930a9a6ee8
syzbot reported a f2fs bug as below:
Oops: gen[ 107.736417][ T5848] Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 1 UID: 0 PID: 5848 Comm: syz-executor263 Tainted: G W 6.17.0-rc1-syzkaller-00014-g0e39a731820a #0 PREEMPT_{RT,(full)}
RIP: 0010:strcmp+0x3c/0xc0 lib/string.c:284
Call Trace:
<TASK>
f2fs_check_quota_consistency fs/f2fs/super.c:1188 [inline]
f2fs_check_opt_consistency+0x1378/0x2c10 fs/f2fs/super.c:1436
__f2fs_remount fs/f2fs/super.c:2653 [inline]
f2fs_reconfigure+0x482/0x1770 fs/f2fs/super.c:5297
reconfigure_super+0x224/0x890 fs/super.c:1077
do_remount fs/namespace.c:3314 [inline]
path_mount+0xd18/0xfe0 fs/namespace.c:4112
do_mount fs/namespace.c:4133 [inline]
__do_sys_mount fs/namespace.c:4344 [inline]
__se_sys_mount+0x317/0x410 fs/namespace.c:4321
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
The direct reason is f2fs_check_quota_consistency() may suffer null-ptr-deref
issue in strcmp().
The bug can be reproduced w/ below scripts:
mkfs.f2fs -f /dev/vdb
mount -t f2fs -o usrquota /dev/vdb /mnt/f2fs
quotacheck -uc /mnt/f2fs/
umount /mnt/f2fs
mount -t f2fs -o usrjquota=aquota.user,jqfmt=vfsold /dev/vdb /mnt/f2fs
mount -t f2fs -o remount,usrjquota=,jqfmt=vfsold /dev/vdb /mnt/f2fs
umount /mnt/f2fs
So, before old_qname and new_qname comparison, we need to check whether
they are all valid pointers, fix it.
Reported-by: syzbot+d371efea57d5aeab877b@syzkaller.appspotmail.com
Fixes:
|
||
|---|---|---|
| Documentation | ||
| LICENSES | ||
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| io_uring | ||
| ipc | ||
| kernel | ||
| lib | ||
| mm | ||
| net | ||
| rust | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .clippy.toml | ||
| .cocciconfig | ||
| .editorconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| .pylintrc | ||
| .rustfmt.toml | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
README
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.