CVE-2025-21976
- Source
- https://nvd.nist.gov/vuln/detail/CVE-2025-21976
- Import Source
- https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2025-21976.json
- JSON Data
- https://api.test.osv.dev/v1/vulns/CVE-2025-21976
- Downstream
- Related
- Published
- 2025-04-01T15:47:07.120Z
- Modified
- 2025-11-14T14:50:34.358627Z
- Summary
- fbdev: hyperv_fb: Allow graceful removal of framebuffer
- Details
-
In the Linux kernel, the following vulnerability has been resolved:
fbdev: hyperv_fb: Allow graceful removal of framebuffer
When a Hyper-V framebuffer device is unbind, hyperv_fb driver tries to release the framebuffer forcefully. If this framebuffer is in use it produce the following WARN and hence this framebuffer is never released.
[ 44.111220] WARNING: CPU: 35 PID: 1882 at drivers/video/fbdev/core/fbinfo.c:70 framebufferrelease+0x2c/0x40 < snip > [ 44.111289] Call Trace: [ 44.111290] <TASK> [ 44.111291] ? showregs+0x6c/0x80 [ 44.111295] ? _warn+0x8d/0x150 [ 44.111298] ? framebufferrelease+0x2c/0x40 [ 44.111300] ? reportbug+0x182/0x1b0 [ 44.111303] ? handlebug+0x6e/0xb0 [ 44.111306] ? excinvalidop+0x18/0x80 [ 44.111308] ? asmexcinvalidop+0x1b/0x20 [ 44.111311] ? framebufferrelease+0x2c/0x40 [ 44.111313] ? hvfbremove+0x86/0xa0 [hypervfb] [ 44.111315] vmbusremove+0x24/0x40 [hvvmbus] [ 44.111323] deviceremove+0x40/0x80 [ 44.111325] devicereleasedriverinternal+0x20b/0x270 [ 44.111327] ? busfind_device+0xb3/0xf0
Fix this by moving the release of framebuffer and assosiated memory to fbops.fbdestroy function, so that framebuffer framework handles it gracefully.
While we fix this, also replace manual registrations/unregistration of framebuffer with devmregisterframebuffer.
- References
Affected packages
Git / git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Affected ranges
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introduced68a2d20b79b105f02dcbc52c211d7e62f98996b7Fixed4545e2aa121aea304d33903099c03e29ed4fe50a
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introduced68a2d20b79b105f02dcbc52c211d7e62f98996b7Fixeda7b583dc99c6cf4a96877017be1d08247e1ef2c7
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introduced68a2d20b79b105f02dcbc52c211d7e62f98996b7Fixedea2f45ab0e53b255f72c85ccd99e2b394fc5fceb
Affected versions
v3.*
v3.10
v3.10-rc1
v3.10-rc2
v3.10-rc3
v3.10-rc4
v3.10-rc5
v3.10-rc6
v3.10-rc7
v3.11
v3.11-rc1
v3.11-rc2
v3.11-rc3
v3.11-rc4
v3.11-rc5
v3.11-rc6
v3.11-rc7
v3.12
v3.12-rc1
v3.12-rc2
v3.12-rc3
v3.12-rc4
v3.12-rc5
v3.12-rc6
v3.12-rc7
v3.13
v3.13-rc1
v3.13-rc2
v3.13-rc3
v3.13-rc4
v3.13-rc5
v3.13-rc6
v3.13-rc7
v3.13-rc8
v3.14
v3.14-rc1
v3.14-rc2
v3.14-rc3
v3.14-rc4
v3.14-rc5
v3.14-rc6
v3.14-rc7
v3.14-rc8
v3.15
v3.15-rc1
v3.15-rc2
v3.15-rc3
v3.15-rc4
v3.15-rc5
v3.15-rc6
v3.15-rc7
v3.15-rc8
v3.16
v3.16-rc1
v3.16-rc2
v3.16-rc3
v3.16-rc4
v3.16-rc5
v3.16-rc6
v3.16-rc7
v3.17
v3.17-rc1
v3.17-rc2
v3.17-rc3
v3.17-rc4
v3.17-rc5
v3.17-rc6
v3.17-rc7
v3.18
v3.18-rc1
v3.18-rc2
v3.18-rc3
v3.18-rc4
v3.18-rc5
v3.18-rc6
v3.18-rc7
v3.19
v3.19-rc1
v3.19-rc2
v3.19-rc3
v3.19-rc4
v3.19-rc5
v3.19-rc6
v3.19-rc7
v4.*
v4.0
v4.0-rc1
v4.0-rc2
v4.0-rc3
v4.0-rc4
v4.0-rc5
v4.0-rc6
v4.0-rc7
v4.1
v4.1-rc1
v4.1-rc2
v4.1-rc3
v4.1-rc4
v4.1-rc5
v4.1-rc6
v4.1-rc7
v4.1-rc8
v4.10
v4.10-rc1
v4.10-rc2
v4.10-rc3
v4.10-rc4
v4.10-rc5
v4.10-rc6
v4.10-rc7
v4.10-rc8
v4.11
v4.11-rc1
v4.11-rc2
v4.11-rc3
v4.11-rc4
v4.11-rc5
v4.11-rc6
v4.11-rc7
v4.11-rc8
v4.12
v4.12-rc1
v4.12-rc2
v4.12-rc3
v4.12-rc4
v4.12-rc5
v4.12-rc6
v4.12-rc7
v4.13
v4.13-rc1
v4.13-rc2
v4.13-rc3
v4.13-rc4
v4.13-rc5
v4.13-rc6
v4.13-rc7
v4.14
v4.14-rc1
v4.14-rc2
v4.14-rc3
v4.14-rc4
v4.14-rc5
v4.14-rc6
v4.14-rc7
v4.14-rc8
v4.15
v4.15-rc1
v4.15-rc2
v4.15-rc3
v4.15-rc4
v4.15-rc5
v4.15-rc6
v4.15-rc7
v4.15-rc8
v4.15-rc9
v4.16
v4.16-rc1
v4.16-rc2
v4.16-rc3
v4.16-rc4
v4.16-rc5
v4.16-rc6
v4.16-rc7
v4.17
v4.17-rc1
v4.17-rc2
v4.17-rc3
v4.17-rc4
v4.17-rc5
v4.17-rc6
v4.17-rc7
v4.18
v4.18-rc1
v4.18-rc2
v4.18-rc3
v4.18-rc4
v4.18-rc5
v4.18-rc6
v4.18-rc7
v4.18-rc8
v4.19
v4.19-rc1
v4.19-rc2
v4.19-rc3
v4.19-rc4
v4.19-rc5
v4.19-rc6
v4.19-rc7
v4.19-rc8
v4.2
v4.2-rc1
v4.2-rc2
v4.2-rc3
v4.2-rc4
v4.2-rc5
v4.2-rc6
v4.2-rc7
v4.2-rc8
v4.20
v4.20-rc1
v4.20-rc2
v4.20-rc3
v4.20-rc4
v4.20-rc5
v4.20-rc6
v4.20-rc7
v4.3
v4.3-rc1
v4.3-rc2
v4.3-rc3
v4.3-rc4
v4.3-rc5
v4.3-rc6
v4.3-rc7
v4.4
v4.4-rc1
v4.4-rc2
v4.4-rc3
v4.4-rc4
v4.4-rc5
v4.4-rc6
v4.4-rc7
v4.4-rc8
v4.5
v4.5-rc1
v4.5-rc2
v4.5-rc3
v4.5-rc4
v4.5-rc5
v4.5-rc6
v4.5-rc7
v4.6
v4.6-rc1
v4.6-rc2
v4.6-rc3
v4.6-rc4
v4.6-rc5
v4.6-rc6
v4.6-rc7
v4.7
v4.7-rc1
v4.7-rc2
v4.7-rc3
v4.7-rc4
v4.7-rc5
v4.7-rc6
v4.7-rc7
v4.8
v4.8-rc1
v4.8-rc2
v4.8-rc3
v4.8-rc4
v4.8-rc5
v4.8-rc6
v4.8-rc7
v4.8-rc8
v4.9
v4.9-rc1
v4.9-rc2
v4.9-rc3
v4.9-rc4
v4.9-rc5
v4.9-rc6
v4.9-rc7
v4.9-rc8
v5.*
v5.0
v5.0-rc1
v5.0-rc2
v5.0-rc3
v5.0-rc4
v5.0-rc5
v5.0-rc6
v5.0-rc7
v5.0-rc8
v5.1
v5.1-rc1
v5.1-rc2
v5.1-rc3
v5.1-rc4
v5.1-rc5
v5.1-rc6
v5.1-rc7
v5.10
v5.10-rc1
v5.10-rc2
v5.10-rc3
v5.10-rc4
v5.10-rc5
v5.10-rc6
v5.10-rc7
v5.11
v5.11-rc1
v5.11-rc2
v5.11-rc3
v5.11-rc4
v5.11-rc5
v5.11-rc6
v5.11-rc7
v5.12
v5.12-rc1
v5.12-rc1-dontuse
v5.12-rc2
v5.12-rc3
v5.12-rc4
v5.12-rc5
v5.12-rc6
v5.12-rc7
v5.12-rc8
v5.13
v5.13-rc1
v5.13-rc2
v5.13-rc3
v5.13-rc4
v5.13-rc5
v5.13-rc6
v5.13-rc7
v5.14
v5.14-rc1
v5.14-rc2
v5.14-rc3
v5.14-rc4
v5.14-rc5
v5.14-rc6
v5.14-rc7
v5.15
v5.15-rc1
v5.15-rc2
v5.15-rc3
v5.15-rc4
v5.15-rc5
v5.15-rc6
v5.15-rc7
v5.16
v5.16-rc1
v5.16-rc2
v5.16-rc3
v5.16-rc4
v5.16-rc5
v5.16-rc6
v5.16-rc7
v5.16-rc8
v5.17
v5.17-rc1
v5.17-rc2
v5.17-rc3
v5.17-rc4
v5.17-rc5
v5.17-rc6
v5.17-rc7
v5.17-rc8
v5.18
v5.18-rc1
v5.18-rc2
v5.18-rc3
v5.18-rc4
v5.18-rc5
v5.18-rc6
v5.18-rc7
v5.19
v5.19-rc1
v5.19-rc2
v5.19-rc3
v5.19-rc4
v5.19-rc5
v5.19-rc6
v5.19-rc7
v5.19-rc8
v5.2
v5.2-rc1
v5.2-rc2
v5.2-rc3
v5.2-rc4
v5.2-rc5
v5.2-rc6
v5.2-rc7
v5.3
v5.3-rc1
v5.3-rc2
v5.3-rc3
v5.3-rc4
v5.3-rc5
v5.3-rc6
v5.3-rc7
v5.3-rc8
v5.4
v5.4-rc1
v5.4-rc2
v5.4-rc3
v5.4-rc4
v5.4-rc5
v5.4-rc6
v5.4-rc7
v5.4-rc8
v5.5
v5.5-rc1
v5.5-rc2
v5.5-rc3
v5.5-rc4
v5.5-rc5
v5.5-rc6
v5.5-rc7
v5.6
v5.6-rc1
v5.6-rc2
v5.6-rc3
v5.6-rc4
v5.6-rc5
v5.6-rc6
v5.6-rc7
v5.7
v5.7-rc1
v5.7-rc2
v5.7-rc3
v5.7-rc4
v5.7-rc5
v5.7-rc6
v5.7-rc7
v5.8
v5.8-rc1
v5.8-rc2
v5.8-rc3
v5.8-rc4
v5.8-rc5
v5.8-rc6
v5.8-rc7
v5.9
v5.9-rc1
v5.9-rc2
v5.9-rc3
v5.9-rc4
v5.9-rc5
v5.9-rc6
v5.9-rc7
v5.9-rc8
v6.*
v6.0
v6.0-rc1
v6.0-rc2
v6.0-rc3
v6.0-rc4
v6.0-rc5
v6.0-rc6
v6.0-rc7
v6.1
v6.1-rc1
v6.1-rc2
v6.1-rc3
v6.1-rc4
v6.1-rc5
v6.1-rc6
v6.1-rc7
v6.1-rc8
v6.10
v6.10-rc1
v6.10-rc2
v6.10-rc3
v6.10-rc4
v6.10-rc5
v6.10-rc6
v6.10-rc7
v6.11
v6.11-rc1
v6.11-rc2
v6.11-rc3
v6.11-rc4
v6.11-rc5
v6.11-rc6
v6.11-rc7
v6.12
v6.12-rc1
v6.12-rc2
v6.12-rc3
v6.12-rc4
v6.12-rc5
v6.12-rc6
v6.12-rc7
v6.12.1
v6.12.10
v6.12.11
v6.12.12
v6.12.13
v6.12.14
v6.12.15
v6.12.16
v6.12.17
v6.12.18
v6.12.19
v6.12.2
v6.12.3
v6.12.4
v6.12.5
v6.12.6
v6.12.7
v6.12.8
v6.12.9
v6.13
v6.13-rc1
v6.13-rc2
v6.13-rc3
v6.13-rc4
v6.13-rc5
v6.13-rc6
v6.13-rc7
v6.13.1
v6.13.2
v6.13.3
v6.13.4
v6.13.5
v6.13.6
v6.13.7
v6.14-rc1
v6.14-rc2
v6.2
v6.2-rc1
v6.2-rc2
v6.2-rc3
v6.2-rc4
v6.2-rc5
v6.2-rc6
v6.2-rc7
v6.2-rc8
v6.3
v6.3-rc1
v6.3-rc2
v6.3-rc3
v6.3-rc4
v6.3-rc5
v6.3-rc6
v6.3-rc7
v6.4
v6.4-rc1
v6.4-rc2
v6.4-rc3
v6.4-rc4
v6.4-rc5
v6.4-rc6
v6.4-rc7
v6.5
v6.5-rc1
v6.5-rc2
v6.5-rc3
v6.5-rc4
v6.5-rc5
v6.5-rc6
v6.5-rc7
v6.6
v6.6-rc1
v6.6-rc2
v6.6-rc3
v6.6-rc4
v6.6-rc5
v6.6-rc6
v6.6-rc7
v6.7
v6.7-rc1
v6.7-rc2
v6.7-rc3
v6.7-rc4
v6.7-rc5
v6.7-rc6
v6.7-rc7
v6.7-rc8
v6.8
v6.8-rc1
v6.8-rc2
v6.8-rc3
v6.8-rc4
v6.8-rc5
v6.8-rc6
v6.8-rc7
v6.9
v6.9-rc1
v6.9-rc2
v6.9-rc3
v6.9-rc4
v6.9-rc5
v6.9-rc6
v6.9-rc7
Database specific
vanir_signatures
[
{
"signature_version": "v1",
"source": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git@4545e2aa121aea304d33903099c03e29ed4fe50a",
"signature_type": "Function",
"id": "CVE-2025-21976-02f7c57e",
"target": {
"function": "hvfb_remove",
"file": "drivers/video/fbdev/hyperv_fb.c"
},
"digest": {
"length": 383.0,
"function_hash": "4723937194981309835601563176638893945"
},
"deprecated": false
},
{
"signature_version": "v1",
"source": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git@a7b583dc99c6cf4a96877017be1d08247e1ef2c7",
"signature_type": "Function",
"id": "CVE-2025-21976-0521d480",
"target": {
"function": "hvfb_remove",
"file": "drivers/video/fbdev/hyperv_fb.c"
},
"digest": {
"length": 383.0,
"function_hash": "4723937194981309835601563176638893945"
},
"deprecated": false
},
{
"signature_version": "v1",
"source": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git@ea2f45ab0e53b255f72c85ccd99e2b394fc5fceb",
"signature_type": "Line",
"id": "CVE-2025-21976-0e033053",
"target": {
"file": "drivers/video/fbdev/hyperv_fb.c"
},
"digest": {
"line_hashes": [
"255271629970840444459931929482554237423",
"155132735019990250823920034479904214824",
"92024950652233186978634578680971484702",
"110096427894966600932499321358452850365",
"136179657463301112017334245657137683134",
"330926436966910744786992427881929153101",
"229111067236857937349733401661563387159",
"293693877700702415171117687194477363695",
"329250281698873047162194650837994224066",
"95174197051183411380285872099965436372",
"50219213689285972088035714147789527940",
"206571877941868401480064915622866356893",
"311262387233600008543486087649935669096",
"268554210364986211638472641393903039505",
"256174547368992140233381370494240960841",
"288436947148882576345158198401054699198",
"220142174506305666789251538370622967954",
"15434405990131881930065879511872847404",
"260573424494323627904571476939660251794",
"46625573129927011582190047257281144696",
"257391517529756882552899075268875483108",
"29124675417065050017414877817897962434",
"302030890170360865091836438277420716591"
],
"threshold": 0.9
},
"deprecated": false
},
{
"signature_version": "v1",
"source": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git@4545e2aa121aea304d33903099c03e29ed4fe50a",
"signature_type": "Line",
"id": "CVE-2025-21976-1c76148e",
"target": {
"file": "drivers/video/fbdev/hyperv_fb.c"
},
"digest": {
"line_hashes": [
"255271629970840444459931929482554237423",
"155132735019990250823920034479904214824",
"92024950652233186978634578680971484702",
"110096427894966600932499321358452850365",
"136179657463301112017334245657137683134",
"330926436966910744786992427881929153101",
"229111067236857937349733401661563387159",
"293693877700702415171117687194477363695",
"329250281698873047162194650837994224066",
"95174197051183411380285872099965436372",
"50219213689285972088035714147789527940",
"206571877941868401480064915622866356893",
"311262387233600008543486087649935669096",
"268554210364986211638472641393903039505",
"256174547368992140233381370494240960841",
"288436947148882576345158198401054699198",
"220142174506305666789251538370622967954",
"15434405990131881930065879511872847404",
"260573424494323627904571476939660251794",
"46625573129927011582190047257281144696",
"257391517529756882552899075268875483108",
"29124675417065050017414877817897962434",
"302030890170360865091836438277420716591"
],
"threshold": 0.9
},
"deprecated": false
},
{
"signature_version": "v1",
"source": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git@a7b583dc99c6cf4a96877017be1d08247e1ef2c7",
"signature_type": "Line",
"id": "CVE-2025-21976-3aaf4622",
"target": {
"file": "drivers/video/fbdev/hyperv_fb.c"
},
"digest": {
"line_hashes": [
"255271629970840444459931929482554237423",
"155132735019990250823920034479904214824",
"92024950652233186978634578680971484702",
"110096427894966600932499321358452850365",
"136179657463301112017334245657137683134",
"330926436966910744786992427881929153101",
"229111067236857937349733401661563387159",
"293693877700702415171117687194477363695",
"329250281698873047162194650837994224066",
"95174197051183411380285872099965436372",
"50219213689285972088035714147789527940",
"206571877941868401480064915622866356893",
"311262387233600008543486087649935669096",
"268554210364986211638472641393903039505",
"256174547368992140233381370494240960841",
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