linux.git/fs, branch v5.9-rc2

Merge branch 'work.epoll' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2020-08-23T00:11:38+00:00

Pull epoll fixes from Al Viro:
 "Fix reference counting and clean up exit paths"

* 'work.epoll' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  do_epoll_ctl(): clean the failure exits up a bit
  epoll: Keep a reference on files added to the check list

do_epoll_ctl(): clean the failure exits up a bit

2020-08-22T22:25:52+00:00

Signed-off-by: Al Viro

epoll: Keep a reference on files added to the check list

2020-08-22T22:23:57+00:00

When adding a new fd to an epoll, and that this new fd is an
epoll fd itself, we recursively scan the fds attached to it
to detect cycles, and add non-epool files to a "check list"
that gets subsequently parsed.

However, this check list isn't completely safe when deletions
can happen concurrently. To sidestep the issue, make sure that
a struct file placed on the check list sees its f_count increased,
ensuring that a concurrent deletion won't result in the file
disapearing from under our feet.

Cc: stable@vger.kernel.org
Signed-off-by: Marc Zyngier 
Signed-off-by: Al Viro

Merge tag 'io_uring-5.9-2020-08-21' of git://git.kernel.dk/linux-block

2020-08-21T21:59:16+00:00

Pull io_uring fixes from Jens Axboe:

 - Make sure the head link cancelation includes async work

 - Get rid of kiocb_wait_page_queue_init(), makes no sense to have it as
   a separate function since you moved it into io_uring itself

 - io_import_iovec cleanups (Pavel, me)

 - Use system_unbound_wq for ring exit work, to avoid spawning tons of
   these if we have tons of rings exiting at the same time

 - Fix req->flags overflow flag manipulation (Pavel)

* tag 'io_uring-5.9-2020-08-21' of git://git.kernel.dk/linux-block:
  io_uring: kill extra iovec=NULL in import_iovec()
  io_uring: comment on kfree(iovec) checks
  io_uring: fix racy req->flags modification
  io_uring: use system_unbound_wq for ring exit work
  io_uring: cleanup io_import_iovec() of pre-mapped request
  io_uring: get rid of kiocb_wait_page_queue_init()
  io_uring: find and cancel head link async work on files exit

Merge branch 'akpm' (patches from Andrew)

2020-08-21T21:44:48+00:00

Merge misc fixes from Andrew Morton:
 "11 patches.

  Subsystems affected by this: misc, mm/hugetlb, mm/vmalloc, mm/misc,
  romfs, relay, uprobes, squashfs, mm/cma, mm/pagealloc"

* emailed patches from Andrew Morton :
  mm, page_alloc: fix core hung in free_pcppages_bulk()
  mm: include CMA pages in lowmem_reserve at boot
  squashfs: avoid bio_alloc() failure with 1Mbyte blocks
  uprobes: __replace_page() avoid BUG in munlock_vma_page()
  kernel/relay.c: fix memleak on destroy relay channel
  romfs: fix uninitialized memory leak in romfs_dev_read()
  mm/rodata_test.c: fix missing function declaration
  mm/vunmap: add cond_resched() in vunmap_pmd_range
  khugepaged: adjust VM_BUG_ON_MM() in __khugepaged_enter()
  hugetlb_cgroup: convert comma to semicolon
  mailmap: add Andi Kleen

Merge tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

2020-08-21T18:03:38+00:00

Pull ext4 updates from Ted Ts'o:
 "Improvements to ext4's block allocator performance for very large file
  systems, especially when the file system or files which are highly
  fragmented. There is a new mount option, prefetch_block_bitmaps which
  will pull in the block bitmaps and set up the in-memory buddy bitmaps
  when the file system is initially mounted.

  Beyond that, a lot of bug fixes and cleanups. In particular, a number
  of changes to make ext4 more robust in the face of write errors or
  file system corruptions"

* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (46 commits)
  ext4: limit the length of per-inode prealloc list
  ext4: reorganize if statement of ext4_mb_release_context()
  ext4: add mb_debug logging when there are lost chunks
  ext4: Fix comment typo "the the".
  jbd2: clean up checksum verification in do_one_pass()
  ext4: change to use fallthrough macro
  ext4: remove unused parameter of ext4_generic_delete_entry function
  mballoc: replace seq_printf with seq_puts
  ext4: optimize the implementation of ext4_mb_good_group()
  ext4: delete invalid comments near ext4_mb_check_limits()
  ext4: fix typos in ext4_mb_regular_allocator() comment
  ext4: fix checking of directory entry validity for inline directories
  fs: prevent BUG_ON in submit_bh_wbc()
  ext4: correctly restore system zone info when remount fails
  ext4: handle add_system_zone() failure in ext4_setup_system_zone()
  ext4: fold ext4_data_block_valid_rcu() into the caller
  ext4: check journal inode extents more carefully
  ext4: don't allow overlapping system zones
  ext4: handle error of ext4_setup_system_zone() on remount
  ext4: delete the invalid BUGON in ext4_mb_load_buddy_gfp()
  ...

afs: Fix NULL deref in afs_dynroot_depopulate()

2020-08-21T17:56:40+00:00

If an error occurs during the construction of an afs superblock, it's
possible that an error occurs after a superblock is created, but before
we've created the root dentry.  If the superblock has a dynamic root
(ie.  what's normally mounted on /afs), the afs_kill_super() will call
afs_dynroot_depopulate() to unpin any created dentries - but this will
oops if the root hasn't been created yet.

Fix this by skipping that bit of code if there is no root dentry.

This leads to an oops looking like:

	general protection fault, ...
	KASAN: null-ptr-deref in range [0x0000000000000068-0x000000000000006f]
	...
	RIP: 0010:afs_dynroot_depopulate+0x25f/0x529 fs/afs/dynroot.c:385
	...
	Call Trace:
	 afs_kill_super+0x13b/0x180 fs/afs/super.c:535
	 deactivate_locked_super+0x94/0x160 fs/super.c:335
	 afs_get_tree+0x1124/0x1460 fs/afs/super.c:598
	 vfs_get_tree+0x89/0x2f0 fs/super.c:1547
	 do_new_mount fs/namespace.c:2875 [inline]
	 path_mount+0x1387/0x2070 fs/namespace.c:3192
	 do_mount fs/namespace.c:3205 [inline]
	 __do_sys_mount fs/namespace.c:3413 [inline]
	 __se_sys_mount fs/namespace.c:3390 [inline]
	 __x64_sys_mount+0x27f/0x300 fs/namespace.c:3390
	 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
	 entry_SYSCALL_64_after_hwframe+0x44/0xa9

which is oopsing on this line:

	inode_lock(root->d_inode);

presumably because sb->s_root was NULL.

Fixes: 0da0b7fd73e4 ("afs: Display manually added cells in dynamic root mount")
Reported-by: syzbot+c1eff8205244ae7e11a6@syzkaller.appspotmail.com
Signed-off-by: David Howells 
Signed-off-by: Linus Torvalds

squashfs: avoid bio_alloc() failure with 1Mbyte blocks

2020-08-21T16:52:53+00:00

This is a regression introduced by the patch "migrate from ll_rw_block
usage to BIO".

Bio_alloc() is limited to 256 pages (1 Mbyte).  This can cause a failure
when reading 1 Mbyte block filesystems.  The problem is a datablock can be
fully (or almost uncompressed), requiring 256 pages, but, because blocks
are not aligned to page boundaries, it may require 257 pages to read.

Bio_kmalloc() can handle 1024 pages, and so use this for the edge
condition.

Fixes: 93e72b3c612a ("squashfs: migrate from ll_rw_block usage to BIO")
Reported-by: Nicolas Prochazka 
Reported-by: Tomoatsu Shimada 
Signed-off-by: Phillip Lougher 
Signed-off-by: Andrew Morton 
Reviewed-by: Guenter Roeck 
Cc: Philippe Liard 
Cc: Christoph Hellwig 
Cc: Adrien Schildknecht 
Cc: Daniel Rosenberg 
Cc: 
Link: http://lkml.kernel.org/r/20200815035637.15319-1-phillip@squashfs.org.uk
Signed-off-by: Linus Torvalds

romfs: fix uninitialized memory leak in romfs_dev_read()

2020-08-21T16:52:53+00:00

romfs has a superblock field that limits the size of the filesystem; data
beyond that limit is never accessed.

romfs_dev_read() fetches a caller-supplied number of bytes from the
backing device.  It returns 0 on success or an error code on failure;
therefore, its API can't represent short reads, it's all-or-nothing.

However, when romfs_dev_read() detects that the requested operation would
cross the filesystem size limit, it currently silently truncates the
requested number of bytes.  This e.g.  means that when the content of a
file with size 0x1000 starts one byte before the filesystem size limit,
->readpage() will only fill a single byte of the supplied page while
leaving the rest uninitialized, leaking that uninitialized memory to
userspace.

Fix it by returning an error code instead of truncating the read when the
requested read operation would go beyond the end of the filesystem.

Fixes: da4458bda237 ("NOMMU: Make it possible for RomFS to use MTD devices directly")
Signed-off-by: Jann Horn 
Signed-off-by: Andrew Morton 
Reviewed-by: Greg Kroah-Hartman 
Cc: David Howells 
Cc: 
Link: http://lkml.kernel.org/r/20200818013202.2246365-1-jannh@google.com
Signed-off-by: Linus Torvalds

afs: Fix key ref leak in afs_put_operation()

2020-08-20T17:41:45+00:00

The afs_put_operation() function needs to put the reference to the key
that's authenticating the operation.

Fixes: e49c7b2f6de7 ("afs: Build an abstraction around an "operation" concept")
Reported-by: Dave Botsch 
Signed-off-by: David Howells 
Signed-off-by: Linus Torvalds