CVE-2024-39467: f2fs: fix to do sanity check on i_xattr_nid in sanity_check_inode()
In the Linux kernel, the following vulnerability has been resolved:
f2fs: fix to do sanity check on ixattrnid in sanitycheckinode()
syzbot reports a kernel bug as below:
F2FS-fs (loop0): Mounted with checkpoint version = 48b305e4 ================================================================== BUG: KASAN: slab-out-of-bounds in f2fstestbit fs/f2fs/f2fs.h:2933 [inline] BUG: KASAN: slab-out-of-bounds in currentnataddr fs/f2fs/node.h:213 [inline] BUG: KASAN: slab-out-of-bounds in f2fsgetnodeinfo+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> dumpstack lib/dumpstack.c:88 [inline] dumpstacklvl+0x241/0x360 lib/dumpstack.c:114 printaddressdescription mm/kasan/report.c:377 [inline] printreport+0x169/0x550 mm/kasan/report.c:488 kasanreport+0x143/0x180 mm/kasan/report.c:601 f2fstestbit fs/f2fs/f2fs.h:2933 [inline] currentnataddr fs/f2fs/node.h:213 [inline] f2fsgetnodeinfo+0xece/0x1200 fs/f2fs/node.c:600 f2fsxattrfiemap fs/f2fs/data.c:1848 [inline] f2fsfiemap+0x55d/0x1ee0 fs/f2fs/data.c:1925 ioctlfiemap fs/ioctl.c:220 [inline] dovfsioctl+0x1c07/0x2e50 fs/ioctl.c:838 dosysioctl fs/ioctl.c:902 [inline] sesysioctl+0x81/0x170 fs/ioctl.c:890 dosyscallx64 arch/x86/entry/common.c:52 [inline] dosyscall64+0xf5/0x240 arch/x86/entry/common.c:83 entrySYSCALL64afterhwframe+0x77/0x7f
The root cause is we missed to do sanity check on ixattrnid during f2fsiget(), so that in fiemap() path, currentnataddr() will access natbitmap w/ offset from invalid ixattrnid, result in triggering kasan bug report, fix it.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
debian/linuxto a version that resolves this vulnerability.Fixed in 5.10.223-1Fixed in 5.10.234-1Fixed in 6.1.129-1Fixed in 6.1.135-1Fixed in 6.12.25-1Fixed in 6.12.27-1
Event History
Frequently Asked Questions
What is the severity of CVE-2024-39467?
CVE-2024-39467 has a medium severity level due to its potential impact on kernel functionality.
How do I fix CVE-2024-39467?
To fix CVE-2024-39467, upgrade to the patched versions of the Linux kernel: 5.10.223-1, 5.10.226-1, 6.1.119-1, 6.1.123-1, 6.12.10-1, or 6.12.11-1.
What software is affected by CVE-2024-39467?
CVE-2024-39467 affects the Linux kernel in versions prior to the specified patched releases.
What does CVE-2024-39467 exploit?
CVE-2024-39467 exploits the lack of sanity checks on the i_xattr_nid value in the f2fs filesystem.
How can I verify if my system is vulnerable to CVE-2024-39467?
You can verify vulnerability to CVE-2024-39467 by checking your kernel version against the versions listed as unaffected.