GHSA-MJ4M-5R47-3F8J
Vulnerability from github – Published: 2026-08-10 15:33 – Updated: 2026-08-19 18:32In the Linux kernel, the following vulnerability has been resolved:
media: pwc: Drain fill_buf on start_streaming() failure
pwc_isoc_init() submits its isochronous URBs with usb_submit_urb(.., GFP_KERNEL) in a loop. After the first URB is submitted, its completion handler pwc_isoc_handler() can run on another CPU before the loop finishes:
start_streaming() pwc_isoc_init() usb_submit_urb(urbs[0], GFP_KERNEL) pwc_isoc_handler(urbs[0]) pdev->fill_buf = pwc_get_next_fill_buf(pdev) usb_submit_urb(urbs[i>0], ..) -> fails pwc_isoc_cleanup(pdev) / kills URBs / return ret; pwc_cleanup_queued_bufs(pdev, VB2_BUF_STATE_QUEUED)
pwc_get_next_fill_buf() detaches a buffer from pdev->queued_bufs and stores it in pdev->fill_buf. The error path in start_streaming() only drains pdev->queued_bufs, so the buffer parked in pdev->fill_buf is leaked. vb2_start_streaming() then triggers WARN_ON(owned_by_drv_count).
stop_streaming() already handles this since commit 80b0963e1698 ("[media] pwc: fix WARN_ON"), which added the fill_buf drain in the teardown path but not in the start_streaming() error path. Mirror that handling on failure so start_streaming() returns with no buffer owned by the driver.
Issue identified by automated review of the INV-003 series at https://sashiko.dev/
{
"affected": [],
"aliases": [
"CVE-2026-68217"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-08-10T13:20:09Z",
"severity": null
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nmedia: pwc: Drain fill_buf on start_streaming() failure\n\npwc_isoc_init() submits its isochronous URBs with\nusb_submit_urb(.., GFP_KERNEL) in a loop. After the first URB is\nsubmitted, its completion handler pwc_isoc_handler() can run on another\nCPU before the loop finishes:\n\n start_streaming()\n pwc_isoc_init()\n usb_submit_urb(urbs[0], GFP_KERNEL)\n pwc_isoc_handler(urbs[0])\n pdev-\u003efill_buf =\n pwc_get_next_fill_buf(pdev)\n usb_submit_urb(urbs[i\u003e0], ..) -\u003e fails\n pwc_isoc_cleanup(pdev) /* kills URBs */\n return ret;\n pwc_cleanup_queued_bufs(pdev, VB2_BUF_STATE_QUEUED)\n\npwc_get_next_fill_buf() detaches a buffer from pdev-\u003equeued_bufs and\nstores it in pdev-\u003efill_buf. The error path in start_streaming() only\ndrains pdev-\u003equeued_bufs, so the buffer parked in pdev-\u003efill_buf is\nleaked. vb2_start_streaming() then triggers\nWARN_ON(owned_by_drv_count).\n\nstop_streaming() already handles this since commit 80b0963e1698\n(\"[media] pwc: fix WARN_ON\"), which added the fill_buf drain in the\nteardown path but not in the start_streaming() error path. Mirror that\nhandling on failure so start_streaming() returns with no buffer owned\nby the driver.\n\nIssue identified by automated review of the INV-003 series at\nhttps://sashiko.dev/",
"id": "GHSA-mj4m-5r47-3f8j",
"modified": "2026-08-19T18:32:11Z",
"published": "2026-08-10T15:33:41Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-68217"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/5d4812668b03f823b5044789d6aa77fe56b42587"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/906e410dcffbbd99fb4081abab817a830033aa28"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/97f3c15957ec7e6d249f05407ad947c0644df24d"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/9afd605dcd96c7a45f338eded1de16679b30e1df"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/a4afffd148991a826e8995362fb10cf8705c1130"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/a56e7641e09bd80b976e944ae759109b86fd5b38"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/acc789b2173070638cad89c2b61d33ed338be0dd"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/eabe9a59640698137d7382d5b549e95dc37f7565"
}
],
"schema_version": "1.4.0",
"severity": []
}
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