high CVSS 7.1

CVE-2024-39469·Kernel vulnerability

In the Linux kernel, the following vulnerability has been resolved: nilfs2: fix nilfs_empty_dir() misjudgment and long loop on I/O errors The error handling in nilfs_empty_dir() when a directory folio/page read fails is incorrect, as in the old ext2 implementation, and if the folio/page cannot be read or nilfs_check_folio() fails, it will falsely determine the directory as empty and corrupt the file system. In addition, since nilfs_empty_dir() does not immediately return on a failed folio/page read, but continues to loop, this can cause a long loop with I/O if i_size of the directory's inode is also corrupted, causing the log writer thread to wait and hang, as reported by syzbot. Fix these issues by making nilfs_empty_dir() immediately return a false value (0) if it fails to get a directory folio/page.

Severity
high
Software
Kernel
Fixed in
6.9.5
Published
2024-06-25

Affected versions

From: 6.7

Until: 6.9.5

Fixed in: 6.9.5

How to fix this CVE

Update your Linux kernel to version 6.9.5 or later to resolve a critical directory validation flaw in the NILFS2 filesystem. This vulnerability causes incorrect empty directory detection and potential filesystem corruption. Systems running kernel versions 6.7 through 6.9.4 should apply this update immediately through your distribution's package manager.

sudo dnf update kernel kernel-devel

Defensia detects this vulnerability

How to check if you are affected

  1. Step 1: Check your current kernel version with `uname -r` and verify if it falls between 6.7 and 6.9.4
  2. Step 2: Confirm NILFS2 filesystem usage on your system by running `mount | grep nilfs2` or checking `/etc/fstab` for nilfs2 entries
  3. Step 3: Review kernel logs for I/O errors related to directory folio reads with `sudo journalctl -xb | grep -i 'nilfs\|folio\|directory'`
  4. Step 4: After patching, verify the new kernel version loads with `uname -r` and confirm no persistent NILFS2 corruption with `sudo fsck.nilfs2 -n /dev/[device]` (read-only check)

FAQ

What is CVE-2024-39469?

This vulnerability affects the NILFS2 filesystem driver in the Linux kernel, causing incorrect directory validation logic that can falsely identify non-empty directories as empty, leading to filesystem corruption and potential data loss. Additionally, failed directory page reads trigger infinite loops during I/O errors, causing kernel threads to hang.

Is CVE-2024-39469 being actively exploited?

No, this CVE is not currently listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, and no public exploits are available. However, the vulnerability can be triggered through malformed filesystem structures or I/O degradation.

What versions of Kernel are affected by CVE-2024-39469?

Linux kernel versions 6.7 through 6.9.4 are vulnerable. The fix is included in kernel 6.9.5 and later.

How do I check if my server is vulnerable to CVE-2024-39469?

Run `uname -r` to check your kernel version; if it returns a version between 6.7 and 6.9.4, you are vulnerable. Then run `mount | grep nilfs2` to confirm NILFS2 usage on your system.

Does Defensia detect CVE-2024-39469?

Yes — Defensia's CVE advisory scanner compares installed package versions against the NVD database. If the Linux kernel is installed on a monitored server, CVE-2024-39469 will appear in your dashboard with remediation steps.

Related Kernel CVEs

CVE-2024-42256CVSS 9.8In the Linux kernel, the following vulnerability has been resolved: cifs: Fix server re-repick on subrequest retry When a subrequest is marked for needing retry, netfs will call cifs_prepare_write() which will make cifs repick the server for the op before renegotiating credits; it then calls cifs_issue_write() which invokes smb2_async_writev() - which re-repicks the server. If a different server is then selected, this causes the increment of server->in_flight to happen against one record and the decrement to happen against another, leading to misaccounting. Fix this by just removing the repick code in smb2_async_writev(). As this is only called from netfslib-driven code, cifs_prepare_write() should always have been called first, and so server should never be NULL and the preparatory step is repeated in the event that we do a retry. The problem manifests as a warning looking something like: WARNING: CPU: 4 PID: 72896 at fs/smb/client/smb2ops.c:97 smb2_add_credits+0x3f0/0x9e0 [cifs] ... RIP: 0010:smb2_add_credits+0x3f0/0x9e0 [cifs] ... smb2_writev_callback+0x334/0x560 [cifs] cifs_demultiplex_thread+0x77a/0x11b0 [cifs] kthread+0x187/0x1d0 ret_from_fork+0x34/0x60 ret_from_fork_asm+0x1a/0x30 Which may be triggered by a number of different xfstests running against an Azure server in multichannel mode. generic/249 seems the most repeatable, but generic/215, generic/249 and generic/308 may also show it.
CVE-2024-36031CVSS 9.8In the Linux kernel, the following vulnerability has been resolved: keys: Fix overwrite of key expiration on instantiation The expiry time of a key is unconditionally overwritten during instantiation, defaulting to turn it permanent. This causes a problem for DNS resolution as the expiration set by user-space is overwritten to TIME64_MAX, disabling further DNS updates. Fix this by restoring the condition that key_set_expiry is only called when the pre-parser sets a specific expiry.
CVE-2024-38612CVSS 9.8In the Linux kernel, the following vulnerability has been resolved: ipv6: sr: fix invalid unregister error path The error path of seg6_init() is wrong in case CONFIG_IPV6_SEG6_LWTUNNEL is not defined. In that case if seg6_hmac_init() fails, the genl_unregister_family() isn't called. This issue exist since commit 46738b1317e1 ("ipv6: sr: add option to control lwtunnel support"), and commit 5559cea2d5aa ("ipv6: sr: fix possible use-after-free and null-ptr-deref") replaced unregister_pernet_subsys() with genl_unregister_family() in this error path.
CVE-2024-38623CVSS 9.8In the Linux kernel, the following vulnerability has been resolved: fs/ntfs3: Use variable length array instead of fixed size Should fix smatch warning: ntfs_set_label() error: __builtin_memcpy() 'uni->name' too small (20 vs 256)
CVE-2021-47548CVSS 9.8In the Linux kernel, the following vulnerability has been resolved: ethernet: hisilicon: hns: hns_dsaf_misc: fix a possible array overflow in hns_dsaf_ge_srst_by_port() The if statement: if (port >= DSAF_GE_NUM) return; limits the value of port less than DSAF_GE_NUM (i.e., 8). However, if the value of port is 6 or 7, an array overflow could occur: port_rst_off = dsaf_dev->mac_cb[port]->port_rst_off; because the length of dsaf_dev->mac_cb is DSAF_MAX_PORT_NUM (i.e., 6). To fix this possible array overflow, we first check port and if it is greater than or equal to DSAF_MAX_PORT_NUM, the function returns.

References

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