CVE-2024-49881: ext4: update orig_path in ext4_find_extent()
First published: Mon Oct 21 2024(Updated: )
In the Linux kernel, the following vulnerability has been resolved: ext4: update orig_path in ext4_find_extent() In ext4_find_extent(), if the path is not big enough, we free it and set *orig_path to NULL. But after reallocating and successfully initializing the path, we don't update *orig_path, in which case the caller gets a valid path but a NULL ppath, and this may cause a NULL pointer dereference or a path memory leak. For example: ext4_split_extent path = *ppath = 2000 ext4_find_extent if (depth > path[0].p_maxdepth) kfree(path = 2000); *orig_path = path = NULL; path = kcalloc() = 3000 ext4_split_extent_at(*ppath = NULL) path = *ppath; ex = path[depth].p_ext; // NULL pointer dereference! ================================================================== BUG: kernel NULL pointer dereference, address: 0000000000000010 CPU: 6 UID: 0 PID: 576 Comm: fsstress Not tainted 6.11.0-rc2-dirty #847 RIP: 0010:ext4_split_extent_at+0x6d/0x560 Call Trace: <TASK> ext4_split_extent.isra.0+0xcb/0x1b0 ext4_ext_convert_to_initialized+0x168/0x6c0 ext4_ext_handle_unwritten_extents+0x325/0x4d0 ext4_ext_map_blocks+0x520/0xdb0 ext4_map_blocks+0x2b0/0x690 ext4_iomap_begin+0x20e/0x2c0 [...] ================================================================== Therefore, *orig_path is updated when the extent lookup succeeds, so that the caller can safely use path or *ppath.
Credit: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 416baaa9-dc9f-4396-8d5f-8c081fb06d67
| Affected Software | Affected Version | How to fix |
|---|---|---|
| Linux Kernel | >=3.18<5.10.227 | |
| Linux Kernel | >=5.11<5.15.168 | |
| Linux Kernel | >=5.16<6.1.113 | |
| Linux Kernel | >=6.2<6.6.55 | |
| Linux Kernel | >=6.7<6.10.14 | |
| Linux Kernel | >=6.11<6.11.3 | |
| debian/linux | <=5.10.223-1 | 5.10.234-1 6.1.129-1 6.1.128-1 6.12.21-1 |
| debian/linux-6.1 | 6.1.129-1~deb11u1 |
Never miss a vulnerability like this again
Sign up to SecAlerts for real-time vulnerability data matched to your software, aggregated from hundreds of sources.
Reference Links
- https://git.kernel.org/stable/c/11b230100d6801c014fab2afabc8bdea304c1b96
- https://git.kernel.org/stable/c/5b4b2dcace35f618fe361a87bae6f0d13af31bc1
- https://git.kernel.org/stable/c/6766937d0327000ac1b87c97bbecdd28b0dd6599
- https://git.kernel.org/stable/c/6801ed1298204d16a38571091e31178bfdc3c679
- https://git.kernel.org/stable/c/a9fcb1717d75061d3653ed69365c8d45331815cd
- https://git.kernel.org/stable/c/b63481b3a388ee2df9e295f97273226140422a42
- https://git.kernel.org/stable/c/ec0c0beb9b777cdd1edd7df9b36e0f3e67e2bdff
- https://git.kernel.org/stable/c/f55ecc58d07a6c1f6d6d5b5af125c25f8da0bda2
- https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2024-49881
- https://nvd.nist.gov/vuln/detail/CVE-2024-49881
- https://launchpad.net/bugs/cve/CVE-2024-49881
- https://security-tracker.debian.org/tracker/CVE-2024-49881
- https://ubuntu.com/security/CVE-2024-49881
- https://git.kernel.org/linus/5b4b2dcace35f618fe361a87bae6f0d13af31bc1
Frequently Asked Questions
What is the severity of CVE-2024-49881?
CVE-2024-49881 has been classified as a medium severity vulnerability in the Linux kernel.
Which versions of the Linux kernel are affected by CVE-2024-49881?
CVE-2024-49881 affects Linux kernel versions from 3.18 up to 6.11.3, excluding specific patched versions.
How do I fix CVE-2024-49881?
To fix CVE-2024-49881, update to the latest patched version of the Linux kernel as listed in your distribution's repository.
What type of vulnerability is CVE-2024-49881?
CVE-2024-49881 is related to a flaw in the ext4 filesystem handling within the Linux kernel.
Can CVE-2024-49881 be exploited remotely?
CVE-2024-49881 requires local access to the system to be exploited, making remote exploitation unlikely.
- agent/title
- agent/first-publish-date
- agent/type
- agent/remedy
- agent/severity
- agent/weakness
- agent/author
- agent/references
- collector/mitre-cve
- source/MITRE
- agent/last-modified-date
- agent/trending
- collector/usn-cve
- source/Ubuntu
- collector/nvd-cve
- source/NVD
- agent/software-canonical-lookup
- agent/software-canonical-lookup-request
- collector/nvd-api
- collector/launchpad-cve
- source/Launchpad
- agent/source
- agent/softwarecombine
- agent/description
- agent/tags
- collector/security-tracker-debian
- source/Debian
- agent/event
- vendor/linux
- canonical/linux kernel
- version/linux kernel/3.18
- version/linux kernel/5.11
- version/linux kernel/5.16
- version/linux kernel/6.2
- version/linux kernel/6.7
- version/linux kernel/6.11
- package-manager/debian