CVE-2026-68150 (GCVE-0-2026-68150)

Vulnerability from cvelistv5 – Published: 2026-08-10 11:59 – Updated: 2026-08-17 04:59
VLAI
Title
fs/super: fix emergency thaw double-unlock of s_umount
Summary
In the Linux kernel, the following vulnerability has been resolved: fs/super: fix emergency thaw double-unlock of s_umount do_thaw_all() iterates over all superblocks via __iterate_supers() with SUPER_ITER_EXCL, which acquires s_umount exclusively before calling the callback and releases it afterwards. However, the callback do_thaw_all_callback() calls thaw_super_locked() which unconditionally releases s_umount on every code path. This results in a second unlock attempt in __iterate_supers() that corrupts the rwsem state, triggering a DEBUG_RWSEMS warning: [ 182.601148] sysrq: Emergency Thaw of all frozen filesystems [ 182.601865] ------------[ cut here ]------------ [ 182.602375] DEBUG_RWSEMS_WARN_ON((rwsem_owner(sem) != current) && !rwsem_test_oflags(sem, RWSEM_NONSPINNABLE)): count = 0x0, magic = 0xffff99b1011e5870, owner = 0x0, curr 0xffff99b101b06c80, list not empty [ 182.603817] WARNING: kernel/locking/rwsem.c:1412 at up_write+0xa3/0x170, CPU#2: kworker/2:1/53 [ 182.604578] Modules linked in: [ 182.604864] CPU: 2 UID: 0 PID: 53 Comm: kworker/2:1 Not tainted 7.2.0-rc4-00001-gbd3bd93ea98a-dirty #4 PREEMPT(lazy) [ 182.605711] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1kylin1 04/01/2014 [ 182.606417] Workqueue: events do_thaw_all [ 182.606750] RIP: 0010:up_write+0xaf/0x170 [ 182.607076] Code: 19 3a 92 48 0f 44 c2 48 8b 55 08 48 8b 55 00 4c 8b 45 08 48 8b 55 00 48 8d 3d ad 91 e0 01 48 8b 4d 20 50 48 c7 c6 f0 8c 26 92 <67> 48 0f b9 3a e8 d7 93 4e 00 58 eb 81 48 83 7f 18 00 48 c7 c2 8d [ 182.608563] RSP: 0018:ffffb670001d7e08 EFLAGS: 00010246 [ 182.609007] RAX: ffffffff92349e8d RBX: 0000000000000000 RCX: ffff99b1011e5870 [ 182.609595] RDX: 0000000000000000 RSI: ffffffff92268cf0 RDI: ffffffff92914d10 [ 182.610283] RBP: ffff99b1011e5870 R08: 0000000000000000 R09: ffff99b101b06c80 [ 182.610847] R10: ffff99b10139a808 R11: fefefefefefefeff R12: 0000000000000000 [ 182.611414] R13: ffffffff90cf74d0 R14: 0000000000000000 R15: ffff99b1011e5800 [ 182.612009] FS: 0000000000000000(0000) GS:ffff99b1eaaee000(0000) knlGS:0000000000000000 [ 182.612670] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 182.613146] CR2: 00000000005c631c CR3: 00000000013ee000 CR4: 00000000000006f0 [ 182.613722] Call Trace: [ 182.613946] <TASK> [ 182.614130] __iterate_supers+0x128/0x150 [ 182.614463] do_thaw_all+0x1b/0x30 [ 182.614759] process_scheduled_works+0xbb/0x3f0 [ 182.615150] ? __pfx_worker_thread+0x10/0x10 [ 182.615499] worker_thread+0x129/0x270 [ 182.615816] ? __pfx_worker_thread+0x10/0x10 [ 182.616201] kthread+0xe2/0x120 [ 182.616469] ? __pfx_kthread+0x10/0x10 [ 182.616792] ret_from_fork+0x15b/0x240 [ 182.617115] ? __pfx_kthread+0x10/0x10 [ 182.617426] ret_from_fork_asm+0x1a/0x30 [ 182.617761] </TASK> [ 182.617968] ---[ end trace 0000000000000000 ]--- [ 182.618412] Emergency Thaw complete Fix this by switching to SUPER_ITER_UNLOCKED and acquiring s_umount in the callback via super_lock_excl() before calling thaw_super_locked(). This matches the locking pattern expected by thaw_super_locked() and eliminates the double unlock. While at it, remove the dead 'return;' at the end of do_thaw_all_callback().
Severity
No CVSS data available.
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: 2992476528aeecbaee17ba0a6396a817481205a3 , < c78e38745ff1b0457c4551e7f75ea15842df1169 (git)
Affected: 2992476528aeecbaee17ba0a6396a817481205a3 , < 64017df6e61a3ce7159cee284109b92009985361 (git)
Affected: 2992476528aeecbaee17ba0a6396a817481205a3 , < 503d67fbaec6fdeaba391cb497675071db9d16ea (git)
guessed Create a notification for this product.
Linux Linux Affected: 6.16
Unaffected: 0 , < 6.16 (semver)
Unaffected: 6.18.42 , ≤ 6.18.* (semver)
Unaffected: 7.1.6 , ≤ 7.1.* (semver)
Unaffected: 7.2 , ≤ * (original_commit_for_fix)
guessed Create a notification for this product.
Show details on NVD website
To clipboard 

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/super.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "c78e38745ff1b0457c4551e7f75ea15842df1169",
              "status": "affected",
              "version": "2992476528aeecbaee17ba0a6396a817481205a3",
              "versionType": "git"
            },
            {
              "lessThan": "64017df6e61a3ce7159cee284109b92009985361",
              "status": "affected",
              "version": "2992476528aeecbaee17ba0a6396a817481205a3",
              "versionType": "git"
            },
            {
              "lessThan": "503d67fbaec6fdeaba391cb497675071db9d16ea",
              "status": "affected",
              "version": "2992476528aeecbaee17ba0a6396a817481205a3",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "fs/super.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.16"
            },
            {
              "lessThan": "6.16",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.42",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.6",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.42",
                  "versionStartIncluding": "6.16",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1.6",
                  "versionStartIncluding": "6.16",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2",
                  "versionStartIncluding": "6.16",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nfs/super: fix emergency thaw double-unlock of s_umount\n\ndo_thaw_all() iterates over all superblocks via __iterate_supers()\nwith SUPER_ITER_EXCL, which acquires s_umount exclusively before\ncalling the callback and releases it afterwards. However, the\ncallback do_thaw_all_callback() calls thaw_super_locked() which\nunconditionally releases s_umount on every code path. This results\nin a second unlock attempt in __iterate_supers() that corrupts the\nrwsem state, triggering a DEBUG_RWSEMS warning:\n\n[  182.601148] sysrq: Emergency Thaw of all frozen filesystems\n[  182.601865] ------------[ cut here ]------------\n[  182.602375] DEBUG_RWSEMS_WARN_ON((rwsem_owner(sem) != current) \u0026\u0026 !rwsem_test_oflags(sem, RWSEM_NONSPINNABLE)): count = 0x0, magic = 0xffff99b1011e5870, owner = 0x0, curr 0xffff99b101b06c80, list not empty\n[  182.603817] WARNING: kernel/locking/rwsem.c:1412 at up_write+0xa3/0x170, CPU#2: kworker/2:1/53\n[  182.604578] Modules linked in:\n[  182.604864] CPU: 2 UID: 0 PID: 53 Comm: kworker/2:1 Not tainted 7.2.0-rc4-00001-gbd3bd93ea98a-dirty #4 PREEMPT(lazy)\n[  182.605711] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1kylin1 04/01/2014\n[  182.606417] Workqueue: events do_thaw_all\n[  182.606750] RIP: 0010:up_write+0xaf/0x170\n[  182.607076] Code: 19 3a 92 48 0f 44 c2 48 8b 55 08 48 8b 55 00 4c 8b 45 08 48 8b 55 00 48 8d 3d ad 91 e0 01 48 8b 4d 20 50 48 c7 c6 f0 8c 26 92 \u003c67\u003e 48 0f b9 3a e8 d7 93 4e 00 58 eb 81 48 83 7f 18 00 48 c7 c2 8d\n[  182.608563] RSP: 0018:ffffb670001d7e08 EFLAGS: 00010246\n[  182.609007] RAX: ffffffff92349e8d RBX: 0000000000000000 RCX: ffff99b1011e5870\n[  182.609595] RDX: 0000000000000000 RSI: ffffffff92268cf0 RDI: ffffffff92914d10\n[  182.610283] RBP: ffff99b1011e5870 R08: 0000000000000000 R09: ffff99b101b06c80\n[  182.610847] R10: ffff99b10139a808 R11: fefefefefefefeff R12: 0000000000000000\n[  182.611414] R13: ffffffff90cf74d0 R14: 0000000000000000 R15: ffff99b1011e5800\n[  182.612009] FS:  0000000000000000(0000) GS:ffff99b1eaaee000(0000) knlGS:0000000000000000\n[  182.612670] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n[  182.613146] CR2: 00000000005c631c CR3: 00000000013ee000 CR4: 00000000000006f0\n[  182.613722] Call Trace:\n[  182.613946]  \u003cTASK\u003e\n[  182.614130]  __iterate_supers+0x128/0x150\n[  182.614463]  do_thaw_all+0x1b/0x30\n[  182.614759]  process_scheduled_works+0xbb/0x3f0\n[  182.615150]  ? __pfx_worker_thread+0x10/0x10\n[  182.615499]  worker_thread+0x129/0x270\n[  182.615816]  ? __pfx_worker_thread+0x10/0x10\n[  182.616201]  kthread+0xe2/0x120\n[  182.616469]  ? __pfx_kthread+0x10/0x10\n[  182.616792]  ret_from_fork+0x15b/0x240\n[  182.617115]  ? __pfx_kthread+0x10/0x10\n[  182.617426]  ret_from_fork_asm+0x1a/0x30\n[  182.617761]  \u003c/TASK\u003e\n[  182.617968] ---[ end trace 0000000000000000 ]---\n[  182.618412] Emergency Thaw complete\n\nFix this by switching to SUPER_ITER_UNLOCKED and acquiring s_umount\nin the callback via super_lock_excl() before calling\nthaw_super_locked(). This matches the locking pattern expected by\nthaw_super_locked() and eliminates the double unlock.\n\nWhile at it, remove the dead \u0027return;\u0027 at the end of\ndo_thaw_all_callback()."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-17T04:59:44.707Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/c78e38745ff1b0457c4551e7f75ea15842df1169"
        },
        {
          "url": "https://git.kernel.org/stable/c/64017df6e61a3ce7159cee284109b92009985361"
        },
        {
          "url": "https://git.kernel.org/stable/c/503d67fbaec6fdeaba391cb497675071db9d16ea"
        }
      ],
      "title": "fs/super: fix emergency thaw double-unlock of s_umount",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-68150",
    "datePublished": "2026-08-10T11:59:15.647Z",
    "dateReserved": "2026-07-30T09:28:09.371Z",
    "dateUpdated": "2026-08-17T04:59:44.707Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-68150",
      "date": "2026-08-20",
      "epss": "0.00173",
      "percentile": "0.07081"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-68150\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2026-08-10T13:20:01.010\",\"lastModified\":\"2026-08-17T05:18:15.183\",\"vulnStatus\":\"Received\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"In the Linux kernel, the following vulnerability has been resolved:\\n\\nfs/super: fix emergency thaw double-unlock of s_umount\\n\\ndo_thaw_all() iterates over all superblocks via __iterate_supers()\\nwith SUPER_ITER_EXCL, which acquires s_umount exclusively before\\ncalling the callback and releases it afterwards. However, the\\ncallback do_thaw_all_callback() calls thaw_super_locked() which\\nunconditionally releases s_umount on every code path. This results\\nin a second unlock attempt in __iterate_supers() that corrupts the\\nrwsem state, triggering a DEBUG_RWSEMS warning:\\n\\n[  182.601148] sysrq: Emergency Thaw of all frozen filesystems\\n[  182.601865] ------------[ cut here ]------------\\n[  182.602375] DEBUG_RWSEMS_WARN_ON((rwsem_owner(sem) != current) \u0026\u0026 !rwsem_test_oflags(sem, RWSEM_NONSPINNABLE)): count = 0x0, magic = 0xffff99b1011e5870, owner = 0x0, curr 0xffff99b101b06c80, list not empty\\n[  182.603817] WARNING: kernel/locking/rwsem.c:1412 at up_write+0xa3/0x170, CPU#2: kworker/2:1/53\\n[  182.604578] Modules linked in:\\n[  182.604864] CPU: 2 UID: 0 PID: 53 Comm: kworker/2:1 Not tainted 7.2.0-rc4-00001-gbd3bd93ea98a-dirty #4 PREEMPT(lazy)\\n[  182.605711] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1kylin1 04/01/2014\\n[  182.606417] Workqueue: events do_thaw_all\\n[  182.606750] RIP: 0010:up_write+0xaf/0x170\\n[  182.607076] Code: 19 3a 92 48 0f 44 c2 48 8b 55 08 48 8b 55 00 4c 8b 45 08 48 8b 55 00 48 8d 3d ad 91 e0 01 48 8b 4d 20 50 48 c7 c6 f0 8c 26 92 \u003c67\u003e 48 0f b9 3a e8 d7 93 4e 00 58 eb 81 48 83 7f 18 00 48 c7 c2 8d\\n[  182.608563] RSP: 0018:ffffb670001d7e08 EFLAGS: 00010246\\n[  182.609007] RAX: ffffffff92349e8d RBX: 0000000000000000 RCX: ffff99b1011e5870\\n[  182.609595] RDX: 0000000000000000 RSI: ffffffff92268cf0 RDI: ffffffff92914d10\\n[  182.610283] RBP: ffff99b1011e5870 R08: 0000000000000000 R09: ffff99b101b06c80\\n[  182.610847] R10: ffff99b10139a808 R11: fefefefefefefeff R12: 0000000000000000\\n[  182.611414] R13: ffffffff90cf74d0 R14: 0000000000000000 R15: ffff99b1011e5800\\n[  182.612009] FS:  0000000000000000(0000) GS:ffff99b1eaaee000(0000) knlGS:0000000000000000\\n[  182.612670] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\\n[  182.613146] CR2: 00000000005c631c CR3: 00000000013ee000 CR4: 00000000000006f0\\n[  182.613722] Call Trace:\\n[  182.613946]  \u003cTASK\u003e\\n[  182.614130]  __iterate_supers+0x128/0x150\\n[  182.614463]  do_thaw_all+0x1b/0x30\\n[  182.614759]  process_scheduled_works+0xbb/0x3f0\\n[  182.615150]  ? __pfx_worker_thread+0x10/0x10\\n[  182.615499]  worker_thread+0x129/0x270\\n[  182.615816]  ? __pfx_worker_thread+0x10/0x10\\n[  182.616201]  kthread+0xe2/0x120\\n[  182.616469]  ? __pfx_kthread+0x10/0x10\\n[  182.616792]  ret_from_fork+0x15b/0x240\\n[  182.617115]  ? __pfx_kthread+0x10/0x10\\n[  182.617426]  ret_from_fork_asm+0x1a/0x30\\n[  182.617761]  \u003c/TASK\u003e\\n[  182.617968] ---[ end trace 0000000000000000 ]---\\n[  182.618412] Emergency Thaw complete\\n\\nFix this by switching to SUPER_ITER_UNLOCKED and acquiring s_umount\\nin the callback via super_lock_excl() before calling\\nthaw_super_locked(). This matches the locking pattern expected by\\nthaw_super_locked() and eliminates the double unlock.\\n\\nWhile at it, remove the dead \u0027return;\u0027 at the end of\\ndo_thaw_all_callback().\"}],\"affected\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"affectedData\":[{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"unaffected\",\"programFiles\":[\"fs/super.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"2992476528aeecbaee17ba0a6396a817481205a3\",\"lessThan\":\"c78e38745ff1b0457c4551e7f75ea15842df1169\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"2992476528aeecbaee17ba0a6396a817481205a3\",\"lessThan\":\"64017df6e61a3ce7159cee284109b92009985361\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"2992476528aeecbaee17ba0a6396a817481205a3\",\"lessThan\":\"503d67fbaec6fdeaba391cb497675071db9d16ea\",\"versionType\":\"git\",\"status\":\"affected\"}]},{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"affected\",\"programFiles\":[\"fs/super.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"6.16\",\"status\":\"affected\"},{\"version\":\"0\",\"lessThan\":\"6.16\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.18.42\",\"lessThanOrEqual\":\"6.18.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.1.6\",\"lessThanOrEqual\":\"7.1.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.2\",\"lessThanOrEqual\":\"*\",\"versionType\":\"original_commit_for_fix\",\"status\":\"unaffected\"}]}]}],\"metrics\":{},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/503d67fbaec6fdeaba391cb497675071db9d16ea\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/64017df6e61a3ce7159cee284109b92009985361\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/c78e38745ff1b0457c4551e7f75ea15842df1169\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}",
    "redhat_vex": {
      "aggregate_severity": "Low",
      "current_release_date": "2026-08-14T01:30:07+00:00",
      "cve": "CVE-2026-68150",
      "id": "CVE-2026-68150",
      "initial_release_date": "2026-08-10T00:00:00+00:00",
      "product_status:known_not_affected": "276",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: fs/super: fix emergency thaw double-unlock of s_umount",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-68150.json",
      "version": "3"
    },
    "suse_vex": {
      "aggregate_severity": "low",
      "current_release_date": "2026-08-17T16:29:48Z",
      "cve": "CVE-2026-68150",
      "id": "CVE-2026-68150",
      "initial_release_date": "2026-08-17T16:29:48Z",
      "product_status:known_not_affected": "296",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2026-68150",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-68150.json",
      "version": "2"
    }
  }
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.