CVE-2022-49522
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedIn the Linux kernel, the following vulnerability has been resolved: mmc: jz4740: Apply DMA engine limits to maximum segment size Do what is done in other DMA-enabled MMC host drivers (cf. host/mmci.c) and limit the maximum segment size based on the DMA engine's capabilities. This is needed to avoid warnings like the following with CONFIG_DMA_API_DEBUG=y. ------------[ cut here ]------------ WARNING: CPU: 0 PID: 21 at kernel/dma/debug.c:1162 debug_dma_map_sg+0x2f4/0x39c DMA-API: jz4780-dma 13420000.dma-controller: mapping sg segment longer than device claims to support [len=98304] [max=65536] CPU: 0 PID: 21 Comm: kworker/0:1H Not tainted 5.18.0-rc1 #19 Workqueue: kblockd blk_mq_run_work_fn Stack : 81575aec 00000004 80620000 80620000 80620000 805e7358 00000009 801537ac 814c832c 806276e3 806e34b4 80620000 81575aec 00000001 81575ab8 09291444 00000000 00000000 805e7358 81575958 ffffffea 8157596c 00000000 636f6c62 6220646b 80387a70 0000000f 6d5f6b6c 80620000 00000000 81575ba4 00000009 805e170c 80896640 00000001 00010000 00000000 00000000 00006098 806e0000 ... Call Trace: [<80107670>] show_stack+0x84/0x120 [<80528cd8>] __warn+0xb8/0xec [<80528d78>] warn_slowpath_fmt+0x6c/0xb8 [<8016f1d4>] debug_dma_map_sg+0x2f4/0x39c [<80169d4c>] __dma_map_sg_attrs+0xf0/0x118 [<8016a27c>] dma_map_sg_attrs+0x14/0x28 [<804f66b4>] jz4740_mmc_prepare_dma_data+0x74/0xa4 [<804f6714>] jz4740_mmc_pre_request+0x30/0x54 [<804f4ff4>] mmc_blk_mq_issue_rq+0x6e0/0x7bc [<804f5590>] mmc_mq_queue_rq+0x220/0x2d4 [<8038b2c0>] blk_mq_dispatch_rq_list+0x480/0x664 [<80391040>] blk_mq_do_dispatch_sched+0x2dc/0x370 [<80391468>] __blk_mq_sched_dispatch_requests+0xec/0x164 [<80391540>] blk_mq_sched_dispatch_requests+0x44/0x94 [<80387900>] __blk_mq_run_hw_queue+0xb0/0xcc [<80134c14>] process_one_work+0x1b8/0x264 [<80134ff8>] worker_thread+0x2ec/0x3b8 [<8013b13c>] kthread+0x104/0x10c [<80101dcc>] ret_from_kernel_thread+0x14/0x1c ---[ end trace 0000000000000000 ]---
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysisA detailed technical summary for this CVE is being prepared.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data< 5.4.198>= 5.5, < 5.10.121>= 5.11, < 5.15.46>= 5.16, < 5.17.14>= 5.18, < 5.18.3CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Local
- Complexity
- Low
- Privileges
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped5.4.1985.10.1215.15.46
Linux kernel >= 5.4.198, >= 5.10.121, >= 5.15.46, or >= 5.17.14 (depending on which branch is in use)
- Identify the current kernel version running on affected systems using `uname -r`
- Determine which kernel branch is in use (e.g., 5.4.x, 5.10.x, 5.15.x, or 5.17.x)
- Upgrade the Linux kernel to a fixed version: for 5.4.x branch use >= 5.4.198, for 5.10.x branch use >= 5.10.121, for 5.15.x branch use >= 5.15.46, or for 5.17.x branch use >= 5.17.14
- After kernel upgrade, reboot the system to load the fixed kernel
- Verify the fix is applied by checking the kernel version with `uname -r` and confirming the mmc/jz4740 driver no longer produces DMA debug warnings
Generated from the published advisory — verify against the referenced sources before acting.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2022-49522 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2022-49522 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.
A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data