CVE-2024-35852: mlxsw: spectrum_acl_tcam: Fix memory leak when canceling rehash work
In the Linux kernel, the following vulnerability has been resolved:
mlxsw: spectrumacltcam: Fix memory leak when canceling rehash work
The Linux kernel CVE team has assigned CVE-2024-35852 to this issue.
Upstream advisory: https://lore.kernel.org/linux-cve-announce/2024051740-CVE-2024-35852-9e9a@gregkh/T
Other sources
In the Linux kernel, the following vulnerability has been resolved:
mlxsw: spectrumacltcam: Fix memory leak when canceling rehash work
The rehash delayed work is rescheduled with a delay if the number of credits at end of the work is not negative as supposedly it means that the migration ended. Otherwise, it is rescheduled immediately.
After "mlxsw: spectrumacltcam: Fix possible use-after-free during rehash" the above is no longer accurate as a non-negative number of credits is no longer indicative of the migration being done. It can also happen if the work encountered an error in which case the migration will resume the next time the work is scheduled.
The significance of the above is that it is possible for the work to be pending and associated with hints that were allocated when the migration started. This leads to the hints being leaked [1] when the work is canceled while pending as part of ACL region dismantle.
Fix by freeing the hints if hints are associated with a work that was canceled while pending.
Blame the original commit since the reliance on not having a pending work associated with hints is fragile.
[1] unreferenced object 0xffff88810e7c3000 (size 256): comm "kworker/0:16", pid 176, jiffies 4295460353 hex dump (first 32 bytes): 00 30 95 11 81 88 ff ff 61 00 00 00 00 00 00 80 .0......a....... 00 00 61 00 40 00 00 00 00 00 00 00 04 00 00 00 ..a.@........... backtrace (crc 2544ddb9): [<00000000cf8cfab3>] kmalloctrace+0x23f/0x2a0 [<000000004d9a1ad9>] objagghintsget+0x42/0x390 [<000000000b143cf3>] mlxswspaclerprehashhintsget+0xca/0x400 [<0000000059bdb60a>] mlxswspacltcamvregionrehashwork+0x868/0x1160 [<00000000e81fd734>] processonework+0x59c/0xf20 [<00000000ceee9e81>] workerthread+0x799/0x12c0 [<00000000bda6fe39>] kthread+0x246/0x300 [<0000000070056d23>] retfromfork+0x34/0x70 [<00000000dea2b93e>] retfromforkasm+0x1a/0x30
— NVD
Affected Software
Remediation
Event History
Frequently Asked Questions
What is the severity of CVE-2024-35852?
CVE-2024-35852 is classified as a memory leak vulnerability in the Linux kernel.
How do I fix CVE-2024-35852?
To fix CVE-2024-35852, update the kernel to versions 5.4.276, 5.10.217, 5.15.159, 6.1.91, 6.6.31, 6.8.10 or later.
What software versions are affected by CVE-2024-35852?
CVE-2024-35852 affects Linux kernel versions below 5.4.276, 5.10.217, 5.15.159, 6.1.91, 6.6.31, and 6.8.10.
Is CVE-2024-35852 related to a specific Linux distribution?
Yes, CVE-2024-35852 primarily affects Red Hat and Debian Linux distributions.
What are the consequences of CVE-2024-35852?
The consequences of CVE-2024-35852 include potential performance degradation due to memory leaks in the Linux kernel.