{"id":"CVE-2025-39782","title":"jbd2: prevent softlockup in jbd2_log_do_checkpoint()","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\njbd2: prevent softlockup in jbd2_log_do_checkpoint()\n\nBoth jbd2_log_do_checkpoint() and jbd2_journal_shrink_checkpoint_list()\nperiodically release j_list_lock after pro…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= f93ea411b73594f7d144855fd34278bcf34a9afc < f683d611518d30334813eecf9a8c687453e2800e","Linux >= f93ea411b73594f7d144855fd34278bcf34a9afc < f7ee8fd689e6d534f9fd2494b9266f7998082e65","Linux >= f93ea411b73594f7d144855fd34278bcf34a9afc < 84ff98c1ea19acd3f9389e4bb6061364e943f85e","Linux >= f93ea411b73594f7d144855fd34278bcf34a9afc < 26cb9aad94cb1811d8fae115594cc71fa3d91ab0","Linux >= f93ea411b73594f7d144855fd34278bcf34a9afc < 41f40038de62e8306897cf6840791b268996432a","Linux >= f93ea411b73594f7d144855fd34278bcf34a9afc < 429d50cbaff45090d52a1ea850d5de8c14881ee7","Linux >= f93ea411b73594f7d144855fd34278bcf34a9afc < 3faac5e1d14c63260fd1bf789d96bde3ab3d9e54","Linux >= f93ea411b73594f7d144855fd34278bcf34a9afc < 9d98cf4632258720f18265a058e62fde120c0151","Linux 2.6.16"],"published":"2025-09-11","updated":"2026-09-08","sourceUpdated":"2026-09-08T08:42:18.616Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2025-39782","references":[{"url":"https://git.kernel.org/stable/c/f683d611518d30334813eecf9a8c687453e2800e"},{"url":"https://git.kernel.org/stable/c/f7ee8fd689e6d534f9fd2494b9266f7998082e65"},{"url":"https://git.kernel.org/stable/c/84ff98c1ea19acd3f9389e4bb6061364e943f85e"},{"url":"https://git.kernel.org/stable/c/26cb9aad94cb1811d8fae115594cc71fa3d91ab0"},{"url":"https://git.kernel.org/stable/c/41f40038de62e8306897cf6840791b268996432a"},{"url":"https://git.kernel.org/stable/c/429d50cbaff45090d52a1ea850d5de8c14881ee7"},{"url":"https://git.kernel.org/stable/c/3faac5e1d14c63260fd1bf789d96bde3ab3d9e54"},{"url":"https://git.kernel.org/stable/c/9d98cf4632258720f18265a058e62fde120c0151"}],"tags":["cve.org"],"epss":0.00125,"epssPercentile":0.01904,"ingestedAt":"2026-09-08T15:33:26.997Z","slug":"CVE-2025-39782","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\njbd2: prevent softlockup in jbd2_log_do_checkpoint()\n\nBoth jbd2_log_do_checkpoint() and jbd2_journal_shrink_checkpoint_list()\nperiodically release j_list_lock after processing a batch of buffers to\navoid long hold times on the j_list_lock. However, since both functions\ncontend for j_list_lock, the combined time spent waiting and processing\ncan be significant.\n\njbd2_journal_shrink_checkpoint_list() explicitly calls cond_resched() when\nneed_resched() is true to avoid softlockups during prolonged operations.\nBut jbd2_log_do_checkpoint() only exits its loop when need_resched() is\ntrue, relying on potentially sleeping functions like __flush_batch() or\nwait_on_buffer() to trigger rescheduling. If those functions do not sleep,\nthe kernel may hit a softlockup.\n\nwatchdog: BUG: soft lockup - CPU#3 stuck for 156s! [kworker/u129:2:373]\nCPU: 3 PID: 373 Comm: kworker/u129:2 Kdump: loaded Not tainted 6.6.0+ #10\nHardware name: Huawei TaiShan 2280 /BC11SPCD, BIOS 1.27 06/13/2017\nWorkqueue: writeback wb_workfn (flush-7:2)\npstate: 20000005 (nzCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)\npc : native_queued_spin_lock_slowpath+0x358/0x418\nlr : jbd2_log_do_checkpoint+0x31c/0x438 [jbd2]\nCall trace:\n native_queued_spin_lock_slowpath+0x358/0x418\n jbd2_log_do_checkpoint+0x31c/0x438 [jbd2]\n __jbd2_log_wait_for_space+0xfc/0x2f8 [jbd2]\n add_transaction_credits+0x3bc/0x418 [jbd2]\n start_this_handle+0xf8/0x560 [jbd2]\n jbd2__journal_start+0x118/0x228 [jbd2]\n __ext4_journal_start_sb+0x110/0x188 [ext4]\n ext4_do_writepages+0x3dc/0x740 [ext4]\n ext4_writepages+0xa4/0x190 [ext4]\n do_writepages+0x94/0x228\n __writeback_single_inode+0x48/0x318\n writeback_sb_inodes+0x204/0x590\n __writeback_inodes_wb+0x54/0xf8\n wb_writeback+0x2cc/0x3d8\n wb_do_writeback+0x2e0/0x2f8\n wb_workfn+0x80/0x2a8\n process_one_work+0x178/0x3e8\n worker_thread+0x234/0x3b8\n kthread+0xf0/0x108\n ret_from_fork+0x10/0x20\n\nSo explicitly call cond_resched() in jbd2_log_do_checkpoint() to avoid\nsoftlockup.\n\n## Affected\n\n- `Linux >= f93ea411b73594f7d144855fd34278bcf34a9afc < f683d611518d30334813eecf9a8c687453e2800e`\n- `Linux >= f93ea411b73594f7d144855fd34278bcf34a9afc < f7ee8fd689e6d534f9fd2494b9266f7998082e65`\n- `Linux >= f93ea411b73594f7d144855fd34278bcf34a9afc < 84ff98c1ea19acd3f9389e4bb6061364e943f85e`\n- `Linux >= f93ea411b73594f7d144855fd34278bcf34a9afc < 26cb9aad94cb1811d8fae115594cc71fa3d91ab0`\n- `Linux >= f93ea411b73594f7d144855fd34278bcf34a9afc < 41f40038de62e8306897cf6840791b268996432a`\n- `Linux >= f93ea411b73594f7d144855fd34278bcf34a9afc < 429d50cbaff45090d52a1ea850d5de8c14881ee7`\n- `Linux >= f93ea411b73594f7d144855fd34278bcf34a9afc < 3faac5e1d14c63260fd1bf789d96bde3ab3d9e54`\n- `Linux >= f93ea411b73594f7d144855fd34278bcf34a9afc < 9d98cf4632258720f18265a058e62fde120c0151`\n- `Linux 2.6.16`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}