CVE-2022-49073
HighIn the Linux kernel, the following vulnerability has been resolved: ata: sata_dwc_460ex: Fix crash due to OOB write the driver uses libata's "tag" values from in various arrays. Since the mentioned patch bumped the ATA_TAG_INTERNAL to 32, the value of the SATA_DWC_QCMD_MAX needs to account for that. Otherwise ATA_TAG_INTERNAL usage cause similar crashes like this as reported by Tice Rex on the OpenWrt Forum and reproduced (with symbols) here: | BUG: Kernel NULL pointer dereference at 0x00000000 | Faulting instruction address: 0xc03ed4b8 | Oops: Kernel access of bad area, sig: 11 [#1] | BE PAGE_SIZE=4K PowerPC 44x Platform | CPU: 0 PID: 362 Comm: scsi_eh_1 Not tainted 5.4.163 #0 | NIP: c03ed4b8 LR: c03d27e8 CTR: c03ed36c | REGS: cfa59950 TRAP: 0300 Not tainted (5.4.163) | MSR: 00021000 <CE,ME> CR: 42000222 XER: 00000000 | DEAR: 00000000 ESR: 00000000 | GPR00: c03d27e8 cfa59a08 cfa55fe0 00000000 0fa46bc0 [...] | [..] | NIP [c03ed4b8] sata_dwc_qc_issue+0x14c/0x254 | LR [c03d27e8] ata_qc_issue+0x1c8/0x2dc | Call Trace: | [cfa59a08] [c003f4e0] __cancel_work_timer+0x124/0x194 (unreliable) | [cfa59a78] [c03d27e8] ata_qc_issue+0x1c8/0x2dc | [cfa59a98] [c03d2b3c] ata_exec_internal_sg+0x240/0x524 | [cfa59b08] [c03d2e98] ata_exec_internal+0x78/0xe0 | [cfa59b58] [c03d30fc] ata_read_log_page.part.38+0x1dc/0x204 | [cfa59bc8] [c03d324c] ata_identify_page_supported+0x68/0x130 | [...] This is because sata_dwc_dma_xfer_complete() NULLs the dma_pending's next neighbour "chan" (a *dma_chan struct) in this '32' case right here (line ~735): > hsdevp->dma_pending[tag] = SATA_DWC_DMA_PENDING_NONE; Then the next time, a dma gets issued; dma_dwc_xfer_setup() passes the NULL'd hsdevp->chan to the dmaengine_slave_config() which then causes the crash. With this patch, SATA_DWC_QCMD_MAX is now set to ATA_MAX_QUEUE + 1. This avoids the OOB. But please note, there was a worthwhile discussion on what ATA_TAG_INTERNAL and ATA_MAX_QUEUE is. And why there should not be a "fake" 33 command-long queue size. Ideally, the dw driver should account for the ATA_TAG_INTERNAL. In Damien Le Moal's words: "... having looked at the driver, it is a bigger change than just faking a 33rd "tag" that is in fact not a command tag at all." BugLink: https://github.com/openwrt/openwrt/issues/9505
CVSS 3.1 score
7.8
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Weakness type
CWE-787CVE-2022-49073 is a Out-of-bounds Write vulnerability
What is Out-of-bounds Write?
The product writes data past the end or before the beginning of the intended buffer. Learn more on MITRE CWE
Affected versions
Linux kernel versions
4.18
and later are affected. Fixed in
4.19.238,
5.4.189,
5.10.111,
5.15.34,
5.16.20,
5.17.3,
5.18
and their respective stable series.
References
The following references provide additional information about CVE-2022-49073 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.
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PatchKernel patch commithttps://git.kernel.org/stable/c/234c0132f76f0676d175757f61b0025191a3d935
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PatchKernel patch commithttps://git.kernel.org/stable/c/3a8751c0d4e24129e72dcec0139e99833b13904a
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PatchKernel patch commithttps://git.kernel.org/stable/c/55e1465ba79562a191708a40eeae3f8082a209e3
Frequently asked questions
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What is CVE-2022-49073?
CVE-2022-49073 is a High severity Linux kernel vulnerability with a CVSS score of 7.8 out of 10 , classified as an Out-of-bounds Write flaw (CWE-787) . It affects Linux kernel versions from 4.18 onward and has been patched in 4.19.238, 5.4.189, 5.10.111 and others. CVE-2022-49073 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
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What is the CVSS score for CVE-2022-49073?
CVE-2022-49073 has a CVSS score of 7.8 out of 10, rated High severity (CVSS 3.1). The vector string is
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. -
Is there a patch available for CVE-2022-49073?
Yes — CVE-2022-49073 has been patched. Fixed versions include 4.19.238, 5.4.189, 5.10.111 and others. If you are running Linux kernel 4.18 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2022-49073 actively exploited?
No — CVE-2022-49073 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.
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What is Out-of-bounds Write (CWE-787)?
The product writes data past the end or before the beginning of the intended buffer. View CWE-787 on MITRE CWE →