linux-stable.git/fs/fat, branch linux-5.4.y

fat: fix uninitialized variable

2024-11-08T15:20:47+00:00

commit 963a7f4d3b90ee195b895ca06b95757fcba02d1a upstream.

syszbot produced this with a corrupted fs image.  In theory, however an IO
error would trigger this also.

This affects just an error report, so should not be a serious error.

Link: https://lkml.kernel.org/r/87r08wjsnh.fsf@mail.parknet.co.jp
Link: https://lkml.kernel.org/r/66ff2c95.050a0220.49194.03e9.GAE@google.com
Signed-off-by: OGAWA Hirofumi 
Reported-by: syzbot+ef0d7bc412553291aa86@syzkaller.appspotmail.com
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Greg Kroah-Hartman

fat: fix uninitialized field in nostale filehandles

2024-04-13T10:51:23+00:00

[ Upstream commit fde2497d2bc3a063d8af88b258dbadc86bd7b57c ]

When fat_encode_fh_nostale() encodes file handle without a parent it
stores only first 10 bytes of the file handle. However the length of the
file handle must be a multiple of 4 so the file handle is actually 12
bytes long and the last two bytes remain uninitialized. This is not
great at we potentially leak uninitialized information with the handle
to userspace. Properly initialize the full handle length.

Link: https://lkml.kernel.org/r/20240205122626.13701-1-jack@suse.cz
Reported-by: syzbot+3ce5dea5b1539ff36769@syzkaller.appspotmail.com
Fixes: ea3983ace6b7 ("fat: restructure export_operations")
Signed-off-by: Jan Kara 
Acked-by: OGAWA Hirofumi 
Cc: Amir Goldstein 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Sasha Levin

treewide: Remove uninitialized_var() usage

2023-06-09T08:29:01+00:00

commit 3f649ab728cda8038259d8f14492fe400fbab911 upstream.

Using uninitialized_var() is dangerous as it papers over real bugs[1]
(or can in the future), and suppresses unrelated compiler warnings
(e.g. "unused variable"). If the compiler thinks it is uninitialized,
either simply initialize the variable or make compiler changes.

In preparation for removing[2] the[3] macro[4], remove all remaining
needless uses with the following script:

git grep '\buninitialized_var\b' | cut -d: -f1 | sort -u | \
	xargs perl -pi -e \
		's/\buninitialized_var\(([^\)]+)\)/\1/g;
		 s:\s*/\* (GCC be quiet|to make compiler happy) \*/$::g;'

drivers/video/fbdev/riva/riva_hw.c was manually tweaked to avoid
pathological white-space.

No outstanding warnings were found building allmodconfig with GCC 9.3.0
for x86_64, i386, arm64, arm, powerpc, powerpc64le, s390x, mips, sparc64,
alpha, and m68k.

[1] https://lore.kernel.org/lkml/20200603174714.192027-1-glider@google.com/
[2] https://lore.kernel.org/lkml/CA+55aFw+Vbj0i=1TGqCR5vQkCzWJ0QxK6CernOU6eedsudAixw@mail.gmail.com/
[3] https://lore.kernel.org/lkml/CA+55aFwgbgqhbp1fkxvRKEpzyR5J8n1vKT1VZdz9knmPuXhOeg@mail.gmail.com/
[4] https://lore.kernel.org/lkml/CA+55aFz2500WfbKXAx8s67wrm9=yVJu65TpLgN_ybYNv0VEOKA@mail.gmail.com/

Reviewed-by: Leon Romanovsky  # drivers/infiniband and mlx4/mlx5
Acked-by: Jason Gunthorpe  # IB
Acked-by: Kalle Valo  # wireless drivers
Reviewed-by: Chao Yu  # erofs
Signed-off-by: Kees Cook 
Signed-off-by: Greg Kroah-Hartman

fat: add ratelimit to fat*_ent_bread()

2022-06-14T16:11:30+00:00

[ Upstream commit 183c3237c928109d2008c0456dff508baf692b20 ]

fat*_ent_bread() can be the cause of too many report on I/O error path.
So use fat_msg_ratelimit() instead.

Link: https://lkml.kernel.org/r/87bkxogfeq.fsf@mail.parknet.co.jp
Signed-off-by: OGAWA Hirofumi 
Reported-by: qianfan 
Tested-by: qianfan 
Signed-off-by: Andrew Morton 
Signed-off-by: Sasha Levin

fat: don't allow to mount if the FAT length == 0

2020-06-17T14:40:36+00:00

commit b1b65750b8db67834482f758fc385bfa7560d228 upstream.

If FAT length == 0, the image doesn't have any data. And it can be the
cause of overlapping the root dir and FAT entries.

Also Windows treats it as invalid format.

Reported-by: syzbot+6f1624f937d9d6911e2d@syzkaller.appspotmail.com
Signed-off-by: OGAWA Hirofumi 
Signed-off-by: Andrew Morton 
Cc: Marco Elver 
Cc: Dmitry Vyukov 
Link: http://lkml.kernel.org/r/87r1wz8mrd.fsf@mail.parknet.co.jp
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

fat: fix uninit-memory access for partial initialized inode

2020-03-12T12:00:19+00:00

commit bc87302a093f0eab45cd4e250c2021299f712ec6 upstream.

When get an error in the middle of reading an inode, some fields in the
inode might be still not initialized.  And then the evict_inode path may
access those fields via iput().

To fix, this makes sure that inode fields are initialized.

Reported-by: syzbot+9d82b8de2992579da5d0@syzkaller.appspotmail.com
Signed-off-by: Andrew Morton 
Signed-off-by: OGAWA Hirofumi 
Cc: 
Link: http://lkml.kernel.org/r/871rqnreqx.fsf@mail.parknet.co.jp
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

fat: delete an unnecessary check before brelse()

2019-09-26T00:51:40+00:00

brelse() tests whether its argument is NULL and then returns immediately.
Thus the test around the call is not needed.

This issue was detected by using the Coccinelle software.

Link: http://lkml.kernel.org/r/cfff3b81-fb5d-af26-7b5e-724266509045@web.de
Signed-off-by: Markus Elfring 
Acked-by: OGAWA Hirofumi 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

fat: work around race with userspace's read via blockdev while mounting

2019-09-24T22:54:06+00:00

If userspace reads the buffer via blockdev while mounting,
sb_getblk()+modify can race with buffer read via blockdev.

For example,

            FS                               userspace
    bh = sb_getblk()
    modify bh->b_data
                                  read
				    ll_rw_block(bh)
				      fill bh->b_data by on-disk data
				      /* lost modified data by FS */
				      set_buffer_uptodate(bh)
    set_buffer_uptodate(bh)

Userspace should not use the blockdev while mounting though, the udev
seems to be already doing this.  Although I think the udev should try to
avoid this, workaround the race by small overhead.

Link: http://lkml.kernel.org/r/87pnk7l3sw.fsf_-_@mail.parknet.co.jp
Signed-off-by: OGAWA Hirofumi 
Reported-by: Jan Stancek 
Tested-by: Jan Stancek 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

fs: fat: Initialize filesystem timestamp ranges

2019-08-30T14:27:18+00:00

Fill in the appropriate limits to avoid inconsistencies
in the vfs cached inode times when timestamps are
outside the permitted range.

Some FAT variants indicate that the years after 2099 are not supported.
Since commit 7decd1cb0305 ("fat: Fix and cleanup timestamp conversion")
we support the full range of years that can be represented, up to 2107.

Signed-off-by: Deepa Dinamani 
Acked-by: Jeff Layton 
Cc: hirofumi@mail.parknet.co.jp

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 282

2019-06-05T15:36:37+00:00

Based on 1 normalized pattern(s):

  this software is licensed under the terms of the gnu general public
  license version 2 as published by the free software foundation and
  may be copied distributed and modified under those terms this
  program is distributed in the hope that it will be useful but
  without any warranty without even the implied warranty of
  merchantability or fitness for a particular purpose see the gnu
  general public license for more details

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 285 file(s).

Signed-off-by: Thomas Gleixner 
Reviewed-by: Alexios Zavras 
Reviewed-by: Allison Randal 
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190529141900.642774971@linutronix.de
Signed-off-by: Greg Kroah-Hartman