high CVSS 7.8

CVE-2024-42105·Kernel vulnerability

In the Linux kernel, the following vulnerability has been resolved: nilfs2: fix inode number range checks 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.

Severity: high
Software: Kernel
Fixed in: 6.9.9
Published: 2024-07-30

Affected versions

From: 6.7

Until: 6.9.9

Fixed in: 6.9.9

How to fix this CVE

Update your Linux kernel to version 6.9.9 or later to resolve inode number validation issues in the NILFS2 filesystem. This patch corrects improper bounds checking that could allow reserved inode ranges to be overwritten on corrupted filesystems. Systems running kernels 6.7 through 6.9.8 should prioritize this update, especially those using NILFS2 as their primary filesystem.

sudo dnf update kernel kernel-devel

Defensia detects this vulnerability

How to check if you are affected

Run 'uname -r' to check your current kernel version and confirm if it falls in the 6.7–6.9.8 range
Check if NILFS2 is mounted: grep -i nilfs2 /etc/fstab or mount | grep nilfs2
If NILFS2 is in use, examine the filesystem superblock with 'nilfs-tune -l /dev/your-device' to identify the ns_first_ino value
After applying the patch, re-run 'uname -r' to verify the kernel has been updated to 6.9.9 or newer

FAQ

What is CVE-2024-42105?

This vulnerability affects NILFS2 filesystem inode validation in the Linux kernel. A corrupted or malicious superblock can set the first non-reserved inode number to overlap with reserved inode ranges, causing internal filesystem structures to become exposed and potentially corrupted.

Is CVE-2024-42105 being actively exploited?

No, CVE-2024-42105 is not listed on the CISA Known Exploited Vulnerabilities catalog and no public exploits are available. However, it can be triggered by corrupted or intentionally crafted NILFS2 filesystems.

What versions of Kernel are affected by CVE-2024-42105?

Linux kernel versions 6.7 through 6.9.8 are affected. Version 6.9.9 and later contain the necessary fixes.

How do I check if my server is vulnerable to CVE-2024-42105?

Run 'uname -r' to display your kernel version. If the output is 6.7.x, 6.8.x, or 6.9.x (up to 6.9.8), your system is vulnerable if NILFS2 is mounted. Verify with 'mount | grep nilfs2'.

Does Defensia detect CVE-2024-42105?

Yes — Defensia's CVE advisory scanner compares installed kernel package versions against the NVD database. If a vulnerable kernel version is detected on a monitored server, CVE-2024-42105 will appear in your dashboard with remediation steps and patch availability.

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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