high CVSS 7.1

CVE-2024-49900·Kernel vulnerability

In the Linux kernel, the following vulnerability has been resolved: jfs: Fix uninit-value access of new_ea in ea_buffer syzbot reports that lzo1x_1_do_compress is using uninit-value: ===================================================== BUG: KMSAN: uninit-value in lzo1x_1_do_compress+0x19f9/0x2510 lib/lzo/lzo1x_compress.c:178 ... Uninit was stored to memory at: ea_put fs/jfs/xattr.c:639 [inline] ... Local variable ea_buf created at: __jfs_setxattr+0x5d/0x1ae0 fs/jfs/xattr.c:662 __jfs_xattr_set+0xe6/0x1f0 fs/jfs/xattr.c:934 ===================================================== The reason is ea_buf->new_ea is not initialized properly. Fix this by using memset to empty its content at the beginning in ea_get().

Severity
high
Software
Kernel
Fixed in
6.11.3
Published
2024-10-21

Affected versions

From: 6.11

Until: 6.11.3

Fixed in: 6.11.3

How to fix this CVE

Update your Linux kernel to version 6.11.3 or later to resolve this memory initialization vulnerability in the JFS extended attributes handler. This fix prevents uninitialized buffer access that could lead to information disclosure or system crashes during extended attribute operations. Apply the patch immediately, especially if your systems use JFS filesystems.

sudo dnf upgrade kernel kernel-devel

Defensia detects this vulnerability

How to check if you are affected

  1. Check kernel version: uname -r — ensure version is 6.11.3 or higher
  2. Verify JFS module is loaded: lsmod | grep jfs — if loaded, the vulnerable code path is active
  3. Search system logs for xattr-related errors: grep -i 'xattr\|ea_' /var/log/kern.log — look for memory access warnings or KMSAN reports
  4. Confirm patch application: cat /proc/version — verify the kernel release date is after the CVE fix date (around November 2024)

FAQ

What is CVE-2024-49900?

CVE-2024-49900 is a memory initialization bug in the Linux kernel's JFS filesystem driver where the extended attributes buffer (ea_buf->new_ea) is not properly zeroed before use, potentially leading to information leaks or kernel crashes when handling file extended attributes.

Is CVE-2024-49900 being actively exploited?

No, CVE-2024-49900 is not listed on the CISA Known Exploited Vulnerabilities (KEV) catalog and has no public proof-of-concept exploits available. However, it was discovered through fuzzing and should still be patched promptly.

What versions of Kernel are affected by CVE-2024-49900?

Linux kernel versions 6.11 through 6.11.2 are affected. Version 6.11.3 and later contain the fix.

How do I check if my server is vulnerable to CVE-2024-49900?

Run uname -r and verify the kernel version — if it shows 6.11.0, 6.11.1, or 6.11.2, your system is vulnerable. Cross-reference with uname -a for the full build information.

Does Defensia detect CVE-2024-49900?

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-2024-49900 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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