + + If unsure, say N. + +config XFS_DRAIN_INTENTS + bool + select JUMP_LABEL if HAVE_ARCH_JUMP_LABEL + +config XFS_LIVE_HOOKS + bool + select JUMP_LABEL if HAVE_ARCH_JUMP_LABEL + +config XFS_MEMORY_BUFS + bool + +config XFS_BTREE_IN_MEM + bool + +config XFS_ONLINE_SCRUB + bool "XFS online metadata check support" + default y + depends on XFS_FS + depends on TMPFS && SHMEM + select XFS_LIVE_HOOKS + select XFS_DRAIN_INTENTS + select XFS_MEMORY_BUFS + help + If you say Y here you will be able to check metadata on a + mounted XFS filesystem. This feature is intended to reduce + filesystem downtime by supplementing xfs_repair. The key + advantage here is to look for problems proactively so that + they can be dealt with in a controlled manner. + + See the xfs_scrub man page in section 8 for additional information. + +config XFS_ONLINE_SCRUB_STATS + bool "XFS online metadata check usage data collection" + default y + depends on XFS_ONLINE_SCRUB + depends on DEBUG_FS + help + If you say Y here, the kernel will gather usage data about + the online metadata check subsystem. This includes the number + of invocations, the outcomes, and the results of repairs, if any. + This may slow down scrub slightly due to the use of high precision + timers and the need to merge per-invocation information into the + filesystem counters. + + Usage data are collected in /sys/kernel/debug/xfs/scrub. + +config XFS_ONLINE_REPAIR + bool "XFS online metadata repair support" + default y + depends on XFS_FS && XFS_ONLINE_SCRUB + select XFS_BTREE_IN_MEM + help + If you say Y here you will be able to repair metadata on a + mounted XFS filesystem. This feature is intended to reduce + filesystem downtime by fixing minor problems before they cause the + filesystem to go down. However, it requires that the filesystem be + formatted with secondary metadata, such as reverse mappings and inode + parent pointers. + + See the xfs_scrub man page in section 8 for additional information. + +config XFS_WARN + bool "XFS Verbose Warnings" + depends on XFS_FS && !XFS_DEBUG + help + Say Y here to get an XFS build with many additional warnings. + It converts ASSERT checks to WARN, so will log any out-of-bounds + conditions that occur that would otherwise be missed. It is much + lighter weight than XFS_DEBUG and does not modify algorithms and will + not cause the kernel to panic on non-fatal errors. + + However, similar to XFS_DEBUG, it is only advisable to use this if you + are debugging a particular problem. + +config XFS_DEBUG + bool "XFS Debugging support" + depends on XFS_FS + help + Say Y here to get an XFS build with many debugging features, + including ASSERT checks, function wrappers around macros, + and extra sanity-checking functions in various code paths. + + Note that the resulting code will be HUGE and SLOW, and probably + not useful unless you are debugging a particular problem. + + Say N unless you are an XFS developer, or you play one on TV. + +config XFS_DEBUG_EXPENSIVE + bool "XFS expensive debugging checks" + depends on XFS_FS && XFS_DEBUG + help + Say Y here to get an XFS build with expensive debugging checks + enabled. These checks may affect performance significantly. + + Note that the resulting code will be HUGER and SLOWER, and probably + not useful unless you are debugging a particular problem. + + Say N unless you are an XFS developer, or you play one on TV. + +config XFS_ASSERT_FATAL + bool "XFS fatal asserts" + default y + depends on XFS_FS && XFS_DEBUG + help + Set the default DEBUG mode ASSERT failure behavior. + + Say Y here to cause DEBUG mode ASSERT failures to result in fatal + errors that BUG() the kernel by default. If you say N, ASSERT failures + result in warnings. + + This behavior can be modified at runtime via sysfs. -- cgit v1.3.1