{"id":"CVE-2026-68150","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-68150","generatedAt":"2026-10-28T04:46:37.023Z","title":"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…","description":"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) && !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 <67> 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]  <TASK>\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]  </TASK>\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 'return;' at the end of\ndo_thaw_all_callback().","published":"2026-08-10T13:20:01.000Z","lastModified":"2026-08-23T13:16:34.000Z","status":"Received","sourceIdentifier":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","cvss":null,"cwe":[],"affected":[],"epss":{"score":0.00175,"percentile":0.06994,"date":"2026-10-27","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"unknown","text":"Not yet scored. NVD analysis is pending; check back once CVSS and EPSS values are published."},"changes":[],"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/79e04370657a2581e3189f9c7fc166e7c4fbab3a","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/c78e38745ff1b0457c4551e7f75ea15842df1169","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-68150","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}