commit e2fec219a36e0993642844be0f345513507031f4 upstream.
Patch series "nilfs2: fix potential issues related to reserved inodes".
This series fixes one use-after-free issue reported by syzbot, caused by
nilfs2's internal inode being exposed in the namespace on a corrupted
filesystem, and a couple of flaws that cause problems if the starting
number of non-reserved inodes written in the on-disk super block is
intentionally (or corruptly) changed from its default value.
This patch (of 3):
In the current implementation of nilfs2, "nilfs->ns_first_ino", which
gives the first non-reserved inode number, is read from the superblock,
but its lower limit is not checked.
As a result, if a number that overlaps with the inode number range of
reserved inodes such as the root directory or metadata files is set in the
super block parameter, the inode number test macros (NILFS_MDT_INODE and
NILFS_VALID_INODE) will not function properly.
In addition, these test macros use left bit-shift calculations using with
the inode number as the shift count via the BIT macro, but the result of a
shift calculation that exceeds the bit width of an integer is undefined in
the C specification, so if "ns_first_ino" is set to a large value other
than the default value NILFS_USER_INO (=11), the macros may potentially
malfunction depending on the environment.
Fix these issues by checking the lower bound of "nilfs->ns_first_ino" and
by preventing bit shifts equal to or greater than the NILFS_USER_INO
constant in the inode number test macros.
Also, change the type of "ns_first_ino" from signed integer to unsigned
integer to avoid the need for type casting in comparisons such as the
lower bound check introduced this time.
Link: https://lkml.kernel.org/r/20240623051135.4180-1-konishi.ryusuke@gmail.com
Link: https://lkml.kernel.org/r/20240623051135.4180-2-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit d61d0ab573649789bf9eb909c89a1a193b2e3d10 upstream.
When mounting a filesystem image with a block size larger than the page
size, nilfs2 repeatedly outputs long error messages with stack traces to
the kernel log, such as the following:
getblk(): invalid block size 8192 requested
logical block size: 512
...
Call Trace:
dump_stack_lvl+0x92/0xd4
dump_stack+0xd/0x10
bdev_getblk+0x33a/0x354
__breadahead+0x11/0x80
nilfs_search_super_root+0xe2/0x704 [nilfs2]
load_nilfs+0x72/0x504 [nilfs2]
nilfs_mount+0x30f/0x518 [nilfs2]
legacy_get_tree+0x1b/0x40
vfs_get_tree+0x18/0xc4
path_mount+0x786/0xa88
__ia32_sys_mount+0x147/0x1a8
__do_fast_syscall_32+0x56/0xc8
do_fast_syscall_32+0x29/0x58
do_SYSENTER_32+0x15/0x18
entry_SYSENTER_32+0x98/0xf1
...
This overloads the system logger. And to make matters worse, it sometimes
crashes the kernel with a memory access violation.
This is because the return value of the sb_set_blocksize() call, which
should be checked for errors, is not checked.
The latter issue is due to out-of-buffer memory being accessed based on a
large block size that caused sb_set_blocksize() to fail for buffers read
with the initial minimum block size that remained unupdated in the
super_block structure.
Since nilfs2 mkfs tool does not accept block sizes larger than the system
page size, this has been overlooked. However, it is possible to create
this situation by intentionally modifying the tool or by passing a
filesystem image created on a system with a large page size to a system
with a smaller page size and mounting it.
Fix this issue by inserting the expected error handling for the call to
sb_set_blocksize().
Link: https://lkml.kernel.org/r/20231129141547.4726-1-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
