Linus Torvalds d1a819a2ec splice: teach splice pipe reading about empty pipe buffers ... Tetsuo Handa reports that splice() can return 0 before the real EOF, if the data in the splice source pipe is an empty pipe buffer. That empty pipe buffer case doesn't happen in any normal situation, but you can trigger it by doing a write to a pipe that fails due to a page fault. Tetsuo has a test-case to show the behavior: #define _GNU_SOURCE #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> #include <unistd.h> int main(int argc, char *argv[]) { const int fd = open("/tmp/testfile", O_WRONLY | O_CREAT, 0600); int pipe_fd[2] = { -1, -1 }; pipe(pipe_fd); write(pipe_fd[1], NULL, 4096); /* This splice() should wait unless interrupted. */ return !splice(pipe_fd[0], NULL, fd, NULL, 65536, 0); } which results in write(5, NULL, 4096) = -1 EFAULT (Bad address) splice(4, NULL, 3, NULL, 65536, 0) = 0 and this can confuse splice() users into believing they have hit EOF prematurely. The issue was introduced when the pipe write code started pre-allocating the pipe buffers before copying data from user space. This is modified verion of Tetsuo's original patch. Fixes: a194dfe6e6 ("pipe: Rearrange sequence in pipe_write() to preallocate slot") Link:https://lore.kernel.org/linux-fsdevel/20201005121339.4063-1-penguin-kernel@I-love.SAKURA.ne.jp/ Reported-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Acked-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2020-10-06 10:27:22 -07:00
..
9p	treewide: Use fallthrough pseudo-keyword	2020-08-23 17:36:59 -05:00
adfs	treewide: Use fallthrough pseudo-keyword	2020-08-23 17:36:59 -05:00
affs	affs: fix basic permission bits to actually work	2020-08-31 12:20:31 +02:00
afs	Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net	2020-09-03 18:50:48 -07:00
autofs	autofs: use __kernel_write() for the autofs pipe writing	2020-09-29 17:18:34 -07:00
befs	block: move struct block_device to blk_types.h	2020-06-24 09:16:02 -06:00
bfs
btrfs	for-5.9-rc7-tag	2020-10-02 10:09:40 -07:00
cachefiles	cachefiles: switch to kernel_write	2020-07-08 08:27:56 +02:00
ceph	We have an inode number handling change, prompted by s390x which is	2020-08-28 10:33:04 -07:00
cifs	cifs: fix DFS mount with cifsacl/modefromsid	2020-09-06 23:59:53 -05:00
coda
configfs	treewide: Use fallthrough pseudo-keyword	2020-08-23 17:36:59 -05:00
cramfs
crypto	mm, treewide: rename kzfree() to kfree_sensitive()	2020-08-07 11:33:22 -07:00
debugfs	debugfs: Fix module state check condition	2020-09-04 18:12:52 +02:00
devpts
dlm	treewide: Use fallthrough pseudo-keyword	2020-08-23 17:36:59 -05:00
ecryptfs	mm, treewide: rename kzfree() to kfree_sensitive()	2020-08-07 11:33:22 -07:00
efivarfs	efi/efivars: Expose RT service availability via efivars abstraction	2020-07-09 10:14:29 +03:00
efs	block: move struct block_device to blk_types.h	2020-06-24 09:16:02 -06:00
erofs	treewide: Use fallthrough pseudo-keyword	2020-08-23 17:36:59 -05:00
exfat	exfat: retain 'VolumeFlags' properly	2020-08-12 08:31:13 +09:00
exportfs
ext2	ext2: don't update mtime on COW faults	2020-09-05 10:00:05 -07:00
ext4	\n	2020-08-28 10:57:14 -07:00
f2fs	f2fs: Return EOF on unaligned end of file DIO read	2020-09-08 20:31:33 -07:00
fat	fat: fix fat_ra_init() for data clusters == 0	2020-08-12 10:58:01 -07:00
freevxfs
fscache	Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next	2020-06-03 16:27:18 -07:00
fuse	fuse: fix the ->direct_IO() treatment of iov_iter	2020-09-17 17:26:56 -04:00
gfs2	Fix memory leak on filesystem withdraw	2020-08-28 10:41:00 -07:00
hfs	block: move block-related definitions out of fs.h	2020-06-24 09:16:02 -06:00
hfsplus	treewide: Use fallthrough pseudo-keyword	2020-08-23 17:36:59 -05:00
hostfs
hpfs	hpfs: fix warning due to superfluous semicolon	2020-06-06 10:08:17 -07:00
hugetlbfs	hugetlbfs: prevent filesystem stacking of hugetlbfs	2020-08-12 10:57:56 -07:00
iomap	treewide: Use fallthrough pseudo-keyword	2020-08-23 17:36:59 -05:00
isofs	Remove uninitialized_var() macro for v5.9-rc1	2020-08-04 13:49:43 -07:00
jbd2	jbd2: clean up checksum verification in do_one_pass()	2020-08-19 12:04:35 -04:00
jffs2	treewide: Use fallthrough pseudo-keyword	2020-08-23 17:36:59 -05:00
jfs	block: move struct block_device to blk_types.h	2020-06-24 09:16:02 -06:00
kernfs	fsnotify: pass dir and inode arguments to fsnotify()	2020-07-27 23:15:48 +02:00
lockd
minix	fs/minix: remove expected error message in block_to_path()	2020-08-12 10:58:00 -07:00
nfs	pNFS/flexfiles: Be consistent about mirror index types	2020-09-18 09:25:33 -04:00
nfs_common	treewide: Use fallthrough pseudo-keyword	2020-08-23 17:36:59 -05:00
nfsd	Fixes:	2020-08-25 18:01:36 -07:00
nilfs2	treewide: Use fallthrough pseudo-keyword	2020-08-23 17:36:59 -05:00
nls	treewide: replace '---help---' in Kconfig files with 'help'	2020-06-14 01:57:21 +09:00
notify	treewide: Use fallthrough pseudo-keyword	2020-08-23 17:36:59 -05:00
ntfs	ntfs: fix ntfs_test_inode and ntfs_init_locked_inode function type	2020-08-07 11:33:21 -07:00
ocfs2	treewide: Use fallthrough pseudo-keyword	2020-08-23 17:36:59 -05:00
omfs	treewide: Remove uninitialized_var() usage	2020-07-16 12:35:15 -07:00
openpromfs
orangefs	orangefs: remove unnecessary assignment to variable ret	2020-08-04 15:01:58 -04:00
overlayfs	Remove uninitialized_var() macro for v5.9-rc1	2020-08-04 13:49:43 -07:00
proc	mm, oom: make the calculation of oom badness more accurate	2020-08-12 10:57:56 -07:00
pstore	treewide: Use fallthrough pseudo-keyword	2020-08-23 17:36:59 -05:00
qnx4
qnx6	fs: convert mpage_readpages to mpage_readahead	2020-06-02 10:59:07 -07:00
quota	treewide: Use fallthrough pseudo-keyword	2020-08-23 17:36:59 -05:00
ramfs
reiserfs	\n	2020-08-06 19:28:26 -07:00
romfs	romfs: fix uninitialized memory leak in romfs_dev_read()	2020-08-21 09:52:53 -07:00
squashfs	squashfs: avoid bio_alloc() failure with 1Mbyte blocks	2020-08-21 09:52:53 -07:00
sysfs	RDMA 5.8 merge window pull request	2020-06-05 14:05:57 -07:00
sysv
tracefs
ubifs	treewide: Use fallthrough pseudo-keyword	2020-08-23 17:36:59 -05:00
udf	treewide: Use fallthrough pseudo-keyword	2020-08-23 17:36:59 -05:00
ufs	treewide: Use fallthrough pseudo-keyword	2020-08-23 17:36:59 -05:00
unicode
vboxsf	Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2020-09-22 15:08:41 -07:00
verity	fs-verity: use smp_load_acquire() for ->i_verity_info	2020-07-21 16:02:41 -07:00
xfs	Fixes (2) for 5.9:	2020-09-05 10:04:53 -07:00
zonefs	zonefs: add zone-capacity support	2020-08-11 17:42:24 +09:00
aio.c	treewide: Use fallthrough pseudo-keyword	2020-08-23 17:36:59 -05:00
anon_inodes.c
attr.c
bad_inode.c	fs: move the fiemap definitions out of fs.h	2020-06-03 23:16:55 -04:00
binfmt_aout.c
binfmt_elf_fdpic.c	Merge branch 'work.fdpic' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2020-08-07 13:29:39 -07:00
binfmt_elf.c	kill elf_fpxregs_t	2020-07-27 14:29:23 -04:00
binfmt_em86.c	Merge branch 'akpm' (patches from Andrew)	2020-06-04 19:18:29 -07:00
binfmt_flat.c	binfmt_flat: revert "binfmt_flat: don't offset the data start"	2020-08-24 08:49:13 +10:00
binfmt_misc.c	Merge branch 'akpm' (patches from Andrew)	2020-06-04 19:18:29 -07:00
binfmt_script.c	Merge branch 'akpm' (patches from Andrew)	2020-06-04 19:18:29 -07:00
block_dev.c	for-5.9/io_uring-20200802	2020-08-03 13:01:22 -07:00
buffer.c	treewide: Use fallthrough pseudo-keyword	2020-08-23 17:36:59 -05:00
char_dev.c
compat_binfmt_elf.c	Split the old READ_IMPLIES_EXEC workaround from executable PT_GNU_STACK	2020-06-05 13:45:21 -07:00
compat.c
coredump.c	coredump: add %f for executable filename	2020-08-12 10:58:01 -07:00
d_path.c
dax.c	treewide: Use fallthrough pseudo-keyword	2020-08-23 17:36:59 -05:00
dcache.c	vfs: Use sequence counter with associated spinlock	2020-07-29 16:14:27 +02:00
dcookies.c
direct-io.c	block: remove the bd_queue field from struct block_device	2020-07-01 08:08:20 -06:00
drop_caches.c
eventfd.c
eventpoll.c	ep_create_wakeup_source(): dentry name can change under you...	2020-09-24 19:41:58 -04:00
exec.c	mm/gup: remove task_struct pointer for all gup code	2020-08-12 10:58:04 -07:00
fcntl.c	treewide: Use fallthrough pseudo-keyword	2020-08-23 17:36:59 -05:00
fhandle.c
file_table.c	Revert "fs: Do not check if there is a fsnotify watcher on pseudo inodes"	2020-06-29 09:40:55 -07:00
file.c	Merge branch 'hch.init_path' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2020-08-07 09:40:34 -07:00
filesystems.c
fs_context.c	treewide: Use fallthrough pseudo-keyword	2020-08-23 17:36:59 -05:00
fs_parser.c
fs_pin.c
fs_struct.c	vfs: Use sequence counter with associated spinlock	2020-07-29 16:14:27 +02:00
fs_types.c
fs-writeback.c	fs/fs-writeback.c: adjust dirtytime_interval_handler definition to match prototype	2020-09-19 13:13:39 -07:00
fsopen.c	treewide: Use fallthrough pseudo-keyword	2020-08-23 17:36:59 -05:00
init.c	init: add an init_dup helper	2020-08-04 21:02:38 -04:00
inode.c	AFS Changes	2020-06-05 16:26:36 -07:00
internal.h	Merge branch 'hch.init_path' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2020-08-07 09:40:34 -07:00
io_uring.c	io_uring-5.9-2020-10-02	2020-10-02 14:38:10 -07:00
io-wq.c	io-wq: fix hang after cancelling pending hashed work	2020-08-23 11:38:50 -06:00
io-wq.h	io_uring/io-wq: move RLIMIT_FSIZE to io-wq	2020-07-24 13:00:44 -06:00
ioctl.c	fs: remove ksys_ioctl	2020-07-31 08:16:01 +02:00
Kconfig	tmpfs: support 64-bit inums per-sb	2020-08-07 11:33:24 -07:00
Kconfig.binfmt	treewide: replace '---help---' in Kconfig files with 'help'	2020-06-14 01:57:21 +09:00
libfs.c	treewide: Use fallthrough pseudo-keyword	2020-08-23 17:36:59 -05:00
locks.c	treewide: Use fallthrough pseudo-keyword	2020-08-23 17:36:59 -05:00
Makefile	init: add an init_mount helper	2020-07-31 08:17:51 +02:00
mbcache.c
mount.h
mpage.c	fs: convert mpage_readpages to mpage_readahead	2020-06-02 10:59:07 -07:00
namei.c	exec: restore EACCES of S_ISDIR execve()	2020-08-14 19:56:56 -07:00
namespace.c	Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2020-08-07 21:03:25 -07:00
no-block.c
nsfs.c
open.c	exec: move S_ISREG() check earlier	2020-08-12 10:58:01 -07:00
pipe.c	pipe: remove pipe_wait() and fix wakeup race with splice	2020-10-01 19:14:36 -07:00
pnode.c
pnode.h
posix_acl.c	vfs: clean up posix_acl_permission() logic aroudn MAY_NOT_BLOCK	2020-06-08 11:04:19 -07:00
proc_namespace.c	Merge branch 'proc-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace	2020-06-04 13:54:34 -07:00
read_write.c	autofs: use __kernel_write() for the autofs pipe writing	2020-09-29 17:18:34 -07:00
readdir.c	fs: remove ksys_getdents64	2020-07-31 08:16:00 +02:00
select.c	pselect6() and friends: take handling the combined 6th/7th args into helper	2020-05-29 19:10:42 -04:00
seq_file.c	treewide: Use fallthrough pseudo-keyword	2020-08-23 17:36:59 -05:00
signalfd.c	treewide: Use fallthrough pseudo-keyword	2020-08-23 17:36:59 -05:00
splice.c	splice: teach splice pipe reading about empty pipe buffers	2020-10-06 10:27:22 -07:00
stack.c
stat.c	New code for 5.8:	2020-06-02 19:45:12 -07:00
statfs.c
super.c	Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2020-06-10 16:09:11 -07:00
sync.c	overlayfs update for 5.8	2020-06-09 15:40:50 -07:00
timerfd.c
userfaultfd.c	A set of locking fixes and updates:	2020-08-10 19:07:44 -07:00
utimes.c	fs: expose utimes_common	2020-07-31 08:16:01 +02:00
xattr.c	xattr: add a function to check if a namespace is supported	2020-07-13 17:27:03 -04:00