high CVSS 7.1

CVE-2024-47723·Kernel vulnerability

In the Linux kernel, the following vulnerability has been resolved: jfs: fix out-of-bounds in dbNextAG() and diAlloc() In dbNextAG() , there is no check for the case where bmp->db_numag is greater or same than MAXAG due to a polluted image, which causes an out-of-bounds. Therefore, a bounds check should be added in dbMount(). And in dbNextAG(), a check for the case where agpref is greater than bmp->db_numag should be added, so an out-of-bounds exception should be prevented. Additionally, a check for the case where agno is greater or same than MAXAG should be added in diAlloc() to prevent out-of-bounds.

Severity
high
Software
Kernel
Fixed in
6.11.2
Published
2024-10-21

Affected versions

From: 6.11

Until: 6.11.2

Fixed in: 6.11.2

How to fix this CVE

Update your Linux kernel to version 6.11.2 or later to patch out-of-bounds memory access vulnerabilities in the JFS filesystem allocation routines. These flaws could allow local attackers with filesystem access to trigger kernel crashes or information disclosure. Apply the kernel update through your distribution's package manager and reboot to activate the patched version.

sudo dnf update kernel kernel-devel && sudo reboot

Defensia detects this vulnerability

How to check if you are affected

  1. Run 'uname -r' to check your current kernel version; versions 6.11 through 6.11.1 are vulnerable
  2. Check if JFS filesystem is mounted: 'mount | grep jfs' — if output is empty, JFS is not active; if present, you may be exposed
  3. Search kernel logs for JFS-related errors or out-of-bounds exceptions: 'sudo dmesg | grep -i jfs' or 'sudo grep -i jfs /var/log/kern.log'
  4. Verify the fix: after patching, run 'uname -r' and confirm kernel version is 6.11.2 or later, then inspect dmesg for absence of JFS allocation errors

FAQ

What is CVE-2024-47723?

CVE-2024-47723 is a kernel vulnerability in the JFS filesystem code where missing boundary checks in the dbNextAG() and diAlloc() functions allow out-of-bounds memory access. A corrupted JFS filesystem image combined with local filesystem access can trigger crashes or leak sensitive kernel memory.

Is CVE-2024-47723 being actively exploited?

No, CVE-2024-47723 is not currently listed on the CISA KEV catalog and has no known public exploits. However, it can still cause denial of service if a system mounts a maliciously crafted JFS volume.

What versions of Kernel are affected by CVE-2024-47723?

Linux kernel versions 6.11, 6.11.1, and 6.11.2 (prior to patching) are affected. Version 6.11.2 and later contain the fix.

How do I check if my server is vulnerable to CVE-2024-47723?

Run 'uname -r' to see your kernel version. If the output is 6.11.0, 6.11.1, or 6.11.2 (before the security patch), and you have JFS filesystems mounted (check with 'mount | grep jfs'), your system is vulnerable.

Does Defensia detect CVE-2024-47723?

Yes — Defensia's CVE advisory scanner compares installed package versions against the NVD database. If Linux kernel is installed on a monitored server, CVE-2024-47723 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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