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

isofs: Verify inode mode when loading from disk

2025-08-28T14:21:15+00:00

commit 0a9e7405131380b57e155f10242b2e25d2e51852 upstream.

Verify that the inode mode is sane when loading it from the disk to
avoid complaints from VFS about setting up invalid inodes.

Reported-by: syzbot+895c23f6917da440ed0d@syzkaller.appspotmail.com
CC: stable@vger.kernel.org
Signed-off-by: Jan Kara 
Link: https://lore.kernel.org/20250709095545.31062-2-jack@suse.cz
Acked-by: Christian Brauner 
Signed-off-by: Christian Brauner 
Signed-off-by: Greg Kroah-Hartman

isofs: Prevent the use of too small fid

2025-05-02T05:39:20+00:00

commit 0405d4b63d082861f4eaff9d39c78ee9dc34f845 upstream.

syzbot reported a slab-out-of-bounds Read in isofs_fh_to_parent. [1]

The handle_bytes value passed in by the reproducing program is equal to 12.
In handle_to_path(), only 12 bytes of memory are allocated for the structure
file_handle->f_handle member, which causes an out-of-bounds access when
accessing the member parent_block of the structure isofs_fid in isofs,
because accessing parent_block requires at least 16 bytes of f_handle.
Here, fh_len is used to indirectly confirm that the value of handle_bytes
is greater than 3 before accessing parent_block.

[1]
BUG: KASAN: slab-out-of-bounds in isofs_fh_to_parent+0x1b8/0x210 fs/isofs/export.c:183
Read of size 4 at addr ffff0000cc030d94 by task syz-executor215/6466
CPU: 1 UID: 0 PID: 6466 Comm: syz-executor215 Not tainted 6.14.0-rc7-syzkaller-ga2392f333575 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call trace:
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:466 (C)
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0xe4/0x150 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:408 [inline]
 print_report+0x198/0x550 mm/kasan/report.c:521
 kasan_report+0xd8/0x138 mm/kasan/report.c:634
 __asan_report_load4_noabort+0x20/0x2c mm/kasan/report_generic.c:380
 isofs_fh_to_parent+0x1b8/0x210 fs/isofs/export.c:183
 exportfs_decode_fh_raw+0x2dc/0x608 fs/exportfs/expfs.c:523
 do_handle_to_path+0xa0/0x198 fs/fhandle.c:257
 handle_to_path fs/fhandle.c:385 [inline]
 do_handle_open+0x8cc/0xb8c fs/fhandle.c:403
 __do_sys_open_by_handle_at fs/fhandle.c:443 [inline]
 __se_sys_open_by_handle_at fs/fhandle.c:434 [inline]
 __arm64_sys_open_by_handle_at+0x80/0x94 fs/fhandle.c:434
 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49
 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
 el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:744
 el0t_64_sync_handler+0x84/0x108 arch/arm64/kernel/entry-common.c:762
 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600

Allocated by task 6466:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x40/0x78 mm/kasan/common.c:68
 kasan_save_alloc_info+0x40/0x50 mm/kasan/generic.c:562
 poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
 __kasan_kmalloc+0xac/0xc4 mm/kasan/common.c:394
 kasan_kmalloc include/linux/kasan.h:260 [inline]
 __do_kmalloc_node mm/slub.c:4294 [inline]
 __kmalloc_noprof+0x32c/0x54c mm/slub.c:4306
 kmalloc_noprof include/linux/slab.h:905 [inline]
 handle_to_path fs/fhandle.c:357 [inline]
 do_handle_open+0x5a4/0xb8c fs/fhandle.c:403
 __do_sys_open_by_handle_at fs/fhandle.c:443 [inline]
 __se_sys_open_by_handle_at fs/fhandle.c:434 [inline]
 __arm64_sys_open_by_handle_at+0x80/0x94 fs/fhandle.c:434
 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49
 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
 el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:744
 el0t_64_sync_handler+0x84/0x108 arch/arm64/kernel/entry-common.c:762
 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600

Reported-by: syzbot+4d7cd7dd0ce1aa8d5c65@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=4d7cd7dd0ce1aa8d5c65
Tested-by: syzbot+4d7cd7dd0ce1aa8d5c65@syzkaller.appspotmail.com
CC: stable@vger.kernel.org
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Edward Adam Davis 
Signed-off-by: Jan Kara 
Link: https://patch.msgid.link/tencent_9C8CB8A7E7C6C512C7065DC98B6EDF6EC606@qq.com
Signed-off-by: Greg Kroah-Hartman

isofs: fix KMSAN uninit-value bug in do_isofs_readdir()

2025-04-10T12:29:41+00:00

[ Upstream commit 81a82e8f33880793029cd6f8a766fb13b737e6a7 ]

In do_isofs_readdir() when assigning the variable
"struct iso_directory_record *de" the b_data field of the buffer_head
is accessed and an offset is added to it, the size of b_data is 2048
and the offset size is 2047, meaning
"de = (struct iso_directory_record *) (bh->b_data + offset);"
yields the final byte of the 2048 sized b_data block.

The first byte of the directory record (de_len) is then read and
found to be 31, meaning the directory record size is 31 bytes long.
The directory record is defined by the structure:

	struct iso_directory_record {
		__u8 length;                     // 1 byte
		__u8 ext_attr_length;            // 1 byte
		__u8 extent[8];                  // 8 bytes
		__u8 size[8];                    // 8 bytes
		__u8 date[7];                    // 7 bytes
		__u8 flags;                      // 1 byte
		__u8 file_unit_size;             // 1 byte
		__u8 interleave;                 // 1 byte
		__u8 volume_sequence_number[4];  // 4 bytes
		__u8 name_len;                   // 1 byte
		char name[];                     // variable size
	} __attribute__((packed));

The fixed portion of this structure occupies 33 bytes. Therefore, a
valid directory record must be at least 33 bytes long
(even without considering the variable-length name field).
Since de_len is only 31, it is insufficient to contain
the complete fixed header.

The code later hits the following sanity check that
compares de_len against the sum of de->name_len and
sizeof(struct iso_directory_record):

	if (de_len < de->name_len[0] + sizeof(struct iso_directory_record)) {
		...
	}

Since the fixed portion of the structure is
33 bytes (up to and including name_len member),
a valid record should have de_len of at least 33 bytes;
here, however, de_len is too short, and the field de->name_len
(located at offset 32) is accessed even though it lies beyond
the available 31 bytes.

This access on the corrupted isofs data triggers a KASAN uninitialized
memory warning. The fix would be to first verify that de_len is at least
sizeof(struct iso_directory_record) before accessing any
fields like de->name_len.

Reported-by: syzbot 
Tested-by: syzbot 
Closes: https://syzkaller.appspot.com/bug?extid=812641c6c3d7586a1613
Fixes: 2deb1acc653c ("isofs: fix access to unallocated memory when reading corrupted filesystem")
Signed-off-by: Qasim Ijaz 
Signed-off-by: Jan Kara 
Link: https://patch.msgid.link/20250211195900.42406-1-qasdev00@gmail.com
Signed-off-by: Sasha Levin

isofs: handle CDs with bad root inode but good Joliet root directory

2024-04-13T10:51:38+00:00

[ Upstream commit 4243bf80c79211a8ca2795401add9c4a3b1d37ca ]

I have a CD copy of the original Tom Clancy's Ghost Recon game from
2001. The disc mounts without error on Windows, but on Linux mounting
fails with the message "isofs_fill_super: get root inode failed". The
error originates in isofs_read_inode, which returns -EIO because de_len
is 0. The superblock on this disc appears to be intentionally corrupt as
a form of copy protection.

When the root inode is unusable, instead of giving up immediately, try
to continue with the Joliet file table. This fixes the Ghost Recon CD
and probably other copy-protected CDs too.

Signed-off-by: Alex Henrie 
Signed-off-by: Jan Kara 
Message-Id: <20240208022134.451490-1-alexhenrie24@gmail.com>
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

isofs: Fix out of bound access for corrupted isofs image

2021-11-12T13:43:03+00:00

commit e96a1866b40570b5950cda8602c2819189c62a48 upstream.

When isofs image is suitably corrupted isofs_read_inode() can read data
beyond the end of buffer. Sanity-check the directory entry length before
using it.

Reported-and-tested-by: syzbot+6fc7fb214625d82af7d1@syzkaller.appspotmail.com
CC: stable@vger.kernel.org
Signed-off-by: Jan Kara 
Signed-off-by: Greg Kroah-Hartman

isofs: joliet: Fix iocharset=utf8 mount option

2021-09-15T07:47:27+00:00

[ Upstream commit 28ce50f8d96ec9035f60c9348294ea26b94db944 ]

Currently iocharset=utf8 mount option is broken. To use UTF-8 as iocharset,
it is required to use utf8 mount option.

Fix iocharset=utf8 mount option to use be equivalent to the utf8 mount
option.

If UTF-8 as iocharset is used then s_nls_iocharset is set to NULL. So
simplify code around, remove s_utf8 field as to distinguish between UTF-8
and non-UTF-8 it is needed just to check if s_nls_iocharset is set to NULL
or not.

Link: https://lore.kernel.org/r/20210808162453.1653-5-pali@kernel.org
Signed-off-by: Pali Rohár 
Signed-off-by: Jan Kara 
Signed-off-by: Sasha Levin

isofs: release buffer head before return

2021-03-04T09:26:30+00:00

[ Upstream commit 0a6dc67a6aa45f19bd4ff89b4f468fc50c4b8daa ]

Release the buffer_head before returning error code in
do_isofs_readdir() and isofs_find_entry().

Fixes: 2deb1acc653c ("isofs: fix access to unallocated memory when reading corrupted filesystem")
Link: https://lore.kernel.org/r/20210118120455.118955-1-bianpan2016@163.com
Signed-off-by: Pan Bian 
Signed-off-by: Jan Kara 
Signed-off-by: Sasha Levin

Merge tag 'y2038-vfs' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/playground

2019-09-19T16:42:37+00:00

Pull y2038 vfs updates from Arnd Bergmann:
 "Add inode timestamp clamping.

  This series from Deepa Dinamani adds a per-superblock minimum/maximum
  timestamp limit for a file system, and clamps timestamps as they are
  written, to avoid random behavior from integer overflow as well as
  having different time stamps on disk vs in memory.

  At mount time, a warning is now printed for any file system that can
  represent current timestamps but not future timestamps more than 30
  years into the future, similar to the arbitrary 30 year limit that was
  added to settimeofday().

  This was picked as a compromise to warn users to migrate to other file
  systems (e.g. ext4 instead of ext3) when they need the file system to
  survive beyond 2038 (or similar limits in other file systems), but not
  get in the way of normal usage"

* tag 'y2038-vfs' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/playground:
  ext4: Reduce ext4 timestamp warnings
  isofs: Initialize filesystem timestamp ranges
  pstore: fs superblock limits
  fs: omfs: Initialize filesystem timestamp ranges
  fs: hpfs: Initialize filesystem timestamp ranges
  fs: ceph: Initialize filesystem timestamp ranges
  fs: sysv: Initialize filesystem timestamp ranges
  fs: affs: Initialize filesystem timestamp ranges
  fs: fat: Initialize filesystem timestamp ranges
  fs: cifs: Initialize filesystem timestamp ranges
  fs: nfs: Initialize filesystem timestamp ranges
  ext4: Initialize timestamps limits
  9p: Fill min and max timestamps in sb
  fs: Fill in max and min timestamps in superblock
  utimes: Clamp the timestamps before update
  mount: Add mount warning for impending timestamp expiry
  timestamp_truncate: Replace users of timespec64_trunc
  vfs: Add timestamp_truncate() api
  vfs: Add file timestamp range support

isofs: Initialize filesystem timestamp ranges

2019-08-30T15:11:25+00:00

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

Reference: http://www.ecma-international.org/publications/standards/Ecma-119.htm

Signed-off-by: Deepa Dinamani 
Acked-by: Jeff Layton