CVE-2024-39467
Description
From CVE.org
In the Linux kernel, the following vulnerability has been resolved: f2fs: fix to do sanity check on i_xattr_nid in sanity_check_inode() syzbot reports a kernel bug as below: F2FS-fs (loop0): Mounted with checkpoint version = 48b305e4 ================================================================== BUG: KASAN: slab-out-of-bounds in f2fs_test_bit fs/f2fs/f2fs.h:2933 [inline] BUG: KASAN: slab-out-of-bounds in current_nat_addr fs/f2fs/node.h:213 [inline] BUG: KASAN: slab-out-of-bounds in f2fs_get_node_info+0xece/0x1200 fs/f2fs/node.c:600 Read of size 1 at addr ffff88807a58c76c by task syz-executor280/5076 CPU: 1 PID: 5076 Comm: syz-executor280 Not tainted 6.9.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114 print_address_description mm/kasan/report.c:377 [inline] print_report+0x169/0x550 mm/kasan/report.c:488 kasan_report+0x143/0x180 mm/kasan/report.c:601 f2fs_test_bit fs/f2fs/f2fs.h:2933 [inline] current_nat_addr fs/f2fs/node.h:213 [inline] f2fs_get_node_info+0xece/0x1200 fs/f2fs/node.c:600 f2fs_xattr_fiemap fs/f2fs/data.c:1848 [inline] f2fs_fiemap+0x55d/0x1ee0 fs/f2fs/data.c:1925 ioctl_fiemap fs/ioctl.c:220 [inline] do_vfs_ioctl+0x1c07/0x2e50 fs/ioctl.c:838 __do_sys_ioctl fs/ioctl.c:902 [inline] __se_sys_ioctl+0x81/0x170 fs/ioctl.c:890 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f The root cause is we missed to do sanity check on i_xattr_nid during f2fs_iget(), so that in fiemap() path, current_nat_addr() will access nat_bitmap w/ offset from invalid i_xattr_nid, result in triggering kasan bug report, fix it.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 5.5 | 7.1 | 7.8 |
| Attack Vector | Local | Local | Local |
| Attack Complexity | Low | Low | Low |
| Privileges Required | Low | Low | Low |
| User Interaction | None | None | None |
| Scope | Unchanged | Unchanged | Unchanged |
| Confidentiality | None | High | High |
| Integrity Impact | None | None | High |
| Availability Impact | High | High | High |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
NVD: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
cve.org: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Understanding the Weakness (CWE)
Confidentiality
Technical Impact: Read Memory
An attacker could get secret values such as cryptographic keys, PII, memory addresses, or other information that could be used in additional attacks.
Confidentiality
Technical Impact: Bypass Protection Mechanism
Out-of-bounds memory could contain memory addresses or other information that can be used to bypass ASLR and other protection mechanisms in order to improve the reliability of exploiting a separate weakness for code execution.
Availability
Technical Impact: DoS: Crash, Exit, or Restart
An attacker could cause a segmentation fault or crash by causing memory to be read outside of the bounds of the buffer. This is especially likely when the code reads a variable amount of data and assumes that a sentinel exists to stop the read operation, such as a NUL in a string.
Other
Technical Impact: Varies by Context
The read operation could produce other undefined or unexpected results.
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