linux/fs
Dave Marchevsky b138777786 fuse: Rearrange fuse_allow_current_process checks
This is a followup to a previous commit of mine [0], which added the
allow_sys_admin_access && capable(CAP_SYS_ADMIN) check.  This patch
rearranges the order of checks in fuse_allow_current_process without
changing functionality.

Commit 9ccf47b26b ("fuse: Add module param for CAP_SYS_ADMIN access
bypassing allow_other") added allow_sys_admin_access &&
capable(CAP_SYS_ADMIN) check to the beginning of the function, with the
reasoning that allow_sys_admin_access should be an 'escape hatch' for users
with CAP_SYS_ADMIN, allowing them to skip any subsequent checks.

However, placing this new check first results in many capable() calls when
allow_sys_admin_access is set, where another check would've also returned
1.  This can be problematic when a BPF program is tracing capable() calls.

At Meta we ran into such a scenario recently.  On a host where
allow_sys_admin_access is set but most of the FUSE access is from processes
which would pass other checks - i.e.  they don't need CAP_SYS_ADMIN 'escape
hatch' - this results in an unnecessary capable() call for each fs op.  We
also have a daemon tracing capable() with BPF and doing some data
collection, so tracing these extraneous capable() calls has the potential
to regress performance for an application doing many FUSE ops.

So rearrange the order of these checks such that CAP_SYS_ADMIN 'escape
hatch' is checked last.  Add a small helper, fuse_permissible_uidgid, to
make the logic easier to understand.  Previously, if allow_other is set on
the fuse_conn, uid/git checking doesn't happen as current_in_userns result
is returned.  These semantics are maintained here: fuse_permissible_uidgid
check only happens if allow_other is not set.

Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
Suggested-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2022-11-23 09:10:50 +01:00
..
9p 9p: Fix some kernel-doc comments 2022-07-02 18:52:21 +09:00
adfs fs: Convert block_read_full_page() to block_read_full_folio() 2022-05-09 16:21:44 -04:00
affs affs: move from strlcpy with unused retval to strscpy 2022-08-19 13:03:10 +02:00
afs struct file-related stuff 2022-10-06 17:13:18 -07:00
autofs autofs: remove unused ino field inode 2022-07-17 17:31:42 -07:00
befs befs: Convert befs_symlink_read_folio() to use a folio 2022-08-02 12:34:03 -04:00
bfs fs: Convert block_read_full_page() to block_read_full_folio() 2022-05-09 16:21:44 -04:00
btrfs 22 hotfixes. 8 are cc:stable and the remainder address issues which were 2022-11-11 17:18:42 -08:00
cachefiles cachefiles: use vfs_tmpfile_open() helper 2022-09-24 07:00:00 +02:00
ceph ceph: fix NULL pointer dereference for req->r_session 2022-11-14 10:29:05 +01:00
cifs cifs: add check for returning value of SMB2_set_info_init 2022-11-16 12:24:26 -06:00
coda coda: Convert coda_symlink_filler() to use a folio 2022-08-02 12:34:03 -04:00
configfs
cramfs cramfs: read_mapping_page() is synchronous 2022-08-02 12:34:02 -04:00
crypto fscrypt: fix keyring memory leak on mount failure 2022-10-19 20:54:43 -07:00
debugfs debugfs: use DEFINE_SHOW_ATTRIBUTE to define debugfs_regset32_fops 2022-09-24 15:00:48 +02:00
devpts
dlm Networking changes for 6.1. 2022-10-04 13:38:03 -07:00
ecryptfs whack-a-mole: constifying struct path * 2022-10-06 17:31:02 -07:00
efivarfs efi: efivars: Fix variable writes without query_variable_store() 2022-10-21 11:09:40 +02:00
efs efs: Convert efs symlinks to read_folio 2022-05-09 16:21:45 -04:00
erofs Changes since last update: 2022-11-15 10:30:34 -08:00
exfat treewide: use get_random_u32() when possible 2022-10-11 17:42:58 -06:00
exportfs Change calling conventions for filldir_t 2022-08-17 17:25:04 -04:00
ext2 treewide: use prandom_u32_max() when possible, part 2 2022-10-11 17:42:58 -06:00
ext4 Fix a number of bug fixes, including some regressions, the most 2022-11-06 10:30:29 -08:00
f2fs Random number generator fixes for Linux 6.1-rc1. 2022-10-16 15:27:07 -07:00
fat treewide: use get_random_u32() when possible 2022-10-11 17:42:58 -06:00
freevxfs freevxfs: Convert vxfs_immed_read_folio() to use a folio 2022-08-02 12:34:03 -04:00
fscache fscache: add tracepoint when failing cookie 2022-08-09 14:13:59 +01:00
fuse fuse: Rearrange fuse_allow_current_process checks 2022-11-23 09:10:50 +01:00
gfs2 gfs2 debugfs improvements 2022-10-10 20:13:22 -07:00
hfs hfs: replace kmap() with kmap_local_page() in btree.c 2022-09-11 21:55:09 -07:00
hfsplus hfsplus: convert kmap() to kmap_local_page() in btree.c 2022-09-11 21:55:05 -07:00
hostfs hostfs: move from strlcpy with unused retval to strscpy 2022-09-19 22:46:25 +02:00
hpfs hpfs: Convert symlinks to read_folio 2022-05-09 16:21:45 -04:00
hugetlbfs hugetlbfs: don't delete error page from pagecache 2022-11-08 15:57:22 -08:00
iomap iomap: add a tracepoint for mappings returned by map_blocks 2022-10-02 11:42:19 -07:00
isofs - hfs and hfsplus kmap API modernization from Fabio Francesco 2022-10-12 11:00:22 -07:00
jbd2 - Yu Zhao's Multi-Gen LRU patches are here. They've been under test in 2022-10-10 17:53:04 -07:00
jffs2 mtd: always initialize 'stats' in struct mtd_oob_ops 2022-09-21 10:38:07 +02:00
jfs Folio changes for 6.0 2022-08-03 10:35:43 -07:00
kernfs kernfs: Fix spurious lockdep warning in kernfs_find_and_get_node_by_id() 2022-11-10 19:03:42 +01:00
ksmbd 24 ksmbd server fixes 2022-10-07 08:19:26 -07:00
lockd SUNRPC: Parametrize how much of argsize should be zeroed 2022-09-26 14:02:42 -04:00
minix vfs: open inside ->tmpfile() 2022-09-24 07:00:00 +02:00
netfs netfs: Fix dodgy maths 2022-11-15 16:56:07 +00:00
nfs nfs4: Fix kmemleak when allocate slot failed 2022-10-27 15:52:11 -04:00
nfs_common
nfsd Fixes: 2022-11-17 09:04:50 -08:00
nilfs2 nilfs2: fix use-after-free bug of ns_writer on remount 2022-11-08 15:57:24 -08:00
nls
notify Merge tag 'fsnotify-for_v6.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs 2022-10-07 08:28:50 -07:00
ntfs - hfs and hfsplus kmap API modernization from Fabio Francesco 2022-10-12 11:00:22 -07:00
ntfs3 treewide: use get_random_u32() when possible 2022-10-11 17:42:58 -06:00
ocfs2 ocfs2: clear dinode links count in case of error 2022-10-20 21:27:22 -07:00
omfs fs: Convert block_read_full_page() to block_read_full_folio() 2022-05-09 16:21:44 -04:00
openpromfs fs: allocate inode by using alloc_inode_sb() 2022-03-22 15:57:03 -07:00
orangefs Orangefs: change iterate to iterate_shared 2022-10-13 09:56:14 -07:00
overlayfs tmpfile API change 2022-10-10 19:45:17 -07:00
proc mm: /proc/pid/smaps_rollup: fix maple tree search 2022-10-20 21:27:23 -07:00
pstore Revert "pstore: migrate to crypto acomp interface" 2022-09-30 08:16:06 -07:00
qnx4 fs: Convert block_read_full_page() to block_read_full_folio() 2022-05-09 16:21:44 -04:00
qnx6 fs/qnx6: delete unnecessary checks before brelse() 2022-09-11 21:55:07 -07:00
quota quota: Add more checking after reading from quota file 2022-09-29 15:37:30 +02:00
ramfs tmpfile API change 2022-10-10 19:45:17 -07:00
reiserfs - hfs and hfsplus kmap API modernization from Fabio Francesco 2022-10-12 11:00:22 -07:00
romfs romfs: Convert romfs to read_folio 2022-05-09 16:21:46 -04:00
smbfs_common smb3: define missing create contexts 2022-10-05 01:55:27 -05:00
squashfs squashfs: fix buffer release race condition in readahead code 2022-10-28 13:37:21 -07:00
sysfs kobject: kobj_type: remove default_attrs 2022-04-05 15:39:19 +02:00
sysv Not a lot of material this cycle. Many singleton patches against various 2022-05-27 11:22:03 -07:00
tracefs tracefs: Only clobber mode/uid/gid on remount if asked 2022-09-08 17:10:54 -04:00
ubifs Random number generator fixes for Linux 6.1-rc1. 2022-10-16 15:27:07 -07:00
udf udf: Fix a slab-out-of-bounds write bug in udf_find_entry() 2022-11-09 12:24:42 +01:00
ufs ufs: replace ll_rw_block() 2022-09-11 20:26:07 -07:00
unicode
vboxsf vboxsf: Convert vboxsf to read_folio 2022-05-09 16:21:46 -04:00
verity for-6.1-tag 2022-10-06 17:36:48 -07:00
xfs xfs: rename XFS_REFC_COW_START to _COWFLAG 2022-10-31 08:58:22 -07:00
zonefs zonefs: Remove to_attr() helper function 2022-11-16 16:08:31 +09:00
aio.c aio: use atomic_try_cmpxchg in __get_reqs_available 2022-09-11 21:55:08 -07:00
anon_inodes.c dynamic_dname(): drop unused dentry argument 2022-08-20 11:34:04 -04:00
attr.c vfs: Check the truncate maximum size in inode_newsize_ok() 2022-08-08 10:39:29 -07:00
bad_inode.c vfs: open inside ->tmpfile() 2022-09-24 07:00:00 +02:00
binfmt_elf_fdpic.c
binfmt_elf_test.c
binfmt_elf.c fs/binfmt_elf: Fix memory leak in load_elf_binary() 2022-10-25 15:11:21 -07:00
binfmt_flat.c binfmt_flat: Remove shared library support 2022-04-22 10:57:18 -07:00
binfmt_misc.c
binfmt_script.c
buffer.c - hfs and hfsplus kmap API modernization from Fabio Francesco 2022-10-12 11:00:22 -07:00
char_dev.c
compat_binfmt_elf.c
coredump.c - Yu Zhao's Multi-Gen LRU patches are here. They've been under test in 2022-10-10 17:53:04 -07:00
d_path.c d_path.c: typo fix... 2022-08-20 11:34:33 -04:00
dax.c Merge branch 'for-6.0/dax' into libnvdimm-fixes 2022-09-24 18:14:12 -07:00
dcache.c tmpfile API change 2022-10-10 19:45:17 -07:00
direct-io.c block: remove PSI accounting from the bio layer 2022-09-20 08:24:38 -06:00
drop_caches.c
eventfd.c eventfd: guard wake_up in eventfd fs calls as well 2022-09-21 10:30:42 -06:00
eventpoll.c epoll: use try_cmpxchg in list_add_tail_lockless 2022-09-11 21:55:07 -07:00
exec.c 23 hotfixes. 2022-10-29 17:49:33 -07:00
fcntl.c keep iocb_flags() result cached in struct file 2022-06-10 16:10:23 -04:00
fhandle.c do_sys_name_to_handle(): constify path 2022-09-01 17:36:39 -04:00
file_table.c locks: fix TOCTOU race when granting write lease 2022-08-16 10:59:54 -04:00
file.c gfs2: Add glockfd debugfs file 2022-06-29 13:07:16 +02:00
filesystems.c
fs_context.c
fs_parser.c
fs_pin.c
fs_struct.c
fs_types.c
fs-writeback.c fs: record I_DIRTY_TIME even if inode already has I_DIRTY_INODE 2022-09-29 23:02:00 -04:00
fsopen.c uninline may_mount() and don't opencode it in fspick(2)/fsopen(2) 2022-05-19 23:25:10 -04:00
init.c
inode.c saner inode_init_always() 2022-10-06 16:49:00 -07:00
internal.h whack-a-mole: constifying struct path * 2022-10-06 17:31:02 -07:00
ioctl.c Fixes for 5.18-rc1: 2022-04-01 19:35:56 -07:00
Kconfig hugetlb: make hugetlb depends on SYSFS or SYSCTL 2022-09-11 20:26:10 -07:00
Kconfig.binfmt Xtensa updates for v6.1 2022-10-10 14:21:11 -07:00
kernel_read_file.c fs/kernel_read_file: allow to read files up-to ssize_t 2022-06-16 19:58:21 -07:00
libfs.c fs: uninline inode_maybe_inc_iversion() 2022-10-03 14:21:43 -07:00
locks.c locks: Fix dropped call to ->fl_release_private() 2022-08-17 15:08:58 -04:00
Makefile a.out: Remove the a.out implementation 2022-09-27 07:11:02 -07:00
mbcache.c mbcache: Avoid nesting of cache->c_list_lock under bit locks 2022-09-30 23:46:52 -04:00
mount.h switch try_to_unlazy_next() to __legitimize_mnt() 2022-07-05 16:18:21 -04:00
mpage.c Folio changes for 6.0 2022-08-03 10:35:43 -07:00
namei.c tmpfile API change 2022-10-10 19:45:17 -07:00
namespace.c fs: require CAP_SYS_ADMIN in target namespace for idmapped mounts 2022-08-17 11:27:11 +02:00
no-block.c
nsfs.c dynamic_dname(): drop unused dentry argument 2022-08-20 11:34:04 -04:00
open.c struct file-related stuff 2022-10-06 17:13:18 -07:00
pipe.c dynamic_dname(): drop unused dentry argument 2022-08-20 11:34:04 -04:00
pnode.c
pnode.h
posix_acl.c - Yu Zhao's Multi-Gen LRU patches are here. They've been under test in 2022-10-10 17:53:04 -07:00
proc_namespace.c vfs: escape hash as well 2022-06-28 13:58:05 -04:00
read_write.c [coredump] don't use __kernel_write() on kmap_local_page() 2022-09-28 14:28:40 -04:00
readdir.c Change calling conventions for filldir_t 2022-08-17 17:25:04 -04:00
remap_range.c - The usual batches of cleanups from Baoquan He, Muchun Song, Miaohe 2022-08-05 16:32:45 -07:00
select.c
seq_file.c rxrpc: Fix locking issue 2022-05-22 21:03:01 +01:00
signalfd.c
splice.c iter_to_pipe(): switch to advancing variant of iov_iter_get_pages() 2022-08-08 22:37:23 -04:00
stack.c
stat.c vfs: support STATX_DIOALIGN on block devices 2022-09-11 19:47:12 -05:00
statfs.c
super.c fscrypt: fix keyring memory leak on mount failure 2022-10-19 20:54:43 -07:00
sync.c riscv: compat: syscall: Add compat_sys_call_table implementation 2022-04-26 13:36:25 -07:00
sysctls.c
timerfd.c
userfaultfd.c fs/userfaultfd: Fix maple tree iterator in userfaultfd_unregister() 2022-11-07 12:58:26 -08:00
utimes.c
xattr.c xattr: always us is_posix_acl_xattr() helper 2022-09-21 12:01:29 +02:00